to sugar-coated almonds and is derived from the name of a cook in the
employ of Marshal du Plessis, which was Pralins. This “chef” belonged
to the age of Louis XIV. and was the first to make these sweetmeats.
But now the term is applied to sweetmeats of various forms, soft
fruit-sugar, marmalade, cream, nut-paste etc. respectively enveloped
in chocolate. The special formulae employed in the preparation of
different kinds of pralinés are comprised in the confectioner’s art,
and do not need to be dealt with here.
The substances themselves are called fondants. Formerly the sugar was
boiled, placed upon a slab, and there manipulated with a spatula, an
operation difficult to manage, indeed almost impossible in the last
stages. In consequence of the increased demand for such preparations,
machines were introduced several years ago whereby the operation is
mechanically performed. Such a machine is shown in fig. 70.
[Illustration: Fig. 70.]
The bed-plate as well as all the working parts of the machine are
constructed of stout copper. The working parts admit of being raised
or lowered by means of the hand-wheel above, and they remain fixed
whilst the bed-plate turns and its underside is played upon by water.
The machine is capable of working up pure fondant without any syrup
addition, as well as that made up with syrup. The boiled sugar is
poured on the bed-plate of the fondant machine, cooled down from 10-20
minutes according to the syrup content, and to such an extent that the
machine can be set in motion, whilst the working parts are gradually
lowered to the previously mentioned bed-plate. The sugar poured out
is then cooled by means of the action of a ventilator fitted on a
crossbeam, occurring in the middle of the wooden cooler, and working
in conjunction with the ventilator, in consequence whereof a cooling
current of air is brought to strike the hot sugar centrally.—When pure
sugar is used, the fondant is finished within six minutes, but in the
case of a syrup addition the time required is lengthened.
[Illustration: Fig. 71.]
A quite recent type of fondant machine is given in fig. 71. It achieves
its end by employing an air-current and a cylinder with screw, which is
provided with water cooling apparatus. The _modus operandi_ presents
many and obvious advantages, chief among which is the possibility of
conducting new material to the machine uninterruptedly, and further the
preservation of the flavour of the chocolate worked up. The result is
a production of first-class quality in respect to taste and flavour,
which is quite ready to be passed on to the next processes.
[Illustration: Fig. 72.]
The fondant is then diluted with colouring matter in boiling pans,
and so prepared for subsequent treatment. The figures which have to
be poured in are then transferred to gypsum moulds, lined with starch
powder, and the fondant sugar is in its turn poured over these either
by means of pans held in the hand or such as are machine-driven.
Hand-pouring postulates a considerable amount of skill on the part of
the man in charge, especially when even weights of the separate pieces
are required. We annex an illustration of a motor-driven depositing
machine (fig. 72).
The sugar is here introduced into receivers heated by means of a
water-bath. The receiving boxes are moved under the outflow one
after another, after having been dusted with powder and filled with
chocolate, whilst the adjustment of the weight of each separate piece
is effected by the operation of a very ingenious mechanism, even from
0-8 grammes.
[Illustration: Fig. 73.]
After a stay of several hours in the drying room, the molten figures
are so hard that they can be raised out of the powder with the aid of
a shovel. Fig. 73 shows such a machine, whilst Fig. 74 illustrates a
machine where the work goes on unbrokenly, and from which the chocolate
figures are removed with a shovel.
The sweetmeats are next dipped into liquified chocolate (covering
stuff) to coat them with a layer of that material. The mass employed
for this purpose must contain up to 15 % more butter than that used
for ordinary chocolate, so that it may be kept soft long enough for
continuous working.[121] This is performed in the machine fig. 75. On
a bed-plate coming into contact with steam or cold water, as required,
occur rake-like stirrers, and a small ventilator introduced above
assists in cooling off the material. For the purpose of discharging,
there is an outlet on the rim of the pan. For storage of the tempered
coverings and also for occasional alleviations with cacao butter, a
machine illustrated in fig. 76 is utilised.
[Illustration: Fig. 74.]
[Illustration: Fig. 75.]
[Illustration: Fig. 76.]
The dipping of pralinés for the purpose of coating them was formerly
carried out by means of a fork, the nucleus masses being dropped into
the coating material, taken out with a fork, and placed upon metal
plates. Various kinds of ornamentation were designed by the same
instrument. In the preparation of the higher priced coated fondants,
a similar method of procedure is still in vogue, although such
manipulation presupposes a high degree of skill on the part of the
mechanics are at the machine. For articles of more general consumption,
whether ornamented or not, machines have been introduced for the
purpose by divers manufacturers, some of which function excellently.
Two of that kind which in every way respond to the calls made on them
are here described, but we shall not waste time and labour over the
more complicated and expensive machines.
[Illustration: Fig. 77.]
[Illustration: Fig. 78.]
The first method of coating fondants, patented by A. Reiche of
Dresden-Plauen, is not based on mechanical principles, but rather
relies on a series of small appliances, represented in fig. 77. The
jacketed casing _a_, fig. 77 contains water, and into it the pan
containing coating material can be placed: that is kept in a liquid
condition by heating the water in the jacket by spirit lamps or gas
jets underneath. The adjoining vessel _b_ is closed on all sides,
filled with water, and also kept warm in the same manner; it serves
for the preparatory warming of the objects to be coated, which are
spread upon a wire network, and for that purpose two of these wire
frames can be hung upon the hooks inside the box. The mass dropping
from the wire frame is conveyed into the covering box _a_, by means
of a sheet of metal placed above it; _c_ serves as an apparatus for
turning, and we give it on a larger scale in fig. 78.
[Illustration: Fig. 79.]
The tracings _h_ and _i_ in fig. 79 show the cross section and top view
of the wire gratings, on which cylindrical and ball-shaped sugar goods
are deposited. The other two kinds of grating are illustrated at _L_
and _M_ (fig. 80).
The size of the meshes of the sieve gratings depends on that of the
centres to be coated.
The method of covering is as follows:
The centres for the pralinés etc. are placed in the cavities of the
gratings, and, as soon as one of the gratings is full, the latter is
covered up by the fine-meshed grating the half of the cross-section of
which is shown in Fig. 79 and the full view in Fig. 80 (see K and N
respectively), K representing the cover-grating.
Both gratings are held simultaneously by the operator at their handles
and then dipped together in the liquid covering contained in the vessel
a, Fig. 77, after which the superfluous covering mass is removed by
knocking. The gratings are now deposited on the mechanism C, Figs.
77 or 78, as the case may be, the top sieve removed and a sheet of
paper or a metal plate put in its place. It is then turned by hand to
the opposite side, the grating with the impressions is removed and
the cover centres are found lying in regular order, and at regular
distances apart, on the metal plate. The object of the intervals
between the covered centres is to prevent the running together of the
latter.
[Illustration: Fig. 80.]
Beans and rings are only dipped up to the middle, and the process
repeated with the other half of the centre after the first half has
cooled. This ensures a pleasing, round appearance, and has further
the advantage that the cover grating need not be put on during the
operation. When dipping cylindrical or ball-shaped centres, the grating
K which has first been removed on dipping, is at once transferred to
the heater, to prevent it cooling and withdrawing too much warmth from
the covering material at the next immersion.
The dipping of pralinés etc. is exceedingly easy if the new type of
dipping machine is used, a full view of which is given in Fig. 81
and which has the highly appreciable advantage of simultaneously
cooling the dipped centres. All the parts are, in the main, worked
by hand, only the shaking and stirring contrivances and the cooling
fan requiring to be driven by motor power. The middle piece carries
the actual dipping apparatus, underneath which the tank holding the
covering chocolate is fixed, while the lefthand sidepiece serves for
feeding; as many as four operators can be engaged simultaneously at
the latter, the work consisting of laying the centres in the gratings
corresponding to the mouldings desired. The construction of these
gratings is, in the main, similar to the stamped trays of Anton Reiche,
but they are not provided with handles and are despatched along the
guide-rails by hand. The filled grating is then placed in a frame,
which is dipped by means of a winch into the liquid chocolate. The top
grating on the dipping frame is adjustable, and the object of this
grating is to keep the centres down, as without this arrangement some
of the centres might rise to the surface of the covering. The top
grating is, before commencing to dip, pushed over the filled grating
with the centres and is thus immersed with them. The frame having been
removed, the shaker is put in action to remove the superfluous material
from both the gratings and the centres. The grating is drawn out
after use from below the top grating and transferred to a book-shaped
ejector, on one side of which is a metal sheet covered with paper. The
whole of the centres are then discharged on to the sheet, by reversing
the two flap-sections.
The sheet containing the covered centres is then transferred to the
cooling apparatus at the right, in which it is gradually lowered on a
“paternoster” apparatus by turning round a handle. It is then conducted
to the left by an endless band, and finally discharged in a cooled
state by the machine. The ventilator should be supplied with air from
the cellars and is arranged to blow it out in the opposite direction to
the goods in the cooling apparatus.
[Illustration: Fig. 81.]
The shape of the design-gratings is reproduced in high relief on the
goods, and it will therefore be readily understood that further designs
or fancy shapes can be made on the gratings. For the production of
semi-dipped goods or such as are dipped round and remain uncovered at
the bottom, a device is attached to the striking gear which renders
it possible to regulate the depth of each immersion at will. The tank
containing the covering material is surrounded by a water-jacket,
which is heated by steam. The heat of the water is indicated by a
thermometer. The receptacle containing the covering can easily be drawn
out towards the front. In addition to this, the whole of the outside
of the machine, which also constitutes a complete water-jacket, is
heated by steam, and finally the ejector. The gratings containing the
impressions are taken out of the ejector after use and transferred to
the feeding side to be used again, so that, at the very most, four
gratings are required for each design.
The daily output of the machine is 300-600 kilos, and the size of the
gratings 280 by 400 millimetres, the output naturally depending on
whether the machine is operated by two, three or more persons.
B. The Manufacture of Cocoa Powder and “Soluble” Cocoa.
a. The various methods of disintegrating or opening up the tissues of
cacao.
The comparatively high fat content of pure cacao, which would deter
certain persons, especially those suffering from stomach disorders,
from taking it, has given rise to the now extensive demand for a cacao
preparation containing a less amount of fat and the constituents of
which are capable of being easily assimilated in the human organism. At
the same time the desire to obtain a cacao preparation easily capable
of complete and uniform suspension in milk or water may have played
its part, as this quality, in consequence of which the preparation can
rapidly and without difficulty be rendered ready for consumption, is
obviously a great advantage. The best way to obtain this appeared to
be the pulverisation of the cacao, which, when reduced to a powder,
more readily satisfies the above conditions. As, however, it was not
possible to pulverise cacao which still contained its full amount of
natural fat, it became necessary to devote attention to the operation
of extracting the cacao butter. It is many years since the first
appearance of certain preparations in Germany which went under the name
of “Cacogna”, and which had been deprived of their fat to the extent
of 20-25 %. This problem, however, was recognised and attempts and all
manner of experiments made to solve it at a much earlier period in
Holland. The founder of the well-known Dutch firm of J. C. van Houten
& Sons in Weesp, Mr. C. J. van Houten, was the first to attempt the
expression of the fat from cacao (1828) and to treat it with chemical
agents with a view to opening up or bringing about the disintegration
of the tissues, in order to render the cacao a fit and welcome article
of food, not only for healthy persons, but also for invalids and
convalescent persons.
It was not until the Dutch cocoa thus manufactured had been introduced
into England and Germany, where, as well as in Holland, it became very
popular, that manufacturers in Germany and Switzerland began to devote
their attention to the treatment with chemical agents. The consumption
of so-called “soluble” cocoa has increased to such an extent of late
years that it is now almost as large as that of chocolate goods.
The term “soluble”, as now generally applied to cocoa powders, is
undoubtedly a misnomer, inasmuch as such preparations are practically
not soluble at all. We have therefore termed cocoa for drinking
purposes in this book “disintegrated” cacao, as the processes described
in the following pages only render the elements of cacao, as, for
instance, the cellulose, capable of suspension in liquids. It would be
quite impossible to render cacao, by any special treatment, soluble
in the real sense of the term, as is the case with salt or sugar. It
will thus be readily understood that the expression “disintegrated” is
correcter and more logical than the term “soluble The degree to which
disintegration has been carried, i. e. the efficiency of the opening-up
processes adopted, is marked by the absence of any sediment worth
speaking of in the beverage prepared with boiling water, even after it
has been left standing some time. The greater the power of suspension
of the preparation, the less particles of cacao will settle to the
bottom, and the higher the beverage will be esteemed.
The disintegrating agents are, in practice, applied either to the raw
or roasted, but otherwise untreated beans, or to the more or less
defatted cacao, as follows:
a) by treating the cacao with hot water, without or under pressure;
b) by treatment with alkalis, such as carbonate of kali or
sodium, carbonate of magnesia (Dutch method), spirits of ammonia
(sal-ammoniac) and carbonate of ammonia (German method).
The chemical and physical effects brought about by these agents consist
chiefly in the swelling or steeping of the cellulose by the action
of the alkalis, as a consequence of which they sink less rapidly in
liquids than would be the case with untreated cacao. A further effect
is the partial neutralisation of the acids present, besides which the
cacao-red or pigment is also attacked, a result which may be regarded
as less desirable, as the cacao-red is the secreter of the aroma, which
naturally suffers with it. If the cacao is treated with steam or hot
water, the starch is apt to gelatinise, and the acids to begin to
ferment.
As the treatment with steam, for the reasons given above, is nowadays
rarely practised, we will at once proceed to consider the method of
disintegrating cacao most in use. Modifications of the methods of
manufacture bearing on this point will be dealt with in their place
under the corresponding heading later in this book.
b. Methods of Disintegration.
1. ~Preliminary Treatment of the Beans.~
The method of manufacture of disintegrated cocoa comprises the
following operations:
a) The cleaning and sorting of the raw bean;
b) Roasting;
c) Shelling, breaking and grinding;
d) Treatment with alkalis or water;
e) Expression of the fat or cacao butter;
f) Pulverising.
The order of the above processes is subject under certain conditions
to various modifications arising from the fact that the alkalis are
applied at various stages in the course of manufacture, i. e.:
I. before roasting;
II. during roasting;
III. after roasting,
and further
a) before pressing;
b) after pressing (treatment of the defatted beans).
The cleaning and sorting of the raw beans, or, in short, the complete
treatment to which the raw cacao is subjected (a to c) is in all
methods effected by the same machines, a description of which has been
given on pages [Transcriber’s Note: Rest of line missing]
Some manufacturers proceed at once to treat the cacao with alkali on
completion of the above operations.
C. Stähle[122] effects the disintegration of cacao by subjecting the
beans to the chemical action of a mixture of ammonia and steam, at a
temperature not exceeding 100 Deg. C. The next process (roasting) is
then supposed to draw out the ammonia introduced into the material,
which, being volatile, easily escapes, and enables the flavour to
develop.
Pieper[123] moistens the raw beans with water, to which alkali has
been added, and this has the effect of neutralising the acids present
in the bean; afterwards the beans are fermented, dried and roasted.
The fermentation is described as rendering the particles of albumin or
protein bodies easily digestible and further imparts to the beans a
fine, reddish brown colour. This process is therefore nothing but an
after-fermentation of the cacao under the influence of alkalis. From a
scientific point of view, the process does not possess the advantages
which Pieper claims for it, with the exception of the really evident
improvement in colour. This effect can, however, be obtained equally
well by suitable treatment with water alone.
G. Wendt[124] has patented a method of improving the colour and
facilitating the disintegration of cacao, in which the beans are
treated, before roasting, with lime water and milk of lime (lime
solutions) and further washed with the solution during roasting.
We now turn to the methods of disintegration by means of fixed alkalis
(carbonate of magnesia, potash and sodium) first employed by the Dutch,
concerning which the following description will be useful.
The cleaned beans are first very superficially roasted, to facilitate
winnowing, and the cacao thus treated (half roasted cacao) broken
as small as possible, which is an equally important factor in the
shelling and winnowing processes. It should be observed here that the
less the cacao has been roasted, the finer it should be broken. The
material is then impregnated by one of the above-mentioned alkaline
solutions, which is sprayed on to the beans. The chief agent employed
is potash (carbonate of potassium) in the proportion of 1½-2 (3 at
the outside) parts of potash to 20-30 parts of water, for every hundred
parts of the defatted material to be treated. Some manufacturers use
sodium or a mixture of sodium and carbonate of magnesia in place of
the potash. As soon as the cacao has been uniformly impregnated by the
alkaline solution, the roasting process should be completed. Still more
care should be devoted to the roasting of cacao for pulverising than is
required in the case of eating chocolates, as taste and smell play a
more important part and the point of complete roasting is not so easily
recognised. The cacao being roughly broken and the shells removed, the
second roasting process must of course be conducted over a low fire.
The most suitable machines for this purpose are the large roasting
machines illustrated on page 93, Fig. 14, as in these machines there
is little possibility of over-roasting, even when dealing with large
quantities and the machine is intensely heated; another advantage is
the easy accessibility of the roasting drum, which can be immediately
exposed by removing the front cover, for cleaning; cleaning is very
necessary in roasting machines. Broken and moistened cacao chars
much more readily than raw beans which have not been deprived of
their shells. If it is not possible to thoroughly clean the interior
of the roasting drum, as is often the case with spherical roasters,
the particles of cacao remaining in the drum continually undergo
re-roasting, finally falling in a completely charred state into the
cacao, thereby greatly prejudicing its taste.
If necessary, the cacao can now be passed through the breaking machine
again, from which it is transferred to the triple cacao mill, which
provides for fine grinding. The material is then deposited in heated
pans (see page 117, Fig. 27) where it remains until ready for the next
process, the expression of the fat. The object of the fine grinding
in the mill is to render the cacao on being ground again after the
defatting process, easily capable of being sifted, and to obtain a
preparation which, on being mixed with hot water, leaves as little
sediment as possible.
2. ~Expression of the Fat.~
Hydraulic presses are nowadays exclusively used for this most important
operation in the manufacture of “soluble” cocoa. The methods of
pressing have, in common with the other operations in the course of
manufacture, undergone considerable modification and improvement.
According to Macquer (see Mitscherlich, S. 58) the butter was
extracted during the last century by pulverising the seeds, boiling
them in water and cleansing the fat, which, on cooling, congealed on
the surface of the water, by re-melting. According to Desprez (see
Mitscherlich, S. 58), burned, shelled and finely pulverised beans were
spread to a height of 12-15 inches on coarse linen or canvas, which
was spanned across a vessel containing boiling water, to expose the
fine powder thoroughly to the action of the hot vapour. The powder
was then pressed, in linen bags, between two tin plates, whereby some
50% of pure cacao butter was obtained. At a later period the heatable
hydraulic pot-presses came into use. The mass had, however, to be
introduced into these pots tied up in a cloth or sack, to facilitate
which it was previously treated with water, forming a thickish syrup
very convenient for pressing. All these methods, however, were
attended with the great disadvantage that the cocoa, after being
stored some time, acquired a grey colour, or became mouldy. To avoid
these undesirable results presses were constructed which rendered
it possible to liquefy the mass without any further treatment in the
receptacle in which the pressing was conducted. Such a press, likewise
acting hydraulically, is shown in Fig. 82 on the opposite page.