_By_ WALTER G. SACKETT
PUBLISHED BY THE EXPERIMENT STATION
FORT COLLINS, COLORADO
1913
[Page 2]
=The Agricultural Experiment Station=
Fort Collins, Colorado
=Term=
=The State Board of Agriculture Expires=
HON. F.E. BROOKS Colorado Springs, 1915
HON. J.S.CALKINS Westminster, 1915
HON. J.C.BELL Montrose, 1917
HON. WILLIAM HARRISON Clifton, 1917
HON. CHAS. PEARSON Durango, 1919
HON. R.W. CORWIN Pueblo, 1919
MRS. J.B. BELFORD Denver, 1921
HON. A.A. EDWARDS Fort Collins, 1921
GOVERNOR E.M. AMMONS, _Ex-Officio_
PRESIDENT CHAS. A. LORY, _Ex-Officio_
L.M. TAYLOR, SECRETARY J.S. JONES, TREASURER
=EXECUTIVE COMMITTEE IN CHARGE=
A.A. EDWARDS, _Chairman_
J.S.CALKINS E.M. AMMONS
=STATION STAFF=
W.P. HEADDEN, A.M., Ph.D. CHEMIST
C.P. GILLETTE, M.S., _Entomologist_ DIRECTOR
G.H. GLOVER, M.S., D.V.M. VETERINARIAN
W.G. SACKETT, B.S. BACTERIOLOGIST
ALVIN KEYSER, A.M. AGRONOMIST
J.O. WILLIAMS, B.S.A., _U.S. expert-in-charge_ HORSE BREEDING
E.P. SANDSTEN, Ph.D. HORTICULTURIST
B.O. LONGYEAR, B.S. BOTANIST
G.E. MORTON M.L., B.S.A. ANIMAL HUSBANDSMAN
E.B. HOUSE, B.S. (E.E.), M.S. IRRIGATION ENGINEER
V.M. CONE, B.S. IRRIGATION INVESTIGATIONS
R.E. TRIMBLE, B.S. ASSISTANT IRRIGATION INVESTIGATIONS
P.K. BLINN, B.S., ROCKY FORD ALFALFA INVESTIGATIONS
EARL DOUGLASS, M.S. ASSISTANT CHEMIST
S. ARTHUR JOHNSON, M.S. ASSISTANT ENTOMOLOGIST
L.C. BRAGG ASSISTANT IN ENTOMOLOGY
J.W. ADAMS, B.S., _Cheyenne Wells_ AGRONOMY ASSISTANT, DRY FARMING
ELWOOD D. ROOD, A.B. ASSISTANT CHEMIST
W.W. ROBBINS, M.A. ASSISTANT BOTANIST
PAUL S. JONES, B.S. ASSISTANT IRRIGATION INVESTIGATIONS
RALPH L. PARSHALL, B.S. ASSISTANT IRRIGATION INVESTIGATIONS
JAMES D. BELL, B.S. ASSISTANT IRRIGATION INVESTIGATIONS
=OFFICERS=
CHAS. A. LORY, LL.D. _President_
C.P. GILLETTE, M.S. _Director_
L.M. TAYLOR _Secretary_
MARGARET MURRAY _Executive Clerk_
[Page 3]
=HOME-MADE CIDER VINEGAR
By Walter G. Sackett.=
In driving through the fruit-growing sections of the United States,
one cannot fail to be impressed with the fact that thousands of
bushels of apples and other fruit are allowed to go to waste annually
just because it is too much trouble to gather it up and make some use
of it. This is particularly true during a season when prices are low
owing to an overproduction. Such a practice would be condemned, most
certainly, by any commercial firm, and rightfully so, as a most
extravagant waste and far removed from any principle of scientific
management. Talk with any captain of industry, and he will invariably
tell you that the largest profits in his business accrue from the
complete utilization of the waste products.
Indifference to the needs of others and ignorance of the latent
possibilities in this second grade fruit are largely responsible for
the fruit grower’s short-sightedness. He is apt to forget that there
are a few more than ninety-three million others in this country who
are dependent upon him for orchard products such as cider, apple
butter, jelly and vinegar, all of which could be made from this fruit
which he permits to rot unnoticed under the trees. Could he only be
shown the roll of greenbacks or catch the glitter of the gold which
would represent his actual net return from the complete utilization
of this unnecessary waste, rotten apples, wormy apples, green apples
and everything would be cleaned up the next time we should pass by
his orchard.
In spite of the fact that thousands of gallons of white wine vinegar,
which has never been near a wine press, are produced yearly by a
purely chemical process from alcohol, there is still a market for
good, old-fashioned, apple cider vinegar. The genuine article will
never be entirely replaced by the artificial product. But where is
the public to obtain pure apple vinegar of acceptable quality? It is
not for sale at the local groceries except in sealed bottles at
twenty-five cents a quart. Beside it on the shelf may be found the
distilled vinegar, artificially colored with caramel, and the white
pickling vinegar at fifteen cents a bottle. In bulk the distilled
vinegar can be bought for forty cents the gallon with a reliable
guarantee behind it for strength and quality. But you say, [Page 4]
"Surely you must be mistaken about not being able to get cider
vinegar from your grocer in bulk." No, gentle reader, do not be
deceived by the stencil mark on the end of the barrel. If, perchance,
this particular lot came from a nearby ranch, the odds are in favor
of its not being worth carrying home. Do not understand me to speak
thus lightly of all home-made vinegar for there is some to be found
of splendid quality, but it is the exception. As a rule the
storekeeper will apologize to the customer for his farm vinegar, but
with that which comes from the wholesale dealer it is different. Most
certainly a sad condition, when the first and best vinegar that was
ever made came from the farm home! What is more, it cannot be
obtained from the farmer or apple grower today for most of them are
buying all of the vinegar they use.
What has become of our apple vinegar industry, and why have the
merchants turned their attention to the distilled article? The answer
to this can be had without pursuing an extensive investigation into
the economics of the question. It is simply this—the average run of
farm vinegar is so inferior to the distilled product that the
merchants cannot afford to handle it. The quality is so variable and
the strength is so unreliable that the good housewife has learned
through the repeated experience of having her pickles spoil not to
ask for cider vinegar.
There is no good reason why this condition of affairs should exist
which has resulted in placing a boycott on the farm product, but in
the light of the facts as they actually exist, is not the consumer
justified in taking this stand? There is no doubt that the synthetic
article has come to stay, but this does not mean that genuine apple
vinegar is a thing of the past. However, until we are able to produce
as good or better vinegar on the farm and in the orchard and can
guarantee its quality and strength to be reasonably constant, we have
no right to ask or to expect the public to buy an inferior product or
to help build up the industry by its patronage.
It is just as easy to make high-grade apple vinegar at home when one
understands the different operations and principles involved as it is
to make good butter or good bread. If the housewife knew as little
about making butter and baking bread as the average farmer or
orchardist knows about making vinegar, we should all forsake the
staff of life and take refuge in the nearest sanitarium.
[Page 5]
_Selection of the Apples._
What has been said above concerning second grade fruit for cider and
vinegar is not to be construed as meaning rotten, wormy, dirty, or
unripe fruit. Nothing is gained by such a practice and often all is
lost. In the first place, it is impossible to cover up the flavor of
the spoiled apples in the vinegar, and in the second place, when
decayed and dirty fruit is employed, it is practically out of the
question to control the fermentations in the cider upon which the
quality of the finished product depends almost entirely.
There is no reason why apples which have merely been bruised should
not be used, and where they are not too badly rotted, the soft
portion can be cut out. Children are always glad to have a hand in
cider making and this is just where their services will fit in
nicely. Remember that many hands make light work and likewise clean,
acceptable cider, and you will be surprised to see in how short a
time the spoiled parts can be removed from the bushels of otherwise
worthless apples.
The importance of washing the apples thoroughly with clean water
before they go to the mill to be ground cannot be overestimated.
There is bound to be a quantity of soil and dust clinging to the
outside, particularly where the orchards lie along a public road and
are clean cultivated so that the apples fall on plowed ground. This
can be carried out very conveniently in an ordinary washtub, after
which the apples should be allowed to drain before they are ground.
One is always astonished at the amount of mud in the water after such
an operation, even when relatively clean, hand-picked fruit is
employed.
Let us see next whether all varieties of apples are equally well
suited to cider vinegar making; whether a good cider apple is
necessarily a good vinegar apple; and what constituent or
constituents of the apple determine its usefulness for these
different purposes.
In answer to the first question, it may be said that apples differ
very widely in their adaptability to cider and vinegar making; some
appear to have been created for this very purpose, while others would
not do at all.
Concerning the second point, we find it is quite often the case that
an apple which makes an excellent cider to drink would not make good
vinegar. This is due to the fact that most tastes demand a cider that
is not too sweet and with a slight acidity. Such [Page 6] apple juice
would be very apt to make weak vinegar because of the relatively
small amount of sugar present.
This reference to sugar brings us to the third item, namely, the
important constituents of the apple so far as cider and vinegar are
concerned. Several years ago, Dr. Van Slyke of the Geneva, N. Y.,
Experiment Station, reported a series of analyses of apple juices
representing eighty-three different American-grown varieties. He
gives the average composition of these juices as follows:
Solids 13.52 per cent
Total sugar as invert sugar 10.91 per cent
Ash .29 per cent
Fixed acid (malic) .52 per cent
The sugar is unquestionably the most important of these substances so
far as the part which it plays in the making of cider vinegar since
the degree of sourness due to the vinegar acid (acetic) is directly
proportional to the fermentable sugar present; in other words, all of
the acid which was not originally present in the cider as natural
apple acid, or malic acid, is produced from the sugar by processes
which are soon to be described. Therefore, since from a given amount
of sugar just so much acid and no more can be made, we can understand
quite readily that for a high grade vinegar of maximum acidity the
apple juice containing the most sugar will be the most desirable. The
amount of natural acid present in the juice plays an insignificant
part in the final acidity of the vinegar, since the small quantity
that is present in the apple juice practically all disappears during
the change into vinegar. From this it is clear that it is the sugar
and not the natural apple acid that is to be considered in cider for
vinegar.
Now, as has been stated above, cider for table use is usually more
pleasant to drink when it is not too heavy and when the sugar is
lower and the acid somewhat higher than the standard for vinegar
cider requires.
The composition of the juice of some of our common commercial
varieties, especially the sugar content, may be of interest at this
time in connection with what has been said with reference to the
suitability of different ciders for vinegar making. The [Page 7]
analyses which I am submitting are those given by Dr. Van Slyke* for
eastern apples.
*Van Slyke, L, L., Bulletin 258, Geneva, N, Y., Exp. Sta. "A Study of
the Chemistry of Home-Made Cider Vinegar," 1904.
_Table I —— Analyses of Apple Juice of Different Varieties of American
Apples._
=Specific Solids. Equivalent of total Fixed=
=Variety of Apple. Gravity. sugar in form of acid as=
=invert sugar. malic.=
=Per cent. Per cent. Per cent.=
Baldwin 1.072 16.82 15.39 .67
Belleflower 1.061 14.09 12.82 .58
Ben Davis 1.052 12.77 10.60 .46
Ben Davis 1.046 10.69 6.74 .44
Gano 1.046 10.16 8.61 .41
Gano 1.056 13.92 11.32 .41
Grimes Golden 1.070 18.18 14.05 .74
Jonathan 1.056 14.62 11.60 .32
Maiden Blush 1.051 12.70 9.99 .67
Northern Spy 1.052 13.77 9.77 .69
Red Siberian Crab 1.070 17.34 11.83 .97
Rome Beauty 1.048 11.37 8.70 .37
Wealthy 1.057 15.26 11.64 .66
Whitney 1.060 14.16 11.39 .40
Winesap 1.065 16.45 13.34 .58
Yellow Transparent 1.049 11.71 9.76 .87
An examination of the above table shows us that there is a wide
variation in the percentage of sugar in the apple juice of different
varieties, varying from 6.74 per cent. in one sample of Ben Davis to
15.39 per cent. in the Baldwin; that the quantity of sugar in any
given variety may vary as much as 4 per cent. (Ben Davis 6.74-10.60).
The amount of sugar depends upon a number of factors such as soil,
climate, culture, variety, and ripeness, unripe and over-ripe apples
containing less sugar than ripe ones.
+ Browne has shown very clearly the changes that take place in the
sugar content of apples at different periods of ripeness:
+ Browne, Annual Rept. Penn. Dept. Agr, 1899. p. 541.
_Table II —— Sugar in Baldwin Apple at Different Periods._
=Equivalent of Total Sugar in=
=Date Condition. Form of Invert Sugar.=
Aug. 7, 1899 Very Green 8.11
Sept. 13, 1899 Green 10.72
Nov. 15, 1899 Ripe 14.87
Dec. 15, 1899 Over-ripe 14.85
The question is sometimes asked whether the so-called "sweet apples"
will make as good vinegar as the tarter varieties. All things being
equal, there is no reason why they should not, provided they contain
as much sugar as the more acid kinds. This statement may seem
somewhat paradoxical, but it should be remembered that [Page 8] it is
the presence of acid rather than the absence of sugar that makes an
apple taste sour. As a matter of fact, some of our very sourest sorts
contain as much and more sugar than the sweetest sweet apples. Cider
for vinegar should not contain less than 8.5 per cent. of sugar.
_Storage of the Cider._
The most satisfactory containers for both cider and vinegar are
whisky and brandy barrels. Molasses barrels and old vinegar barrels
should be used only when no others are available, and then not until
they have been very carefully and thoroughly cleaned. Too much stress
cannot be laid upon the necessity of scalding old vinegar barrels
with either live steam or boiling water to remove the last trace of
the old vinegar. There is, perhaps, no one factor which is
responsible for more failures in farm vinegar making than the
time-honored but pernicious custom of using old vinegar barrels for
sweet cider without even rinsing out the dregs of former years. Mere
rinsing is not sufficient. They must be scalded to make them fit for
use. If this is not done in such a manner as to kill all of the
organisms in the barrel, the probability is that the sweet cider which
is put in them subsequently will never make vinegar. The reason for
this will be given a little later. In a recent number of a certain
farm journal, the following is given under directions for making
apple vinegar:
"Get a barrel in which good vinegar has been made and use it, or get
some of the scum off of the top of good vinegar and rinse out the new
barrels with this as soon as they cool after having been thoroughly
washed out with boiling water. Put fresh cider into these barrels."
No procedure more absurd and dangerous to the success of apple
vinegar could possibly be undertaken than is contained in this
recommendation. In fact, it would be difficult to find a better
recipe for vinegar failures than this. Never, under, any
consideration, put either "mother" or old vinegar into sweet cider.
It is never safe to use metallic containers for holding cider even
for an interval of a few hours, since the acid of the juice attacks
the metal, dissolving a portion of it. Such cider, because of the
metal in solution, might produce metallic poisoning in the person
drinking it.
The sweet cider as it comes from the press may either be placed at
once in barrels, which should not be filled more than two-thirds to
three-fourths full, or if one has suitable wooden tubs or vats in a
clean, cool place, it may be stored there for twelve to [Page 9]
twenty-four hours to permit settling, after which it should be
transferred to barrels. The bung should be left out and a loose
stopper of cotton batting inserted in the hole to decrease
evaporation and prevent dirt from falling in. The barrels should not
be tightly stoppered until the vinegar contains at least 4.5 to 5.0
per cent. of acetic acid, at which time they should be filled
entirely full and securely bunged. Throughout the entire period of
vinegar making, the casks should be placed on their side and not on
the end. This gives the cider a larger free surface exposed to the
air, which is quite essential to rapid vinegar formation. It may be
of some advantage in admitting air to bore a one and one-half inch
hole in each end of the barrel along the upper edge. If this is done,
the holes should be covered with fine wire gauze or two thicknesses
of cheese cloth to exclude small vinegar flies.
_The Alcoholic Fermentation._
A few days after the cider is put into the barrels, the
characteristic frothing appears at the bung-hole. To use a common
expression, "It is beginning to work." This indicates that the
alcoholic fermentation, the first step in the vinegar making process,
has begun, and the sugar of the apple juice is being converted into
alcohol and carbon dioxide gas.
The first of these substances is too well known to need any further
comment other than to state that it is this element of "hard" cider
that gives it its intoxicating property. With carbon dioxide, many of
us are not as well acquainted. It is this gas escaping from the
fermenting cider that causes the frothing and likewise the foamy
appearance of the bread sponge. It is this gas dissolved in the cider
or in the carbonated drinks at the soda-water fountains that imparts
to them the characteristic bite or tingle, and upon escaping from the
stomach produces that peculiar sensation in the head and nose.
Strangely enough, this same gas is the active principle of
practically all chemical fire extinguishers.
Now, what is the exciting agent which starts up the fermentation in
the bread sponge and in the sweet cider? In both cases it is the
same: a microscopic organism, the yeast plant. In the one instance we
add a yeast cake to the bread mixture; in the other we either trust
to the wild yeasts of the air and the skin of the apples or following
the more recent, approved method, we add a yeast cake or a pure
culture of a yeast selected especially for this purpose.
To depend upon the wild yeasts of the air to accomplish the
fermentation is too uncertain since many of them are able to
[Page 10] convert only a small part of the sugar into alcohol, while
others act so slowly that they are impracticable. Inasmuch as the
percentage of acetic acid in the vinegar depends directly upon the
amount of alcohol produced, it is very essential to secure as large a
yield of alcohol as possible from the sugar present. This means
converting all of the sugar into alcohol in the shortest time
possible. The most satisfactory way of doing this is to add one cake
of compressed yeast, stirred up in a little cooled, boiled water, to
each five gallons of sweet cider. In place of this, one quart of
liquid wine yeast, propagated from a pure culture, may be used for
each thirty gallons of cider.
During the alcoholic fermentation, the cider should be kept at a
temperature of 65 to 80 degrees F. Here is where many make the very
serious mistake of putting their fresh cider into a cool cellar where
the fermentation takes place entirely too slowly. If the cider is
made in the fall, the barrels should be left out of doors for a while
on the protected, sunny side of a building and kept warm, unless a
regular vinegar-cellar, artificially heated, is at hand.
If yeast is added and the proper temperature is maintained, the
alcoholic fermentation should be completed in six weeks to three
months in place of seven to ten months as in the old fashioned way.
Experiments along this line have shown that when yeast is added and a
temperature of 70 degrees F. is held, the cider at the end of one
month contained 7.25 per cent. of alcohol as against .11 per cent.
when no yeast was used and the temperature was between 45 and 55
degrees F. Cider kept in a cellar at 45 to 55 degrees with no yeast
added required seven months to make 6.79 per cent. of alcohol.
Temperature, alone, is an important factor as shown by an experiment
wherein cider to which no yeast was added was held for three months
at 70 degrees F. and yielded 6.41 per cent. of alcohol.
There is no question but that the time required for completing the
alcoholic fermentation can be reduced at least one half by adding
yeast and by maintaining the proper temperatures. By hastening this
operation, the loss of alcohol by evaporation is reduced, and the
acetic fermentation can be started that much sooner.
Theoretically, 100 parts of sugar should give 51 parts of alcohol and
49 parts of carbon dioxide gas. This figure has been shown by Browne
to be a little high. In actual practice, 45-47 parts of alcohol from
100 parts of sugar is a fair average.
But why not add "mother" or vinegar to sweet cider or put [Page 11]
sweet cider into an old vinegar barrel? Here is the reason: We have
seen from what has gone before that alcohol is produced from the
fermentation of the sugar. We shall soon learn that the acetic acid
of the vinegar is formed from this alcohol. Now, in order to obtain
the maximum amount of acetic acid, it is necessary to have as much
alcohol as possible in the hard cider, and this can be obtained only
by the complete conversion of all the sugar into alcohol and carbon
dioxide gas. The complete destruction of the sugar can be
accomplished only by the uninterrupted action of the yeast, and the
presence of "mother" of vinegar by producing acetic acid interferes
seriously with this fermentation. The yeast cells are either killed
or their useful activity is checked long before all of the sugar has
been changed into alcohol. This is the condition of a very large
percentage of farm vinegar—just hard cider that will not and never
will make vinegar. It means just this:
A small part of the sugar was made into alcohol and this alcohol was
at once changed to acetic acid by the "mother" present; this acetic
acid killed the yeast so that no more sugar could be changed to
alcohol and no more alcohol being found, no more acetic acid could be
made by the "mother." We have a weak, worthless something neither
vinegar nor hard cider with considerable unfermented sugar still
present and incapable of further fermentation because no yeast can
develop in the weak acetic acid solution.
_The Acetic Acid Fermentation._
The second step in vinegar making is the change of the alcohol of the
hard cider into the acetic acid of the finished product. This is
accomplished by the acetic acid germ, another microscopic plant still
smaller than the yeast. In some peculiar way it is able to bring
about a union between the alcohol of the hard cider and the oxygen of
the air so that the alcohol is transformed into acetic acid and water.
As soon as the alcoholic fermentation, described in the preceding
section, is completed, draw off the clear liquid, being very careful
not to disturb the sediment in the barrel. Wash out the barrel
thoroughly and replace the hard cider. It is believed that removing
this sediment permits the acetic acid to form somewhat more quickly,
and furthermore, the sediment may undergo decomposition and impart a
disagreeable flavor to the cider. Again, these dregs may harbor
living bacteria which either destroy acetic acid or interfere with
its formation.
This done, we are now ready to introduce the acetic acid [Page 12]
germs. This may be carried out in a number of different ways, but
preferably by means of a pure culture of a desirable organism which
has been selected because of its ability to produce strong acetic
acid and to impart an agreeable flavor to the vinegar. In place of
the pure culture starter, one may add two to four quarts of good
cider vinegar containing more or less "mother" for each barrel. The
introduction of a desirable organism is left to chance in this case.
A serious objection to this latter method is that sometimes one
introduces foreign organisms with the "mother" which may prove
detrimental to the vinegar. The pure culture starter is free from
this objection. On the whole, the indiscriminate use of "mother"
alone is to be discouraged, since the popular idea of what
constitutes "mother" is apt to be wrong. Pure "mother" is made up
exclusively of acetic acid bacteria and is recognized as the thin,
white, glistening, gelatinous membrane that forms on the surface of
vinegar. It seldom becomes one sixteenth of an inch in thickness and
should be translucent or white in color, It is entirely distinct from
the thick, tough, dark brown, slipping, leathery masses which form in
vinegar and are usually regarded as "mothy of vinegar." Such
accumulations contain the acetic acid germ, in all probability, but
in an impure state. In addition to this organism there may be present
yeast cells and numerous bacteria which are positively harmful to the
vinegar. Often these growths undergo decomposition and give the
vinegar a flavor of rotten oranges. Again the germs present may cause
the partial or complete loss of the acid, particularly if the barrels
are not full and tightly stoppered. All things taken into
consideration, the use of this sort of "mother" is a rather dangerous
procedure.
With the acetic fermentation, as with the alcoholic, the higher
temperatures favor the changes. Experimental work shows that hard
cider to which no acetic acid bacteria were added other than those
that came from the air, and kept at 65 degrees F., when six months
old, contained 7.03 per cent. of acetic acid, while that held at 55
degrees F. showed only 3.63 per cent.
The addition of some kind of an acetic acid starter, either as a pure
culture of the acetic organism or as good vinegar, hastens the
fermentation and reduces appreciably the time required for making
marketable vinegar.
For most satisfactory results we would recommend using the pure
cultures and holding the vinegar at a temperature of 65 to 75 degrees
F. Under these conditions, salable vinegar can be obtained in three
to six months in place of two to three years, as is often [Page 13]
the case. Theoretically, 100 parts of alcohol should give about 130
parts of acetic acid, but in actual practice this will probably fall
below 120.
When the acetic acid has reached 4.5 to 5 per cent., fill the barrels
as full as possible and cork tightly. In this way, contact of the air
with the vinegar is cut off and the acetic acid organisms soon cease
their activity. If this is not done and the acetic and other bacteria
are allowed to develop indefinitely, there is apt to be a reverse
reaction resulting in a partial or complete loss of the acetic acid.
Such vinegar is, of course, worthless.
_Clarification of Vinegar._
For those who desire an extra fancy product of extraordinary
brightness, suitable for bottling, it will be necessary to subject
the vinegar to a special process of clarification known as fining.
According to Bioletti*, the best results are obtained by using
isinglass. This is employed at the rate of from one-half to
three-fourths of an ounce of isinglass to each one hundred gallons of
vinegar.
* Bioletti, Frederic T., Grape Vinegar, Bull. 227, California Exp.
Sta., 1912.
"The isinglass is cut into small pieces and soaked for twelve to
twenty-four hours in a little water containing acetic or tartaric
acid equal in weight to the isinglass used. When thoroughly soft it
is then rubbed several times through a fine sieve, gradually adding a
little more water until a perfectly fluid liquid is obtained. This
fluid is then well mixed with a little vinegar and thoroughly stirred
into the cask. With some vinegars it is necessary to add a little
tannin, from one-half to one-seventh the amount of the isinglass
used. This tannin should be added at least twenty-four hours before
the finings.
When the finings have settled and the vinegar is perfectly bright it
is ready for bottling."
_Pure Cultures for Vinegar Making._
Reference has been made above to the use of pure cultures, both yeast
and acetic acid bacteria, for vinegar making. For a little more than
one year, the Bacteriological Laboratory of the Colorado Experiment
Station has been supplying these at fifty cents (50c) per set, post
paid, sufficient for one barrel, to those who care to give them a
trial. Full printed directions for their use are included. These
cultures have been selected because of certain properties which they
possess which make them especially suited to the vinegar industry. No
guarantee, either expressed or [Page 14] implied, goes with the
cultures, since it is not the purpose of the Experiment Station to
exploit these products, but rather to distribute them at the cost of
production for experimental purposes. Inasmuch as one of the cultures
is to be added to the sweet cider, the set should be obtained a few
days, not longer, before the cider is to be made.
Requests for cultures should be addressed to the Bacteriological
Laboratory, Colorado Experiment Station, Fort Collins, Colorado, and
should be accompanied by a remittance of fifty cents (50c).
_Directions For Using Pure Cultures in Making Vinegar Preparation of
Yeast Culture._
1. For each barrel of sweet cider, sterilize one two-quart Mason jar
by washing thoroughly and boiling for five minutes in clean water.
2. Cover the top of the jar with a single layer of clean muslin or
cheese cloth just removed from boiling water and secure it in place
by a string tied about the neck of the can.
3. Select 6 or 8 medium sized _ripe_ apples; pare and quarter or slice
them; add one quart of water and boil till soft; strain liquid
through clean cloth while hot into Mason jar, first removing the
cloth covering from the top.
4. Make up the volume of liquid to approximately one quart with
boiling water; add 4 tablespoonfuls of sugar and replace the cloth
immediately.
5. When the liquid has cooled thoroughly, partly remove the cloth
covering and add the contents of the culture bottle marked "Yeast."
Replace the cloth. Just previous to opening the culture bottle, shake
thoroughly and immerse the lip and cork only, ten second in boiling
water. Do not touch the lip while removing cork.
6. Keep the jar in subdued light at a temperature of 75 degrees F. to
90 degrees F. After two to four days the foaming characteristic of
alcoholic fermentation should appear.
7. After four to six days, add the entire contents of the _yeast_ jar
to the barrel of freshly made _sweet_ cider. _The barrel must not be
more than two-thirds full;_ it should be placed on its side, and the
bung-hole be left open, or, better, plugged loosely with a tuft of
clean cotton batting.