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London: SIMPKIN, MARSHALL, & CO.
THE CHEMISTRY OF COOKERY
BY
W. MATTIEU WILLIAMS
AUTHOR OF ‘THE FUEL OF THE SUN’ ‘SCIENCE IN SHORT CHAPTERS’
‘A SIMPLE TREATISE ON HEAT’ ETC.
[Illustration]
_SECOND EDITION_
London
CHATTO & WINDUS, PICCADILLY
1892
PRINTED BY
SPOTTISWOODE AND CO., NEW-STREET SQUARE
LONDON
PREFACE.
DURING the infancy of the Birmingham and Midland Institute, when
my classes in Cannon Street constituted the whole of its teaching
machinery, I delivered a course of lectures to ladies on ‘Household
Philosophy,’ in which ‘The Chemistry of Cookery’ was included. In
collecting material for these lectures, I was surprised at the strange
neglect of the subject by modern chemists.
On taking it up again, after an interval of nearly thirty years, I find
that (excepting the chemistry of wine cookery), absolutely nothing
further, worthy of the name of research, has in the meantime been
brought to bear upon it.
This explanation is demanded as an apology for what some may consider
the egotism that permeates this little work. I have been continually
compelled to put forth my own explanations of familiar phenomena, my
own speculations, concerning the changes effected by cookery, and
my own small contributions to the experimental investigation of the
subject.
Under these difficult circumstances I have endeavoured to place
before the reader a simple and readable account of what is known of
‘The Chemistry of Cookery,’ explaining technicalities as they occur,
rather than abstaining from the use of them by means of cumbrous
circumlocution or patronising baby-talk.
With a moderate effort of attention, any unlearned but intelligent
reader of either sex may understand all the contents of these chapters;
and I venture to anticipate that scientific chemists may find in them
some suggestive matter.
If these expectations are justified by results, this preliminary essay
will fulfil its double object. It will diffuse a knowledge of what
is at present knowable of ‘The Chemistry of Cookery’ among those who
greatly need it, and will contribute to the extension of such knowledge
by opening a wide and very promising field of scientific research.
I should add that the work is based on a series of papers that appeared
in ‘Knowledge’ during the years 1883 and 1884.
W. MATTIEU WILLIAMS.
STONEBRIDGE PARK, LONDON, N.W.
_March 1885._
CONTENTS.
CHAPTER PAGE
I. INTRODUCTORY 1
II. THE BOILING OF WATER 8
III. ALBUMEN 19
IV. GELATIN, FIBRIN, AND THE JUICES OF MEAT 32
V. ROASTING AND GRILLING 47
VI. COUNT RUMFORD’S ROASTER 63
VII. FRYING 84
VIII. STEWING 111
IX. CHEESE 127
X. FAT—MILK 156
XI. THE COOKERY OF VEGETABLES 173
XII. GLUTEN—BREAD 194
XIII. VEGETABLE CASEIN AND VEGETABLE JUICES 211
XIV. COUNT RUMFORD’S COOKERY AND CHEAP DINNERS 227
XV. COUNT RUMFORD’S SUBSTITUTE FOR TEA AND COFFEE 245
XVI. THE COOKERY OF WINE 265
XVII. THE VEGETARIAN QUESTION 294
XVIII. MALTED FOOD 303
XIX. THE PHYSIOLOGY OF NUTRITION 313
INDEX 325
THE
CHEMISTRY OF COOKERY.
CHAPTER I.
INTRODUCTORY.
THE philosopher who first perceived and announced the fact that all the
physical doings of man consist simply in changing the places of things,
made a very profound generalisation, and one that is worthy of more
serious consideration than it has received.
All our handicraft, however great may be the skill employed, amounts
to no more than this. The miner moves the ore and the fuel from their
subterranean resting-places, then they are moved into the furnace,
and by another moving of combustibles the working of the furnace is
started; then the metals are moved to the foundries and forges, then
under hammers, or squeezers, or into melting-pots, and thence to
moulds. The workman shapes the bars, or plates, or castings by removing
a part of their substance, and by more and more movings of material
produces the engine, which does its work when fuel and water are moved
into its fireplace and boiler.
The statue is within the rough block of marble; the sculptor merely
moves away the outer portions, and thereby renders his artistic
conception visible to his fellow-men.
The agriculturist merely moves the soil in order that it may receive
the seed, which he then moves into it, and when the growth is
completed, he moves the result, and thereby makes his harvest.
The same may be said of every other operation. Man alters the position
of physical things in such wise that the forces of Nature shall operate
upon them, and produce the changes or other results that he requires.
My reasons for this introductory digression will be easily understood,
as this view of the doings of man and the doings of Nature displays
fundamentally the business of human education, so far as the physical
proceedings and physical welfare of mankind are concerned.
It clearly points out two well-marked natural divisions of such
education—education or training in the movements to be made, and
education in a knowledge of the consequences of such movements—_i.e._
in a knowledge of the forces of Nature which actually do the work when
man has suitably arranged the materials.
The education ordinarily given to apprentices in the workshop, or
the field, or the studio—or, as relating to my present subject, the
kitchen—is the first of these, the second and equally necessary being
simply and purely the teaching of physical science as applied to the
arts.
I cannot proceed any further without a protest against a very general
(so far as this country is concerned) misuse of a now very popular
term, a misuse that is rather surprising, seeing that it is accepted
by scholars who have devoted the best of their intellectual efforts to
the study of words. I refer to the word _technical_ as applied in the
designation ‘technical education.’
So long as our workshops are separated from our science schools
and colleges, it is most desirable, in order to avoid continual
circumlocution, to have terms that shall properly distinguish between
the work of the two, and admit of definite and consistent use. The two
words are ready at hand, and, although of Greek origin, have become, by
analogous usage, plain simple English. I mean the words _technical_ and
_technological_.
The Greek noun _techne_ signifies an art, trade, or profession, and our
established usage of this root is in accordance with its signification.
Therefore, ‘technical education’ is a suitable and proper designation
of the training which is given to apprentices, &c., in the strictly
technical details of their trades, arts, or professions—_i.e._ in the
skilful moving of things. When we require a name for the science or the
philosophy of anything, we obtain it by using the Greek root _logos_,
and appending it in English form to the Greek name of the general
subject, as geology, the science of the earth; anthropology, the
science of man; biology, the science of life, &c.
Why not then follow this general usage, and adopt ‘technology’ as
the science of trades, arts, or professions, and thereby obtain
consistent and convenient terms to designate the two divisions of
education—technical education, that given in the workshop, &c., and
technological education, that which _should be_ given as supplementary
to all such technical education?
In accordance with this, the present work will be a contribution to
the technology of cookery, or to the technological education of cooks,
whose technical education is quite beyond my reach.
The kitchen is a chemical laboratory in which are conducted a number of
chemical processes by which our food is converted from its crude state
to a condition more suitable for digestion and nutrition, and made more
agreeable to the palate.
It is the _rationale_ or _ology_ of these processes that I shall
endeavour to explain; but at the outset it is only fair to say that
in many instances I shall not succeed in doing this satisfactorily,
as there still remain some kitchen mysteries that have not yet come
within the firm grasp of science. The _whole_ story of the chemical
differences between a roast, a boiled, and a raw leg of mutton has not
yet been told. You and I, gentle reader, aided by no other apparatus
than a knife and fork, can easily detect the difference between a
cut out of the saddle of a three-year-old Southdown and one from a
ten-months-old meadow-fed Leicester, but the chemist in his laboratory,
with all his reagents, test-tubes, beakers, combustion-tubes,
potash-bulbs, &c. &c., and his balance turning to one-thousandth of a
grain, cannot physically demonstrate the sources of these differences
of flavour.
Still I hope to show that modern chemistry can throw into the kitchen a
great deal of light that shall not merely help the cook in doing his or
her work more efficiently, but shall also elevate both the work and the
worker, and render the kitchen far more interesting to all intelligent
people who have an appetite for knowledge, as well as for food; more so
than it can be while the cook is groping in rule-of-thumb darkness—is
merely a technical operator unenlightened by technological intelligence.
In the course of these papers I shall draw largely on the practical
and philosophical work of that remarkable man, Benjamin Thompson, the
Massachusetts ’prentice-boy and schoolmaster; afterwards the British
soldier and diplomatist, Colonel Sir Benjamin Thompson; then Colonel
of Horse and General Aide-de-Camp of the Elector Charles Theodore of
Bavaria; then Major-General of Cavalry, Privy Councillor of State and
head of War Department of Bavaria; then Count Rumford of the Holy
Roman Empire and Order of the White Eagle; then Military Dictator of
Bavaria, with full governing powers during the absence of the Elector;
then a private resident in Brompton Road, and founder of the Royal
Institution in Albemarle Street; then a Parisian _citoyen_, the husband
of the ‘Goddess of Reason,’ the widow of Lavoisier; but, above all, a
practical and scientific cook, whose exploits in economic cookery are
still but very imperfectly appreciated, though he himself evidently
regarded them as the most important of all his varied achievements.
His faith in cookery is well expressed in the following, where he is
speaking of his experiments in feeding the Bavarian army and the poor
of Munich. He says:
‘I constantly found that the richness or quality of a soup depended
more upon the proper choice of the ingredients, and a proper management
of the fire in the combination of these ingredients, than upon the
quantity of solid nutritious matter employed; much more upon the art
and skill of the cook than upon the sums laid out in the market.’
A great many fallacies are continually perpetrated, not only by
ignorant people, but even by eminent chemists and physiologists, by
inattention to what is indicated in this passage. In many chemical
and physiological works may be found elaborately minute tables of the
chemical composition of certain articles of food, and with these the
assumption (either directly stated or implied as a matter of course)
that such tables represent the practical nutritive value of the food.
The illusory character of such assumption is easily understood. In the
first place the analysis is usually that of the article of food in its
raw state, and thus all the chemical changes involved in the process of
cookery are ignored.
Secondly, the difficulty or facility of assimilation is too often
unheeded. This depends both upon the original condition of the food and
the changes which the cookery has produced—changes which may double
its nutritive value without effecting more than a small percentage
of alteration in its chemical composition as revealed by laboratory
analysis.
In the recent discussion on whole-meal bread, for example, chemical
analyses of the bran, &c., are quoted, and it is commonly assumed that
if these can be shown to contain more of the theoretical bone-making or
brain-making elements, that they are, therefore, in reference to these
requirements, more nutritious than the fine flour. But before we are
justified in asserting this, it must be made clear that these outer
and usually rejected portions of the grain are as easily digested and
assimilated as the finer inner flour.
I think I shall be able to show that the practical failure of this
whole-meal bread movement (which is not a novelty, but only a revival)
is mainly due to the disregard of the cookery question; that whole-meal
prepared as bread by simple baking is less nutritious than fine flour
similarly prepared; but that whole-meal otherwise prepared may be, and
has been, made more nutritious than fine white bread.
Another preliminary example. A pound of biscuit contains more solid
nutritive matter than a pound of beefsteak, but may not, when eaten by
ordinary mortals, do so much nutritive work. Why is this?
It is a matter of preparation—not exactly what is called cooking, but
equivalent to what cooking should be. It is the preparation which has
converted the grass food of the ox into another kind of food which we
can assimilate very easily.
The fact that we use the digestive and nutrient apparatus of sheep,
oxen, &c., for the preparation of our food, is merely a transitory
barbarism, to be ultimately superseded when my present subject is
sufficiently understood and applied to enable us to prepare the
constituents of the vegetable kingdom in such a manner that they shall
be as easily assimilated as the prepared grass which we call beef and
mutton, and which we now use only on account of our ignorance of the
subject treated in the following chapters. I do not presume to assert
or suggest that my efforts towards the removal of this ignorance will
transport us at once into a vegetarian millennium, but if they only
open the gate and show us that there is a road on which we may travel
towards great improvements in the preparation of our food as regards
flavour, economy, and wholesomeness, my reasonable readers will not be
disappointed.
So much of cookery being effected by the application of heat, a sketch
of the general laws of heat might be included in this introductory
chapter, but for the necessary extent of the subject.
I omit it without compunction, having already written ‘A Simple
Treatise on Heat,’ which is divested of technical difficulties by
presenting simply the phenomena and laws of Nature without any
artificial scholastic complications. Messrs. Chatto & Windus have
brought out this little essay in a cheap form, and, in spite of the
risk of being accused of puffing my own wares, I recommend its perusal
to those who are earnestly studying the whole philosophy of cookery.
CHAPTER II.
THE BOILING OF WATER.
AS this is one of the most rudimentary of the operations of cookery,
and the most frequently performed, it naturally takes a first place in
treating the subject.
Water is boiled in the kitchen for two distinct purposes: 1st, for the
cooking of itself; 2nd, for the cooking of other things. A dissertation
on the difference between raw water and cooked water may appear
pedantic, but, as I shall presently show, it is considerable, very
practical, and important.
The best way to study any physical subject is to examine it
experimentally, but this is not always possible with everyday means. In
this case, however, there is no difficulty.
Take a thin[1] glass vessel, such as a flask, or, better, one of the
‘beakers,’ or thin tumbler-shaped vessels, so largely used in chemical
laboratories; partially fill it with ordinary household water, and
then place it over the flame of a spirit-lamp, or Bunsen’s, or other
smokeless gas-burner. Carefully watch the result, and the following
will be observed: first of all, little bubbles will be formed,
adhering to the sides of the glass, but ultimately rising to the
surface, and there becoming dissipated by diffusion in the air.
This is not boiling, as may be proved by trying the temperature with
the finger. What, then, is it?
It is the yielding back of the atmospheric gases which the water
has dissolved or condensed within itself. These bubbles have been
collected, and by analysis proved to consist of oxygen, nitrogen, and
carbonic acid, obtained from the air; but in the water they exist by no
means in the same proportions as originally in the air, nor in constant
proportions in different samples of water. I need not here go into the
quantitative details of these proportions, nor the reasons of their
variation, though they are very interesting subjects.
Proceeding with our investigation, we shall find that the bubbles
continue to form and rise until the water becomes too hot for the
finger to bear immersion. At about this stage something else begins to
occur. Much larger bubbles, or rather blisters, are now formed on the
bottom of the vessel, immediately over the flame, and they continually
collapse into apparent nothingness. Even at this stage a thermometer
immersed in the water will show that the boiling-point is not reached.
As the temperature rises, these blisters rise higher and higher,
become more and more nearly spherical, finally quite so, then detach
themselves and rise towards the surface; but the first that make this
venture perish in the attempt—they gradually collapse as they rise, and
vanish before reaching the surface. The thermometer now shows that the
boiling-point is nearly reached, but not quite. Presently the bubbles
rise completely to the surface and break there. Now the water is
boiling, and the thermometer stands at 212° Fahr. or 100° Cent.
With the aid of suitable apparatus it can be shown that the atmospheric
gases above named continue to be given off along with the steam for a
considerable time after the boiling has commenced; the complete removal
of their last traces being a very difficult, if not an impossible,
physical problem.
After a moderate period of boiling, however, we may practically regard
the water as free from these gases. In this condition I venture to call
it cooked water. Our experiment so far indicates one of the differences
between cooked and raw water. The cooked water has been deprived of
the atmospheric gases that the raw water contained. By cooling some
of the cooked water and tasting it, the difference of flavour is very
perceptible; by no means improved, though it is quite possible to
acquire a preference for this flat, tasteless liquid.
If a fish be placed in such cooked water it swims for a while with its
mouth at the surface, for just there is a film that is reacquiring its
charge of oxygen, &c., by absorbing it from the air; but this film is
so thin, and so poorly charged, that after a short struggle the fish
dies for lack of oxygen in its blood; drowned as truly and completely
as an air-breathing animal when immersed in any kind of water.
Spring water and river water that have passed through or over
considerable distances in calcareous districts suffer another change
in boiling. The origin and nature of this change may be shown by
another experiment as follows: Buy a pennyworth of lime-water from a
druggist, and procure a small glass tube of about quill size, or the
stem of a fresh tobacco-pipe may be used. Half fill a small wine-glass
with the lime-water, and blow through it by means of the tube or
tobacco-pipe. Presently it will become turbid. Continue the blowing,
and the turbidity will increase up to a certain degree of milkiness. Go
on blowing with ‘commendable perseverance,’ and an inversion of effect
will follow; the turbidity diminishes, and at last the water becomes
clear again.
The chemistry of this is simple enough. From the lungs a mixture
of nitrogen, oxygen, and carbonic acid is exhaled. The carbonic
acid combines with the soluble lime, and forms a carbonate of lime
which is insoluble in mere water. But this carbonate of lime is to a
certain extent soluble in water saturated with carbonic acid, and such
saturation is effected by the continuation of blowing.
Now take some of the lime-water that has been thus treated, place it in
a clean glass flask, and boil it. After a short time the flask will be
found incrusted with a thin film of something. This is the carbonate
of lime which has been thrown down again by the action of boiling,
which has driven off its solvent, the carbonic acid. This crust will
effervesce if a little acid is added to it.
In this manner our tea-kettles, engine-boilers, &c., become incrusted
when fed with calcareous waters, and most waters are calcareous; those
supplied to London, which is surrounded by chalk, are largely so. Thus,
the boiling or cooking of such water effects a removal of its mineral
impurities more or less completely. Other waters contain such mineral
matter as salts of sodium and potassium. These are not removable
by mere boiling, being equally soluble in hot or cold, aerated, or
non-aerated water.
Usually we have no very strong motive for removing either these or
the dissolved carbonate of lime, or the atmospheric gases from water,
but there is another class of impurities of serious importance. These
are the organic matters dissolved in all water that has run over land
covered with vegetable growth, or, more especially, that which has
received contributions from sewers or any other form of house drainage.
Such water supplies nutriment to those microscopic abominations, the
_micrococci_, _bacilli_, _bacteria_, &c., which are now shown to be
connected with blood poisoning. These little pests are harmless, and
probably nutritious, when cooked, but in their raw and growing state
are horribly prolific in the blood of people who are in certain states
of what is called ‘receptivity.’ They (the bacteria, &c.) appear to be
poisoned or somehow killed off by the digestive secretions of the blood
of some people, and nourished luxuriantly in the blood of others. As
nobody can be quite sure to which class he belongs, or may presently
belong, or whether the water supplied to his household is free from
blood-poisoning organisms, cooked water is a safer beverage than raw
water. I should add that this germ theory of disease is disputed by
some who maintain that the source of the diseases attributed to such
microbia is chemical poison, the microbia (_i.e._ little living things)
are merely accidental, or creatures fed on the disease-producing
poison. In either case the boiling is effectual, as such organic
poisons when cooked lose their original virulent properties.
The requirement for this simple operation of cooking increases with the
density of our population, which, on reaching a certain degree, renders
the pollution of all water obtained from the ordinary sources almost
inevitable.
Reflecting on this subject, I have been struck with a curious fact that
has hitherto escaped notice, viz. that in the country which over all
others combines a very large population with a very small allowance
of cleanliness, the ordinary drink of the people is boiled water,
flavoured by an infusion of leaves. These people, the Chinese, seem in
fact to have been the inventors of boiled-water beverages. Judging from
travellers’ accounts of the state of the rivers, rivulets, and general
drainage and irrigation arrangements of China, its population could
scarcely have reached its present density if Chinamen were drinkers of
raw instead of cooked water. This is especially remarkable in the case
of such places as Canton, where large numbers are living afloat on the
mouths of sewage-laden rivers or estuaries.
The ordinary everyday domestic beverage is a weak infusion of tea,
made in a large teapot, kept in a padded basket to retain the heat.
The whole family is supplied from this reservoir. The very poorest
drink plain hot water, or water tinged by infusing the spent tea-leaves
rejected by their richer neighbours.
Next to the boiling of water for its own sake, comes the boiling
of water as a medium for the cooking of other things. Here, at the
outset, I have to correct an error of language which, as too often
happens, leads by continual suggestion to false ideas. When we speak
of ‘boiled beef,’ ‘boiled mutton,’ ‘boiled eggs,’ ‘boiled potatoes,’
we talk nonsense; we are not merely using an elliptical expression, as
when we say, ‘the kettle boils,’ which we all understand to mean the
contents of the kettle, but we are expounding a false theory of what
has happened to the beef, &c.—as false as though we should describe the
material of the kettle that has held boiling water as boiled copper or
boiled iron. No boiling of the food takes place in any such cases as
the above-named—it is merely heated by immersion in boiling water; the
changes that actually take place in the food are essentially different
from those of ebullition. Even the water contained in the meat is not
boiled in ordinary cases, as its boiling-point is higher than that of
the surrounding water, owing to the salts it holds in solution.
Thus, as a matter of chemical fact, a ‘boiled leg of mutton’ is one
that has been cooked, but not boiled; while a roasted leg of mutton is
one that has been partially boiled. Much of the constituent water of
flesh is boiled out, fairly driven away as vapour during roasting or
baking, and the fat on its surface is also boiled, and, more or less,
dissociated into its chemical elements, carbon and water, as shown by
the browning, due to the separated carbon.
As I shall presently show, this verbal explanation is no mere verbal
quibble, but it involves important practical applications. An enormous
waste of precious fuel is perpetrated every day, throughout the whole
length and breadth of Britain and other countries where English
cookery prevails, on account of the almost universal ignorance of the
philosophy of the so-called boiling of food.
When it is once fairly understood that the meat is not to be boiled,
but is merely to be warmed by immersion in water raised to a maximum
temperature of 212°, and when it is further understood that water
cannot (under ordinary atmospheric pressure) be raised to a higher
temperature than 212° by any amount of violent boiling, the popular
distinction between ‘simmering’ and boiling, which is so obstinately
maintained as a kitchen superstition, is demolished.
The experiment described on pages 8 and 9 showed that immediately the
bubbles of steam reach the surface of the water and break there—that
is, when simmering commences—the thermometer reaches the boiling-point,
and that however violently the boiling may afterwards occur, the
thermometer rises no higher. Therefore, as a medium for heating the
substances to be cooked, simmering water is just as effective as
‘walloping’ water. There are exceptional operations of cookery, wherein
useful mechanical work is done by violent boiling; but in all ordinary
cookery simmering is just as effective. The heat that is applied to
do more than the smallest degree of simmering is simply wasted in
converting water into useless steam. The amount of such waste may be
easily estimated. To raise a given quantity of water from the freezing
to the boiling point demands an amount of heat represented by 180° in
Fahrenheit’s thermometer, or 100° Centigrade. To convert this into
steam, 990° Fahr. or 550° Cent. is necessary—just five-and-a-half times
as much.
On a properly-constructed hot-plate or sand-bath a dozen saucepans
may be kept at the true cooking temperature, with an expenditure of
fuel commonly employed in England to ‘boil’ one saucepan. In the
great majority of so-called boiling operations, even simmering is
unnecessary. Not only is a ‘boiled leg of mutton’ not itself boiled,
but even the water in which it is cooked should not be kept boiling, as
we shall presently see.
The following, written by Count Rumford nearly 100 years ago, remains
applicable at the present time, in spite of all our modern research and
science teaching:
‘The process by which food is most commonly prepared for the
table—BOILING—is so familiar to everyone, and its effects are so
uniform and apparently so simple, that few, I believe, have taken
the trouble to inquire _how_ or in _what manner_ these effects are
produced; and whether any and what improvements in that branch of
cookery are possible. So little has this matter been an object of
inquiry that few, very few indeed I believe, among the _millions of
persons_ who for so many ages have been _daily_ employed in this
process, have ever given themselves the trouble to bestow one serious
thought upon the subject.
‘The cook knows _from experience_ that if his joint of meat be kept
a certain time immersed in boiling water it will be _done_, as it is
called in the language of the kitchen; but if he be asked what is done
to it, or _how_ or _by what agency_ the change it has undergone has
been effected—if he understands the question—it is ten to one but he
will be embarrassed. If he does not understand he will probably answer
without hesitation, that “_The meat is made tender and eatable by being
boiled_.” Ask him if the boiling of the water be essential to the
process. He will answer, “_Without doubt_.” Push him a little further
by asking him whether, _were it possible_ to keep the water _equally
hot_ without boiling, the meat would not be cooked _as soon_ and _as
well_ as if the water were made to boil. Here it is probable he will
make the first step towards acquiring knowledge by _learning to doubt_.’
In another place he points to the fact that at Munich, where his chief
cookery operations were performed, water boils at 209½° (on account
of its elevation), while in London the boiling-point is 212°. ‘Yet
nobody, I believe, ever perceived that boiled meat was less done at
Munich than at London. But if meat may without the least difficulty be
cooked with a heat of 209½° at Munich, why should it not be possible
to cook it with the same degree of heat in London? If this can be done
in London (which I think can hardly admit of a doubt), then it is
evident that the process of cookery, which is called _boiling_, may be
performed in water which is not boiling hot.’
He proceeds to say, ‘I well know, from my own experience, how difficult
it is to persuade cooks of this truth, but it is so important that no
pains should be spared in endeavouring to remove their prejudices and
enlighten their understandings. This may be done most effectually in
the case before us by a method I have several times put in practice
with complete success. It is as follows: Take two equal boilers,
containing equal quantities of _boiling hot water_, and put into them
two equal pieces of meat taken from the same carcase—two legs of
mutton, for instance—and boil them during the same time. Under one of
the boilers make a _small fire_, just barely sufficient to keep the
water _boiling hot_, or rather just _beginning to boil_; under the
other make _as vehement a fire as possible_, and keep the water boiling
the whole time with the utmost violence. The meat in the boiler in
which the water has been kept _only just boiling hot_ will be found to
be quite as well done as that in the other. It will even be found to
be much better cooked, that is to say tenderer, more juicy, and much
higher flavoured.’
Rumford at this date (1802) understood perfectly that the water just
boiling hot had the same temperature as that which was boiling with
the utmost violence, but did not understand that the best result is
obtained at a much lower temperature, for in another place he states
that if the meat be cooked in water under pressure, so that the
temperature shall exceed 212°, it will be done proportionally quicker
and as well. My reasons for controverting this will be explained in the
following chapters.
FOOTNOTE:
[1] In applying heat to glass vessels, thickness is a source of
weakness or liability to fracture, on account of the unequal expansion
of the two sides, due to inequality of temperature, which, of course,
increases with the thickness of the glass. Besides this, the thickness
increases the leverage of the breaking strain.
CHAPTER III.
ALBUMEN.
IN order to illustrate some of the changes which take place in the
cooking of animal food, I will first take the simple case of cooking
an egg by means of hot water. These changes are in this case easily
visible and very simple, although the egg itself contains all the
materials of a complete animal. Bones, muscles, viscera, brain, nerves,
and feathers of the chicken—all are produced from the egg, nothing
being added, and little or nothing taken away.
I should, however, add that in eating an egg we do not get _quite_
so much of it as the chicken does. Liebig found by analysis that in
the white and the yolk there is a deficiency of mineral matter for
supplying the bones of the chick, and that this deficiency is supplied
by some of the shell being dissolved by the phosphoric acid which is
formed inside the egg by the combination of the oxygen of the air
(which passes through the shell) with the phosphorus contained in the
soft matter of the egg.
By comparing the shell of a hen’s egg after the chicken is hatched from
it with that of a freshly-laid egg, the difference of thickness may be
easily seen.
When we open a raw egg, we find enveloped in a stoutish membrane
a quantity of glairy, slimy, viscous, colourless fluid, which, as
everybody now knows, is called _albumen_, a Latin translation of
its common name, ‘_the white_.’ Within the white of the egg is the
yolk, chiefly composed of albumen, but with some other constituents
added—notably a peculiar oil. At present I will only consider the
changes which cookery effects on the main constituent of the egg,
merely adding that this same albumen is one of the most important, if
not the one most important, material of animal food, and is represented
by a corresponding nutritious constituent in vegetables.
We all know that when an egg has been immersed during a few minutes in
boiling water, the colourless, slimy liquid is converted into the white
solid to which it owes its name. This coagulation of albumen is one of
the most decided and best understood changes effected by cookery, and
therefore demands especial study.
Place some fresh, raw white of egg in a test-tube or other suitable
glass vessel, and in the midst of it immerse the bulb of a thermometer.
(Cylindrical thermometers, with the degrees marked on the glass stem,
are made for such laboratory purposes.) Place the tube containing the
albumen in a vessel of water, and gradually heat this. When the albumen
attains a temperature of about 134° Fahr., white fibres will begin to
appear within it; these will increase until about 160° is attained,
when the whole mass will become white and nearly opaque.[2] It is now
coagulated, and may be called solid. Now examine some of the result,
and you will find that the albumen thus only just coagulated is a
tender, delicate, jelly-like substance, having every appearance to
sight, touch, and taste of being easily digestible. This is the case.
Having settled these points, proceed with the experiment by heating the
remainder of the albumen (or a new sample) up to 212°, and keeping it
for awhile at this temperature. It will dry, shrink, and become horny.
If the heat is carried a little further, it becomes converted into a
substance which is so hard and tough that a valuable cement is obtained
by simply smearing the edges of the article to be cemented with white
of egg, and then heating it to a little above 212°.[3]
This simple experiment teaches a great deal of what is but little known
concerning the philosophy of cookery. It shows in the first place that,
so far as the coagulation of the albumen is concerned, the cooking
temperature is not 212°, or that of boiling water, but 160°, _i.e._
52° below it. Everybody knows the difference between a tender, juicy
steak, rounded or plumped out in the middle, and a tough, leathery
abomination, that has been so cooked as to shrivel and curl up. The
contraction, drying up, and hornifying of the albumen in the test tube
represents the albumen of the latter, while the tender, delicate,
trembling, semi-solid that was coagulated at 160°, represents the
albumen in the first.
But this is a digression, or rather anticipation, seeing that the
grilling of a beefsteak is a problem of profound complexity that we
cannot solve until we have mastered the rudiments. We have not yet
determined how to practically apply the laws of albumen coagulation as
discovered by our test-tube experiment to the cooking of a breakfast
egg. The non-professional student may do this at the breakfast
fireside. The apparatus required is a saucepan large enough for boiling
a pint of water—the materials, two eggs.
Cook one in the orthodox manner by keeping it in boiling water
three-and-a-half minutes. Then place the other in this same boiling
water; but, instead of keeping the saucepan over the fire, place it on
the hearth and leave it there, with the egg in it, about ten minutes
or more. A still better way of making the comparative experiment is to
use, for the second egg, a water-bath, or _bain-marie_ of the French
cook—a vessel immersed in boiling, or nearly boiling water, like a
glue-pot, and therefore not quite so hot as its source of heat. In this
case a thermometer should be used, and the water surrounding the egg
be kept at or near 180° Fahr. Time of immersion about ten or twelve
minutes.
A comparison of results will show that the egg that has been cooked
at a temperature of more than 30° below the boiling-point of water is
tender and delicate, evenly so throughout, no part being hard while
another part is semi-raw and slimy.
I said ‘ten minutes or more,’ because, when thus cooked, a prolonged
exposure to the hot water does no mischief; if the temperature of 160°
is not exceeded, it may remain twice as long without hardening. The
180° is above-named because the rising of the temperature of the egg
itself is due to the difference between its own temperature and that
of the water, and when that difference is very small, this takes place
very slowly, besides which the temperature of the water is, of course,
lowered in raising that of the cold egg.
In order to test this principle severely, I made the following
experiment. At 10.30 P.M. I placed a new-laid egg in a covered
stoneware jar, of about one-pint capacity, and filled this with boiling
water; then wrapped the jar in many folds of flannel—so many that,
with the egg, they filled a hat-case, in which I placed the bundle and
left it there until breakfast-time next morning, ten hours later. On
unrolling, I found the water cooled down to 95°; the yolk of the egg
was hard, but the white only just solidified and much softer than the
yolk. On repeating the experiment, and leaving the egg in its flannel
coating for four hours, the temperature of the water was 123° and the
egg in similar condition—the white cooked in perfection, delicately
tender, but the yolk too hard. A third experiment of twelve hours,
water at 200° on starting, gave a similar result as regards the state
of the egg.
I thus found that the yolk coagulates firmly at a lower temperature
than the white. Whether this is due to a different condition of the
albumen itself or to the action of the other constituents on the
albumen, requires further research to determine. The albumen of the
yolk has received the name of ‘vitellin,’ and is usually described as
another variety differing from that of the white, as it is differently
affected by chemical reagents; but Lehmann[4] regards it as a mixture
of albumen and casein, and describes experiments which justify his
conclusion. The difference of the temperature of coagulation does not
appear to have been observed, and I cannot understand how the admixture
of casein can effect it.
When eggs are cooked in the ordinary way, the 3½ minutes’ immersion
is insufficient to allow the heat to pass fully to the middle of the
egg, and therefore the white is subjected to a higher temperature than
the yolk. In my experiment there was time for a practically uniform
diffusion of the heat throughout.
I shall describe hereafter what is called the ‘Norwegian’ cooking
apparatus, wherein fowls, &c., are cooked as the eggs were in my
hat-case.
Albumen exists in flesh as one of its juices, rather than in a
definitely-organised condition. It is distributed between the fibres of
the lean (_i.e._ the muscles), and it lubricates the tissues generally,
besides being an important constituent of the blood itself—of that
portion of the blood which remains liquid when the blood is dead—_i.e._
the serum. As blood is not an ordinary article of food, excepting in
the form of ‘black puddings,’ its albumen need not be here considered,
nor the debated question of whether its albumen is identical with the
albumen of the flesh.
Existing thus in a liquid state in our ordinary flesh meats, it is
liable to be wasted in the course of cookery, especially if the cook
has only received the customary technical education and remains in
technological ignorance.
To illustrate this, let us suppose that a leg of mutton, a slice of
cod, or a piece of salmon is to be cooked in water, ‘boiled,’ as the
cook says. Keeping in mind the results of the previously-described
experiments on the egg-albumen, and also the fact that in its liquid
state albumen is diffusible in water, the reader may now stand as
scientific umpire in answering the question whether the fish or the
flesh should be put in hot water at once, or in cold water, and be
gradually heated. The ‘big-endians’ and the ‘little-endians’ of Liliput
were not more definitely divided than are certain cookery authorities
on this question in reference to fish. Referring at random to the
cookery-books that come first to hand, I find them about equally
divided on the question.
Confining our attention at present to the albumen, what must happen
if the fish or flesh is put in cold water, which is gradually heated?
Obviously a loss of albumen by exudation and diffusion through the
water, especially in the case of sliced fish or of meat exposing much
surface of fibres cut across. It is also evident that such loss of
albumen will be shown by its coagulation when the water is sufficiently
heated.
Practical readers will at once recognise in the ‘scum’ which rises to
the surface of the boiling water, and in the milkiness that is more or
less diffused throughout it, the evidence of such loss of albumen. This
loss indicates the desirability of plunging the fish or flesh at once
into water hot enough to immediately coagulate the superficial albumen,
and thereby plug the pores through which the inner albuminous juice
otherwise exudes.
But this is not all. There are other juices besides the albumen; these
are the most important of the _flavouring_ constituents, and, _with
the other constituents of animal food_, have great nutritive value;
so much so, that animal food is quite tasteless and almost worthless
without them. I have laid especial emphasis on the above qualification,
lest the reader should be led into an error originated by the bone-soup
committee of the French Academy, and propagated widely by Liebig—that
of regarding these juices as a concentrated nutriment when taken alone.
They constitute collectively the _extractum carnis_, which, with
the addition of more or less gelatine (the less the better), is
commonly sold as Liebig’s ‘Extract of Meat.’ It is prepared by simply
mincing lean meat, exposing it to the action of cold water, and then
evaporating down the solution of extract thus obtained.
I shall return to this on reaching the subjects of clear soups and
beef-tea, at present merely adding as evidence of the importance of
retaining these juices in cooked meat, that the extracts of beef,
mutton, and pork may be distinguished by their specific flavours. Some
Extract of Kangaroo, sent to me many years ago from Australia by the
Ramornie Company, made a soup that was curiously different in flavour
from the other extract similarly prepared by the same company. Epicures
pronounced it very choice and ‘gamey.’[5] When these juices are removed
from the meat, mutton, beef, pork, &c., the remaining solids are all
alike, so far as the palate alone can distinguish.
Let us now apply these principles practically to the case of a leg
of mutton. First, in order to seal the pores, the meat should be put
into boiling water; the water should be kept boiling for five or ten
minutes. A coating of firmly-coagulated albumen will thus envelop
the joint. Now, instead of boiling or ‘simmering’ the water, set the
saucepan aside, where the water will retain a temperature of about
180°, or 32° below the boiling-point. Continue this about half as long
again, or double the usual time given in the cookery-books for boiling
a leg of mutton, and try the effect. It will be analogous to that of
the egg cooked on the same principles, and appreciated accordingly.
The usual addition of salt to the water is very desirable. It has a
threefold action: first, it directly acts on the superficial albumen
with coagulating effect; second, it slightly raises the boiling-point
of the water; and third, by increasing the density of the water, the
‘exosmosis’ or oozing out of the juices is less active. These actions
are slight, but all co-operate in keeping in the juices.
I should add that a leg of mutton for boiling should be fresh, and not
‘hung’ as for roasting. The reasons for this hereafter.
‘Please, mum, the fish would break to pieces,’ would be the probable
reply of the unscientific cook, to whom her mistress had suggested
the desirability of cooking fish in accordance with the principles
expounded above. Many kinds of fish would thus break if the popular
notions of ‘boiling’ were carried out, and the fish suddenly immersed
in water that was agitated by the act of ebullition. But this
difficulty vanishes when the true theory of cookery is understood and
practically applied by cooking the fish from beginning to end without
ever boiling the water at all.
In the case of the leg of mutton, chosen as a previous example, the
plunging in boiling water and maintenance of boiling-point for a few
minutes was unobjectionable, as the most effectual means of obtaining
the firm coagulation of a superficial layer of albumen; but, in the
case of fragile fish, this advantage can only be obtained in a minor
degree by using water just below the boiling-point; the breaking of
the fish by the agitation of the boiling water does more than merely
disfigure it when served—it opens outlets to the juices, and thereby
depreciates the flavour, besides sacrificing some of the nutritious
albumen.
To demonstrate this experimentally, take two equal slices from the same
salmon, cook one according to Mrs. Beeton and other authorities by
putting it into cold water, or pouring cold water over it, then heating
up to the boiling-point. Cook the other slice by putting it into
water nearly boiling (about 200° Fahr.), and keeping it at about 180°
to 200°, but never boiling at all. Then dish up, examine, and taste.
The second will be found to have retained more of its proper salmon
colour and flavour; the first will be paler and more like cod, or other
white fish, owing to the exosmosis or oozing out of its characteristic
juices. When two similar pieces of split salmon are thus cooked, the
difference between them is still more remarkable. I should add that the
practice of splitting salmon for boiling, once so fashionable, is now
nearly obsolete, and justly so.
I was surprised, and at first considerably puzzled, at what I saw of
salmon-cooking in Norway. As this fish is so abundant there (1_d._ per
lb. would be regarded as a high price in the Tellemark), I naturally
supposed that large experience, operating by natural selection, would
have evolved the best method of cooking it, but found that, not only in
the farmhouses of the interior, but at such hotels as the ‘Victoria,’
in Christiania, the usual cookery was effected by cutting the fish
into small pieces and soddening it in water in such wise that it came
to table almost colourless, and with merely a faint suggestion of what
we prize as the rich flavour of salmon. A few months’ experience and
a little reflection solved the problem. Salmon is so rich, and has so
special a flavour, that when daily eaten it soon palls on the palate.
Everybody has heard the old story of the clause in the indentures of
the Aberdeen apprentices, binding the masters not to feed the boys on
salmon more frequently than twice a week. If the story is not true it
ought to be, for full meals of salmon every day would, ere long, render
the special flavour of this otherwise delicious fish quite sickening.
By boiling out the rich oil of the salmon, the Norwegian reduces it
nearly to the condition of cod-fish, concerning which I learned a
curious fact from two old Doggerbank fishermen, with whom I had a
long sailing cruise from the Golden Horn to the Thames. They agreed
in stating that cod-fish is like bread, that they and all their mates
lived upon it (and sea-biscuits) day after day for months together,
and never tired, while richer fish ultimately became repulsive if
eaten daily. This statement was elicited by an immediate experience.
We were in the Mediterranean, where bonetta were very abundant, and
every morning and evening I amused myself by spearing them from
the martingale of the schooner, and so successfully that all hands
(or rather mouths) were abundantly supplied with this delicious
dark-fleshed, full-blooded, and high-flavoured fish. I began by making
three meals a day on it, but at the end of about a week was glad to
return to the ordinary ship’s fare of salt junk and chickens.
The following account of an experiment of Count Rumford’s is very
interesting and instructive. He says: ‘I had long suspected that it
could hardly be possible that precisely the temperature of 212° (that
of boiling water) should be that which is best adapted for cooking _all
sorts of food_; but it was the unexpected result of an experiment that
I made with another view which made me particularly attentive to this
subject. Desirous of finding out whether it would be possible to roast
meat on a machine that I had contrived for drying potatoes, and fitted
up in the kitchen of the House of Industry at Munich, I put a shoulder
of mutton into it, and after attending to the experiment three hours,
and finding that it showed no signs of being done, I concluded that the
heat was not sufficiently intense, and despairing of success I went
home, rather out of humour at my ill success, and abandoned my shoulder
of mutton to the cookmaids.
‘It being late in the evening and the cookmaids thinking, perhaps, that
the meat would be as safe in the drying machine as anywhere else, left
it there all night. When they came in the morning to take it away,
intending to cook it for their dinner, they were much surprised at
finding it _already cooked_, and not merely eatable, but perfectly well
done, and most singularly well tasted. This appeared to them the more
miraculous, as the fire under the machine was quite gone out before
they left the kitchen in the evening to go to bed, and as they had
locked up the kitchen when they left it, and taken away the key.
‘This wonderful shoulder of mutton was immediately brought to me in
triumph, and though I was at no great loss to account for what had
happened, yet it certainly was quite unexpected; and when I tasted the
meat I was very much surprised indeed to find it very different, both
in taste and flavour, from any I had ever tasted. It was perfectly
tender; but though it was so much done it did not appear to be in the
least sodden or insipid; on the contrary, it was uncommonly savoury and
high flavoured.’
What I have already explained concerning the coagulation of albumen
will render this result fairly intelligible. It will be still more
so after what follows concerning the effect of heat on the other
constituents of a shoulder of mutton.
The Norwegian cooking apparatus, to which I have already alluded,
and which is now commercially supplied in England, does its work
in a somewhat similar manner. It consists of an inner tin pot with
well-fitting lid, which fits into a box, having a thick lining of
ill-conducting material—such as felt, wool, or sawdust (it should be
two or three inches thick bottom and sides). A fowl, for example,
is put into the tin, which is then filled up with boiling water and
covered with a close-fitting cover lined like the box, and firmly
strapped down. This may be left for ten or twelve hours, when the fowl
will be found most delicately cooked. For yachtsmen and ‘camping-out’
parties, &c., it is a very luxurious apparatus.
FOOTNOTES:
[2] Tarchnoff has recently discovered the curious fact that the
white of the eggs of birds that are hatched without feathers remains
transparent when coagulated, while the eggs which produce chickens
and other birds already fledged become opaque when coagulated. This
is familiarly illustrated by the difference between plovers’ eggs and
hens’ eggs when cooked.
[3] ‘Egg-cement,’ made by thickening white of egg with finely-powdered
quicklime, has long been used for mending alabaster, marble, &c. For
joining fragments of fossils and mineralogical specimens, it will be
found very useful. White of egg alone may be used, if carefully heated
afterwards.
[4] _Physiological Chemistry_, vol. ii. p. 356.
[5] It was given to me in 1868. I have just found that some of
it remains unused (December 1884), and that it still retains its
characteristic flavour.
CHAPTER IV.
GELATIN, FIBRIN, AND THE JUICES OF MEAT.
GELATIN is a very important element of animal food; it is, in fact, the
main constituent of the animal tissues, the walls of the cells of which
animals are built up being composed of gelatin. I will not here discuss
the question of whether Haller’s remark, ‘Dimidium corporis humani
gluten est’ (‘half of the human body is gelatin’), should or should
not now, as Lehmann says, ‘be modified to the assertion that half of
the solid parts of the animal body _are convertible, by boiling with
water_, into gelatin.’ Lehmann and others give the name of ‘glutin’ to
the component of the animal tissue as it exists there, and gelatin to
it when acted upon by boiling water. Others indicate this difference by
naming the first ‘gelatin,’ and the second ‘gelatine.’
The difference upon which these distinctions are based is directly
connected with my present subject, as it is just the difference between
the raw and the cooked material, which, as we shall presently see,
consists mainly in solubility.
Even the original or raw gelatin varies materially in this respect.
There is a decidedly practical difference between the solubility of the
cell-walls of a young chicken and those of an old hen. The pleasant
fiction which describes all the pretty gelatine preparations of the
table as ‘calf’s-foot jelly,’ is founded on the greater solubility of
the juvenile hoof, as compared to that of the adult ox or horse, or to
the parings of hides about to be used by the tanner. All these produce
gelatin by boiling, the calves’ feet with comparatively little boiling.
Besides these differences there are decided varieties, or, I might say,
species of gelatin, having slight differences of chemical composition
and chemical relations. There is _Chondrin_, or cartilage gelatin,
which is obtained by boiling the cartilages of the ribs, larynx, or
joints for eighteen or twenty hours in water. Then there is _Fibroin_,
obtained by boiling spiders’ webs and the silk of silkworms or other
caterpillars. These exist as a liquid inside the animal, which
solidifies on exposure. The fibres of sponge contain this modification
of gelatin.
Another kind is _Chitin_, which constituted the animal food of St. John
the Baptist, when he fed upon locusts and wild honey. It is the basis
of the bodily structure of insects; of the spiral tubes which permeate
them throughout, and are so wonderfully displayed when we examine
insect anatomy by aid of the microscope; also of their intestinal
canal, their external skeleton, scales, hairs, &c. It similarly forms
the true skeleton and bodily framework of crabs, lobsters, shrimps, and
other crustacea, bearing the same relation to their shells, muscles,
&c., that ordinary gelatin does to the bones and softer tissues of the
vertebrata; it is ‘the bone of their bones, and the flesh of their
flesh.’ It is obtainable by boiling these creatures down, but is more
difficult of solution than the ordinary gelatin of beef, mutton,
fish, and poultry. To this difficulty of solution in the stomach, the
nightmare that follows lobster suppers is probably attributable.
I once had an experience of the edibility of the shells of a
crustacean. When travelling, I always continue the pursuit of knowledge
in restaurants by ordering anything that appears on the bill of fare
that I have never heard of before, or cannot translate or pronounce.
At a Neapolitan restaurant I found ‘_Gambero di Mare_’ on the _Carta_,
which I translated ‘Leggy things of the sea,’ or sea-creepers, and
ordered them accordingly. They proved to be shrimps fried in their
shells, and were very delicious—like whitebait, but richer. The chitin
of the shells was thus cooked to crispness, and no evil consequences
followed. If reduced to locusts, I should, if possible, cook them in
the same manner, and, as they have similar chemical composition, they
would doubtless be equally good.
Should any epicurean reader desire to try this dish (the shrimps, I
mean), he should fry them as they come from the sea, not as they are
sold by the fishmonger, these being already boiled in salt water;
usually in sea water by the shrimpers who catch them, the chitin being
indurated thereby.
The introduction of fried and tinned locusts as an epicurean delicacy
would be a boon to suffering humanity, by supplying industrial
compensation to the inhabitants of districts subject to periodical
plagues of locust invasion. The idea of eating them appears repulsive
_at first_, so would that of eating such creepy-crawly things
as shrimps, if no adventurous hero had made the first exemplary
experiment. Chitin is chitin, whether elaborated on the land or
secreted in the sea. The vegetarian locust and the cicala are free from
the pungent essential oils of the really unpleasant cockchafer.
That curious epicurean food, the edible birds’-nests, which has been
a subject of much controversy concerning its composition, is commonly
described as a delicate kind of gelatin. This does not appear to be
quite correct. It is certainly gelatinous in its mechanical properties,
but it more nearly resembles the material of the slime and organic
tissue of snails, a substance to which the name of _mucin_ has been
given. Thus the birds’-nest soup of the East and the snail soup of
the West are nearly allied, and that made from callipash and callipee
supplies an intermediate reptilian link.
The birds’-nests, when cleaned for cooking, are entirely composed of
the dried saliva of swallows, or rather swiftlets (_collocalia_), and
this saliva probably contains some amount of digestive ferment or
pepsin, which may render it more digestible than the vulgar product
from shin of beef, and consequently more acceptable to feeble epicures.
Those who have sufficient vital energy to supply their own saliva will
probably prefer the vulgar concoction to the costly secretion. The bird
saliva sells for its own weight in silver, when freed from adhering
impurities.[6]
Those who are disposed to bow too implicitly to mere authority
in scientific matters will do well to study the history and the
treatment which gelatin has received from some of the highest of these
authorities. Our grandmothers believed it to be highly nutritious,
prepared it in the form of jellies for invalids, and estimated the
nutritive value of their soups by the consistency of the jelly which
they formed on cooling, which thickness is due to the gelatin they
contain. Isinglass, which is simply the swim-bladder of the sturgeon
and similar fishes cut into shreds, was especially esteemed, and sold
at high prices. This is the purest natural form of gelatin.
Everybody believed that the callipash and callipee of the alderman’s
turtle soup contributed largely to his proverbial girth, and those
who could not afford to pay for the gelatin of the reptile, made mock
turtle from the gelatinous tissues of calves’-heads and pigs’-feet.
About fifty or sixty years ago, the French Academy of Sciences
appointed a bone-soup commission, consisting of some of the most
eminent _savants_ of the period. They worked for above ten years upon
the problem submitted to them, that of determining whether or not the
soup made by boiling bones until only their mineral matter remained
solid, is, or is not, a nutritious food for the inmates of hospitals,
&c. In the voluminous report which they ultimately submitted to the
Academy, they decided in the negative.
Baron Liebig became the popular exponent of their conclusions, and
vigorously denounced gelatin, as not merely a worthless article of
food, but as loading the system with material that demands wasteful
effort for its removal.
The Academicians fed dogs on gelatin alone, found that they speedily
lost flesh, and ultimately died of starvation. A multitude of similar
experiments showed that gelatin alone will not support animal life, and
hence the conclusion that pure gelatin is worthless as an article of
food, and that ordinary soups containing gelatin owed their nutritive
value to their other constituents. According to the above-named report,
and the statements of Liebig, the following, which I find on a wrapper
of Liebig’s ‘Extract of Meat,’ is justifiable: ‘This Extract of Meat
differs essentially from the gelatinous product obtained from tendons
and muscular fibre, inasmuch as it contains 80 per cent. of nutritive
matter, while the other contains 4 or 5 per cent.’ Here the 4 or 5 per
cent. allowed to exist in the ‘gelatinous product’ (_i.e._ ordinary
kitchen stock or glaze), is attributed to the constituents it contains
over and above the pure gelatin.
The following, from a text-book largely used by medical students,[7]
shows the estimation in which gelatin was held at that date: ‘But there
is another azotised compound, Gelatin, that is furnished by animals,
to which nothing analogous exists in Plants; and this is commonly
reputed to possess highly nutritious properties. It may be confidently
affirmed, however, as a result of experiments made upon a large scale,
that Gelatin is incapable of being converted into Albumen in the animal
body, so that it cannot be applied to the nutrition of the albuminous
tissues. And, although it might _à priori_ be thought not unlikely
that Gelatin, taken in as food, should be applied to the nutrition of
the gelatinous tissues, yet neither observation nor experiment bears
out such a probability.’ Further on, Dr. Carpenter says: ‘The use of
gelatin as food would seem to be limited to its power of furnishing a
certain amount of combustive material that may assist in maintaining
the heat of the body.’
Subsequent experiments, however, have refuted these conclusions. I
must not be tempted to describe them in detail, but only to state the
general results, which are, that while animals fed on gelatin soup,
formed into a soft paste with bread, lost flesh and strength rapidly,
they recovered their original weight when to this same food only a very
small quantity of the sapid and odorous principles of meat were added.
Thus, in the experiments of MM. Edwards and Balzac, a young dog that
had ceased growing, and had lost one-fifth of its original weight when
fed on bread and gelatin for thirty days, was next supplied with the
same food, but to which was added, twice a day, only two tablespoonfuls
of soup made from horseflesh. There was an increase of weight on the
first day, and, ‘in twenty-three days the dog had gained considerably
more than its original weight, and was in the enjoyment of vigorous
health and strength.’
All this difference was due to the savoury constituents of the four
tablespoonfuls of meat soup, which soup contained the juices of the
flesh, to which, as already stated, its flavour is due.
The inferences drawn by M. Edwards from the whole of the experiments
are the following: ‘1. That gelatin alone is insufficient for
alimentation. 2. That, although insufficient, it is not unwholesome. 3.
That gelatin contributes to alimentation, and is sufficient to sustain
it when it is mixed with a due proportion of other products which would
themselves prove insufficient if given alone. 4. That gelatin extracted
from bones, being identical with that extracted from other parts—and
bones being richer in gelatin than other tissues, and able to afford
two-thirds of their weight of it—there is an incontestable advantage in
making them serve for nutrition in the form of soup, jellies, paste,
&c., always, however, taking care to provide a proper admixture of
the other principles in which the gelatin-soup is defective. 5. That
to render gelatin-soup equal in nutritive and digestible qualities to
that prepared from meat alone, it is sufficient _to mix one-fourth of
meat-soup with three-fourths of gelatin-soup_; and that, in fact, no
difference is perceptible between soup thus prepared and that made
solely from meat. 6. That in preparing soup in this way, the great
advantage remains, that while the soup itself is equally nourishing
with meat-soup, three-fourths of the meat which would be requisite
for the latter by the common process of making soup are saved and
made useful in another way—as by roasting, &c. 7. That jellies ought
always to be associated with some other principles to render them both
nutritive and digestible.’[8]
The reader may make a very simple experiment on himself by preparing
first a pure gelatin-soup from isinglass, or the prepared gelatin
commonly sold, and trying to make a meal of this with bread alone. Its
insipidity will be evident with the first spoonful. If he perseveres,
it will become not merely insipid, but positively repulsive; and,
should he struggle through one meal and then another, without any other
food between, he will find it, in the course of time (varying with
constitution and previous alimentation), positively nauseous.
Let him now add to it some of Liebig’s ‘Extract of Meat,’ and he will
at once perceive the difference. Here the natural appetite foreshadows
the result of continuing the experiment, and points the way to
correcting the errors of the Academicians and Baron Liebig. The jellies
that we take at evening parties, or the jujubes used as sweetmeats, are
flavoured with something positive. I have tasted ‘Blue-Ribbon’ jellies
that were wretchedly insipid. This was not merely owing to the absence
of alcohol, of which very little can remain in such preparations, but
rather to the absence of the flavouring ingredients of the wine.
I venture to suggest the further, deliberate, and scientific extension
of this principle, by adding to bone-soup, or other form of insipid
gelatin, the potash, salts, phosphates, &c., which are found in the
juices of meat and vegetables. They may either be prepared in the
manufacturing laboratory, like Parrish’s ‘Chemical Food,’ or ‘Syrup
of phosphates,’ or extracted from fruits, as commercial limejuice is
extracted. I recommend those who are interested to manufacture and
offer for sale a good preparation of limejuice gelatin.
It would seem that gelatin alone, although containing the elements
required for nutrition, requires something more to render it
digestible. We shall probably be not far from the truth if we picture
it to the mind as something too smooth, too neutral, too inert, to
set the digestive organs at work, and that it therefore requires
the addition of a decidedly sapid something that shall make these
organs act. I believe that the proper function of the palate is to
determine our selection of such materials; that its activity is in
direct sympathy with that of all the digestive organs; and that if we
carefully avoid the vitiation of our natural appetites, we have in our
mouths, and the nervous apparatus connected therewith, a laboratory
that is capable of supplying us with information concerning some of the
chemical relations of food which is beyond the grasp of the analytical
machinery of the ablest of our scientific chemists.
What is the chemistry of the cookery of gelatin? What are the chemical
changes effected by cookery upon gelatin? Or, otherwise stated, what
is the chemical difference or differences between cooked and raw
gelatin? I find no satisfactory answer to these questions in any of
our text-books, and therefore will do what I can towards supplying my
own solution of the problem.
In the first place, it should be understood that raw gelatin, or animal
membrane as it exists in its organised condition, is not soluble in
cold water, and not immediately in hot water. Genuine isinglass is the
membrane of the swim-bladder of the sturgeon (that of other fishes is
said to be sometimes substituted). In its unprepared form it is not
easily dissolved, but if soaked in water, especially in warm water,
for some time, it swells. The same with other forms of membrane. This
swelling I regard as the first stage of the cookery. On examination,
I find that it is not only increased in bulk but also in weight, and
that the increase of weight is due to some water that it has taken
into itself. Here, then, we have crude gelatin plus water, or hydrated
gelatin. Proceeding further, by boiling this until it all dissolves,
and then allowing it to harden by very slow evaporation, I find that it
still contains some of its acquired water, and that I cannot drive away
this newly-acquired water without destroying some of its characteristic
properties—its solubility and gluey character. Before returning to its
original weight as crude isinglass, it becomes somewhat carbonised.
Hence, I infer that the cookery of gelatin consists in converting the
original membrane more or less completely into a hydrate of its former
self. According to this, the ‘prepared gelatin’ sold in the shops is
hydrated gelatin, completely hydrated, seeing that it is completely and
readily soluble.
The membranes of our ordinary cooked meat are, if I am right, partially
hydrated, in varying degrees, and thereby prepared for solution in
the course of digestion. The varying degrees are illustrated by the
differences in a knuckle of veal or a calf’s head, according to the
length of time during which it has been stewed, _i.e._ subjected to the
hydrating process.
The second stage of the cookery of gelatin is the solution of this
hydrate, as in soups, &c.
Carpenters’ glue is crude hydrated gelatin, made by stewing or
hydrating hoofs of horses, cattle, &c., or the waste cuttings of hides.
The carpenter knows that if he allows his solution of glue to boil
(such a solution boils at a higher temperature than pure water), it
loses its tenacity, becomes cindery, or, as I should say, dehydrated
or dissociated, without returning to the original condition of the
organised membranes.
Even a frequent reheating at the glue-pot temperature ‘weakens’ the
glue, and therefore he prefers fresh glue, and puts but a little at a
time into his glue-pot.
The applications of this theory will appear as I proceed.
A sheep or an ox, a fowl or a rabbit, is made up, like ourselves, of
organic structures and blood, the organs continually wasting as they
work, and being renewed by the blood; or, otherwise described, the
component molecules of these organs are continually dying of old age as
their work is done, and replaced by new-born successors generated by
the blood.
These molecules are, for the most part, cellular, each cell living
a little life of its own, generated with a definite individuality,
doing its own life-work, then shrivelling in decay, dying in the midst
of vital surroundings, suffering cremation, and thereby contributing
to the animal heat necessary for the life of its successors, and
even giving up a portion of its substance to supply them with
absorption-food. The cell walls are mainly composed of gelatin, or
the substance which produces gelatin, as already explained, while the
contents of the cell are albuminous matter or fat, or the special
constituents of the particular organ it composes. A description of
all these constituents would carry me too far into details. I must,
therefore, only refer to those which constitute the bulk of animal
food, and which are altered in the process of cooking.
In the lean of meat, _i.e._ the muscles of the animal, we have the
albuminous juices already described, the gelatinous membranes, sheaths,
and walls of the muscle fibre, and the fibre itself. This is composed
of _muscle-fibrin_, or _syntonin_, as Lehmann has named it. Living
blood consists of a complex liquid, in which are suspended a multitude
of minute cells, some red, others colourless. When the blood is removed
and dies, it clots or partially solidifies, and is found to contain
a network of extremely fine fibre, to which the name of _fibrin_ is
applied. A similar change takes place in the substance of the muscle
after death. It stiffens, and this stiffening, or _rigor mortis_, is
effected by the formation of a clot analogous to the coagulation of the
blood.
The chief difference between blood-fibrin and muscle-fibrin or
syntonin is, that the latter is readily soluble in water, to which
only 1/1000 of hydrochloric acid has been added, while in such a
solution blood-fibrin only becomes swollen. If the gastric juice
contains a little free hydrochloric acid, this difference is important
in reference to food. I should, however, add that the existence of
such free acid in the human gastric juice is disputed, especially by
Gruenewaldt and Schroeder.
The conflict of able chemists on this point and others concerning the
composition of this fluid leads me to suppose that the secretions
of the human stomach vary with the food habitually taken; that
flesh-eaters acquire a gastric juice similar to that of carnivorous
animals, while vegetable feeders are supplied with digestive solvents
more suitable to their food.
This idea is supported by the testimony of rigid vegetarians. They tell
me that at first the pure vegetarian diet did not appear to satisfy
them, but after a while it became as sustaining as their former food.
This is explained if, in consequence of the modification of the gastric
and other digestive juices, the vegetarian food became more completely
digested after vegetarian habits became established.
The properties of fibrin, so far as cookery is concerned, place it
between albumen and gelatin; it is coagulable like albumen, and soluble
like gelatin, but in a minor degree. Like gelatin, it is tasteless and
non-nutritious _alone_. This has been proved by feeding animals on
lean meat, which has been cut up and subjected to the action of cold
water, which dissolves out the albumen and other juices of the flesh,
and leaves only the muscular fibre and its envelopes. The experiment
has been made in laboratories, and also on a larger scale in Australia,
where the lean beef from which the ‘Extract of Meat’ had been taken out
by cold water was given to dogs, pigs, and other animals; but, after
taking a few mouthfuls, they all rejected it, and suffered starvation
when it was forced upon them without other food.
The same is the case with the spontaneously coagulated fibrin of the
blood; it is, when washed, a yellowish opaque fibrous mass, without
smell or taste, insoluble in cold water, alcohol, or ether, but
imperfectly soluble if digested for a considerable time in hot water.
The following is the chemical composition of these three constituents
of lean meat, according to Mulder:
+-----------+---------+----------+--------+
| -- | Albumen | Gelatine | Fibrin |
+-----------+---------+----------+--------+
|Carbon | 53·5 | 50·40 | 52·7 |
|Hydrogen | 7·0 | 6·64 | 6·9 |
|Nitrogen | 15·5 | 18·34 | 15·4 |
|Oxygen | 22·0 | 24·62 | 23·5 |
|Sulphur | 1·6 | -- | 1·2 |
|Phosphorus | 0·4 | -- | 0·3 |
| +---------+----------+--------+
| | 100·0 | 100·00 | 100·0 |
+-----------+---------+----------+--------+
There are two other constituents of lean meat which are very different
from either of these, viz. _Kreatine_ and _Kreatinine_, otherwise
spelled ‘creatine’ and ‘creatinine.’ They exist in the juice of
the flesh, and are freely soluble in cold or hot water, from which
solution they may be crystallised by evaporating the solvent, just as
we may crystallise common salt, alum, &c. They thus have a resemblance
to mineral substances, and still more so to some of the active
constituents of plants, such as the alkaloids _theine_ and _caffeine_,
upon which depend the stimulating or ‘refreshing’ properties of tea and
coffee. Like these, they are highly nitrogenous, and many theories have
been based upon this, both as regards their exceptionally nutritious
properties and their functions in the living muscle. One of these
theories is that they are the dead matter of muscle, the first and
second products of the combustion which accompanies muscular work, urea
being the final product. According to this their relation to the muscle
is exactly the opposite of that of the albuminous juice, this being
probably the material from which the muscle is built up or renewed. The
following is their composition, according to Liebig’s analyses, and
does not support this hypothesis:
+----------+----------+------------+
| -- | Kreatine | Kreatinine |
+----------+----------+------------+
| Carbon | 36·64 | 42·48 |
| Hydrogen | 6·87 | 6·19 |
| Nitrogen | 32·06 | 37·17 |
| Oxygen | 24·43 | 14·16 |
| +----------+------------+
| | 100·00 | 100·00 |
+----------+----------+------------+
They appear to undergo no change in cooking unless excessively heated;
may be used uncooked, as in cold-drawn extract of meat.
The juices of lean flesh also contain a little lactic acid—the acid
of milk—but this does not appear to be an absolutely essential
constituent. Besides these there are mineral salts of considerable
nutritive importance, though small in quantity. These, with the
kreatine and kreatinine, are the chief constituents of beef-tea
properly so-called, and will be further treated when I come to that
preparation. At present it is sufficient to keep in view the fact that
these juices are essential to complete the nutritive value of animal
food.
FOOTNOTES:
[6] The following, from Francatelli’s _Modern Cook_, is amusing, if
not instructive: ‘Take two dozen garden snails, add to these the hind
quarters only of two dozen stream frogs, previously skinned; bruise
them together in a mortar, after which put them into a stewpan with a
couple of turnips chopped small, a little salt, a quarter of an ounce
of hay-saffron, and three pints of spring water. Stir these on the fire
until the broth begins to boil, then skim it well and set it by the
side of the fire to simmer for half an hour; after which it should be
strained, by pressure through a tammy cloth, into a basin for use. This
broth, from its soothing qualities, often counteracts, successfully,
the straining effects of a severe cough, and alleviates, more than any
other culinary preparation, the sufferings of the consumptive.’
[7] Carpenter’s _Manual of Physiology_, 3rd edition, 1846, p. 267.
[8] Londe, _Nouveaux Éléments d’Hygiène_, 2nd edition, vol. ii. p. 73.
CHAPTER V.
ROASTING AND GRILLING.
I MAY now venture to state my own view of a somewhat obscure
subject—viz. the difference between the roasting or grilling of meat
and the stewing of meat. It appears to me that, as regards the nature
of the operation, it consists simply in the difference between the
cooking media; that a grilled steak or chop, or a roasted joint is meat
that has been stewed in its own juices instead of stewed in water; that
in both cases the changes taking place in the _solid_ parts of the meat
are the same in kind, provided always that the roasting or grilling is
properly performed. The albumen is coagulated in all cases, and the
gelatinous and fibrous tissues are softened by being heated in a liquid
solvent. I shall presently apply this definition in distinguishing
between good and bad cookery.
In the roasted or grilled meat the juices are retained in the meat
(with the exception of those which escape as gravy on the dish), while
in stewing the juices go more or less completely into the water, and
the loosening of the fibres and solution of the gelatin and fibrin may
be carried further, inasmuch as a larger quantity of solvent is used.
Roasting and grilling may be regarded as our national methods of flesh
cookery, and stewing in water that of our continental neighbours.
The difference between the flavour of English roast beef and French
_bouilli_ or Italian _manzo_ is due to the retention or the removal
of the saline and highly-flavoured soluble materials. (Concentrated
kreatine and kreatinine are pungently sapid.) The Frenchman takes
them out of his _bouilli_, or boiled meat, and transfers them to his
_bouillon_, or soup, which, with him, is an essential element of a
meal. If he ate his meat without soup, he would be like the dogs fed
on gelatin by the bone-soup commissioners. To the Englishman, with
his roast or grilled meat, soup is merely a luxury, not an absolutely
necessary element of a complete dietary.
What we call boiled meat, as a boiled leg of mutton or round of beef,
is an intermediate preparation. The heat is here communicated by water,
and the juices partially retained.
Not only do we, in roasting and grilling our meat, keep the juices
within it, but we concentrate them considerably by evaporating away
_some_ of the water by which they are naturally diluted. This is my
explanation of the _rationale_ of the chief difference between boiled
meat and roasted or grilled meat. A further difference—that due to
browning—is discussed in the chapter on Frying. Those accustomed to
such concentration of flavour regard the milder results of boiling as
insipid, for, by this process and by stewing, where much water is used,
the juices are further diluted instead of being concentrated.
It is a fairly debatable question whether the simplicity of taste which
finds satisfaction in the milder diet is better and more desirable than
the appetite for strong meat. The difference has some analogy to that
between the thirst for light wine and that for stiff grog.
The application of the principles above expounded to the processes of
grilling and roasting is simple enough. As the meat is to be stewed
in its own juices, it is evident that these juices must be retained
as completely as possible, and that in order to succeed in this, we
have to struggle with the evaporating energy of the ‘dry heat’ which
effects the cookery, and may not only concentrate the juices by driving
off some of their solvent water, but may volatilise or decompose the
flavouring principles themselves. We must always remember that these
organic compounds are very unstable, most of them being decomposed when
raised to a temperature above the boiling-point of water. The repulsive
energy of heat drives apart or ‘dissociates’ their loosely-combined
elements, and when thus wholly or partially dissociated, all the
characteristic properties of the original compound vanish, and others
take their place.
It should be clearly understood that the so-called ‘dry heat’ may be
communicated by convection or by radiation, or both. When water is
the heating medium, there is convection only—_i.e._ heating by actual
contact with the heated body. In roasting and grilling there is also
some convection-heating due to the hot air which actually touches the
meat; but this is a very small element of efficiency, the work being
chiefly done, when well done, by the heat which is radiated from the
fire directly to the surface of the meat, and which, in the case of
roasting in front of a fire, passes through the intervening air with
very little heating effect thereon.
I am not perpetrating any far-fetched pedantry in pointing out this
difference, as will be understood at once by supposing a beefsteak
to be cooked by suspending it in a chamber filled with hot dry air.
Such air is actively thirsting for the vapour of water, and will
take into itself, from every humid substance it touches, a quantity
proportionate to its temperature. The steak receiving its heat by
convection—_i.e._ the heat conveyed by such hot air, and communicated
by contact—would be _desiccated, but not cooked_.
This distinction is so important, that I will illustrate it still
further, my chief justification for such insistence being that even
Rumford himself evidently failed to understand it, and it has been
generally misunderstood or neglected.
Let us suppose the hot air used for convection cooking to be at the
cooking-point, as the hot water in stewing should be, what will follow
its application to the meat? Evaporation of the water in the juices,
and with that evaporation a lowering of temperature at the surface of
the meat, keeping it below the cooking-point. If the air be heated
above this, the evaporation will go on with proportionate rapidity. As
nearly 1,000 degrees of heat are lost _as temperature_, and converted
into expansive force whenever and wherever evaporation of water
occurs, the film of hot, dry air touching the meat is cooled by this
evaporation, and sinks immediately, to be replaced by a rising film
of lighter, hotter, and drier air. This drinks in more vapour, cools
and sinks, to give place to another, and so on till the inner juices
gradually ooze between the fibres to the porous surface, where they are
carried away by the hot, dry air, and a hard, leathery, unmasticable
mass of desiccated gelatin, albumen, fibrin, &c., is produced.
Now, let us suppose a similar beefsteak to be cooked by radiant heat,
with the least possible co-operation of convection.
To effect this, our source of heat must be a good radiator. Glowing
solids are better radiators than ordinary flames; therefore coke, or
charcoal, or ordinary coal, after its bituminous matter has done
its flaming, should be used, and the steak or chop may be placed in
front or above a surface of such glowing carbon. In ordinary domestic
practice it is placed on a gridiron above the coal, and therefore I
will consider this case first.
The object to be attained is to raise the juices of the meat throughout
to about the temperature of 180° Fahr. as quickly as possible, in order
that the cookery may be completed before the water of these juices
shall have had time to evaporate excessively; therefore the meat should
be placed as near to the surface of the glowing carbon as possible. But
the practical housewife will say that, if placed within two or three
inches, some of the fat will be melted and burn, and then the steak
will be smoked.
Now, here we require a little more chemistry. There is smoking and
smoking; smoking that produces a detestable flavour, and smoking that
does no mischief at all beyond appearances. The flame of an ordinary
coal fire is due to the distillation and combustion of tarry vapours.
If such a flame strikes a comparatively cool surface like that of the
meat, it will condense and deposit thereon a film of crude coal tar and
coal naphtha, most nauseous and rather mischievous; but if the flame be
that which is caused by the combustion of its own fat, the deposit on
a mutton-chop will be a little mutton juice, on a beefsteak a little
beef juice, more or less blackened by mutton-carbon or beef-carbon. But
these have no other flavour than that of cooked mutton and cooked beef;
therefore they are perfectly innocent, in spite of their black, guilty
appearances.
If any of my readers are sceptical, let them appeal to experiment by
putting a mutton-chop to the torture, and taking its own confession.
To do this, divide the chop in equal halves, then hold one half
over a flaming coal, immersing it in the flame, and thus cook it.
Now cut a bit of fat off the other, throw this fat on a surface of
clear, glowing, flameless coal or coke, and, when a good blaze is thus
obtained, immerse the half chop recklessly and unmercifully into _this_
flame; there let it splutter and fizz, let it drop more fat and make
more flame, but hold it there nevertheless for a few minutes, and then
taste the result.
In spite of its blackness, it will be (if just warmed through to
the above-named cooking temperature) a deliciously-cooked, juicy,
nutritious, digestible morsel, apparently raw, but actually more
completely cooked than if it had been held twice as long, at double the
distance, from the surface of the fire.
For further instruction, make a third experiment by imitating the
cautious unscientific cook, who, ignorant of the difference between
the condensation products of coal and those from beef and mutton fat,
carefully raises the gridiron directly the flame from the dropping
fat threatens the object of her solicitude. The result will be an
ordinary domestic chop or steak. I apply this adjective, because in
this particular effort of cookery, the grilling of chops and steaks,
domestic cookery is commonly at fault. The majority of our City men
find that while the joint cooked at home is better than that they
usually get at restaurants and hotels, the chops and steaks are
inferior.
I believe that this inferiority is due, in the first place, to the want
of understanding of the difference between coal-flame and fat-flame;
and in the second, to the advantage afforded to the ‘grill-room’ cook
by his specially-constructed fire, with a large surface of glowing coke
surmounted by a sloping grill, whereon he can expose his chops and
steaks to a maximum of radiant heat with a minimum of convection heat;
the hot air which passes in a current over the coke surface having such
small depth that it barely touches the bars of the grill. (This may
be seen by watching the course of flame produced by the droppings of
the fat.) The same obliquity of draught prevents the serious blacking
of the meat, which, although harmless, is unsightly and calculated to
awaken prejudice.
The high temperature rapidly imparted by radiation to the surface of
the meat forms a thin superficial crust of hardened and semi-carbonised
albumen and fibre, that resists the outrush of vapour, and produces
within a certain degree of high pressure, which probably acts in
loosening the fibres. A well-grilled chop or steak is ‘puffed’
out—made thicker in the middle; an ill-cooked, desiccated specimen
is shrivelled, collapsed, and thinned by the slow departure or
dissociation of its juices.
Happy little couples, living in little houses with only one little
servant—or, happier still, with no servant at all—complain of their
little joints of meat, which, when roasted, are so dry, as compared
with the big succulent joints of larger households. A little reflection
on the principles above applied to the grilling of steaks and chops
will explain the source of this little difficulty, and show how it may
be overcome.
I will here venture upon a little of the mathematics of cookery, as
well as its chemistry. While the weight or quantity of material in a
joint increases with the cube of its through-measured dimensions, its
surface only increases with their square—or, otherwise stated, we do
not nearly double or treble the surface of a joint of given form when
we double or treble its weight; and _vice versâ_, the less the weight,
the greater the surface in proportion to the weight. This is obvious
enough when we consider that we cannot cut a single lump of anything
into halves without exposing or creating two fresh surfaces where no
surfaces were exposed before. As the evaporation of the juices is,
under given conditions, proportionate to the surface exposed, it is
evident that this process of converting the inside middle into two
outside surfaces must increase the amount of evaporation that occurs in
roasting.
What, then, is the remedy for this? It is twofold. First, to seal up
the pores of these additional surfaces as completely as possible; and
secondly, to diminish to the utmost the time of exposure to the dry
air. Logically following up these principles, I arrive at a practical
formula which will probably induce certain orthodox cooks to denounce
me as a culinary paradoxer. It is this: That _the smaller the joint to
be roasted, the higher the temperature to which its surface should be
exposed_. The roasting of a small joint should, in fact, be conducted
in nearly the same manner as the grilling of a chop or steak described
in my last. The surface should be crusted or browned—burned, if you
please—as speedily as possible, in such wise that the juices within
shall be held there under high pressure, and only allowed to escape by
burst and splutters, rather than by steady evaporation.
The best way of doing this is a problem to be solved by the practical
cook. I only expound the principles, and timidly suggest the mode of
applying them. In a metallurgical laboratory, where I am most at home,
I could roast a small joint beautifully by suspending it inside a large
red-hot steel-smelter’s crucible, or, better still, in an apparatus
called a ‘muffle,’ which is a fireclay tunnel open in front, and so
arranged in a suitable furnace as to be easily made red-hot all
round. A small joint placed on a dripping-pan and run into this would
be equally heated by all-round converging radiation, and exquisitely
roasted in the course of ten to thirty minutes, according to its size.
Some such an apparatus has yet to be invented in order that we may
learn the flavour and tenderness of a perfectly-roasted small joint of
beef or mutton.
For roasting large masses of meat, a different proceeding is necessary.
Here we have to contend, not with excessive surface in proportion
to bulk—as in the grilling of chops and steaks, and the roasting of
small joints—but with the contrary, viz. excessive bulk in proportion
to surface. If a baron of beef were to be treated according to my
prescription for a steak, or for a single small wing rib, or other
joint of three to five pounds weight, it would be charred on its
surface long before the heat could reach its centre.
A considerable time is here inevitably demanded. Of course, the
higher the initial outside temperature, the more rapidly the heat
will penetrate; but we cannot apply this law to a lump of meat as we
may to a mass of iron. We may go on heating the outside of the iron
to redness, but not so the meat. So long as the surface of the meat
remains moist, we cannot raise it to a higher temperature than the
boiling-point of the liquid that moistens it. Above this, charring
commences. A little of such charring, such as occurs to the steak
or small joint during the short period of its exposure to the great
heat, does no harm; it simply ‘browns’ the surface; but if this were
continued during the roasting of a large joint, a crust of positively
black charcoal would be formed, with ruinous waste and general
detriment.
As Rumford proved long ago, liquids are very bad conductors, and when
their circulation is prevented by confinement between fibres, as in
the meat, the rate at which heat will travel through the humid mass is
very slow indeed. As few of my readers are likely to fully estimate the
magnitude of this difficulty, I will state a fact that came under my
own observation, and at the time surprised me.
About five-and-twenty years ago I was visiting a friend at Warwick
during the ‘mop,’ or ‘statute fair’—the annual slave market of the
county. In accordance with the old custom, an ox was roasted whole in
the open public market-place. The spitting of the carcass and starting
the cookery was a disgusting sight. We are accustomed to see the
neatly-cut joints ordinarily brought to the kitchen; but the handling
and impaling of the whole body of a huge beast by half a dozen rough
men, while its stiffened limbs were stretching out from its trunk,
presented the carnivorous character of our ordinary feeding very
grossly indeed.
Nevertheless I watched the process, partook of some of its result, and
found it good. The fire was lighted before midnight, the rotation of
the beast on the horizontal spit began shortly after, and continued
until the following midday, all this time being necessary for the
raising of the inner parts of the flesh to the cooking temperature of
about 180° Fahr.
Compare this with the grilling of a steak, which, when well done, is
done in a few minutes, or the roasting of the small joint as above
within thirty minutes, and you will see that I am justified in dwelling
on the great differences of the two processes, and the necessity of
very varied proceeding to meet these different conditions.
The difference of time is so great that the smaller relative surface
is insufficient to compensate for the evaporation that must occur if
the grilling principle, or the pure and simple action of radiant heat,
were only made available, as in the above ideal roasting of the small
joint.
What, then, is added to this? How is the desiccating difficulty
overcome in the large-scale roasting? Simply by _basting_.
All night long and all the next morning men were continuously at work
pouring melted fat over the surface of the slowly-rotating carcass
of the Warwick ox, skilfully directing a ladleful to any part that
indicated undue dryness.
By this device the meat is more or less completely enveloped in a
varnish of hot melted fat, which assists in the communication of heat,
while it checks the evaporation of the juices. In such roasting the
heat is partially communicated by convection through the medium of a
fat-bath, as in stewing it is all supplied by a water-bath.
I have made some experiments wherein this principle is fully carried
out. In a suitably-sized saucepan I melted a sufficient quantity of
mutton-dripping to form a bath, wherein a small joint of mutton could
be completely immersed. The fat was then raised to a high temperature,
350° (as shown by Davis’ _tryometer_, presently to be described). Then
I immersed the joint in this, keeping up the high temperature for a
few minutes. Afterwards I allowed it to fall below 200°, and thus
cooked the joint. It was good and juicy, though a little of the gravy
had escaped and was found in the fat after cooling. The experiment
was repeated with variations of temperature; the best result obtained
when it was about 400° at the beginning, and kept up to above 200°
afterwards. I used loins and half-legs of mutton, exposing considerable
surface.
I find that Sir Henry Thompson, in a lecture delivered at the Fisheries
Exhibition, and now reprinted, has invaded my subject, and has done
this so well that I shall retaliate by annexing his suggestion, which
is that fish should be _roasted_. He says that this mode of cooking
fish should be general, since it is applicable to all varieties. I
fully agree with him, but go a little further in the same direction
by including, not only roasting in a Dutch or American oven _before_
the fire, but also in the side-ovens of kitcheners and in gas-ovens,
which, when used as I have explained, are roasters—_i.e._ they cook by
radiation, without any of the drying anticipated by Sir Henry.
The practical housewife will probably say this is not new, seeing that
people who know what is good have long been in the habit of enjoying
mackerel and haddocks (especially Dublin Bay haddocks) stuffed and
baked, and cods’ heads similarly treated. The Jews do something of
the kind with halibut’s head, which they prize as the greatest of all
piscine delicacies. The John Dory is commonly stuffed and cooked in an
oven by those who understand his merits.
The excellence of Sir Henry Thompson’s idea consists in its breadth as
applicable to _all fish_, on the basis of that fundamental principle
of scientific cookery on which I have so continually and variously
insisted, viz. the retention and concentration of the natural juices of
the viands.
He recommends the placing of the fish entire, if of moderate size, in
a tin or plated copper dish adapted to the form and size of the fish,
but a little deeper than its thickness, so as to retain all the juices,
which on exposure to the heat will flow out; the surface to be lightly
spread with butter with a morsel or two added, and the dish placed
before the fire in a Dutch or American oven, or the special apparatus
made by Burton of Oxford Street, which was exhibited at the lecture.
To this I may add, that if a closed oven be used, Rumford’s device
of a false bottom, shown in Fig. 3, p. 72 (see next chapter),
should be adopted, which may be easily done by simply standing the
above-described fish-dish, on any kind of support to raise it a
little, in a larger tin tray or baking-dish, containing some water.
The evaporation of the water will prevent the drying up of the fish
or of its natural gravy; and if the oven ventilation is treated with
the contempt I shall presently recommend, the fish, if thick, will be
better cooked and more juicy than in an open-faced oven in front of the
fire.
This reminds me of a method of cooking fish which, in the course of my
pedestrian travels in Italy, I have seen practised in the rudest of
osterias, where my fellow-guests were carbonari (charcoal burners),
waggoners, road-making navvies, &c. Their staple ‘_magro_,’ or fast-day
material, is split and dried codfish imported from Norway, which in
appearance resembles the hides that are imported to the Bermondsey
tanneries. A piece is hacked out from one of these, soaked for awhile
in water, and carefully rolled in a piece of paper saturated with olive
oil. A hole is then made in the white embers of the charcoal fire,
the paper parcel of fish inserted and carefully buried in ashes of
selected temperature. It comes out wonderfully well cooked considering
the nature of the raw material. Luxurious cookery _en papillote_ is
conducted on the same principle and especially applied to red mullets,
the paper being buttered and the sauce enveloped with the fish. In all
these cases the retention of the natural juices is the primary object.
I should add that Sir Henry Thompson directs, as a matter of course,
that the roasted fish should be served in the dish wherein it was
cooked. He suggests that ‘portions of fish, such as fillets, may be
treated as well as entire fish; garnishes of all kinds, as shell-fish,
&c., may be added, flavouring also with fine herbs and condiments
according to taste.’ ‘Fillets of plaice or skate with a slice or two of
bacon; the dish to be filled or garnished with some previously-boiled
haricots,’ is wisely recommended as a savoury meal for a poor man, and
one that is highly nutritious. A chemical analysis of six-pennyworth of
such a combination would prove its nutritive value to be equal to fully
eighteen-pennyworth of beefsteak.
Some people may be inclined to smile at what I am about to say, viz.
that such savoury dishes, serving to vary the monotony of the poor
hard-working man’s ordinary fare, afford considerable moral, as well as
physical, advantage.
An instructive experience of my own will illustrate this. When
wandering alone through Norway in 1856, I lost the track in crossing
the Kjolen fjeld, struggled on for twenty-three hours without food or
rest, and arrived in sorry plight at Lom, a very wild region. After
a few hours’ rest I pushed on to a still wilder region and still
rougher quarters, and continued thus to the great Jostedal table-land,
an unbroken glacier of 500 square miles; then descended the Jostedal
itself to its opening on the Sogne fjord—five days of extreme hardship
with no other food than flatbrod (very coarse oatcake), and bilberries
gathered on the way, varied on one occasion with the luxury of two raw
turnips. Then I reached a comparatively luxurious station (Ronnei),
where ham and eggs and claret were obtainable. The first glass of
claret produced an effect that alarmed me—a craving for more and for
stronger drink, that was almost irresistible. I finished a bottle of
St. Julien, and nothing but a violent effort of will prevented me from
then ordering brandy.
I attribute this to the exhaustion consequent upon the excessive work
and insufficient unsavoury food of the previous five days; have made
many subsequent observations on the victims of alcohol, and have no
doubt that overwork and scanty, tasteless food is the primary source
of the craving for strong drink that so largely prevails with such
deplorable results among the class that is the most exposed to such
privation. I do not say that this is the only source of such depraved
appetite. It may also be engendered by the opposite extreme of
excessive luxurious pandering to general sensuality.
The practical inference suggested by this experience and these
observations is, that speech-making, pledge-signing, and blue-ribbon
missions can only effect temporary results unless supplemented by
satisfying the natural appetite of hungry people by supplies of food
that are not only nutritious, but savoury and _varied_. Such food need
be no more expensive than that which is commonly eaten by the poorest
of Englishmen, but it must be far better cooked.
Comparing the domestic economy of the poorer classes of our countrymen
with that of the corresponding classes in France and Italy (with
both of which I am well acquainted), I find that the raw material of
the dietary of the French and Italians is inferior to that of the
English, but a far better result is obtained by better cookery.
The Italian peasantry are better fed than the French. In the poor
osterias above referred to, not only the Friday salt fish, but all the
other viands, were incomparably better cooked than in corresponding
places in England, and the variety was greater than is common in many
middle-class houses. The ordinary supper of the ‘roughs’ above-named
was of three courses: first, a ‘_minestra_,’ _i.e._ a soup of some
kind, continually varied, or a savoury dish of macaroni; then a ragoût
or savoury stew of vegetables and meat, followed by an excellent salad;
the beverage, a flask of thin but genuine wine. When I come to the
subject of cheese, I will describe their mode of cooking and using it.
My first walk through Italy extended from the Alps to Naples, and from
Messina to Syracuse. I thus spent nearly a year in Italy during a
season of great abundance, and never saw a drunken Italian. A few years
after this I walked through a part of Lombardy, and found the little
osterias as bad as English beershops or low public-houses. It was a
period of scarcity and trouble, ‘the three plagues,’ as they called
them—the potato disease, the silkworm fungus, and the grape disease—had
brought about general privation. There was no wine at all; potato
spirit and coarse beer had taken its place. Monotonous ‘polenta,’ a
sort of paste or porridge made from Indian corn meal, to which they
give the contemptuous name of ‘miserabile,’ was then the general food,
and much drunkenness was the natural consequence.
CHAPTER VI.
COUNT RUMFORD’S ROASTER.
IN the third volume of his ‘Essays, Political, Economical, and
Philosophical,’ page 129, Count Rumford introduces this subject, with
the following apology, which I repeat and adopt. He says: ‘I shall, no
doubt, be criticised by many for dwelling so long on a subject which to
them will appear low, vulgar, and trifling; but I must not be deterred
by fastidious criticisms from doing all I can do to succeed in what I
have undertaken. Were I to treat my subject superficially, my writing
would be of no use to anybody, and my labour would be lost; but by
investigating it thoroughly, I may, perhaps, engage others to pay that
attention to it which, from its importance, it deserves.’
This subject of roasting occupied a large amount of Count Rumford’s
attention while he was in England residing in Brompton Road, and
founding the Royal Institution. His efforts were directed not merely to
cooking the meat effectively, but to doing so economically. Like all
others who have contemplated thoughtfully the habits of Englishmen, he
was shocked at the barbaric waste of fuel that everywhere prevailed in
this country, even to a greater extent then than now.
The first fact that necessarily presented itself to his mind was the
great amount of heat that is wasted, when an ordinary joint of meat is
suspended in front of an ordinary coal fire to intercept and utilise
only a small fraction of its total radiation.
As far as I am aware, there is no other country in Europe where such
a process is indigenous. I say ‘indigenous,’ because there certainly
are hotels where this or any other English extravagance is perpetrated
to please Englishmen who choose to pay for it. What is usually called
roast meat in countries not inhabited by English-speaking people, is
what we should call ‘baked meat,’ the very name of which sets all
the gastronomic bristles of an orthodox Englishman in a position of
perpendicularity.
I have a theory of my own respecting the origin of this prejudice.
Within the recollection of many still living, the great middle class of
Englishmen lived in town; their sitting-rooms were back parlours behind
their shops, or factories, or warehouses; their drawing-rooms were on
the first-floor, and kitchens in the basement.
They kept one general servant of the ‘Marchioness’ type. The
corresponding class now live in suburban villas, keep cook, housemaid,
and parlour-maid, besides the gardener and his boy, and they dine at
supper-time.
In the days of the one marchioness and the basement kitchen, these
citizens ‘of credit and renown’ dined at dinner-time, and were in
the habit of placing a three-legged open iron triangle in a brown
earthenware dish, then spreading a stratum of peeled potatoes on said
dish, and a joint of meat above, on the open triangular support. This
edifice was carried by the marchioness to the bakehouse round the
corner at about 11 A.M., and brought back steaming and savoury at 1 P.M.
This was especially the case on Sundays; but there were exceptions, as
when, for example, the condition of the mistress’s wardrobe offered
no particular motive for going to church, and she stayed at home and
roasted the Sunday dinner. The experience thus obtained demonstrated a
material difference between the flavour of the roasted and the baked
meat very decidedly in favour of the home roasted. Why?
The principal reason was, I believe, that the baker’s large bread-oven
contained at dinner-time a curious medley of meats—mutton, beef, pork,
geese, veal, &c., including stuffing with sage and onions, besides
the possibility of a joint or two that had been hung longer than was
necessary for procuring tenderness. The vapours of these would induce
a confusion of flavours in the milder meats, fully accounting for the
observed superiority of the home-roasted joints.
A little reflection on the principles already expounded will show that,
theoretically regarded, a given piece of meat would be better roasted
in a closed chamber radiating heat _from all sides_ towards the meat
than it could be when suspended in front of a fire and heated only on
one side, while the other side was turned away to cool more or less,
according to the rate of rotation.
If I agreed with the popular belief in the advantage of open-air
exposure to direct radiation from glowing coal, I should suggest that
for large joints a special roasting fire be constructed, by building
an upright cylinder of fire-brick, and erecting within this a smaller
cylinder or grating of iron bars, so that the fuel should be placed
between these, and thus form an upright cylindrical ring or shirt of
fire, enclosed outside by the bricks, but open and glowing towards the
inside of the hollow cylinder, in the midst of which the meat should be
suspended to receive the radiation from all sides.
The whole apparatus might stand under a dome, terminating in an
ordinary chimney, like a glass-house or a steel-maker’s cementing
furnace; or, in this respect, like those wondrous kitchens of the old
seraglio at Constantinople, where each apartment is a huge chimney,
outspreading downwards, so that the cooks, and their materials and
apparatus, as well as the huge fires themselves, are all under the
great central chimney shaft.
I do not, however, recommend such an apparatus, even to the most
wealthy and luxurious epicure, because I am convinced, not merely from
theoretical considerations, but also from practical experiments, that
all kinds of meat may be not merely as well roasted in a close oven
as before an open fire, but that the close chamber, properly managed,
produces _better results in every respect_ than can possibly be
obtained by roasting in the open air.
To obtain such results there must be no compromise, no concession
to any false theory respecting a necessity for special ventilation,
excepting in the case of semi-putrid game or venison, which require to
be carbonised and disinfected as well as cooked, and, of course, also
demand the speedy removal of their noxious vapours.
Not so with fresh meats. There is nothing in the vapour of beef that
can injure the flavour of beef, nor in the vapour of mutton that is
damaging to mutton, and so on with the rest. But there is much that
can, and does actually improve them; or, more strictly speaking,
prevents the deterioration to which they are liable when roasted before
an open fire. I will endeavour to explain this.
Carefully-conducted experiments have demonstrated the general law
that atmospheric air is a vacuum to the vapour of water and other
similar vapours, while each particular vapour is a plenum to itself,
though not to other vapours; or, otherwise stated, if a given space,
at a given temperature, be filled with air, the quantity of aqueous
vapour that it is capable of holding is the same as though this space
contained no air at all, nor anything else. But this same space
may contain a much smaller quantity of aqueous vapour, and yet be
absolutely impenetrable to aqueous vapour, provided its temperature is
unaltered.
Thus, if a bell-glass, filled with air, under ordinary pressure, at the
temperature of 100° Fahr., be placed over a dish of water at the same
temperature, a quantity of vapour, equal to 1/30th (in round numbers)
of the weight of the air, will rise into the bell-glass, and there
remain diffused throughout. If there were less air, or no air at all
(temperature remaining the same), the bell-glass would obtain and hold
the same quantity of vapour.
If, instead of being filled with air, it contained at the outset only
this 1/30th of aqueous vapour, it would now be an impenetrable plenum,
behaving like a solid to aqueous vapour—no more could be forced into it
while its temperature remained the same.
But while thus charged with aqueous vapour, there would still be room
for vapour of alcohol, or turpentine, or ether, or chloroform, &c. It
would be a vacuum to these, though a plenum to itself. On the other
hand, if the alcohol, turpentine, ether, or chloroform were allowed to
evaporate into the bell-glass, a certain quantity of either of these
vapours would presently enter it, and then this vapour would act like
a solid mass in resisting the entry of any more of its own kind, while
it would be freely pervious to the vapour of water or that of the other
liquids.
A practical example will further illustrate this. Some years ago I was
engaged in the distillation of paraffin oil, and had a few thousand
gallons of the crude liquid in a still with a tall head and a rising
condenser. In spite of severe firing, the distillation proceeded very
slowly. Then I threw into the still, just above the surface of the oil,
a jet of steam. The rate of distillation immediately increased with
the same firing, although the steam was of much lower temperature than
the boiling oil, and, therefore, wasted much heat. The _rationale_ of
this was, that at first an atmosphere of oil vapour stood over the
oil, and this was impervious to more oil vapour, but on sweeping this
out and replacing it by steam, the atmosphere above the liquid oil was
permeable by oil vapour. This principle is largely applied in similar
distillations.
Always keeping in view that the primary problem in roasting is to raise
the temperature throughout to the cooking heat without desiccation
of the natural juices of the meat, and applying to this problem the
laws of vapour diffusion expounded in my last, it is easy enough to
understand the theoretical advantages of roasting in a closed oven, the
space within which speedily becomes saturated with those particular
vapours that resist further vaporisation of these juices.
In all open-air roasting, whether by the one-sided fire of ordinary
construction or the surrounding fire that I have suggested, convection
currents are necessarily at work desiccating and toughening the meat in
spite of the basting, though tempered thereby.
I say ‘theoretical,’ because I despair of practically convincing any
thoroughbred Englishman that baked meat is better than roasted meat by
any reasoning whatever. If, however, he is sufficiently ‘un-English’ to
test the question experimentally, he may possibly convince himself.
To do this fairly, a large joint of meat should be equally divided,
one half roasted in front of the fire, the other in a non-ventilated
oven over a little water by a cook who knows how to heat the oven. This
condition is essential, as some intelligence is demanded in regulating
the temperature of an oven, while any barbarian can carry out the
modern modification of the ordinary device of the savage, who skewers a
bit of meat, and holds this near enough to a fire to make it frizzle.
Having settled this question to my own satisfaction more than twenty
years ago, I now amuse myself occasionally by experimenting upon
others, and continually find that the most uncompromising theoretical
haters of baked meat practically prefer it to orthodox roasted meat,
provided always that they eat it in ignorance.
Part II. of Count Rumford’s ‘Tenth Essay’ is devoted to his roaster
and roasting generally, and occupies ninety-four pages, including
the special preface. This preface is curious now, as it contains the
following apology for delay of publication: ‘During several months,
almost the whole of my time was taken up with the business of the
Royal Institution; and those who are acquainted with the objects of
that noble establishment will, no doubt, think that I judged wisely in
preferring its interest to every other concern.’
To those who attend the fashionable gatherings held on Friday evenings
in ‘that noble establishment’ during the London season, it is almost
comical to read what its founder says concerning the object for which
it was instituted—viz. the noble purpose of DIFFUSING THE KNOWLEDGE
AND FACILITATING THE GENERAL INTRODUCTION OF NEW AND USEFUL INVENTIONS
AND IMPROVEMENTS.’ The capitals are Rumford’s, and he illustrates their
meaning by reference to ‘the repository of this new establishment,’
where specimens of pots and kettles, ovens, roasters, fireplaces,
gridirons, tea-kettles, kitchen-boilers, &c., might be inspected.
Some years ago, when I was sufficiently imprudent to accept an
invitation to describe Rumford’s scientific researches in _one_
Friday evening lecture, rigidly limited to fifty-seven minutes (and
consequently muddled my subject in the vain struggle to condense it),
I tried to find the original roaster, but failed; all that remained
of the original ‘repository’ being a few models put out of the way as
though they were empty wine-bottles. I am not finding fault, as the
noble work that has been done there by Davy, Faraday, and Tyndall must
have profoundly gladdened the supervising soul of Rumford (supposing
that it does such spiritual supervision), in spite of his neglected
roaster, which I must now describe without further digression.
It is shown open and out of its setting in Fig. 1, and there seen
as a hollow cylinder of sheet-iron, which, for ordinary use, may be
about 18 inches in diameter and 24 inches long, closed permanently
at one end, and by a hinged double door of sheet-iron (_dd_) at the
other. The doubling of the door is for the purpose of retaining the
heat by means of an intervening lining of ill-conducting material.
Or a single door of sheet-iron, with a panel of wood outside, may be
used. The whole to be set horizontally in brickwork, as shown in Fig.
4, the door-front being flush with the front of the brickwork. The
flame of the small fire below plays freely all round it by filling the
enveloping flue-space indicated by the dotted lines on Fig. 4. Inside
the cylinder is a shelf to support the dripping-pan (_d_) Fig. 1,
which is separately shown in Figs. 2 and 3.
[Illustration: FIG. 1.]
[Illustration: FIG. 2.]
This dripping-pan is an important element of the apparatus. Fig.
3 shows it in cross section, made up of two tin-plate dishes, one
above the other, arranged to leave a space (_w_) between. This space
contains water, half to three-quarters of an inch in depth. Above is
a gridiron, shown in plan, Fig. 2, on which the meat rests; the bars
of this are shown in section in Fig. 3. The object of this arrangement
is to prevent the fat which drips from the meat from being overheated
and filling the roaster with the fumes of burnt—_i.e._ partially
decomposed, fat and gravy, to the tainting influence of which Rumford
attributed the English prejudice against baked meat. So long as any
water remains the dripping cannot be raised more than two or three
degrees above 212°.
[Illustration: FIG. 3.]
[Illustration: FIG. 4.]
The tube _v_, Fig. 1, is for carrying away vapour, if necessary. This
tube may be opened or closed by means of a damper moved by the little
handle shown on the right. The _heat_ of the roaster is regulated
by means of the register _c_, Fig. 4, in the ash-pit door of the
fire-place, its _dryness_ by the above-named damper of the steam tube
_v_, and also by the blowpipes, _b p_.
These are iron tubes, about 2½ in. in diameter, placed underneath, so
as to be in the midst of the flame as it ascends from the fire into
the enveloping flue, shown by the dotted lines, Fig. 4, where their
external openings are shown at _b p_, _b p_, and the plugs by which
they may be opened or closed in Fig. 1. It is evident that by removing
these plugs, and opening the damper of the steam pipe, a blast of hot
dry air will be delivered into the roaster at its back part, and it
must pass forward to escape by the steam pipe. As these blowpipes are
raised to a red heat when the fire is burning briskly, the temperature
of this blast of air may be very high; with even a very moderate fire,
sufficiently high to desiccate and spoil the meat if they were kept
open during all the time of cooking. They are accordingly to be kept
closed until the last stage of the roasting is reached; then the fire
is urged by opening the ash-pit register, and when the blowpipes are
about red-hot, their plugs are removed, and the steam-pipe damper is
opened for a few minutes to brown the meat by means of the hot wind
thus generated.
It will be observed that a special fire directly under the roaster is
here designed, and that this fire is enclosed in brickwork. This is a
general feature of Rumford’s arrangements. The economy of the whole
device will be understood by the fact that in a test experiment at the
Foundling Institution of London, he roasted 112 lbs. of beef with a
consumption of only 22 lbs. of coal (three pennyworth, at 25_s._ per
ton).
Rumford tells us that ‘when these roasters were first proposed, and
before their merit was established, many doubts were entertained
respecting the taste of the food prepared in them,’ but that, after
many practical trials, it was proved that ‘meat of every kind, without
any exception, roasted in a roaster, is _better tasted, higher
flavoured, and much more juicy and delicate_ than when roasted on a
spit before an open fire.’ These italics are in the original, and the
testimony of competent judges is quoted.
I must describe one experiment in detail. Two legs of mutton from the
same carcass made equal in weight before cooking were roasted, one
before the fire and the other in a roaster. When cooked, both were
weighed, and the joint roasted in the roaster proved to be heavier than
the other by 6 per cent. They were brought upon table at the same time,
‘and a large and perfectly unprejudiced company was assembled to eat
them.’ Both were found good, but a decided preference given to that
cooked in the roaster; ‘it was much more juicy, and was thought better
tasted.’ Both were fairly eaten up, nothing remaining of either that
was eatable, and the fragments collected. ‘Of the leg of mutton which
had been roasted in the roaster, hardly anything visible remained,
excepting the bare bone, while a considerable heap was formed of scraps
not eatable which remained of that roasted on a spit.’
This was an eloquent experiment; the gain of 6 per cent. tells of
juices retained with consequent gain of flavour, tenderness, and
digestibility, and the subsequent testimony of the scraps describes the
difference in the condition of the tendonous, integumentary portions of
the joints, which are just those that present the toughest practical
problems to the cook, especially in roasting.
But why are these roasters not in general use? Why did they die with
their inventor, notwithstanding the fact, mentioned in his essay, that
Mr. Hopkins, of Greek Street, Soho, had sold above 200, and others were
making them?
Those of my readers who have had practical experience in using hot
air or in superheating steam, will doubtless have already detected a
weak point in the ‘blowpipes.’ When iron pipes are heated to redness,
or thereabouts, and a blast of air or steam passes through them, they
work admirably for a while, but presently the pipe gives way, for iron
is a combustible substance, and burns slowly when heated and supplied
with abundant oxygen, either by means of air or water; the latter being
decomposed, its hydrogen set free, while its oxygen combines with the
iron, and reduces it to friable oxide. Rumford does not appear to have
understood this, or he would have made his blowpipes of fire-clay or
other refractory non-oxidisable material.
The records of the Great Seal Office contain specifications of hundreds
of ingenious inventions that have failed most vexatiously from this
defect; and I could tell of joint-stock companies that have been
‘floated’ to carry out inventions involving the use of heated air or
super-heated steam that have worked beautifully and with apparent
economy while the shares were in the market, and then collapsed just
when the calls were paid up, the cost of renewal of superheaters and
hot-air chambers having worse than annulled the economy of working
fuel described in the prospectus. Thus a vessel driven by heated air,
as a substitute for steam, was fitted up with its caloric engine, and
crossed the Atlantic with passengers on board. The voyage practically
demonstrated a great saving of coal; the patent rights were purchased
accordingly for a very large amount, and shares went up buoyantly until
the oxidation of the great air chamber proved that the engine burned
iron as well as coal at a ruinous cost.
Although no mention is made by Rumford of such destruction of the
blowpipes, he was evidently conscious of the costliness of his original
roaster, as he describes another which may be economically substituted
for it. This has an air chamber formed by bringing down the body of
the oven so as to enclose the space occupied by the blowpipes shown in
Fig. 1, and placing the dripping-pan on a false bottom joined to the
front face of the roaster just below the door, but not extending quite
to the back. An adjustable register door opens at the front into this
air chamber, and when this is opened the air passes along from front to
back under the false bottom, and rises behind to an outlet pipe like
that shown at _v_, Fig. 1. In thus passing along the hot bottom of the
oven the air is heated, but not so greatly as by the blowpipes, which
being surrounded by the flame on all sides, are heated above as well as
below, and the air in passing through them is much more exposed to heat
than in passing through the air-chamber.
To increase the heat transmitted in the latter, Rumford proposes that
‘a certain quantity of iron wire, in loose coils, or of iron turnings,
be put into the air chamber.’
This modification he called a ‘roasting-oven,’ to distinguish it from
the first described, the ‘roaster.’ He states that the roasting-oven
is not quite so effective as the roaster, but from its greater
cheapness may be largely used. This anticipation has been realised. The
modern ‘kitchener,’ which in so many forms is gradually and steadily
supplanting the ancient open range, is an apparatus in which roasting
in the open air before a fire is superseded by roasting in a closed
chamber or roasting-oven. Having made three removals within the last
twelve years, each preceded by a tedious amount of house-hunting, I
have seen a great many kitchens of newly-built houses, and find that
about 90 per cent. of these have closed kitcheners, and only about 10
per cent. are fitted with open ranges of the old pattern. Bottle-jacks,
like smoke-jacks and spits, are gradually falling into disuse.
When these kitcheners were first introduced, a great point was made
by the manufacturer of the distinction between the roasting and the
baking-oven; the first being provided with a special apparatus for
effecting ventilation by devices more or less resembling that in
Rumford’s roasting-oven. Gradually these degenerated into mere shams,
and now in the best kitcheners even a pretence to ventilation is
abandoned. Having reasoned out my own theory of the conditions demanded
for perfect roasting some time ago (about 1860, when I lectured on
‘Household Philosophy,’ to a class of ladies at the Birmingham and
Midland Institute), I have watched the gradual disappearance of
these concessions to popular prejudice with some interest, as they
show how practical experience has confirmed my theory, which, as
already expounded, is that _fresh meat should be cooked by the action
of radiant heat, projected towards it from all sides, while it is
immersed in an atmosphere nearly saturated with its own vapours_.
Let it be clearly understood that I refer to the vapours as they rise
from the meat, and not to the vapour of burnt dripping, which Rumford
describes. The acrid properties of the products of such partial
dissociation are far better understood by modern chemists than they
were in Rumford’s time.
His water dripping-pan effectually prevents their formation. It is
still manufactured of the precise pattern shown in the drawing, copied
from Rumford’s, and cooks who understand their business at all use it
as a matter of course.
The few domestic fireplace-ovens that existed in Rumford’s time were
clumsily heated by raking some of the fire from the grate into a space
left below the oven. Those of the best modern kitcheners are heated by
flues going round them, generally starting from the top, which thus
attains the highest temperature. The radiation from this does the
‘browning’ for which Rumford’s blowpipes were designed.
Here I differ from my teacher, as, according to my view of the
philosophy of roasting, the browning, or the application of the
highest temperature, should take place at the beginning rather than
the end of the process, in order that a crust of firmly coagulated
albumen may surround the joint and retain the juices of the meat.
All that is necessary to obtain this effect in a sufficient degree
is to raise the roasting-oven to an excessive temperature before the
meat is put in. Supposing an equal fire is maintained all the while,
this excessive initial temperature will presently decline, because,
when the meat is in the oven, the radiant heat from its sides is
intercepted by the joint and doing work upon it; heat cannot do work
without a corresponding fall of temperature. While the oven is empty
the radiations from each side cross the open space to reinforce the
temperature of the other sides.
When I first decided to write on this subject I made some designs for
kitchen thermometers intending to have them made, and to recommend
their use; but was not successful. When a man condemns his own
inventions, his verdict may be safely accepted without further inquiry.
I afterwards learned that Messrs. Davis & Co. had already constructed
special oven thermometers, to be so attached to the oven-door that the
bulb should be inside and the tube having the expansion of the mercury
outside, and therefore readable without opening the door, as shown in
Fig. 5, and another for standing inside the oven, Fig. 6.
I learned by these thermometers the cause of my own failure. I tried
to do too much—to construct one form of thermometer to do all kinds of
kitchen work. A thermometer suitable for the oven is not applicable
to trying the temperature of a fat-bath used in frying. I accordingly
wrote to Messrs. Davis asking them to devise a thermometer for this
purpose. They have done so. It is described in the next chapter.
[Illustration: FIG. 5.]
[Illustration: FIG. 6.]
Is there, then, any difference at all between roasting and baking?
There is. In roasting, the temperature, after the first start, is
maintained about uniformly throughout; while in baking bread by the
old-fashioned method, the temperature continually declines from the
beginning to the end of the process; but in order that a dweller in
cities, or the cook of an ordinary town household, may understand this
difference, some explanation is necessary. The old-fashioned oven, such
as was generally used in Rumford’s time, and is still used in country
houses and by old-fashioned bakers, is an arched cavity of brick with
a flat brick floor. This cavity is closed by a suitable door, which
in its primitive, and perhaps its best form, was a flat tile pressed
against the opening and luted round with clay. Such ovens were, and
still are, heated by simply spreading on the brick floor a sufficient
quantity of wood—preferably well-dried twigs; these, being lighted,
raise the temperature of the arched roof to a glowing heat, and that
of the floor in a somewhat lower degree. When this heating is completed
(the judgement of which constitutes the chief element of skill in
thus baking) the embers are carefully brushed out from the floor, the
loaves, &c., inserted by means of a flat battledore with a long handle,
called a ‘peel,’ and the door closed and firmly luted round, not to
be opened until the operation is complete. Baked clay is an excellent
radiator, and therefore the surface of bricks forming the arched roof
of the oven radiates vigorously upon its contents below, which are
thus heated at top by radiation from the roof, and at bottom by direct
contact with the floor of the oven. The difference between the compact
bottom crust, and the darker bubble-bearing top crust of an ordinary
loaf is thus explained.
As the baking of a large joint of meat is a longer operation than the
baking of bread, there is another reason besides that already given for
the inferiority of meat when baked in a baker’s oven constructed on
this principle. The slow cooling-down must tend to produce a flabbiness
and insipidity similar to that of the roast meat which is served at
restaurants where a joint remains ‘in cut’ for two or three hours. Of
this I speak theoretically, not having had an opportunity of tasting a
joint that has been cooked in a brick oven of the construction above
described; but I have observed the advantage of maintaining a steady
heat throughout the process of roasting (after the first higher heating
above described), in the iron oven of a kitchener, or American stove,
or gas oven.
Another and somewhat original method of roasting is that which is
carried out in ‘Captain Warren’s Cooking Pot,’ concerning the practical
result of which I hear conflicting opinions. It is a large pot
containing water, inside which is suspended—like the glue chamber of a
glue-pot—an inner vessel. The meat to be cooked is placed without water
in this inner closed vessel, which dips into the water of the outer
vessel, the steam from which is led away by a side opening or pipe.
This outer water being kept boiling, the meat is surrounded only by its
own vapour, in the midst of which it is cooked at a low temperature.
The result is similar to boiled meat, with the advantage of retaining
those juices that pass away into the water in ordinary boiling. This
advantage is unquestionable, and so far the apparatus may be safely
recommended. But some of the claims made in the prospectuses that are
freely distributed are questionable.
The method of roasting with Warren’s pot is to cook the meat as above
described in its own vapour, then dredge with flour, and hang before
the fire twenty minutes. The result is a tender imitation of roast
meat, but more like boiled than roasted meat in flavour. This is much
approved by many, but I am told that meat thus cooked and eaten daily
palls upon the appetite. I know one, a youth (not one of our fastidious
fops of the period), who, fed upon this at school during a few years,
has thereby acquired a fixed aversion to boiled meat of all kinds.
Regarding the subject theoretically, it appears to me that the method
recommended by Captain Warren, and followed by those who use his
cooker, should be reversed for roasting; that the meat should have
the twenty minutes before the fire—or in a hot oven—before, instead
of after, its stewing in its own vapour. Some experiments I have made
confirm this view so far as they go, but are not sufficiently numerous
to settle the question.
For stewing of all kinds, and for such concoctions as Rumford’s
soup (_see_ Chapter XIV.), it is an admirable apparatus, and the
contrivances for carrying the steam from the outer vessel to a
vegetable steamer above the cooking chamber, before described, is very
ingenious and effective.
The statement in the prospectus, that the ‘nourishing juices’ otherwise
wasted ‘are by that mode condensed, and form at the bottom of the
vessel a rich gelatinous body,’ is misleading.
Gelatin is not volatile; the gelatinous body at the bottom of the
vessel is not composed of condensed vapours, though condensed vapour
of water is concerned in its formation. It is simply some of the
gelatin of the joint dissolved by the water which condenses upon it,
and finally drips down from the joint, carrying with it the dissolved
gelatin.
CHAPTER VII.
FRYING.
THE process of frying follows next in natural order to those of
roasting and grilling. A little reflection will show that in frying the
heat is not communicated to the food by radiation from a heated surface
at some distance, but by direct contact with the heating medium, which
is the hot fat commonly, but erroneously, described as ‘boiling fat.’
As I am writing for intelligent readers who desire to understand the
philosophy of the common processes of cookery, so far as they are
understandable, this fallacy concerning boiling fat should be pushed
aside at once.
Generally speaking, ordinary animal fats are not boilable under the
pressure of our atmosphere (one of the constituent fatty acids of
butter, butyric acid, is an exception; it boils at 314° Fahr.). Before
reaching their boiling-point, _i.e._ the temperature at which they
pass completely into the state of vapour, their constituents are more
or less dissociated or separated by the repulsive agency of the heat,
new compounds being in many cases formed by recombinations of their
elements.
When water is heated to 212° it is converted completely into a gas,
which gas, on cooling below 212°, returns to the fluid state without
any loss. In like manner if we raise an essential oil, such as
turpentine, to 320°, or oil of peppermint to 340°, or orange-peel oil
to 345°, or patchouli to 489°, and other such oils to certain other
temperatures, they pass into a state of vapour, and these vapours,
when cooled, recondense into their original form of liquid oil without
alteration. Hence they are called ‘volatile oils,’ while the greasy
oils which cannot thus be distilled (in which class animal fats are
included) are called ‘fixed oils.’
A very simple practical means of distinguishing these is the following:
make a spot of the oil to be tested on clean blotting-paper. Heat this
by holding it above a spirit-lamp flame, or by toasting before a fire.
If the oil is volatile the spot disappears; if fixed, it remains as a
spot of grease until the heat is raised high enough to char the paper,
of which charring (a result of the dissociation above-named) the oil
partakes.
But the practical cook may say, ‘This is wrong, for the fat in my
frying-pan does boil. I see it boil, and I hear it boil.’ The reply to
this is, that the lard, or dripping, or butter that you put into your
frying-pan is oil mixed with water, and that it is not the oil but the
water that you see boiling. To prove this, take some fresh lard, as
usually supplied, and heat it in any convenient vessel, raising the
temperature gradually. Presently it will begin to splutter. If you
try it with a thermometer you will find that this spluttering-point
agrees with the boiling-point of water, and if you use a retort you may
condense and collect the splutter-matter, and prove it to be water.
So long as the spluttering continues the temperature of the melted
fat, _i.e._ the oil, remains about the same, the water vapour carrying
away the heat. When all the water is driven off the liquid becomes
quiescent, in spite of its temperature rising from 212° to above 400°,
when a pungent smoky vapour comes off and the oil grows darker; this
vapour is not vapour of lard, but vapour of separated and recombined
constituents of the lard, which is now suffering dissociation, the
volatile products passing off while the non-volatile carbon (_i.e._
lard-charcoal) remains behind, colouring the liquid. If the heating
be continued, a residuum of this carbon, in the form of soft coke or
charcoal, will be all that remains in the heated vessel.
We may now understand what happens when something humid—say a sole—is
put into a frying-pan which contains fat heated above 212°. Water, when
suddenly heated above its boiling-point, is a powerful explosive, and
may be very dangerous, simply because it expands to 1,728 times its
original bulk when converted into steam. Steam-engine boilers and the
boilers of kitchen stoves sometimes explode by becoming red-hot while
dry, and then receiving a little water which suddenly expands to steam.
The noise and spluttering that is started immediately the sole is
immersed in the hot fat is due to the explosion of a multitude of small
bubbles formed by the confinement of the suddenly expanding steam in
the viscous fat, from which it releases itself with a certain degree
of violence. It is evident that to effect this amount of eruptive
violence, the temperature must be considerably above the boiling-point
of the exploding water. If it were only just at the boiling-point, the
water would boil quietly.
As we all know, the flavour and appearance of a boiled sole or mackerel
are decidedly different from those of a fried sole or mackerel, and
it is easy to understand that the different results of these cooking
processes are to some extent due to the difference of temperature to
which the fish is subjected. It will be at once understood that my
theory of the chief difference between roasted or grilled meat and
boiled meat applies to fried fish; that the flavouring juices are
retained when the fish is fried, while more or less of them escape into
the water when boiled.
Besides this, the surface of the fried fish, like that of the roasted
or grilled meat, is ‘browned.’ What is the nature, the chemistry of
this browning?
I have endeavoured to find some answer to this question, that I might
quote with authority, but no technological or purely chemical work
within my reach supplies such answer. Rumford refers to it as essential
to roasting, and provides for it in the manner already described,
but he goes no farther into the philosophy of it than admitting its
flavouring effect.
I must therefore struggle with the problem in my own way as I best can.
Has the gentle reader ever attempted the manufacture of ‘hard-bake,’
or ‘toffy,’ or ‘butter-scotch,’ by mixing sugar with butter, fusing
the mixture, and heating further until the well-known hard, brown
confection is produced? I venture to call this fried sugar. If heated
simply without the butter it may be called baked sugar. The scientific
name for this baked sugar is _caramel_.
The chemical changes that take place in the browning of sugar have been
more systematically studied than those which occur in the constituents
of flesh when browned in the course of ordinary cookery. Believing
them to be nearly analogous, I will state, as briefly as possible, the
leading facts concerning the sugar.
Ordinary sugar is crystalline, _i.e._ when it passes from the liquid
to the solid state it assumes regular geometrical forms. If the
solidification takes place undisturbed and slowly, the geometric
crystals are large, as in sugar-candy; if the water is rapidly
evaporated with agitation, the crystals are small, and the whole
mass is a granular aggregation of crystals, such as we see in loaf
sugar. If this crystalline sugar be heated to about 320° Fahr. it
fuses, and without any change of chemical composition undergoes
some sort of internal physical alteration that makes it cohere in a
different fashion. (The learned name for this action is _allotropism_,
and the substance is said to be _allotropic_, other conditioned; or
_dimorphic_, two-shaped). Instead of being crystalline the sugar
now becomes vitreous, it solidifies as a transparent amber-coloured
glass-like substance, the well-known barley-sugar, which differs from
crystalline sugar not only in this respect, but has a much lower
melting-point; it liquefies between 190° and 212°, while loaf-sugar
does not fuse below 320°. Left to itself, vitreous sugar returns
gradually to its original condition, loses transparency, and breaks up
into small crystals. In doing this it gives out the heat which during
its vitreous condition had been doing the work of breaking up its
crystalline structure, and therefore was not manifested as temperature.
This return to the crystalline condition is retarded by adding vinegar
or mucilaginous matter to the heated sugar; hence the confectioners’
name of ‘barley-sugar,’ which, in one of its old-fashioned forms, was
prepared by boiling down ordinary sugar in a decoction of pearl barley.
The French cooks and confectioners carry on the heating of sugar
through various stages bearing different technical names, one of the
most remarkable of which is a splendid crimson variety, largely used
in fancy sweetmeats, and containing no foreign colouring matter, as
commonly supposed. Though nothing is added, something is taken away,
and this is some of the chemically-combined water of the original
sugar, in the parting with which not only a change of colour occurs,
but also a modification of flavour, as anybody may prove by experiment.
When the temperature is gradually raised to 420°, the sugar loses two
equivalents of water, and becomes _caramel_—a dark-brown substance, no
longer sweet, but having a new flavour of its own. It further differs
from sugar by being incapable of fermentation.
The first stage of this cookery of sugar has now an archæological
interest in connection with one of the lost arts of the kitchen, viz.
the ‘spinning’ of sugar. Within the reach of my own recollection no
evening party could pretend to be stylish unless the supper-table was
decorated with a specimen of this art—a temple, a pagoda, or something
of the sort done in barley-sugar. These were made by raising the sugar
to 320°, when it fused and became amorphous, or vitreous, as already
described. The cook then dipped a skewer into it; the melted vitreous
sugar adhered to this, and was drawn out as a thread, which speedily
solidified by cooling. While in the act of solidification it was woven
into the desired form, and the skilful artist did this with wonderful
rapidity. I once witnessed with childish delight the spinning of a
great work of art by the Duke of Cumberland’s French cook in St.
James’s Palace. It was a ship in full sail, the sails of edible wafer,
the hull a basketwork of spun sugar, the masts of massive sugar-sticks,
and the rigging of delicate threads of the same. As nearly as I can
remember, the whole was completed in about an hour.
But to return from high art below stairs to chemical science. The
conversion of sugar into caramel is, as already stated, attended with
a change of flavour; a kind of bitterness replaces the sweetness.
This peculiar flavour, judiciously used, is a powerful adjunct to
cookery, and one which is shamefully neglected in our ordinary English
domestic kitchens. To test this, go to one of those Swiss restaurants
originally instituted in this country by that enterprising Ticinese,
the late Carlo Gatti, and which are now so numerous in London and our
other large towns; call for _maccheroni al sugo_; notice the rich brown
gravy, the ‘sugo.’ Many an English cook would use half a pound of gravy
beef to produce the like; but the basis of this is a halfpennyworth or
less of what I call a caramel compound, as an example of which I copy
the following recipe from the Household Edition of Gouffé’s ‘Royal
Cookery Book:’ ‘Melt half a pound of butter; add one pound of flour;
mix well, and leave on a slow fire, stirring occasionally until it
becomes of a light mahogany colour. When cool it may be kept in the
larder ready for use.’ Gouffé calls this ‘Liaison au Roux;’ the English
for _liaison_ is a thickening. It is really fried flour. Burnt onion is
another form of caramel, with a special flavour superadded. Plain sugar
caramel is improved by the use of a little butter, as in making toffee.
Thus prepared it is really a fried sugar rather than a baked sugar.
_Beurre noir_ (black butter) is another of the caramelised preparations
used by continental cooks.
While engaged upon your macaroni, look around at the other dishes
served to other customers. Instead of the pale slices of meat spread
out in a little puddle of pale watery liquid, that are served in
English restaurants of corresponding class, you will see dainty
morsels, covered with rich brown gravy, or surrounded by vegetables
immersed in the same. This ‘sugo’ is greatly varied according to the
requirements, by additions of stock-broth, tarragon vinegar, ketchup,
&c., but burnt flour, burnt sugar, or burnt onions, or burnt something
is the basis of it all.
To further test the flavouring properties of browning, take some
eels cut up as usual for stewing; divide into two portions; stew one
brutally—by this I mean simply in a little water—serving them with this
water as a pale gravy or juice. Let the second portion be well fried,
fully caramelised or browned, then stewed, and served with brown gravy.
Compare the result. Make a corresponding experiment with a beefsteak.
Cut it in two portions; stew one brutally in plain water; fry the
other, then stew it and serve brown.
Take a highly-baked loaf—better one that is black outside; scrape off
the film of crust that is quite black, _i.e._ completely carbonised,
and you will come to a rich brown layer, especially if you operate
upon the bottom crust. Slice off a thin shaving of this and eat it
critically. Mark its high flavour as compared with the comparatively
insipid crumb of the same loaf, and note especially the resemblance
between this flavour and that of the caramel from sugar, and that of
the browned eels and browned steak. A delicate way of detecting the
flavour due to the browning of bread is to make two bowls of bread and
milk in the same manner, one with the crust the other with the crumb of
the same loaf. I am not suggesting these as examples of better or worse
flavour, but as evidence of the fact that much flavour of some sort is
generated. It may be out of place, as I think it is, in the bread and
milk, or it may be added with much advantage to other things, as it is
by the cook who manipulates caramel and its analogues skilfully.
The largest constituent of bread is starch. Excluding water, it
constitutes about three-fourths of the weight of good wheaten flour.
Starch differs but little from sugar in composition. It is easily
converted into sugar by simply heating it with a little sulphuric
acid, and by other means, of which I shall have to speak more fully
hereafter, when I come to the cookery of vegetables. When simply
heated, it is converted into dextrin or ‘British gum,’ largely used
as a substitute for gum arabic. If the heat is continued a change of
colour takes place; it grows darker and darker, until it blackens just
as sugar does, the final result being nearly the same. Water is driven
off in both cases, but in carbonising sugar we start with more water,
sugar being starch plus water or the elements of water. Thus the brown
material of bread-crust or toast is nearly identical with sugar caramel.
I have often amused myself by watching what occurs when toast and water
is prepared, and I recommend my readers to repeat the observation.
Toast a small piece of bread to blackness, and then float it on water
in a glass vessel. Leave the water at rest, and direct your attention
to the under side of the floating toast. Little threadlike streams of
brown liquid will be seen descending in the water. This is a solution
of the substance which, if I mistake not, is a sort of caramel, and
which ultimately tinges all the water.
Some years ago I commenced a course of experiments with this substance,
but did not complete them. In case I should never do so, I will here
communicate the results attained. I found that this starch caramel
is a disinfectant, and that sugar caramel also has some disinfecting
properties. I am not prepared to say that it is powerful enough to
disinfect sewage, though at the time I had a narrow escape from the
Great Seal Office, where I thought of patenting it for this purpose as
a non-poisonous disinfectant that may be poured into rivers in any
quantity without danger. Though it may not be powerful enough for this,
it has an appreciable effect on water slightly tainted with decomposing
organic matter.
This is a very curious fact. We do not know who invented toast and
water, nor, so far as I can learn, has any theory of its use been
expounded, yet there is extant a vague popular impression that the
toast has some sort of wholesome effect on the water. I suspect that
this must have been originally based on experience, probably on the
experience of our forefathers or foremothers, living in country places
where stagnant water was a common beverage, and various devices were
adopted to render it potable.
Gelatin, fibrin, albumen, &c.—_i.e._ all the materials of animal
food—as already shown, are composed, like starch and sugar, of carbon,
hydrogen and oxygen, with, in the case of these animal substances,
the addition of nitrogen; but this does not prevent their partial
carbonisation (or ‘caramelising,’ if I may invent a name to express the
action which stops short of blackening). Animal fat is a hydrocarbon
which may be similarly browned, and, if I am right in my generalisation
of all these browning processes, an important practical conclusion
follows, viz. that cheap soluble caramel made by skilfully heating
common sugar or flour is really, as well as apparently, as valuable an
element in gravies, &c., as the far more expensive colouring matter of
brown meat gravies, and that our English cooks should use it far more
liberally than they usually do.
The preparation of sugar caramel is easy enough; the sugar should be
gradually heated till it assumes a rich brown colour and has lost its
original sweetness. If carried just far enough, the result is easily
soluble in hot water, and the solution may be kept for a long time,
as it is by cooks who understand its merits. In connection with the
idea of its disinfecting action, I may refer to the cookery of tainted
meat or ‘high’ game. A hare that is repulsively advanced when raw may,
by much roasting and browning, become quite wholesome; and such is
commonly the case in the ordinary cooking of hares. If it were boiled
or merely stewed (without preliminary browning) in this condition, it
would be quite disgusting to ordinary palates.
A leg of mutton for roasting should be hung until it begins to become
odorous; for boiling it should be as fresh as possible. This should be
especially remembered now that we have so much frozen meat imported
from the antipodes. When duly thawed it is in splendid condition for
roasting, but is not usually so satisfactory when boiled. I may here
mention incidentally that such meat is sometimes unjustly condemned on
account of its displaying a raw centre when cooked. This arises from
imperfect thawing. The heat required to thaw a given weight of ice and
bring it up to 60° is about the same as is demanded for the cookery of
an equal quantity of meat, and therefore, while the thawed portion of
the meat is being cooked, the frozen portion is but just thawed, and
remains quite raw.
A much longer time is demanded for thawing—_i.e._ supplying 142° of
latent heat—than might be supposed. To ascertain whether the thawing is
completed, drive an iron skewer through the thickest part of the joint.
If there is a core of ice within it will be distinctly felt by its
resistance.
A correspondent asks me which is the most nutritious—a slice of English
beef in its own gravy or the browned morsel as served in an Italian
restaurant with the caramel addition to the gravy?
This is a very fair question, and not difficult to answer. If both are
equally cooked, neither overdone nor underdone, they must contain,
weight for weight, exactly the same constituents in equally digestible
form, so far as chemical composition is concerned. Whether they will
actually be digested with equal facility and assimilated with equal
completeness depends upon something else not measurable by chemical
analysis, viz. the relish with which they are respectively eaten.
To some persons the undisguised fleshiness of the English slice,
especially if underdone, is very repugnant. To these the corresponding
morsel, cooked according to Gouffé rather than Mrs. Beeton, would be
more nutritious. To the carnivorous John Bull, who regards such dishes
as ‘nasty French messes’ of questionable composition, the slice of
unmistakable ox-flesh, from a visible joint, would obtain all the
advantages of appreciative mastication, and that sympathy between the
brain and the stomach which is so powerful that, when discordantly
exerted, it may produce the effects that are recorded in the case of
the sporting traveller who was invited by a Red Indian chief to a
‘dog-fight,’ and ate with relish the savoury dishes at what he supposed
to be a preliminary banquet. Digestion was tranquilly and healthfully
proceeding, under the soothing influence of the calumet, when he asked
the chief when the fight would commence. On being told that it was
over, and that, in the final ragoût he had praised so highly, the
last puppy-dog possessed by the tribe had been cooked in his honour,
the normal course of digestion of the honoured guest was completely
reversed.
Before leaving the subject of caramel, I should say a few words
about French coffee, or ‘Coffee as in France,’ of which we hear so
much. There are two secrets upon which depend the excellence of our
neighbours in the production of this beverage. First, economy in using
the water; second, flavouring with caramel. As regards the first, it
appears that English housewives have been demoralised by the habitual
use of tea, and apply to the infusion of coffee the popular formula for
that of tea, ‘a spoonful for each person and one for the pot.’
The French after-dinner coffee-cup has about one-third of the liquid
capacity of a full-sized English breakfast-cup, but the quantity
of solid coffee supplied to each cupful is more than equal to that
ordinarily allowed for the larger English measure of water.
Besides this, the coffee is commonly, though not universally, flavoured
with a specially and skilfully-prepared caramel, instead of the chicory
so largely used in England. Much of the so-called ‘French coffee’ now
sold by our grocers in tins is caramel flavoured with coffee rather
than coffee flavoured with caramel, and many shrewd English housewives
have discovered that by mixing the cheapest of these French coffees
with an equal quantity of pure coffee they obtain a better result than
with the common domestic mixture of three parts coffee and one of
chicory.
A few months ago a sample of ‘coffee-finings’ was sent to me for
chemical examination, that I might certify to its composition and
wholesomeness. I described it in my report as ‘a caramel, with a
peculiarly rich aroma and flavour, evidently due to the vegetable
juices or extractive matter naturally united with the saccharine
substance from which it is prepared.’ I had no definite information of
the exact nature of this saccharine substance, but have since learned
that it was a bye-product of sugar refining.
Neither the juice of the beetroot nor the sap of the sugar-cane
consists entirely of pure sugar dissolved in pure water. They both
contain other constituents common to vegetable juices, and some
peculiar to themselves. These mucilaginous matters, when roughly
separated, carry down with them some sugar, and form a sort of coarse
sweetwort, capable by skilful treatment of producing a rich caramel
well suited for mixing with coffee.
Returning to the subject of frying, we encounter a good illustration
of the practical importance of sound theory. A great deal of fish and
other kinds of food is badly and wastefully cooked in consequence of
the prevalence of a false theory of frying. It is evident that many
domestic cooks (not hotel or restaurant cooks) have a vague idea that
the metal plate forming the bottom of the frying-pan should directly
convey the heat of the fire to the fried substance, and that the bit of
butter or lard or dripping put into the pan is used to prevent the fish
from sticking to it or to add to the richness of the fish by smearing
its surface.
The theory which I have propounded above is that the melted fat cooks
by convection of heat, just as water does in the so-called boiling of
meat. If this is correct, it is evident that the fish, &c., should
be completely immersed in a bath of melted fat or oil, and that the
turning over demanded by the greased-plate theory is unnecessary.
Well educated cooks understand this distinctly, and use a deeper
vessel than our common frying-pan, charge this with a quantity of
fat sufficient to cover the fish, which is simply laid upon a wire
support, or frying-basket and left in the hot fat until the browning
of its surface, or of the flour or bread-crumbs with which it is
coated indicates the sufficiency of the cookery. The illustration
is from Gouffé’s excellent cookery-book already quoted, and is
introduced because I have found it so little understood by English
housewives. Frying-kettles may now be purchased at all our best English
ironmongers, though until recently they were difficult to obtain. My
lectures and papers have largely extended the demand and consequent
supply.
[Illustration: FIG. 7.]
At first sight the deep fat bath appears extravagant, as compared
with the practice of greasing the bottom of the pan with a little
dab of fat, but any housewife who will apply to the frying of
sprats, herrings, &c., the method of quantitative inductive
research, described and advocated by Lord Bacon in his ‘Novum Organum
Scientiarum,’ may prove the contrary.
‘Must I read the “Novum Organum,” and buy another dictionary, in
order to translate all this?’ she may exclaim in despair. ‘No!’ is
my reply. This Baconian inductive method, to which we are indebted
for all the triumphs of modern science, is nothing more nor less than
the systematic and orderly application of common sense and definite
measurement to practical questions. In this case it may be applied
simply by frying a weighed quantity of any kind of fish or cutlet, &c.,
in a weighed quantity of fat used as a bath; then weighing the fat that
remains and subtracting the latter weight from the first, to determine
the quantity consumed. If the frying be properly performed, and this
quantity compared with that which is consumed by the method of merely
greasing the pan-bottom, the bath frying will be proved to be the more
economical as well as the more efficient method.
The reason of this is simply that much or all of the fat is burnt
and wasted when only a thin film is spread on the bottom of the pan,
while no such waste occurs when the bath of fat is properly used. The
temperature at which the dissociation of fat _commences_ is below that
required for delicately browning the surface of the fish itself, or
of the flour or bread-crumbs, and therefore no fat is burnt away from
the bath, as it is by the over-heated portions of a merely greased
frying-pan; and as regards the quantity adhering to the fish itself,
this may be reduced to a minimum by withdrawing it from the bath when
_the whole_ is uniformly at the maximum cooking temperature, and
allowing the fluid fat to drain off at once. It may be supposed that
by complete immersion of the fish in the fat-bath, more fat will soak
into it, but such is not the case; the water amidst the fibres of the
fish is boiling and driving out steam so rapidly that no fat can enter
if the heat is well maintained to the last moment, and the frying not
continued too long. When cooked on the greased plate, one side is
necessarily cooling, and the fat settling down into the fish to occupy
the pores left vacuous by the condensing steam, while the other is
being heated from below.
The temperature of the fat-bath may be tested by the ordinary cook’s
method—that of throwing into it a small piece of bread-crumb about the
size of a nut. If it frizzles and produces large bubbles of steam, the
full temperature of frying in the hottest of fat is reached; if it
frizzles slightly, and only gives out small steam-bubbles, you have the
temperature demanded for slow frying.
The bath-frying demands separate supplies of fat[9]—one for fish,
another for cutlets and other similar kinds of meat, a third for such
goody-goodies as apple-fritters—a most wholesome and delicious dish,
too rarely seen on English tables. I suspect that the prevalence of the
greased frying-pan is the reason of its rarity. Cooked by this barbaric
device, apples are scarcely eatable, but when thin slices are immersed
in a bath of melted fat at a temperature of about 300° Fahr., the water
of their juice is suddenly boiled, and as this water is contained in
a multitude of little bladderlike cells, they burst, and the whole
structure is puffed out to a most delicate lightness, far more suitable
for following solid meats than soddened fruit enveloped in heavy
indigestible pudding-paste. Another advantage is that with proper
apparatus (wire basket, kettle, and store of special fat) the fritters
can be prepared and cooked in about one-tenth of the time demanded for
the preparation and cookery of an apple pudding or pie. A few seconds
of immersion in the fat-bath is sufficient.
The fat used in frying requires occasional purification. I may
illustrate the principle on which it should be conducted by describing
the method adopted in the refining of mineral oils, such as petroleum
or the paraffin distillates of bituminous shales. These are dark, tarry
liquids of treacle-like consistency, with a strong and offensive odour.
Nevertheless they are, at but little cost, converted into the ‘crystal
oil’ used for lamps, and that beautiful pearly substance, the solid,
translucent paraffin now so largely used in the manufacture of candles.
Besides these, we obtain from the same dirty source an intermediate
substance, the well-known ‘Vaseline,’ now becoming the basis of most
of the ointments of the pharmacopœia. This purification is effected
by agitation with sulphuric acid, which partly carbonises and partly
combines with the impurities, and separates them in the form of a foul
and acrid black mess, known technically as ‘acid tar.’ When I was
engaged in the distillation of cannel and shale in Flintshire, this
acid tar was a terrible bugbear. It found its way mysteriously into the
Alyn river and poisoned the trout; but now, if I am correctly informed,
the Scotch manufacturers have turned it to profitable account.
Animal fat and vegetable oils are similarly purified. Very
objectionable refuse fat of various kinds is thus made into tallow,
or material for the soap-maker, and grease for lubricating machinery.
Unsavoury stories have been told about the manufacture of butter from
Thames mud or the nodules of fat that are gathered therefrom by the
mudlarks, but they are all false (see paper on ‘The Oleaginous Product
of Thames Mud’ in ‘Science in Short Chapters’). It may be possible
to purify fatty matter from the foulest of admixtures, and do this
so completely as to produce a soft, tasteless fat, _i.e._ a butter
substitute, but such a curiosity would cost more than half a crown per
pound, and therefore the market is safe, especially as the degree of
purification required for soap-making and machinery grease costs but
little and the demand for such fat is very great.
These methods of purification are not available in the kitchen, as oil
of vitriol is a vicious compound. During the siege of Paris some of the
Academicians devoted themselves very earnestly to the subject of the
purification of fat in order to produce what they termed ‘siege butter’
from the refuse of slaughter-houses, &c., and edible salad oils from
crude colza oil, from the rancid fish oils used by the leather-dresser,
&c. Those who are specially interested in the subject may find some
curious papers in the ‘Comptes Rendus’ of that period. In vol. lxxi.,
page 36, M. Boillot describes his method of mixing kitchen-stuff and
other refuse fat with lime-water, agitating the mixture when heated,
and then neutralising with an acid. The product thus obtained is
described as admirably adapted for culinary operations, and the method
is applicable to the purpose here under consideration.
Further on in the same volume is a ‘Note on Suets and Alimentary Fats’
by M. Dubrunfaut, who tells us that the most tainted of alimentary fats
and rancid oils may be deprived of their bad odours by ‘appropriate
frying.’ His method is to raise the temperature of the fat to 140°
to 150° Cent. (284° to 302° Fahr.) in a frying-pan; then cautiously
sprinkle upon it small quantities of water. The steam carries off
the volatile fatty acids which produce the rancidity in such as fish
oils, and also removes the neutral offensive fatty matters that are
decomposable by heat. In another paper by M. Fua this method is applied
to the removal of cellular tissue of crude fats from slaughter-houses.
It is really nothing more than the old farmhouse proceeding of
‘rendering’ lard, by frying the membranous fat until the membranous
matter is browned and aggregated into small nodules, which constitute
the ‘scratchings’—a delicacy greatly relished by our British ploughboys
at pig-killing time, but rather too rich in pork-fat to supply a
suitable meal for people of sedentary vocations.
The action of heat thus applied and long-continued is similar to that
of the strong sulphuric acid. The impurities of the fat are organic
matters more easily decomposable than the fat itself, or otherwise
stated, they are dissociated into carbon and water at about 300° Fahr.,
which is a lower temperature than that required for the dissociation of
the pure oil or fat. By maintaining this temperature, these compounds
become first caramelised, then carbonised nearly to blackness, when all
their powers of offensiveness vanish.
In the more violent factory process of purification by sulphuric acid
the similar action which occurs is due to the powerful affinity of
this acid for water: this may be strikingly shown by adding to thick
syrup or pounded sugar about its own bulk of oil of vitriol, when a
marvellous commotion occurs, and a magnified black cinder is produced
by the separation of the water from the sugar.
The following simple practical formula may be reduced from these data.
When a considerable quantity of much-used frying-fat is accumulated,
heat it to about 300° Fahr., as indicated by the crackling of water
when sprinkled on it, or, better still, by a properly-constructed
thermometer. Then pour the melted fat on hot water. This must be
done carefully, as a large quantity of fat at 300° poured upon a
small quantity of boiling water will illustrate the fact that water
when suddenly heated is an explosive compound. The quantity of water
should exceed that of the fat, and the pouring be done gradually.
Then agitate the fat and water together, and, if the operator is
sufficiently skilful and intelligent, the purification may be carried
further by carefully boiling the water under the fat and allowing its
steam to pass through; but this is a little dangerous, on account of
the possibility of what the practical chemist calls ‘bumping,’ or the
sudden formation of a big bubble of steam that would kick a good deal
of the superabundant fat into the fire.
Whether this supplementary boiling is carried out or not, the fat and
the water should be left together to cool gradually, when a dark layer
of carbonised impurities will be found resting on the surface of the
water, and adhering to the bottom of the cake of fat. This may be
peeled off and put into the waste grease-pot to be further refined with
the next operation. Ultimately the worst of it will sink to the bottom
of the water.
A careful cook may keep the supply of frying fat continually good, by
simply pouring it into a basin (a deep pudding-basin with small area
at bottom is best), letting it solidify there, and then paring away
the bottom sediment. Even this dirty-looking sediment need not be
altogether wasted. When a considerable quantity has accumulated it may
be purified by the method of Dubrunfaut and Fua above described.
As ordinary thermometers register but little above 212°, and laboratory
thermometers are too delicately constructed for kitchen use, I
requested Messrs. Davis & Co. to construct a special thermometer for
testing the temperature of heated fat. They have accordingly made an
instrument that answers the purpose very well. It is like a laboratory
thermometer, _i.e._ a glass tube with long bulb and the degrees
engraved on the glass itself, but the bulb is turned at right angles to
the tube, so that it is horizontal when the tube stands perpendicular,
and lies under a stand just above the level of the bottom of the
kettle. The instrument thus stands alone firmly, with its bulb fully
immersed even in a very shallow bath of fat.
Gouffé says: ‘Fat is the best for frying; the light-coloured dripping
of roast meat, and the fat taken off broth are to be preferred. These
failing, beef suet, chopped fine and melted down on a slow fire,
without browning, will do very well; when the bottom of the stewpan can
be seen through the suet, it is sufficiently melted.’ He is no advocate
for lard, ‘as it always leaves an unpleasant coating of fat on whatever
is fried in it.’ Olive oil of the best quality is almost absolutely
tasteless, and having as high a boiling point as animal fats it is
the best of all frying media. In this country there is a prejudice
against the use of such oil. I have noticed at some of those humble but
most useful establishments where poor people are supplied with penny
or twopenny portions of well-cooked, good fish, that in the front is
an inscription stating ‘only the best beef-dripping is used in this
establishment.’ This means a repudiation of oil.
On my first visit to Arctic Norway I arrived before the garnering
and exportation of the spring cod harvest was completed. The packet
stopped at a score or so of stations on the Lofodens and the mainland.
Foggy weather was no impediment, as an experienced pilot free from
catarrh could steer direct to the harbour by ‘following his nose.’ Huge
cauldrons stood by the shore in which were stewing the last batches of
the livers of codfish caught a month before and exposed in the meantime
to the continuous Arctic sunshine. Their condition must be imagined,
as I abstain from description of details. The business then proceeding
was the extraction of the oil from these livers. It is, of course,
‘cod-liver oil,’ but is known commercially as ‘fish oil,’ or ‘cod oil.’
That which is sold by our druggists as cod-liver oil is described
in Norway as ‘medicine oil,’ and though prepared from the same raw
material, is extracted in a different manner. Only fresh livers are
used for this, and the best quality, the ‘cold-drawn’ oil, is obtained
by pressing the livers without stewing. Those who are unfortunately
familiar with this carefully-prepared, highly-refined product, know
that the fishy flavour clings to it so pertinaciously that all attempts
to completely remove it without decomposing the oil have failed. This
being the case, it is easily understood that the fish oil stewed so
crudely out of the putrid or semi-putrid livers must be nauseous
indeed. It is nevertheless used by some of the fish-fryers, and refuse
‘Gallipoli’ (olive oil of the worst quality) is sold for this purpose.
The oil obtained in the course of salting sardines, herrings, &c., is
also used.
Such being the case, it is not surprising that the use of oil for
frying should, like the oil itself, be in bad odour.
I dwell upon this because we are probably on what, if a fine writer, I
should call the ‘eve of a great revolution’ in respect to frying media.
Two new materials, pure, tasteless, and so cheap as to be capable
of pushing pig-fat (lard) out of the market, have recently been
introduced. These are cotton-seed oil and poppy-seed oil. The first
has been for some time in the market offered for sale under various
fictitious names, which I will not reveal, as I refuse to become a
medium for the advertisement of anything—however good in itself—that is
sold under false pretences.
As every bale of cotton yields half a ton of seed, and every ton
of seed may be made to yield 28 lbs. to 32 lbs. of crude oil, the
available quantity is very great. At present only a small quantity
is made, the surplus seed being used as manure. Its fertilising
value would not be diminished by removing the oil, which is only a
hydro-carbon, _i.e._ material supplied by air and water. All the
fertilising constituents of the seed are left behind in the oil-cake
from which the oil has been pressed.
Hitherto cotton-seed oil has fallen among thieves. It is used as an
adulterant of olive oil; sardines and pilchards are packed in it. The
sardine trade has declined lately, some say from deficient supplies of
the fish. I suspect that there has been a decline in the demand due to
the substitution of this oil for that of the olive. Many people who
formerly enjoyed sardines no longer care for them, and they do not know
why. The substitution of cotton-seed oil explains this in most cases.
It is not rancid, has no decided flavour, but still is unpleasant when
eaten raw, as with salads or sardines. It has a flat, cold character,
and an after taste that is faintly suggestive of castor oil; but faint
as it is, it interferes with the demand for a purely luxurious article
of food. This delicate defect is quite inappreciable in the results
of its use as a frying medium. The very best lard or ordinary kitchen
butter, eaten cold, has more of objectionable flavour than refined
cotton-seed oil.
I have not tasted poppy-seed oil, but am told that it is similar
to that from the cotton-seed. As regards the quantities available,
some idea may be formed by plucking a ripe head from a garden poppy
and shaking out the little round seeds through the windows on the
top. Those who have not tried this will be astonished at the numbers
produced by each flower. As poppies are largely cultivated for the
production of opium, and the yield of the drug itself by each plant is
very small, the supplies of oil may be considerable; 571,542 cwt. of
seeds were exported from India last year, of which 346,031 cwt. went to
France.
Palm oil, though at present practically unknown in the kitchen, may
easily become an esteemed material for the frying-kettle. At present,
the familiar uses of palm oil in candle-making and for railway grease
will cause my suggestion to shock the nerves of many delicate people,
but these should remember that before palm oil was imported at all,
the material from which candles and soap were made, and by which
cart wheels and heavy machinery were greased, was tallow—_i.e._ the
fat of mutton and beef. The reason why our grandmothers did not use
candles for frying when short of dripping or suet was that the mutton
fat constituting the candle was impure, so are the yellow candles
and yellow grease in the axle-boxes of the railway carriages. This
vegetable fat is quite as inoffensive in itself, quite as wholesome,
and—sentimentally regarded—less objectionable, than the fat obtained
from the carcass of a slaughtered animal.
When common sense and true sentiment supplant mere unreasoning
prejudice, vegetable oils and vegetable fats will largely supplant
those of animal origin in every element of our dietary. We are but just
beginning to understand them. Chevreul, who was the first to teach us
the chemistry of fats, is still living, and we are only learning how to
make butter (not ‘inferior Dorset,’ but ‘choice Normandy’) without the
aid of dairy produce. There is, therefore, good reason for anticipating
that the inexhaustible supplies of oil obtainable from the vegetable
world—especially from tropical vegetation—will ere long be freely
available for kitchen uses, and the now popular product of the Chicago
hog factories will be altogether banished therefrom, and used only for
greasing cart-wheels and other machinery.
As a practical conclusion of this part of my subject, I will quote
from the ‘Oil Trade Review’ of this month, December 1884, the current
wholesale prices of some of the oils possibly available for frying
purposes: olive oil, from 43_l._ to 90_l._ per tun of 252 gallons;
cod oil, 36_l._ per tun; sardine or train (_i.e._ the oil that drains
from pilchards, herrings, sardines, &c., when salted), 27_l._ 10_s._
to 28_l._ per tun; cocoanut, from 35_l._ to 38_l._ per ton of 20 cwt.
(This, in the case of oil, is nearly the same as the measured tun.)
Palm, from 38_l._ to 40_l._ 10_s._ per ton; palm-nut or copra, 31_l._
10_s._ per ton; refined cotton-seed, 30_l._ 10_s._ to 31_l._ per ton;
lard, 53_l._ to 55_l._ per ton. The above are the extreme ranges of
each class. I have not copied the technical names and prices of the
intermediate varieties. One penny per lb. is = 9_l._ 6_s._ 8_d._ per
ton, or, in round numbers, 1_l._ per ton may be reckoned as 1/9th of a
penny per lb. Thus the present price of best refined cotton-seed oil
is 3½_d._ per lb.; of cocoanut oil, 3¾_d._; palm oil, from 3½_d._ to
4½_d._, while lard costs 6_d._ per lb. wholesale.
I should add, in reference to the seed-oils, that there is a possible
objection to their use as frying media. Oils extracted from seeds
contain more or less of _linoleine_ (so named from its abundance in
linseed oil), which, when exposed to the air, combines with oxygen,
swells and dries. If the oil from cotton-seed or poppy-seed contains
too much of this, it will thicken inconveniently when kept for a length
of time exposed to the air. Palm oil is practically free from it, but
I am doubtful respecting palm-nut oil, as most of the nut oils are
‘driers.’
Extravagant cooks delude confiding mistresses by demanding butter for
ordinary frying. A veneration for costliness is one of the vulgar
vices, especially dominant below stairs. In many cases a worse motive
induces the denunciation of the dripping and skimmed fat recommended by
Gouffé as above, and the substitution of lard or butter for it. This is
the practice of selling the dripping as ‘kitchen stuff.’
FOOTNOTE:
[9] The necessity for this is not so great as may appear theoretically.
I have tried the experiment of having veal cutlets fried in a bath
previously used for fish, and was not able to detect any fishy flavour
as I expected I should. This was the case even when I knew that the
fish fat had been used, and I was consequently far more critical than
under ordinary circumstances. Even apple-fritters may be cooked in fat
that has been used for fish. I have tried this since the above was
written and am surprised at the result.
CHAPTER VIII.
STEWING.
SOME of my readers may think that I ought to have treated this in
connection with the boiling of meat, as boiling and stewing are
commonly regarded as mere modifications of the same process. According
to my mode of regarding the subject, _i.e._ with reference to the
object to be attained, they are opposite processes.
The object in the so-called ‘boiling’ of, say, a leg of mutton, is to
raise the temperature of the meat throughout just up to the cooking
temperature in such a manner that it shall as nearly as possible retain
all its juices; the hot water merely operating as a vehicle or medium
for conveying the heat.
In stewing nearly all this is reversed. The juices are to be extracted
more or less completely, and the water is required to act as a solvent
as well as a heat-conveyor. Instead of the meat itself surrounding and
enveloping the juices as it should when boiled, roasted, grilled, or
fried, we demand in a stew that the juices shall surround or envelop
the meat. In some cases the separation of the juices is the sole
object, as in the preparation of certain soups and gravies, of which
‘beef-tea’ may be taken as a typical example. _Extractum carnis_, or
Liebig’s ‘Extract of Meat’ is beef-tea (or mutton-tea) concentrated by
evaporation.
The juices of lean meat may be extracted very completely without
cooking the meat at all, merely by mincing it and then placing it in
cold water. _Maceration_ is the proper name for this treatment. The
philosophy of this is interesting, and so little understood in the
kitchen that I must explain its rudiments.
If two liquids capable of mixing together, but of different densities,
be placed in the same vessel, the denser at the bottom, they will
mix together in defiance of gravitation, the heavy liquid rising and
spreading itself throughout the lighter, and the lighter descending and
diffusing itself through the heavier.
Thus, concentrated sulphuric acid (oil of vitriol) which has nearly
double the density of water, may be placed under water by pouring water
in a tall glass jar, and then carefully pouring the acid down a funnel
with a long tube, the bottom end of which touches the bottom of the
jar. At first the heavy liquid pushes up the lighter, and its upper
surface may be distinctly seen with that of the lighter resting upon
it. This is better shown if the water be coloured by a blue tincture
of litmus, which is reddened by the acid. A red stratum indicates the
boundaries of the two liquids. Gradually the reddening proceeds upwards
and downwards, the whole of the water changes from blue to red, and the
acid becomes tinged.
Graham worked for many years upon the determination of the laws of this
diffusion, and the rates at which different liquids diffused into each
other. His method was to fill small jars of uniform size and shape
(about 4 oz. capacity) with the saline or other dense solution, place
upon the ground mouth of the jar a plate-glass cover, then immerse it,
when filled, in a cylindrical glass vessel containing about 20 oz. of
distilled water. The cover being very carefully removed, diffusion was
allowed to proceed for a given time, and then by analysis the amount of
transfer into the distilled water was determined.
I must resist the temptation to expound the very interesting results
of these researches, merely stating that they prove this diffusion
to be no mere accidental mixing, but an action that proceeds with a
regularity reducible to simple mathematical laws. One curious fact
I may mention—viz. that on comparing the solutions of a number of
different salts, those which crystallise in the same forms have similar
rates of diffusion. The law that bears the most directly upon cookery
is that ‘the quantity of any substance diffused from a solution of
uniform strength increases as the temperature rises.’ The application
of this will be seen presently.
It may be supposed that if the jar used in Graham’s diffusion
experiments were tied over with a mechanically air-tight and
water-tight membrane, the brine or other saline solution thus confined
in the jar could not diffuse itself into the pure water above and
around it; people who are satisfied with anything that ‘stands to
reason’ would be quite sure that a bladder which resists the passage of
water, even when the water is pressed up to the bursting-point, cannot
be permeable to a most gentle and spontaneous flow of the same water.
The true philosopher, however, never trusts to any reasoning, not even
mathematical demonstration, until its conclusions are verified by
observations and experiment. In this case all rational preconceptions
or mathematical calculations based upon the amount of attractive force
exerted between the particles of the different liquids are outraged by
the facts.
If a stout, well-tied bladder that would burst rather than allow a
drop of water to be squeezed mechanically through it be partially
filled with a solution of common washing soda, and then immersed in
distilled water, the soda will make its way out of the bladder by
passing through its walls, and the pure water will go in at the same
time; for if, after some time is allowed, the outer water be tested by
dipping into it a strip of red litmus paper, it will be turned blue,
showing the presence of the alkali therein, and if the contents of the
bladder be weighed or measured, they will be found to have increased by
the inflow of fresh water. This inflow is called _endosmosis_, and the
outflow of the solution is called _exosmosis_. If an indiarubber bottle
be filled with water and immersed in alcohol or ether, the endosmosis
of the spirit will be so powerfully exerted as to distend the bottle
considerably. If the bottle be filled with alcohol or ether, and
surrounded by water, it will nearly empty itself.
The force exerted by this action is displayed by the rising of the sap
from the rootlets of a forest giant to the cells of its topmost leaves.
Not only plants, but animals also, are complex osmotic machines. There
is scarcely any vital function—if any at all—in which this osmosis does
not play an important part. I have no doubt that the mental effort I am
at this moment exerting is largely dependent upon the endosmosis and
exosmosis that is proceeding through the delicate membranes of some of
the many miles of blood-vessels that ramify throughout the grey matter
of my brain.
But I must wander no farther beyond the kitchen, having already said
enough to indicate that _diosmosis_ (which is the general term used
for expressing the actions of endosmosis and exosmosis as they occur
simultaneously) does the work of extracting the permanent juices of
meat when it is immersed in either hot or cold water.
I say _permanent_ juices with intent, in order to exclude the albumen,
which being coagulable at the lowest cooking temperature is not
permanent. It is one of that class of bodies to which Graham gave the
name of colloids (glue-like), such as starch, dextrin, gum, &c., to
distinguish them from another class, the crystalloids, or bodies that
crystallise on solidification. The latter diffuse and pass through
membranes by diosmosis readily, the colloids very sluggishly. Thus a
solution of Epsom salts diffuses seven times as rapidly as albumen, and
fourteen times as rapidly as caramel.
The difference is strikingly illustrated by the different diffusibility
of a solution of ordinary crystalline sugar and that of barley-sugar
and caramel, the latter being amorphous or formless colloids that dry
into a gummy mass when their solutions are evaporated, instead of
forming crystals as the original sugar did.
Some of the juices of meat, as already explained, exist between its
fibres, others are within those fibres or cells, enveloped in the
sheath or cell membrane. It is evident that the loose or free juices
will be extracted by simple diffusion, those enveloped in membranes by
exosmosis through the membrane. The result must be the same in both
cases; the meat will be permeated by the water, and the surrounding
water will be permeated by the juices that originally existed within
the meat. As the rate of diffusion—other conditions being equal—is
proportionate to the extent of the surfaces of the diverse liquids that
are exposed to each other, and as the rate of diosmosis is similarly
proportioned to the exposure of membrane, it is evident that the
cutting-up of the meat will assist the extraction of its juices by the
creation of fresh surfaces; hence the well-known advantage of mincing
in the making of beef-tea.
It is interesting to observe the condition of lean meat that has thus
been minced and exposed for a few hours to these actions by immersion
in cold water. On removing and straining such minced meat it will be
found to have lost its colour, and if it is now cooked it is insipid,
and even nauseous if eaten in any quantity. It has been given to dogs
and cats and pigs; these, after eating a little, refuse to take more,
and when supplied with this juiceless meat alone, they languish, become
emaciated, and die of starvation if the experiment is continued.
Experiments of this kind contributed to the fallacious conclusions of
the French Academicians. Although the meat from which the juices are
thus completely extracted is quite worthless _alone_, and meat from
which they are partially extracted is nearly worthless _alone_, either
of them becomes valuable when eaten with the juices. The stewed beef
of the Frenchman would deserve the contempt bestowed upon it by the
prejudiced Englishman if it were eaten as the Englishman eats his roast
beef; but when preceded by a _potage_ containing the juices of the beef
it is quite as nutritious as if roasted, and more easily digested.
Graham found that increase of temperature increases the rate of
diffusion of liquids, and in accordance with this the extraction of the
juices of meat is effected more rapidly by warm than by cold water;
but there is a limit to this advantage, as will be easily understood
from what has already been explained in Chapter III. concerning the
coagulation of albumen, which at the temperature of 134° Fahr. begins
to show signs of losing its fluidity; at 160° becomes a semi-opaque
jelly; at the boiling point of water is a rather tough solid; and if
kept at this temperature, shrinks, and becomes harder and harder,
tougher and tougher, till it attains a consistence comparable to that
of horn tempered with gutta-percha.
I have spoken of beef-tea, or _Extractum carnis_ (Liebig’s ‘Extract of
Meat’), as an extreme case of extracting the juices of meat, and must
now explain the difference between this and the juices of an ordinary
stew. Supposing the juices of the meat to be extracted by maceration in
cold water, and the broth thus obtained to be heated in order to alter
its raw flavour, a scum will be seen to rise upon the surface; this is
carefully removed in the manufacture of Liebig’s ‘Extract,’ or in the
preparation of beef-tea for an invalid, but in thus skimming we remove
a highly-nutritious constituent—viz. the albumen, which has coagulated
during the heating. The pure beef-tea, or _Extractum carnis_, contains
only the kreatine, kreatinine, the soluble phosphates, the lactic
acid, and other non-coagulable saline constituents, that are rather
stimulating than nutritious, and which, properly speaking, are not
digested at all—_i.e._ they are not converted into chyme in the
stomach, do not pass through the pylorus into the duodenum, &c., but,
instead of this, their dilute solution passes, like the water we drink,
directly into the blood by endosmosis through the delicate membrane of
that marvellous network of microscopic blood-vessels which is spread
over the surface of every one of the myriads of little upstanding
filaments which, by their aggregation, constitute the villous or velvet
coat of the stomach. In some states of prostration, where the blood
is insufficiently supplied with these juices, this endosmosis is like
pouring new life into the body, but it is not what is required for the
normal sustenance of the healthy body.
For ordinary food, all the nutritious constituents should be retained,
either in the meat itself or in its liquid surrounding. Regarding it
theoretically, I should demand the retention of the albumen in the
meat, and insist upon its remaining there in the condition of tender
semi-solidity, corresponding to the white of an egg when perfectly
cooked, as described in page 22. Also that the gelatin and fibrin be
softened by sufficient digestion in hot water, and that the saline
juices (those constituting beef-tea) be _partially_ extracted. I say
‘partially,’ because their complete extraction, as in the case of
the macerated minced-meat, would too completely rob the meat of its
sapidity. How, then, may these theoretical desiderata be attained?
It is evident from the principles already expounded that cold
extraction takes out the albumen, therefore this must be avoided; also
that boiling water will harden the albumen to leathery consistence.
This may be shown experimentally by subjecting an ordinary beefsteak to
the action of boiling water for about half an hour. It will come out in
the abominable condition too often obtained by English cooks when they
make an attempt at stewing—an unknown art to the majority of them. Such
an ill-used morsel defies the efforts of ordinary human jaws, and is
curiously curled and distorted. This toughening and curling is a result
of the coagulation, hardening, and shrinkage of the albumen as already
described.
It is evident, therefore, that neither cold water nor boiling water
should be used in stewing, but water at the temperature at which
albumen just begins to coagulate—_i.e._ about 134°, or between this and
160° as the extreme. My definition of stewing demands a qualification
as regards the albumen. Although this is one of the juices of the
meat when cold, it should not be extracted in ordinary stewing, as it
is in the maceration for beef-tea, and thereby appear as a scum to be
rejected. It should be barely coagulated, and thus retained in the meat
in as tender a condition as possible. Being a colloid (see _ante_,
page 115) its liability to diffusion is small. But here we encounter
a serious difficulty. How is the unscientific cook to determine and
maintain this temperature? If you tell her that the water must not
boil, she shifts her stewpan to the side of the fire, where it shall
only simmer, and she firmly believes that such simmering water has a
lower temperature than water that is boiling violently over the fire.
‘It stands to reason’ that it must be so, and if the experimental
philosopher appeals to fact and the evidence of the thermometer, he is
a ‘theorist.’
The French cook escapes this simmering delusion by her common use of
the _bain-marie_ or ‘water-bath,’ as we call it in the laboratory,
where it is also largely used for ‘digesting’ at temperatures below
212°. This is simply a vessel immersed in an outer vessel of water.
The water in the outer vessel may boil, but that in the inner vessel
cannot, as its evaporation keeps it below the temperature of the water
from which its heat is derived. A carpenter’s glue-pot is a very good
and compact form of water-bath. Some ironmongers keep in stock a form
of water-bath which they call a ‘milk-scalder.’ This resembles the
glue-pot, but has an inner vessel of earthenware which is, of course, a
great improvement upon the carpenter’s device, as it may be so easily
cleaned. Captain Warren’s, and other similar ‘cooking-pots,’ may be
used as water-baths by removing the cover of the inner vessel.
One of the incidental advantages of the _bain-marie_ is that the
stewing may be performed in earthenware or even glass vessels, seeing
that they are not directly exposed to the fire. Other forms of such
double vessels are obtainable at the best ironmongers. I have lately
seen a very neat apparatus of this kind, called ‘Dolby’s Extractor,’
made by Messrs. Griffiths & Browett of Birmingham. This consists of
an earthenware vessel that rests on a ledge, and thus hangs in an
outer tin-plate vessel; but, instead of water, there is an air space
surrounding the earthenware pot. A top screws over this, and the whole
stands in an ordinary saucepan of water. The heat is thus very slowly
and steadily communicated through an air-bath, and it makes excellent
beef-tea.
At temperatures _below the boiling point_ evaporation proceeds
superficially, and the rate of evaporation at a given temperature
is proportionate to the surface exposed, irrespective of the total
quantity of water; therefore, the shallower the inner vessel of the
_bain-marie_, and the greater its upper outspread, the lower will be
the temperature of its liquid contents when its sides and bottom are
heated by boiling water. The water in a basin-shaped inner vessel will
have a lower temperature than that in a vessel of similar depth, with
upright sides, and exposing an equal water surface. A good water-bath
for stewing may be extemporised by using a common pudding-basin (I mean
one with projecting rim, as used for tying down the pudding-cloth), and
selecting a saucepan just big enough for this to drop into, and rest
upon its rim. Put the meat, &c., to be stewed into the basin, pour hot
water over them, and hot water into the saucepan, so that the basin
shall be in a water-bath; then let this outer water simmer—very gently,
so as not to jump the basin with its steam. Stew thus for about double
the time usually prescribed in English cookery-books, and compare the
result with similar materials stewed in boiling or ‘simmering’ water.
I have already (page 91) referred to the frying that, in most cases,
should precede stewing. It not only supplies the caramel browning there
described, but moderates the extraction of the juices which, as I have
said above, is desirable on the part of the meat itself when gravy is
not the primary object.
Some further explanation is here necessary, as it is quite possible to
obtain what commonly passes for tenderness by a very flagrant violation
of the principles above expounded. This is done on a large scale and
in extreme degree in the preparation of ordinary Australian tinned
meat. A number of tins are filled with the meat, and soldered down
close, all but a small pin-hole. They are then placed in a bath charged
with a saline substance, such as chloride of zinc, which has a higher
boiling point than water. This is heated up to its boiling point,
and consequently the water which is in the tins with the meat boils
vigorously, and a jet of steam mixed with air blows from the pin-hole.
When all the air is expelled, and the jet is of pure steam only (a
difference detected at once by the trained expert), the tin is removed,
and a little melted solder skilfully dropped on the hole to seal the
tin hermetically. An examination of one of these tins will show this
final soldering with, in some, a flap below to prevent any solder from
falling in amongst the meat. The object of this is to exclude all air,
for if only a very small quantity remains, oxidation and putrefaction
speedily ensues, as shown by a bulging of the tins instead of the
partial collapse that should occur when the steam condenses, the
display of which collapse is an indication of the good quality of the
contents.
By ‘good quality’ I mean good of its kind; but, as everybody knows who
has tried beef and mutton thus prepared, it is not satisfactory. The
preservation from putrefactive decomposition is perfectly successful,
and all the original constituents of the meat are there. It is
_apparently_ tender, but _practically_ tough—_i.e._ it falls to pieces
at a mere touch of the knife, but these fragments offer to the teeth
a peculiar resistance to proper mastication. I may describe their
condition as one of pertinacious fibrosity. The fibres separate, but
they are stubborn fibres still.
This is a very serious matter, for, were it otherwise, the great
problem of supplying our dense population with an abundance of cheap
animal food would have been solved about twenty years ago. As it is,
the plain tinned-meat enterprise has not developed to any important
extent beyond affording a variation with salt junk on board ship.
What is the _rationale_ of this defect? Beyond the general statement
that the meat is ‘overdone,’ I have met with no attempt at explanation,
but am not, therefore, disposed to give up the riddle without
attempting a solution.
Reverting to what I have already said concerning the action of heat on
the constituents of flesh, it is evident that in the first place the
long exposure to the boiling point must harden the albumen. _Syntonin_,
or _muscle-fibrin_, the material of the ultimate contractile fibres
of the muscle, is coagulated by boiling water, and further hardened
by continuous boiling, in the same manner as albumen. Thus the
muscle-fibres themselves, and the lubricating liquor[10] in which they
are imbedded, must be simultaneously toughened by the method above
described, and this explains the pertinacious fibrosity of the result.
But how is the apparent tenderness, the facile separation of the
fibres of the same meat produced? A little further examination of the
anatomy and chemistry of muscle will, I think, explain this quite
satisfactorily. The ultimate fibres of the muscles are enveloped in
a very delicate membrane; a bundle of these is again enveloped in a
somewhat stronger membrane (_areolar tissue_); and a number of these
bundles of _fasciculi_ are further enveloped in a proportionally
stronger sheath of similar membrane. All these binding membranes are
mainly composed of gelatin, or the substance which produces gelatin
when boiled. The boiling that is necessary to drive out all the air
from the tins is sufficient to dissolve this, and effect that easy
separability of the muscular fibres, or fasciculi of fibres, that gives
to such overcooked meat its fictitious tenderness.
I am, however, doubtful whether _all_ the gelatin of these membranes
is thus dissolved. The jelly existing in the tins shows that some
is dissolved and hydrated, if my theory of the cookery is right;
but there does not appear to be as much of this jelly as would be
formed by the stewing of a corresponding quantity of meat at a lower
temperature. Some of the membranous gelatin is, I suspect, dehydrated
when the highest temperature of the process is attained—_i.e._ when
the concentration of the juices raises the boiling point of their
solution considerably above that of pure water. This, if I am right,
would check further solution of the membrane, would hydrate and harden
the remainder, and thus contribute to the hardening of the fibre above
described.
I have entered into these anatomical and chemical details because it is
only by understanding them that the difference between true tenderness
and spurious tenderness of stewed meat can be soundly understood,
especially in this country, where stewed meats are despised because
scientific stewing is practically and generally an unknown art. Ask an
English cook the difference between boiled beef or mutton and stewed
beef or mutton, and in ninety-nine cases out of a hundred her reply
will be to the effect that stewed meat is that which has been boiled or
simmered for a longer time than the boiled meat.
She proceeds, in accordance with this definition, when making an Irish
stew or similar dish, by ‘simmering’ at 212° until, by the coagulation
and hardening of the albumen and syntonin, a leathery mass is obtained;
then she continues the simmering until the gelatin of the areolar
tissue is partially dissolved, and the toughened fibres separate
or become readily separable. Having achieved this disintegration,
she supposes the meat to be tender, the fact being that the fibres
individually are tougher than they were at the leathery stage. The
mischief is not limited to the destruction of the flavour of the meat,
but includes the destruction of the nutritive value of its solid
portion by rendering it all indigestible, with the exception of the
gelatin, which is dissolved in the gravy.
This exception should be duly noted, inasmuch as it is the one
redeeming feature of such proceeding that renders it fairly well
adapted for the cookery of such meat as cow-heels, sheeps’-trotters,
calves’-heads, shins of beef, knuckles of veal, and other viands which
consist mainly of membranous, tendinous, or integumentary matter
composed of gelatin. To treat the prime parts of good beef or mutton in
this manner is to perpetrate a domestic atrocity.
I may here mention an experiment that I have made lately. I killed a
superannuated hen—more than six years old, but otherwise in very good
condition. Cooked in the ordinary way she would have been uneatably
tough. Instead of being thus cooked, she was gently stewed about
four hours. I cannot guarantee to the maintenance of the theoretical
temperature, having suspicion of _some_ simmering. After this she
was left in the water until it cooled, and on the following day was
roasted in the usual manner—_i.e._ in a roasting oven. The result was
excellent; as tender as a full-grown chicken roasted in the ordinary
way, and of quite equal flavour, in spite of the very good broth
obtained by the preliminary stewing. This surprised me. I anticipated
the softening of the tendons and ligaments, but supposed that the
extraction of the juices would have spoiled the flavour. It must have
diluted it, and that so much remained was probably due to the fact that
an old fowl is more fully flavoured than a young chicken. The usual
farmhouse method of cooking old hens is to stew them simply, the rule
in the Midlands being one hour in the pot for every year of age. The
feature of the above experiment was the supplementary roasting. As the
laying season comes to an end, old hens become a drug in the market;
and those among my readers who have not a hen-roost of their own will
much oblige their poulterers by ordering a hen that is warranted to
be four years old or upwards. If he deals fairly he will supply a
specimen upon which they may repeat my experiment very cheaply. It
offers the double economy of utilising a nearly waste product, and
obtaining chicken-broth and roast fowl simultaneously.
Another experiment on the cooking of old hens was recently made by a
neighbour at my suggestion, and proved very successful. The bird was
cut up and gently stewed in fat like the small joints of my experiments
described in p. 57.
I have not yet repeated this experiment, but when I do shall use bacon
liquor (the surplus fat from grilled bacon) for the bath, and hope
thereby to obtain an approach to the effect of ‘larding,’ as practised
in luxurious cookery.
One of the great advantages of stewing is that it affords a means of
obtaining a savoury and very wholesome dish at a minimum of cost. A
small piece of meat may be stewed with a large quantity of vegetables,
the juice of the meat savouring the whole. Besides this, it costs far
less fuel than roasting.
The wife of the French or Swiss landed proprietor—_i.e._ a working
peasant—cooks the family dinner with less than a tenth of the
expenditure of fuel used in England for the preparation of an inferior
meal. A little charcoal under her _bain-marie_ does it all. The economy
of time corresponds to the economy of fuel, for the mixture of viands
required for the stew once put into the pot is left to itself until
dinner-time, or at most an occasional stirring of fresh charcoal into
the embers is all that is demanded.
FOOTNOTE:
[10] I have ventured to ascribe this lubricating function to the
albumen which envelopes the fibres, though doubtful whether it is quite
orthodox to do so. Its identity in composition with the synovial liquor
of the joints, and the necessity for such lubricant, justify this
supposition. It may act as a nutrient fluid at the same time.
CHAPTER IX.
CHEESE.
I NOW come to a very important constituent of animal food, although
it is not contained in beef, mutton, pork, poultry, game, fish, or
any other organised animal substance, unless in egg yolk, as Lehmann
states (see page 23). It is not even proved satisfactorily to exist in
the blood, although it is somehow obtained from the blood by special
glands at certain periods. I refer to _casein_, the substantial basis
of cheese, which, as everybody knows, is the consolidated curd of milk.
It is evident at once that casein must exist in two forms, the soluble
and insoluble, so far as the common solvent, water, is concerned. It
exists in the soluble form, and completely dissolved in milk, and
insoluble in cheese. When precipitated in its insoluble or coagulated
form as the curd of new milk it carries with it the fatty matter or
cream, and therefore, in order to study its properties in a state of
purity, we must obtain it otherwise. This may be done by allowing the
fat globules of the milk to float to the surface, and then removing
them by separating the cream as by the ordinary dairy method. We thus
obtain in the skimmed milk a solution of casein, but there still
remains some of the fat. This may be removed by evaporating the
solution down to solidity, and then dissolving out the fat by means
of ether, which leaves the soluble casein behind. The adhering ether
being evaporated, we have a fairly pure specimen of casein in its
original or soluble form.
This, when dry, is an amber-coloured translucent substance, devoid of
odour, and insipid. The insipidity and absence of odour of the pure
and separated casein are noteworthy, as showing that the condition in
which it exists in milk is very different from that of the casein of
cheese. My object in pointing this out is to show that in the course
of the manufacture of cheese new properties are developed. Skim-milk—a
solution of casein—is tasteless and inodorous, while fresh cheese,
whether made from skimmed or whole milk, has a very decided flavour and
odour.
If we now add some of our dry casein to water, it dissolves, forming a
yellowish viscid fluid, which, on evaporation, becomes covered with a
slight film of insoluble casein, which may be readily drawn off. Some
of my readers will recognise in this description the resemblance of a
now well-known domestic preparation of soluble casein, condensed milk,
where it is mixed with much cream, and in the ordinary preparation also
much sugar. The cream dilutes the yellowness, but does not quite mask
it, and the viscidity is shown by the strings which follow the spoon
when a spoonful is lifted. If a concentrated solution of pure casein is
exposed to the air it rapidly putrefies, and passes through a series of
changes that I must not tarry to describe, beyond stating that ammonia
is given off, and some crystalline substances, such as _leucine_,
_tyrosine_, &c., very interesting to the physiological chemist, but not
important in the kitchen, are formed.
A solution of casein in water is not coagulated by boiling; it may be
repeatedly evaporated to dryness and redissolved. Upon this depends
the practicability of preserving milk by evaporating it down, or
‘condensing.’
This condensed milk, however, loses a little; its albumen is
sacrificed, as everybody will understand who has dipped a spoon in
freshly-boiled milk and observed the skin which the spoon removes from
the surface. This is coagulated albumen.
If alcohol is added to a concentrated solution of casein in water,
a pseudo-coagulation occurs; the casein is precipitated as a white
substance like coagulated albumen, but if only a little alcohol is
used, the solid may be redissolved in water; if, however, it is thus
treated with strong alcohol, the casein becomes difficult of solution,
or even quite insoluble. Alcohol added to solid soluble casein renders
it opaque, and gives it the appearance of coagulated albumen. The
alcohol itself dissolves a little of this.
The characteristic coagulation of casein, or its conversion from the
soluble to the insoluble form, is produced rather mysteriously by
rennet. Acids generally precipitate it either from aqueous solution
or from milk. The coagulation effected by mineral acids from aqueous
solutions is not so complete as that produced by lactic acid from milk,
or vinegar, the former coagulum being more readily redissolved by
alkalies or weaker basic substances than the latter.
A calf has four stomachs, the fourth being that which corresponds to
ours, both in structure and functions. It is lined with a membrane
from which is secreted the gastric juice and other fluids concerned in
effecting the conversion of food into chyme. A weak infusion made from
a small piece of this ‘mucous membrane’ will coagulate the casein of
three thousand times its own quantity of milk, or the coagulation may
be effected by placing a small piece of the stomach (usually salted
and dried for the purpose) in the milk, and warming it for a few hours.
Many theoretical attempts have been made to explain this action of the
rennet. Simon and Liebig suppose that it acts primarily as a ferment,
converting the sugar of milk into lactic acid, and that this lactic
acid coagulates the casein. This theory has been controverted by Selmi
and others, but the balance of evidence is decidedly in its favour. The
coagulation which occurs in the living stomach when milk is taken as
food appears to be due to the lactic acid of the gastric juice.
Casein, when thoroughly coagulated by rennet, then purified and dried,
is a hard and yellowish hornlike substance. It softens and swells in
water, but does not dissolve therein, nor in alcohol nor weak acids.
Strong mineral acids decompose it. Alkalies dissolve it readily, and if
concentrated, decompose it on the application of heat. When moderately
heated, it softens and may be drawn into threads, and becomes elastic;
at a higher temperature it fuses, swells up, carbonises, and develops
nearly the same products of distillation as the other protein compounds.
Note the differences between this and the soluble casein above
described, viz. that obtained by simply removing the fat from the milk,
then evaporating away the water, but using no rennet.
I have good and sufficient reasons for thus specifying the properties
of this constituent of food. I regard it as the most important of all
that I have to describe in connection with my subject—the science
of cookery. It contains (as I shall presently show) more nutritious
material than any other food that is ordinarily obtainable, and its
cookery is singularly neglected, is practically an unknown art,
especially in this country. We commonly eat it raw, although in its
raw state it is peculiarly indigestible, and in the only cooked form
familiarly known among us here, that of a Welsh rabbit, or rarebit, it
is too often rendered still more indigestible, though this need not be
the case.
Here, in this densely-populated country, where we import so much of
our food, cheese demands our most profound attention. The difficulties
and cost of importing all kinds of meat, fish, and poultry are great,
while cheese may be cheaply and deliberately brought to us from any
part of the world where cows or goats can be fed, and it can be stored
more readily and kept longer than other kinds of animal food. All that
is required to render it, next to bread, the staple food of Britons is
scientific cookery.
If I shall be able, in what is to follow, to impart to my
fellow-countrymen, and more especially countrywomen, my own convictions
concerning the cookability, and consequent improved digestibility, of
cheese, I shall have ‘done the State some service!’
Taking muscular fibre without bone—_i.e._ selected best part of the
meat—beef contains on an average 72½ per cent. of water; mutton, 73½;
veal, 74½; pork, 69¾; fowl, 73¾; while Cheshire cheese contains only
30⅓, and other cheeses about the same. Thus, at starting, we have in
every pound of cheese rather more than twice as much solid food as in
a pound of the best meat, or comparing with the average of the whole
carcass, including bone, tendons, &c., the cheese has an advantage of
three to one.
The following results of Mulder’s analysis of casein, when compared
with those by the same chemist of albumen, gelatin and fibrin,
show that there is but little difference in the ultimate chemical
composition of these, so far as the constituents there named are
concerned:
Casein
Carbon 53·83
Hydrogen 7·15
Nitrogen 15·65
Oxygen }
Sulphur } 23·37
Albumen Gelatin Fibrin
Carbon 53·5 50·40 52·7
Hydrogen 7·0 6·64 6·9
Nitrogen 15·5 18·34 15·4
Oxygen 22·0 24·62 23·5
Sulphur 1·6 ” 1·2
Phosphorus 0·4 ” 0·3
We may therefore conclude that, regarding these from the point of
view of nitrogenous or flesh-forming, and carbonaceous or heat-giving
constituents, these chief materials of flesh and of cheese are about
equal.
The same is the case as regards the fat. The quantity in the carcass
of oxen, calves, sheep, lambs, and pigs varies, according to Dr.
Edward Smith, from 16 per cent. to 31·3 per cent. in moderately fatted
animals; while in whole-milk cheeses it varies from 21·68 per cent. to
32·31 per cent., coming down in skim-milk cheeses as low as 6·3. Dr.
Smith includes Neufchâtel cheese, containing 18·74 per cent., among the
whole-milk cheeses. He does not seem to be aware that the cheese made
up between straws and sold under that name is a _ricotta_, or crude
curd of skim-milk cheese. Its just value is about threepence per pound.
In Italy, where it forms the basis of some delicious dishes (such as
_budino di ricotta_[11]), it is sold for about twopence per pound, or
less.
There is a discrepancy in the published analyses of casein which
demands explanation here, as it is of great practical importance. They
generally correspond to the above of Mulder within small fractions, as
shown below in those of Scherer and Dumas:
Scherer Dumas
Carbon 54·665 53·7
Hydrogen 7·465 7·2
Nitrogen 15·724 16·6
Oxygen, sulphur 22·146 22·5
------- -----
100·000 100·0
In these the 100 parts are made up without any phosphate of lime,
while, according to Lehmann (‘Physiological Chemistry,’ vol. i. p.
379, Cavendish Edition), ‘casein that has not been treated with acids
contains about 6 per cent. of phosphate of lime; more, consequently,
than is contained in any of the protein compounds we have hitherto
considered.’
From this it appears that we may have casein with, and casein without,
this necessary constituent of food. In precipitating casein for
laboratory analysis, acids are commonly used, and thus the phosphate
of lime is dissolved out; but I am unable at present to tell my
readers the precise extent to which this actually occurs in practical
cheese-making where rennet is used. What I have at present learned
only indicates generally that this constituent of cheese is very
variable; and I hereby suggest to those chemists who are professionally
concerned in the analysis of food, that they may supply a valuable
contribution to our knowledge of this subject by simply determining
the phosphate of lime contained in the ash of different kinds of
cheese. I would do this myself, but, having during some ten years past
nearly forsaken the laboratory for the writing-table, I have not the
leisure for such work; and, worse still, have not that prime essential
to practical research (especially of endowed research), a staff of
obedient assistants to do the drudgery.
The comparison specially demanded is between cheeses made with rennet,
and those Dutch and factory cheeses the curd of which has been
precipitated by hydrochloric acid. Theoretical considerations point to
the conclusion that in the latter much or even all of the phosphate of
lime may be left in solution in the whey, and thus the food-value of
the cheese seriously lowered. We must, however, suspend judgment in the
meantime.
In comparing the nutritive value of cheese with that of flesh, the
retention of this phosphate of lime corresponds with the retention of
some of the juices of the meat, among which are the phosphates of the
flesh.
These phosphates of lime are the bone-making material of food, and have
something to do in building up the brain and nervous matter, though not
to the extent that is supposed by those who imagine that there is a
special connection between phosphorus and the brain, or phosphorescence
and spirituality. Bone contains about eleven per cent. of phosphorus,
brain less than one per cent.
The value of food in reference to its phosphate of lime is not merely
a matter of percentage, as this salt may exist in a state of solution,
as in milk, or as a solid very difficult of assimilation, as in bones.
That retained in cheese is probably in an intermediate condition—not
actually in solution, but so finely divided as to be readily dissolved
by the acid of the gastric juice.
I may mention, in reference to this, that when a child or other
young animal takes its natural food in the form of milk, the milk is
converted into unpressed cheese, or curd, prior to its digestion.
Supposing that, on an average, cheese contains only one-half of the
6 per cent. of phosphate of lime found, as above, in the casein, and
taking into consideration the water contained in flesh, the bone, &c.,
we may conclude generally that one pound of average cheese contains as
much nutriment as three pounds of the average material of the carcass
of an ox or sheep as prepared for sale by the butcher; or otherwise
stated, a cheese of 20 lbs. weight contains as much food as a sheep
weighing 60 lbs. as it hangs in the butcher’s shop.
Now comes the practical question. Can we assimilate or convert into our
own substance the cheese-food as easily as we may the flesh-food?
I reply that we certainly cannot, if the cheese is eaten raw; but have
no doubt that we may, if it be suitably cooked. Hence the paramount
importance of this part of my subject. A Swiss or Scandinavian
mountaineer can and does digest and assimilate raw cheese as a staple
article of food, and proves its nutritive value by the result; but
feebler bipeds of the plains and towns cannot do the like.
I may here mention that I have recently made some experiments on
the dissolving of cheese by adding sufficient alkali (carbonate of
potash) to neutralise the acid it contains, in order to convert the
casein into its original soluble form as it existed in the milk, and
have partially succeeded both with water and milk as solvents; but
before reporting these results in detail I will describe some of the
practically-established methods of cooking cheese that are so curiously
unknown or little known in this country.
In the fatherland of my grandfather, Louis Gabriel Mattieu, one of the
commonest dishes of the peasant who tills his own freehold and grows
his own food is a _fondu_. This is a mixture of cheese and eggs, the
cheese grated and beaten into the egg as in making omelettes, with a
small addition of new milk or butter. It is placed in a little pan like
a flower-pot saucer, cooked gently, served as it comes off the fire,
and eaten from the vessel in which it is cooked. I have made many a
hearty dinner on one of these, _plus_ a lump of black bread and a small
bottle of genuine but thin wine; the cost of the whole banquet at a
little _auberge_ being usually less than sixpence. The cheese is in a
pasty condition, and partly dissolved in the milk or butter. I have
tested the sustaining power of such a meal by doing some very stiff
mountain climbing and long fasting after it. It is rather too good—over
nutritious—for a man only doing sedentary work.
A diluted and delicate modification of this may be made by taking
slices of bread, or bread and butter, soaking them in a batter made
of eggs and milk—without flour—then placing the slices of soaked
bread in a pie-dish, covering each with a thick coating of grated
cheese, and thus building up a stratified deposit to fill the dish.
The surplus batter may be poured over the top; or if time is allowed
for saturation, the trouble of preliminary soaking may be saved by
simply pouring all the batter thus. This, when gently baked, supplies
a delicious and highly nutritious dish. We call it ‘cheese pudding’
at home, but my own experience convinces me that we make a mistake in
using it to supplement the joint. It is far too nutritious for this;
its savoury character tempts one to eat it so freely that it would be
far wiser to use it as the Swiss peasant uses his _fondu_—_i.e._ as the
substantial dish of a wholesome dinner.
I have tested its digestibility by eating it heartily for supper. No
nightmare has followed. If I sup on a corresponding quantity of raw
cheese my sleep is miserably eventful.
A correspondent writes as follows from the Charlotte Square Young
Ladies’ Institution: ‘I have been trying the various ways of cooking
cheese mentioned in your articles in “Knowledge,” and have one or two
improvements to suggest in the making of cheese pudding. I find the
result is much better when the bread is grated like the cheese, and
thoroughly mixed with it; then the batter poured over both. I think you
will also find it better when baked in a shallow tin, such as is used
for Yorkshire pudding. This gives more of the browned surface, which
is the best of it. Another improvement is to put some of the crumbled
bread (on paper) in the oven till brown, and eat with it (as for game).
I have not succeeded in making any improvement in the _fondu_ (see page
139), which is delightful.’
My recollections of the _fondu_ of the Swiss peasant being so
eminently satisfactory on all points—nutritive or sustaining value,
appetising flavour and economy—I have sought for a recipe in several
cookery-books, and find at last a near approach to it in an old edition
of Mrs. Rundell’s ‘Domestic Cookery.’ A similar dish is described in
that useful book ‘Cre-Fydd’s Family Fare,’ under the name of ‘_Cheese
Soufflé_ or _Fondu_.’[12] I had looked for it in more pretentious
works, especially in the most pretentious and the most disappointing
one I have yet been tempted to purchase, viz. the 27th edition of
Francatelli’s ‘Modern Cook,’ a work which I cannot recommend to anybody
who has less than 20,000_l._ a year and a corresponding luxury of liver.
Amidst all the culinary monstrosities of these ‘high-class’ manuals, I
fail to find anything concerning the cookery of cheese that is worth
the attention of my readers. Francatelli has, under the name of ‘Eggs
à la Suisse,’ a sort of _fondu_, but decidedly inferior to the common
_fondu_ of the humble Swiss osteria, as Francatelli lays the eggs upon
slices of cheese, and prescribes especially that the yolks shall not be
broken; omits the milk, but substitutes (for high-class extravagance’
sake, I suppose) ‘a gill of double cream,’ to be poured over the top.
Thus the cheese is not intermingled with the egg, lest it should spoil
the appearance of the unbroken yolks, its casein is made leathery
instead of being dissolved, and the substitution of sixpenny worth of
double cream for a halfpenny worth of milk supplies the high-class
victim with fivepence halfpenny worth of biliary derangement.
In Gouffé’s ‘Royal Cookery Book’ (the Household Edition of which
contains a great deal that is really useful to an English housewife) I
find a better recipe under the name of ‘_Cheese Soufflés_.’ He says:
‘Put two ounces and a quarter of flour in a stewpan, with one pint and
a half of milk; season with salt and pepper; stew over the fire till
boiling, and should there be any lumps, strain the _soufflé_ paste
through a tammy cloth; add seven ounces of grated Parmesan cheese, and
seven yolks of eggs; whip the whites till they are firm, and add them
to the mixture; fill some paper cases with it, and bake in the oven for
fifteen minutes.’
Cre-Fydd says: ‘Grate six ounces of rich cheese (Parmesan is the best);
put it into an enamelled saucepan, with a teaspoonful of flour of
mustard, a saltspoonful of white pepper, a grain of cayenne, the sixth
part of a nutmeg, grated, two ounces of butter, two tablespoonfuls of
baked flour, and a gill of new milk; stir it over a slow fire till
it becomes like smooth, thick cream (but it must not boil); add the
well-beaten yolks of six eggs, beat for ten minutes, then add the
whites of the eggs beaten to a stiff froth; put the mixture into a tin
or a cardboard mould, and bake in a quick oven for twenty minutes.
Serve immediately.’
Here is a true cookery of cheese by solution, and the result is an
excellent dish. But there is some unnecessary complication and kitchen
pedantry involved. The _soufflé_ part of the business is a mere puffing
up of the mixture for the purpose of displaying the cleverness of the
cook, being quite useless to the consumer, as it subsides before it
can be eaten. It further involves practical mischief, as it cannot be
obtained without toasting the surface of the cheese into an air-tight
leathery skin that is abnormally indigestible. The following is my own
simplified recipe:
Take a quarter of a pound of grated cheese; add it to a gill of
milk in which is dissolved as much powdered _bicarbonate of potash_
as will stand upon a threepenny-piece; mustard, pepper, &c., as
prescribed above by Cre-Fydd.[13] Heat this carefully until the cheese
is completely dissolved. Then beat up three eggs, yolks and whites
together, and add them to this solution of cheese, stirring the whole.
Now take a shallow metal or earthenware dish or tray that will bear
heating; put a little butter on this, and heat the butter till it
frizzles. Then pour the mixture into the tray, and bake or fry it until
it is nearly solidified.
A cheaper dish may be made by increasing the proportion of cheese—say,
six to eight ounces to three eggs, or only one egg to a quarter of a
pound of cheese for a hard-working man with powerful digestion.
Mr. E. D. Girdlestone writes as follows (I quote with permission): ‘As
regards the “cheese _fondu_,” your recipe for which has enabled me to
turn cheese to practical account as _food_, you may be glad to hear
that it has become a common dish in our microscopic _ménage_. Indeed
cheese, which formerly was poison to me, is now alike pleasant and
digestible. But some of your readers may like to know that the addition
of _bread-crumbs_ is, in my judgment at least, a great improvement,
giving greater lightness to the compost, and removing the harshness
of flavour otherwise incidental to a mixture which comprises so large
a proportion of cheese. We (my wife and I) think this a _great_
improvement.’
I have received two other letters making, quite independently, the same
suggestion concerning the bread-crumbs. I have tried the addition,
and agree with Mr. Girdlestone that it is a great improvement as food
for such as ourselves, who are brain-workers, and for all others
whose occupations are at all sedentary. The undiluted _fondu_ is too
nutritious for us, though suitable for the mountaineer.
The chief difficulty in preparing this dish conveniently is that of
obtaining suitable vessels for the final frying or baking, as each
portion should be poured into, and fried or baked in, a separate dish,
so that each may, as in Switzerland, have his own _fondu_ complete,
and eat it from the dish as it comes from the fire. As demand creates
supply, our ironmongers, &c., will soon learn to meet this demand if it
arises. I have written to Messrs. Griffiths & Browett, of Birmingham,
large manufacturers of what is technically called ‘hollow ware’—_i.e._
vessels of all kinds knocked up from a single piece of metal without
any soldering—and they have made suitable _fondu_ dishes according to
my specification, and supply them to the shopkeepers.
The bicarbonate of potash is an original novelty that will possibly
alarm some of my non-chemical readers. I advocate its use for two
reasons: first, it effects a better solution of the casein by
neutralising the free lactic acid that inevitably exists in milk
supplied to towns, and any free acid that may remain in the cheese.
At a farmhouse, where the milk is just drawn from the cow, it is
unnecessary for this purpose, as such new milk is itself slightly
alkaline.
My second reason is physiological, and of greater weight. Salts of
potash are necessary constituents of human food. They exist in all
kinds of wholesome vegetables and fruits, and in the juices of _fresh_
meat, but _they are wanting in cheese_, having, on account of their
great solubility, been left behind in the whey.
This absence of potash appears to me to be the one serious objection to
the free use of cheese diet. The Swiss peasant escapes the mischief by
his abundant salads, which eaten raw contain all their potash salts,
instead of leaving the greater part in the saucepan, as do cabbages,
&c., when cooked in boiling water. In Norway, where salads are scarce,
the bonder and his housemen have at times suffered greatly from scurvy,
especially in the far north, and would be severely victimised but for
special remedies that they use (the mottebeer, cranberry, &c., grown
and preserved especially for the purpose). The Laplanders make a broth
of scurvy-grass and similar herbs; I have watched them gathering these,
and observed that the wild celery was a leading ingredient.
Scurvy on board ship results from eating salt meat, the potash of which
has escaped by exosmosis into the brine or pickle. The sailor now
escapes it by drinking citrate of potash in the form of lime-juice, and
by alternating salt junk with rations of tinned meats.
I once lived for six days on bread and cheese only, tasting no other
food. I had, in company with C. M. Clayton (son of the Senator of
Delaware, who negotiated the Clayton-Bulwer Treaty), taken a passage
from Malta to Athens in a little schooner, and expecting a three days’
journey we took no other rations than a lump of Cheshire cheese and a
supply of bread. Bad weather doubled the expected length of our journey.
We were both young, and proud of our hardihood in bearing privations,
were staunch disciples of Diogenes; but on the last day we succumbed,
and bartered the remainder of our bread and cheese for some of the
boiled horse-beans and cabbage-broth of the forecastle. The cheese,
highly relished at first, had become positively nauseous, and our
craving for the forecastle vegetable broth was absurd, considering the
full view we had of its constituents and of the dirtiness of its cooks.
I attribute this to the lack of potash salts in the cheese and bread.
It was similar to the craving for common salt by cattle that lack
necessary chlorides in their food. I am satisfied that cheese can never
take the place in an economic dietary, otherwise justified by its
nutritious composition, unless this deficiency of potash is somehow
supplied. My device of using it with milk as a solvent supplies it in a
simple and natural manner.
The milk is not necessary, though preferable. I find that a solution
of cheese may be made in water by simply grating or thinly slicing
the cheese, and adding it to about its own bulk of water in which the
bicarbonate of potash is dissolved.
The proportion of bicarbonate, which I theoretically estimate as
demanded for supplying the deficiency of potash, is at the rate of
about a quarter of an ounce to the pound of cheese; and I find that
it will bear this quantity without the flavour of the potash being
detected. The proportion of potash in cows’ milk is more than double
the quantity thus supplied, but I assume that the cheese loses about
half of its original supply, and base this assumption on the fact that
ordinary cheese contains an average of about 4 per cent. of saline
matter, while the proportion of saline matter to the casein and fat of
the milk amounts to 5 per cent. This is a rough practical estimate,
kept rather below the actual quantity demanded; therefore more than the
quarter ounce may be used with impunity. I have doubled it in some of
my experiments, and thus have just detected the bitter flavour of the
salt.
As regards the solubility of the cheese, I should add that there are
great differences in different samples. Generally speaking, the newer
and milder the cheese the more soluble. Some that I have tried leave a
stubbornly insoluble residuum, which is detestably tough. I found the
same cheese to be unusually indigestible when eaten with bread in the
ordinary raw state, and have reason to believe that it is what I have
called ‘bosch cheese,’ to be described presently.
The successful solution, in either alkalised milk or alkalised water,
cools into a custard-like mass, the thickness or viscosity varying, of
course, with the quantity of solvent. It may be kept for use a short
time (from two or three days to two or three weeks, according to the
weather), after which it becomes putrescent.
As now well known to all concerned, a great deal of ‘butterine,’ or
‘oleomargarine,’ or ‘margarine,’ or ‘bosch,’ is made by extracting from
the waste fat of oxen and sheep some of its harder constituents, the
palmitic and stearic acids, then working up the softer remainder with
a little milk, or even without the milk, into a resemblance to butter.
When properly prepared and honestly sold for what it is, no fair
grounds for objection exist; but it is too commonly sold for what it is
not—_i.e._ as butter. For cookery purposes a fair sample of ‘bosch’ is
quite as good as ‘inferior dosset.’ I have tasted some that is scarcely
distinguishable from best Devonshire fresh.
More recently this enterprise has been further developed. Genuine
butter is made from cream skimmed from the milk. The skimmed milk is
then curdled, and to the whey thus precipitated a sufficient quantity
of bosch is added to replace the butter that has been sent to market.
A still more objectionable compound is made by using hogs’ lard as
a substitute for the natural cream. These extraneous fats render
the cheese more indigestible. The curd precipitated from skim-milk
is harder and tougher than that thrown down from whole milk, and
these added fats merely envelop the broken fragments of this. Hence
my suspicion that the cheese leaving the above-described insoluble
residuum was a sample of ‘bosch’ cheese.
* * * * *
Since the above was written I have met with the following in the
_Times_, bringing the subject up to latest date, and I take the liberty
of reprinting the larger part of this interesting and clearly-written
communication:
‘IMITATED DAIRY PRODUCTS.
‘The profitable utilisation of refuse products has
always been one of the most difficult problems which
have confronted manufacturers. Until recently the
disposal of skim-milk was one of the difficulties of
the managers of butter factories, or “creameries” as
they are termed in the United States. Similarly, the
sale of the internal fat of animals slaughtered for
food, with the exception of lard, was practically
restricted to the manufacturers of soap and candles.
It was reserved to a Frenchman, M. Mège-Mauries, to
discover the first step towards a more profitable use
of these substances. He showed that by a judicious
combination of milk and the clarified fat of animals
a substance could be produced which closely resembled
butter. So close, indeed, is the resemblance of
imitation butter to the real article that the skill
of the chemist must be invoked to render detection
positive, if the artificial butter is good of its kind.
So recondite, indeed, is the test of the chemist that
it depends upon the percentage of volatile oils in
butter-fat and in caul-fat respectively.
‘Artificial butter is the result of several processes.
The internal fat of cattle is first chopped into small
pieces, and then passed through a huge and somewhat
modified sausage-machine. The finely-divided suet is
afterwards placed in suitable vessels, and heated
up to 122° Fahr., but a higher temperature must be
avoided, otherwise a portion of the stearine, or true
tallow of the suet, becomes inextricably mixed with
the oleomargarine. It need scarcely be added that the
tallow taste would be fatal to the manufacture of a
first-class article. The melted fat is transferred to
casks and left to cool; afterwards it is put in small
quantities into coarse bags, several of which are made
into a pile with iron plates between them, and placed
in a hydraulic press. The result is the expression of
the pure oleomargarine as a clear yellow oil, the solid
stearine remaining in the bags.
‘The next step is the manufacture of this oleomargarine
into the substance which has been designated
“butterine,” and which is quoted on the London market
as “bosch.” The “oleo” is remelted at the lowest
possible temperature, mixed with a certain proportion
of milk and of butter, and then churned. The result is
the production of a material closely resembling butter,
in fact practically identical so far as appearance is
concerned. It is washed, worked, and otherwise treated
like real butter, and packed to simulate the kinds of
butter which are most in demand on the market to which
it is sent. In London all kinds of butter are sold, and
we believe that they are all more or less imitated.
‘Unfortunately for the consumer of butterine, not
all that is sold, even as butter, is made with so
much regard to care and cleanliness, or with such
comparatively unobjectionable materials. The demand for
oleomargarine, which constitutes about 60 per cent.
of the mass that is churned, has naturally raised its
price, and various substitutes have been tried with
more or less success. Lard has been extensively used,
and is said to answer fairly well. Oils of various
kinds have also had their trial, but used alone their
melting point is too low. Earth-nut oil is used in
small quantities by some makers in order to impart
an agreeable flavour, especially in cases where the
artificial butter has been “weighted” by the addition
of water to the milk, or meal to an inferior oil.
‘The adaptation of M. Mège’s process to the imitation
of other dairy products is a natural sequence to the
success, in a commercial sense, which has attended
the manufacture of artificial butter. The skim-milk
difficulty in the American butter factories has set
their managers to work at the problem of its conversion
into something saleable for some time past. This
difficulty has been increased of late years by the
invention of the cream separator, which deprives the
milk of practically all its cream; but on the large
dairy farms of Denmark, where from 100 to 300 cows are
kept and these separators are used, the skim-milk is
made into skim-cheese, and the working classes in that
country do not object to eat a nutritious article of
diet which they can buy at about fourpence per pound.
But neither the American nor the English labourer, as a
general rule, likes a cheese that is at the same time
exceedingly poor in fat and excessively hard to bite.
‘Obviously the first step was to add fat to the
skim-milk so as to replace the cream which had been
taken off. This, however, was no easy matter, for
neither oleomargarine nor lard would mix with the
skim-milk when directly applied. The imitation cheese
attempted to be made in this way was wretchedly bad;
and, when cut, the added fatty matter was found in
streaks, and to a great extent oozed out in its
original condition. “Lard-cheese,” in fact, soon
became a by-word and a reproach, and it is stated that
last year a large quantity of poor, unsophisticated
cheese was sold under that name, and thus increased its
evil reputation.
‘But the utilisation of the skim-milk still remained a
necessity to the managers of the “creameries,” if they
were to be commercially successful. The question was,
therefore, considered whether it would not be possible
to make an artificial cream which should replace the
natural cream which had been taken off the milk. This
idea was soon put to a practical test, and with most
remarkable results.
‘The process now adopted begins with the manufacture
of artificial cream as follows: A certain quantity of
skim-milk is heated to about 85° Fahr., and one-half
the quantity of either lard, oleomargarine, or olive
oil, as the case may be. These substances are conveyed
through separate pipes into an “emulsion” machine,
which subdivides both materials to a surprising degree,
while it mixes them thoroughly together—the arrangement
insuring that the machine is regularly fed with the due
proportions of the substances which are being used. It
is stated that the artificial cream made with olive oil
in this way is not objected to in the United States for
use in tea and coffee.
‘For the manufacture of imitation cheese, about 4½
per cent. of this imitation cream is added to the
skim-milk. The latter being raised to 85° Fahr., and
the former to 135° Fahr. or upwards, the mixture
attains a temperature of about 90° Fahr. The remainder
of the process is identical with that used in the
manufacture of American Cheddar cheese, except that
a special mechanical agitator is used to insure that
the curd shall be evenly stirred and cooked, so as
to avoid any loss of fat in the whey. Success or
failure in the manufacture of imitation cheese seems
to depend chiefly upon the perfect emulsion of the
skim-milk with the fat in the preliminary process of
making artificial cream. That having been accomplished,
the remaining processes are said to be perfectly easy
and satisfactory. It has been asserted by competent
judges that the best descriptions of oleomargarine
cheese can with difficulty, if at all, be detected from
the ordinary American Cheddar of commerce; but the
imitation product has nevertheless a tendency to become
rapidly mouldy after having been cut.
‘The trade in imitation butter is now something
enormous and increases every year; in the Netherlands
alone there are sixty or seventy factories. Imitation
cheese is only just beginning to appear on the London
market, but there can be little doubt that before long
it will compete successfully with all but the best and
most delicate descriptions of the real article, unless
it is branded so as to show its true character. One
firm alone, in New York State, made 200,000 lbs. of
imitation cheese last year, and their factories are in
full work again this year.’
My first acquaintance with the rational cookery of cheese was in the
autumn of 1842, when I dined with the monks of St. Bernard. Being the
only guest, I was the first to be supplied with soup, and then came
a dish of grated cheese. Being young and bashful, I was ashamed to
display my ignorance by asking what I was to do with the cheese, but
made a bold dash, nevertheless, and sprinkled some of it into my soup.
I then learned that my guess was quite correct; the prior and the monks
did the same.
On walking on to Italy I learned that there such use of cheese is
universal. Minestra without Parmesan would in Italy be regarded as we
in England should regard muffins and crumpets without butter. During
the forty years that have elapsed since my first sojourn in Italy, my
sympathies are continually lacerated when I contemplate the melancholy
spectacle of human beings eating thin soup without any grated cheese.
Not only in soups, but in many other dishes, it is similarly used.
As an example, I may name ‘_Risotto à la Milanese_,’ a delicious,
wholesome, and economical dish—a sort of stew composed of rice and the
giblets of fowls, usually charged about twopence to threepence per
portion at Italian restaurants. This, I suppose, is the reason why I
find no recipe for it in the ‘high-class’ cookery-books. It is always
served with grated Parmesan. The same with the many varieties of paste,
of which macaroni and vermicelli are the best known in this country.
In all these the cheese is sprinkled over, and then stirred into the
soup, &c., while it is hot. The cheese being finely divided is fused
at once, and thus delicately cooked. This is quite different from the
‘macaroni cheese’ commonly prepared in England by depositing macaroni
in a pie-dish, then covering it with a stratum of grated cheese,
and placing this in an oven or before a fire until the cheese is
desiccated, browned, and converted into a horny, caseous form of carbon
that would induce chronic dyspepsia in the stomach of a wild boar if he
fed upon it for a week.
In all preparations of Italian pastes, risottos, purées, &c., the
cheese is intimately mixed throughout, and softened and diffused
thereby in the manner above described.
The Italians themselves imagine that only their own Parmesan cheese
is fit for this purpose, and have infected many Englishmen with the
same idea. Thus it happens that fancy prices are paid in this country
for that particular cheese, which nearly resembles the cheese known in
our midland counties as ‘skim dick’—sold there at about fourpence per
pound, or given by the farmers to their labourers. It is cheese ‘that
has sent its butter to market,’ being made from the skim-milk which
remains in the dairy after the pigs have been fully supplied.
I have used this kind of cheese as a substitute for Parmesan, and I
find it answers the purpose, though it has not the fine flavour of the
best qualities of Parmesan. The only fault of our ordinary whole-milk
English and American cheeses is that they are too rich, and cannot be
so finely grated on account of their more unctuous structure, due to
the cream they contain.
I note that in the recipes of high-class cookery-books, where Parmesan
is prescribed, cream is commonly added. Sensible English cooks, who use
Cheshire, Cheddar, or good American cheese, are practically including
the Parmesan and the cream in natural combination. By allowing these
cheeses to dry, or by setting aside the outer part of the cheese for
the purpose, the difficulty of grating is overcome.
I have now to communicate another result of my cheese-cooking
researches, viz. a new dish—_cheese-porridge_—or, I may say, a new
class of dishes—cheese-porridges. They are not intended for epicures,
who only live to eat, but for men and women who eat in order to live
and work. These combinations of cheese are more especially fitted
for those whose work is muscular, and who work in the open air.
Sedentary brain-workers should use them carefully, lest they suffer
from over-nutrition, which is but a few degrees worse than partial
starvation.
My typical cheese-porridge is ordinary oatmeal-porridge made in the
usual manner, but to which grated cheese, or some of the cheese
solution above described, is added, either while in the cookery-pot
or after it is taken out, and yet as hot as possible. It should be
sprinkled gradually and well stirred in.
Another kind of cheese-porridge or cheese-pudding is made by adding
cheese to _baked_ potatoes—the potatoes to be taken out of their skins
and well mashed while the grated cheese is sprinkled and intermingled.
A little milk may or may not be added, according to taste and
convenience. This is better suited for those whose occupations are
sedentary, potatoes being less nutritious and more easily digested than
oatmeal. They are chiefly composed of starch, which is a heat-giver
or fattener, while the cheese is highly nitrogenous, and supplies the
elements in which the potato is deficient, the two together forming a
fair approach to the theoretically demanded balance of constituents.
I say _baked_ potatoes rather than boiled, and perhaps should explain
my reasons, though in doing so I anticipate what I shall explain more
fully when on the subject of vegetable food.
Raw potatoes contain potash salts which are easily soluble in water.
I find that when the potato is boiled some of the potash comes out
into the water, and thus the vegetable is robbed of a very valuable
constituent. The baked potato contains all its original saline
constituents which, as I have already stated, are specially demanded as
an addition to cheese-food.
Hasty pudding made, as usual, of wheat flour, may be converted from an
insipid to a savoury and highly nutritious porridge by the addition of
cheese in like manner.
The same with boiled rice, whether whole or ground, also sago, tapioca,
and other forms of edible starch. Supposing whole rice is used—and I
think this is the best—the cheese may be sprinkled among the grains of
rice and well stirred or mashed up with them. The addition of a little
brown gravy to this, with or without chicken giblets, gives us an
Italian _risotto_. The Indian-corn stirabout of the poor Irish cottier
would be much improved both in flavour and nutritive value by the
addition of a little grated cheese.
Pease pudding is not improved by cheese. The chemistry of this will
come out when I explain the composition of peas, beans, &c. The same
applies to pea soup.
I might enumerate other methods of cooking cheese by thus adding it in
a finely-divided state to other kinds of food, but if I were to express
my own convictions on the subject I should stir up prejudice by naming
some mixtures which many people would denounce. As an example I may
refer to a dish which I invented more than twenty years ago—viz. fish
and cheese pudding, made by taking the remains from a dish of boiled
codfish, haddock, or other _white_ fish, mashing it with bread-crumbs,
grated cheese, and ketchup, then warming in an oven and serving after
the usual manner of scalloped fish. Any remains of oyster sauce may be
advantageously included.
I find this delicious, but others may not. I frequently add grated
cheese to boiled fish as ordinarily served, and have lately made a fish
sauce by dissolving grated cheese in milk with the aid of a little
bicarbonate of potash, and adding this to ordinary melted butter.
I suggest these cheese mixtures to others with some misgivings as
regards palatability, after learning the revelations of Darwin on the
persistence of heredity. It is quite possible that, being a compound of
the Swiss Mattieu with the Welsh Williams (cheese on both sides), I may
inherit an abnormal fondness for this staple food of the mountaineers.
Be this as it may, so far as the mere palate is concerned; but in the
chemistry of all my advocacy of cheese and its cookery I have full
confidence. Rendered digestible by simple and suitable cookery, and
added with a little potash salt to farinaceous food of all kinds, it
affords exactly what is required to supply a theoretically complete and
a most economical dietary, without the aid of any other kind of animal
food. The potash salts may be advantageously supplied by a liberal
second course of fruit or salad.
One more of my heretical applications of grated cheese must be
specified. It is that of sprinkling it freely over ordinary stewed
tripe, which thus becomes _extraordinary_ stewed tripe. Or a solution
of cheese may be mixed with liquor of the stew. It may not be generally
known that stewed tripe is the most easily digestible of all solid
animal food. This was shown by the experiments of Dr. Beaumont on his
patient, Alexis St. Martin, who was so obliging (from a scientific
point of view) as to discharge a gun in such a manner that it shot away
the front of his own stomach and left there, after the healing of the
wound, a valved window through which, with the aid of a simple optical
contrivance, the work of digestion could be watched. Dr. Beaumont found
that while beef and mutton required three hours for digestion, tripe
was digested in one hour.[14]
I add by way of postscript a recipe for a dish lately invented by my
wife. It is vegetable marrow _au gratin_, prepared by simply boiling
the vegetable as usual, slicing it, placing the slices in a dish,
covering them with grated cheese, and then browning slightly in an oven
or before the fire, as in preparing the well-known ‘cauliflower _au
gratin_.’ I have modified this (with improvement, I believe) by mashing
the boiled marrow and stirring the grated cheese into the midst of it
whilst as hot as possible; or, better still, by adding a little of the
solution of cheese above described to the purée of mashed marrow and
stirring it well in while hot. To please the ladies, and make it look
pretty on the table, a little more grated cheese may be sprinkled on
the top of this and browned in the oven or with a salamander. People
with weak digestive powers should set aside the pretty.
Turnips may be similarly treated as ‘mashed turnips _au gratin_.’
I recommend this especially to my vegetarian friends, who have no
objection to cheese, but do not properly appreciate it.
Taking as I do great interest in their efforts, regarding them as
pioneers of a great and certainly approaching reform, I have frequently
dined at their restaurants (always do so when within reach, as I am
only a flesh-eater for convenience’ sake), and by the experience thus
afforded of their cookery, am convinced that they are losing many
converts by the lack of cheese in many of their most important dishes.
FOOTNOTES:
[11] I am greatly disgusted with the cookery-books, especially the
pretentious volume of Francatelli’s, on being unable to find any recipe
for this delicious Italian dish, and a similar absence of a dozen or
two of equally common and excellent preparations familiar to all who
have dined at the Lepre (Rome), or other good Italian restaurants.
[12] Forty or fifty years ago these cheese _fondus_ were one of the
usual courses at many-course banquets, but now they are rarely found in
the _menu_ of such dinners. There is good reason for this. They are far
too nutritious to be eaten with a dozen other things. Their proper use
is to substitute the joint in an ordinary respectable meal of meat and
pudding.
[13] Before the Adulteration Act was passed, mustard flour was usually
mixed with well-dried wheaten flour, whereby the redundant oil was
absorbed, and the mixture was a dry powder. Now it is different, being
pure powdered mustard seed, and usually rather damp. It not only lies
closer, but is much stronger. Therefore, in following any recipe of old
cookery-books, only about half the stated quantity should be used.
[14] The reader who desires further information on this and kindred
subjects will find it clearly and soundly treated (without any of the
noxious pedantry that too commonly prevails in such treatises) in Dr.
Andrew Combe’s _Physiology of Digestion_, which, although written
by a dying man nearly half a century ago, still remains, like his
_Principles of Physiology_, the best popular work on the subject.
Subsequent editions have been edited and brought up to date by his
nephew, Sir James Coxe.
CHAPTER X.
FAT—MILK.
WE all know that there is a considerable difference between raw fat
and cooked fat; but what is the _rationale_ of this difference? Is it
anything beyond the obvious fusion or semi-fusion of the solid?
These are very natural and simple questions, but in no work on
chemistry or technology can I find any answer to them, or even any
attempt at an answer. I will therefore do the best I can towards
solving the problem in my own way.
All the cookable and eatable fats fall into the class of ‘fixed oils,’
so named by chemists to distinguish them from the ‘volatile oils,’
otherwise described as ‘essential oils.’ The distinction between these
two classes is simple enough. The volatile oils (mostly of vegetable
origin) may be distilled or simply evaporated away like water or
alcohol, and leave no residue. The fixed oils similarly treated are
dissociated more or less completely. This has been already explained in
Chapter VII.
Otherwise expressed, the boiling point of the volatile oils is
below their dissociation point. The fixed oils are those which are
dissociated at a temperature below their boiling point.
My object in thus expressing this difference will be understood upon
a little reflection. The volatile oils, when heated, being distilled
without change are uncookable; while the fixed oils if similarly
heated suffer various degrees of change as their temperature is raised,
and may be completely decomposed by steady application of heat in a
closed vessel without the aid of any other chemical agent than the heat
itself. This ‘destructive distillation’ converts them into solid carbon
and hydro-carbon gases, somewhat similar to those we obtain by the
destructive distillation of coal.
If we watch the changes occurring as the heat advances to this complete
dissociation point we may observe a minor or partial dissociation
proceeding gradually onward, resembling that which I have already
described as occurring when sugar is similarly treated (Chapter VII.
page 87).
But in ordinary cooking we do not go so far as to carbonise the fat
itself, though we do brown or partially carbonise the membrane which
envelopes the fat. What then is the nature of this minor dissociation,
if such occurs?
Before giving my answer to this question I must explain the chemical
constitution of fat. It is a compound of a very weak base with very
weak acids. The basic substance is glycerine, the acids (not sour at
all, but so named because they combine with bases as the actually sour
acids do) are stearic acid, palmitic acid, oleic acid, &c., and bear
the general name of ‘fatty acids.’ They are solid or liquid, according
to temperature. When solid they are pearly crystalline substances, when
fused they are oily liquids.
To simplify, I will take one of these as a type, and that the one which
is the chief constituent of animal fats, viz. stearic acid. I have a
lump of it before me. Newly broken through, it might at a distance
be mistaken for a piece of Carrara marble. It is granular, like the
marble, but not so hard, and, when rubbed with the hand, differs from
the marble in betraying its origin by a small degree of unctuousness,
but it can scarcely be described as greasy.
I find by experiment that this may be mixed with glycerine without
combination taking place, that when heated with glycerine just to its
fusing point, and the two are agitated together, the combination is by
no means complete. Instead of obtaining a soft, smooth fat, I obtain
a granular fat small stearic crystals with glycerine amongst them. It
is a _mixture_ of stearic acid and glycerine, not a chemical compound;
it is stearic acid and glycerine, but not a stearate of glycerine or
glycerine stearate.
A similar separation is what I suppose to occur in the cooking of
animal fat. I find that mutton-fat, beef-fat, or other fat when raw
is perfectly smooth, as tested by rubbing a small quantity, free from
membrane, between the finger and thumb, or by the still more delicate
test of rubbing it between the tip of the tongue and the palate.
But dripping, whether of beef, or mutton, or poultry, is granular,
as anybody who has ever eaten bread and dripping knows well enough,
and the manufacturers of ‘butterine,’ or ‘bosch,’ know too well,
the destruction or prevention of this granulation being one of the
difficulties of their art.
My theory of the cookery of fat is simply that heat, when continued
long enough, or raised sufficiently high, effects an incipient
dissociation of the fatty acids from the glycerine, and thus assists
the digestive organs by presenting the base and the acids in a
condition better fitted (or advanced by one stage) for the new
combinations demanded by assimilation. Some physiologists have lately
asserted that the fat of our food is not assimilated at all—not laid
down again as fat, but is used directly as fuel for the maintenance of
animal heat.
If this is correct, the advantage of the preliminary dissociation is
more decided, for the combustible portion of the fat is its fatty
acids; the glycerine is an impediment to combustion, so much so that
the modern candle-maker removes it, and thereby greatly improves the
combustibility of his candles.
It may be that the glycerine of the fat we eat is assimilated like
sugar, while the fatty acids act directly as fuel. This view may
reconcile some of the conflicting facts (such as the existence of fat
in the carnivora) that stand in the way of the theory of the uses of
fat food above referred to, according to which fat is not fattening,
and those who would ‘Bant’ should eat fat freely to maintain animal
heat, while very abstemious in the consumption of sugar and farinaceous
food.
The difference between tallow and dripping is instructive. Their
origin is the same; both are melted fats—beef or mutton fats—and both
contain the same fatty acids and glycerine, but there is a visible and
tangible difference in their molecular condition. Tallow is smooth and
homogeneous, dripping decidedly granular.
I attribute this difference to the fact that in rendering tallow, the
heat is maintained no longer than is necessary to effect the fusion;
while, in the ordinary production of dripping, the fat is exposed in
the dripping-pan to a long continuance of heat, besides being highly
heated when used in basting. Therefore the dissociation is carried
farther in the case of the dripping, and the result becomes sensible.
I have observed that home-rendered lard, that obtained in English
farmhouses, where the ‘scratchings’ (_i.e._ the membranous parts)
are frizzled, is more granular than the lard we now obtain in such
abundance from Chicago and other wholesale hog regions. I have not
witnessed the lard rendering at Chicago, but have little doubt that
economy of fuel is practised in conducting it, and therefore less
dissociation would be effected than in the domestic retail process.
Some of the early manufacturers of ‘bosch’ purified their fat by
the process recommended and practised by the French Academicians
MM. Dubrunfaut and Fua (see page 102). I wrote about it in 1871,
and consequently received some samples of artificial butter thus
made in the Midlands. It was pure fat, perfectly wholesome, but,
although coloured to imitate butter, had the granular character
of dripping. Since that time great progress has been made in this
branch of industry. I have lately tasted samples of pure ‘bosch’ or
‘oleomargarine’ undistinguishable from churned cream or good butter,
though offered for sale at 8½_d._ per lb. in wholesale packages. In
the preparation of this the high temperatures of the process of the
Academicians are carefully avoided, and the smoothness of pure butter
is obtained. I mention this now merely in confirmation of my theory of
the _rationale_ of fat cookery, but shall return to this subject of
‘bosch’ or butterine again, as it has considerable intrinsic interest
in reference to our food supplies, and should be better understood than
it is.
If this theory of fat cookery and the preceding theoretical
explanations of the cookery of gelatin and fibrin are correct, a
broad practical deduction follows, viz. that in the cookery of fat
the full temperature of 212° or even a much higher temperature does
no mischief, or may be desirable, while all the other constituents of
meat are better cooked at a temperature not exceeding 212°; the albumen
especially at a considerably lower temperature.
There is neither coagulation nor dehydration to be feared as regards
the fat, unless the heat is raised to that of the dissociation of the
fixed oils, which, as already explained, is much above 212°; the change
which then takes place in the fat (analogous to that caramelising
sugar) is not dehydration properly so called, although the _elements_
of water or hydrogen may be driven off.
Hydration is a combining of water _as water_, not with the elements of
water as elements, and the water of most hydrates becomes dissociated
at a temperature a little above the boiling point of water.
My own experiments on gelatin show that hydration occurs when crude
gelatin is exposed to the action of water at or below the boiling
point, and that dehydration takes place at and above the boiling point,
or otherwise stated, the boiling point is the critical temperature
where either hydration or dehydration may occur according to the
circumstances.
The original membrane _immersed in water_ at 212° becomes hydrated,
while hydrated gelatin heated to 212° and exposed to the air is
dehydrated. Fat is only dissociated as regards its glycerine, and is
cooked thereby.
The dietetic value of milk is obvious enough from the fact that the
young of the human species and all the mammalia, whether carnivorous,
graminivorous, or herbivorous, are entirely fed upon it during the
period of their most rapid growth. This, however, does not justify
the practice of describing milk as a model diet and tabulating its
composition as that which should represent the composition of food
for adults. The fallacy of this is evident from the fact that grass
is the model food of the cow, and milk that of the calf. Although the
grass contains all the constituents of the milk, their proportions are
widely different; besides this the grass contains a very great deal of
material that does not exist in milk—silica for example.
The constituents of milk are first water, constituting from 65 to
90 per cent. Nitrogenous matter, consisting of the casein above
described and a little albumen. Fat, sugar, and saline substances. The
proportions of these vary so greatly in the milk from different animals
of the same species, and in that from the same animal at different
times that tabular statements of the percentage composition of the milk
of different animals are very variable. I have five such tables before
me, assembled for the purpose of supplying material for my readers, but
they are so contradictory, though all by good chemists, that I am at a
loss in making a choice. The following is Dr. Miller’s statement of the
mean result of several analyses:
+------------------------+-------+------+------+------+-------+-------+
| | Woman | Cow | Goat | Ass | Sheep | Bitch |
+------------------------+-------+------+------+------+-------+-------+
| Water | 88·6 | 87·4 | 82·0 | 90·5 | 85·6 | 66·3 |
| Fat | 2·6 | 4·0 | 4·5 | 1·4 | 4·5 | 14·8 |
| Sugar and soluble salts| 4·9 | 5·0 | 4·5 | 6·4 | 4·2 | 2·9 |
| Nitrogenous compounds }| | | | | | |
| and insoluble salts }| 3·9 | 3·6 | 9·0 | 1·7 | 5·7 | 16·0 |
+------------------------+-------+------+------+------+-------+-------+
The fat exists in the form of minute globules of oil suspended in the
water. The rising of these to the surface forms the cream. When the
milk is new it is slightly alkaline, and this assists in the admixture
of the oil with the water, forming an emulsion which may be imitated by
whipping olive or other similar oil in water. If the water is slightly
alkaline the milky-looking emulsion is more easily obtained than in
neutral water, still more so than when there is acid in the water.
As milk becomes older lactic acid is formed; at first alkalinity is
exchanged for neutrality, and afterwards the milk becomes acid. This
assists in the separation of the cream.
Butter is merely the oil globules aggregated by agitation or churning.
The condition of the casein has been already described. The sugar of
milk or ‘lactine’ is much less sweet than cane sugar.
The cookery of milk is very simple, but by no means unimportant. That
there is an appreciable difference between raw and boiled milk may be
proved by taking equal quantities of each (the boiled sample having
been allowed to cool down), adding them to equal quantities of the
same infusion of coffee, then critically tasting the mixtures. The
difference is sufficient to have long since established the practice
among all skilful cooks of scrupulously using boiled milk for making
_café au lait_. I have tried a similar experiment on tea, and find that
in this case the cold milk is preferable. Why this should be—why boiled
milk should be better for coffee and raw milk for tea—I cannot tell.
If any of my readers have not done so already, let them try similar
experiments with condensed milk, and I have no doubt that the verdict
of the majority will be that it is passable with coffee, but very
objectionable in tea. This is milk that has been very much cooked.
The chief definable alteration effected by the boiling of milk is
the coagulation of the small quantity of albumen which it contains.
This rises as it becomes solidified, carrying with it some of the
fat globules of the milk, and a little of its sugar and saline
constituents, thus forming a skin-like scum on the surface, which may
be lifted with a spoon and eaten, as it is perfectly wholesome, and
very nutritious.
If all the milk that is poured into London every morning were to flow
down a single channel, it would form a respectable little rivulet.
An interesting example of the self-adjusting operation of demand and
supply is presented by the fact that, without any special legislation
or any dictating official, the quantity required should thus flow with
so little excess that, in spite of its perishable qualities, little or
none is spoiled by souring; and yet at any moment anybody may buy a
pennyworth within two or three hundred yards of any part of the great
metropolis. There is no record of any single day on which the supply
has failed, or even been sensibly deficient.
This is effected by drawing the supplies from a great number of
independent sources, which are not likely to be simultaneously
disturbed in the same direction. Coupled with this advantage is a
serious danger. It has been demonstrated that certain microbia (minute
living abominations), which are said to disseminate malignant diseases,
may live in milk, feed upon it, increase and multiply therein, and by
it be transmitted to human beings with possibly serious and even fatal
results.
This general germ theory of disease has been recently questioned by
some men whose conclusions demand respect. Dr. B. W. Richardson stoutly
opposes it, and in the particular instance of the ‘comma-shaped’
bacillus, so firmly described as the origin of cholera, the refutation
is apparently complete.
The alternative hypothesis is that the class of diseases in question
are caused by a _chemical_ poison, not necessarily organised as a plant
or animal, and therefore not to be found by the microscope.
I speak the more feelingly on this subject, having very recently had
painful experience of it. One of my sons went for a holiday to a
farm-house in Shropshire, where many happy and health-giving holidays
have been spent by all the members of my family. At the end of two or
three weeks he was attacked by scarlet fever, and suffered severely. He
afterwards learned that the cowboy had been ill, and further inquiry
proved that his illness was scarlet fever, though not acknowledged to
be such; that he had milked before the scaling of the skin that follows
the eruption could have been completed, and it was therefore most
probable that some of the scales from his hands fell into the milk.
My son drank freely of uncooked milk, the other inmates of the farm
drinking home-brewed beer, and only taking milk in tea or coffee hot
enough to destroy the vitality of fever germs. He alone suffered. This
infection was the more remarkable, inasmuch as a few months previously
he had been assisting a medical man in a crowded part of London where
scarlet fever was prevalent, and had come into frequent contact with
patients in different stages of the disease without suffering infection.
Had the milk from this farm been sent to London in the usual manner
in cans, and the contents of these particular cans mixed with those
of the rest received by the vendor, the whole of his stock might have
been infected. As some thousands of farms contribute to the supplying
of London with milk, the risk of such contact with infected hands
occurring occasionally in one or another of them is very great, and
fully justifies me in urgently recommending the manager of every
household to strictly enforce the boiling of every drop of milk that
enters the house. At the temperature of 212° the vitality of all
_dangerous_ germs is destroyed, and the boiling point of milk is a
little above 212°. The temperature of tea or coffee, as ordinarily
used, may do it, but is not to be relied upon. I need only refer
generally to the cases of wholesale infection that have recently been
traced to the milk of particular dairies, as the particulars are
familiar to all who read the newspapers.
The necessity for boiling remains the same, whether we accept the
germ theory or that of chemical poison, as such poison must be of
organic origin, and, like other similar organic compounds, subject to
dissociation or other alteration when heated to the boiling point of
water.
It is an open question whether butter may or may not act as a
dangerous carrier of such germs; whether they rise with the cream,
survive the churning, and flourish among the fat. The subject is of
vital importance, and yet, in spite of the research fund of the Royal
Society, the British Association, &c., we have no data upon which to
base even an approximately sound conclusion.
We may theorise, of course; we may suppose that the bacteria, bacilli,
&c., which we see under the microscope to be continually wriggling
about or driving along are doing so in order to obtain fresh food from
the surrounding liquid, and therefore that if imprisoned in butter
they would languish and die. We may point to the analogies of ferment
germs which demand nitrogenous matter, and therefore suppose that the
pestiferous wanderers cannot live upon a mere hydro-carbon like butter.
On the other hand, we know that the germs of such things can remain
dormant under conditions that are fatal to their parents, and develop
forthwith when released and brought into new surroundings. These
speculations are interesting enough, but in such a matter of life and
death to ourselves and our children we require positive facts—direct
microscopic or chemical evidence.
In the meantime the doubt is highly favourable to ‘bosch.’ To
illustrate this, let us suppose the case of a cow grazing on a
sewage-farm, manured from a district on which enteric fever has
existed. The cow lies down, and its teats are soiled with liquid
containing the chemical poison or the germs which are so fearfully
malignant when taken internally. In the course of milking a thousandth
part of a grain of the infected matter containing a few hundred germs
enters the milk, and these germs increase and multiply. The cream that
rises carries some of them with it, and they are thus in the butter,
either dead or alive—we know not which, but have to accept the risk.
Now, take the case of ‘bosch.’ The cow is slaughtered. The waste
fat—that before the days of palm oil and vaseline was sold for
lubricating machinery—is skilfully prepared, made up into 2 lb. rolls,
delicately wrapped in special muslin, or prettily moulded and fitted
into ‘Normandy’ baskets. What is the risk in eating this?
None at all provided always the ‘bosch’ is not adulterated with
cream-butter. The special disease germs do not survive the chemistry of
digestion, do not pass through the glandular tissues of the follicles
that secrete the living fat, and therefore, even though the cow should
have fed on sewage grass, moistened with infected sewage water, its fat
would not be poisoned.
What we require in connection with this is commercial honesty: that
the thousands of tons of ‘bosch’ now annually made shall be sold as
‘bosch,’ or, if preferred, as ‘oleomargarine,’ or ‘butterine,’ or
any other name that shall tell the truth. In order to render such
commercial honesty possible to shopkeepers, more intelligence is
demanded among their customers. A dealer, on whom I can rely, told
me lately that if he offered the ‘bosch’ or ‘butterine’ to his other
customers as he was then offering it to me, at 8½_d._ per lb. in
24-lb. box, or 9_d._ retail, he could not possibly sell it, and his
reputation would be injured by admitting that he kept it; but that the
same people who would be disgusted with it at 9_d._ will buy it freely
at double the price as prime Devonshire fresh butter; and, he added,
significantly, ‘I cannot afford to lose my business and be ruined
because my customers are fools.’ To pastrycooks and others in business
it is sold honestly enough for what it is, and used instead of butter.
In the ‘Journal of the Chemical Society’ for January 1844, page 92, is
an account of experiments made by A. Mayer in order to determine the
comparative nutritive value of ‘bosch’ and cream-butter. They were made
on a man and a boy. The result was that on an average a little above 1½
per cent. less of the ‘bosch’ was absorbed into the system than of the
cream-butter. This is a very trifling difference.
Before leaving the subject of animal food I may say a few words on
the latest, and perhaps the greatest, triumph of science in reference
to food supply—_i.e._ the successful solution of the great problem of
preserving fresh meat for an almost indefinite length of time. It has
long been known that meat which is frozen remains fresh. The Aberdeen
whalers were in the habit of feasting their friends on returning home
on joints that were taken out fresh from Aberdeen, and kept frozen
during a long Arctic voyage. In Norway game is shot at the end of
autumn, and kept in a frozen state for consumption during the whole
winter and far into the spring.
The early attempts to apply the freezing process for the carriage of
fresh meat from South America and Australia by using ice, or freezing
mixtures of ice and salt, failed, but now all the difficulties are
overcome by a simple application of the great principle of the
conservation of energy, whereby the burning of coal may be made to
produce a degree of cold proportionate to the amount of heat it gives
out in burning.
Carcasses of sheep are thereby frozen to stony hardness immediately
they are slaughtered in New Zealand and Australia, then packed in close
refrigerated cars, carried to the ship, and there stowed in chambers
refrigerated by the same means, and thus brought to England in the same
state of stony hardness as that originally produced. I dined to-day
on one of the legs of a sheep that I bought a week ago, and which
was grazing at the Antipodes three months before. I prefer it to any
English mutton ordinarily obtainable.
The grounds of this preference will be understood when I explain that
English farmers, who manufacture mutton as a primary product, kill
their sheep as soon as they are full grown, when a year old or less.
They cannot afford to feed a sheep for two years longer merely to
improve its flavour without adding to its weight. Country gentlemen,
who do not care for expense, occasionally regale their friends on a
haunch or saddle of three-year-old mutton, as a rare and costly luxury.
The Antipodean graziers are wool growers. Until lately mutton was
merely used as manure, and even now it is but a secondary product. The
wool crop improves year by year until the sheep is three or four years
old; therefore it is not slaughtered until this age is attained; and
thus the sheep sent to England are similar to those of the country
squire, and such as the English farmer could not send to market under
eighteenpence per pound.
There is, however, one drawback; but I have tested it thoroughly
(having supplied my own table during the last six months with no other
mutton than that from New Zealand), and find it so trifling as to
be imperceptible unless critically looked for. It is simply that, in
thawing, a small quantity of the juice of the meat oozes out. This is
more than compensated by the superior richness and fulness of flavour
of the meat itself, which is much darker in colour than young mutton.
Legs of frozen mutton should be hung with the thick cut part upwards.
With this precaution the loss of juice is but nominal. If the frozen
sheep is not cut up until completely thawed and required for cooking
there is no loss.
Another successful method of meat-preserving has been more lately
introduced. It is based upon the remarkable antiseptic properties of
boric acid (or boracic acid as it is sometimes named); this is the
characteristic constituent of borax, and, like the fatty acids above
described, has no sour flavour.
The speciality of this process, invented by Mr. Jones, a
Gloucestershire surgeon, is the method by which a small quantity of the
antiseptic is made to permeate the whole of the carcass.
The animal is rendered insensible, either by a stunning blow or by an
anæsthetic, with the heart still beating. A vein—usually the jugular—is
opened, and a small quantity of blood let out. Then a corresponding
quantity of a solution of boric acid, raised to blood heat, is made
to flow into the vein from a vessel raised to a suitable height above
it. The action of the heart carries this through all the capillary
vessels into every part of the body of the animal. The completeness
of this diffusion may be understood by reflecting on the fact that we
cannot puncture any part of the body with the point of a needle without
drawing blood from some of these vessels.
After the completion of this circulation the animal is bled to death in
the usual manner. From three to four ounces of boric acid is sufficient
for a sheep of average weight, and much of this comes away with the
final bleeding. On April 2, 1884, I made a hearty meal on the roasted,
boiled, and stewed flesh of a sheep that was killed on February 8,
the carcass hanging in the meantime in the basement of the Society of
Arts. It was perfectly fresh, and without any perceptible flavour of
the boric acid: very tender, and full-flavoured as fresh meat. On July
19, 1884, I purchased a haunch of the prepared mutton, and hung it
in an ill-constructed larder during the excessively hot weather that
followed. On August 10, after twenty-two days of this severe ordeal,
it was still in good condition. The 11th and 12th were two of the
hottest days of the present century in England. On the 13th I examined
the haunch very carefully, and detected symptoms of giving way. It had
become softer, and was pervaded throughout with a slight malodour. On
the 14th it became worse, and then I had it roasted. It was decidedly
gamey; the fat, or rather the membranous junction between fat and
lean, and the membranous sheaths of the muscles had succumbed, but the
substance of the muscles, the firm lean parts of the meat, were quite
eatable, and eaten by myself and other members of my family. There was
no taste of boric acid, and the meat was unusually tender.
The curious element of this process is the very small quantity of the
boric acid which does the work so effectually.
For some time past most of the milk that is supplied to London has been
similarly treated by adding borax or a preparation chiefly composed of
borax, and named ‘glacialine.’ This suppresses the incipient lactic
fermentation, which, in the course of a few hours, otherwise produces
the souring of milk, and thus prepared the milk remains for a long time
unaltered.
The small quantity of borax that we thus imbibe with our tea, coffee,
&c., is quite harmless. M. de Cyon, who has studied this subject
experimentally, affirms that it is very beneficial.