IMPROVEMENTS IN THE MANUFACTURE OF LEAVEN OR YEAST
Year: 1878

page_text: LETTERS PATENT to Moss Moritz Prager, of Dalston, in the County. of
Middlesex, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
LEAVEN OR YEAST."
Sealed the 18th October 1878, and dated the 8th May 1878.
PROVISIONAL SPECIFICATION left by the said Moss Moritz Prager at the
Office of the Commissioners of Patents on the 8th May 1878.
Moss MORITZ PRAGER, of Dalston, in the County of Middlesex.
MENTS IN THE MANUFACTURE OF LEAVEN OR YEAST."
"IMPROVE-
The object of this Invention is to produce a yeast for baking purposes in a more
economical manner and of greater strength than heretofore.
In carrying out my Invention I take ordinary brewers' or other yeast, and having
thoroughly cleansed and pressed it, I weigh it, and dissolve it in cold water in some
suitable receptacle; I then take from 20 to 30 per cent. of the weight of the yeast
of crushed grain and potatoe starch flour, in equal proportions, and place them in
a suitable receptacle, and well mix them, and add thereto about three per cent. of
bicarbonate of potash, three per cent. sulphate of potash, three per cent. of white
argal, and three-quarters per cent. of magnesia. This mass of grain and chemicals
I then stir into warm water at about 150° Fahr., and allow it to stand for twenty
minutes; I then add maize flour, which I previously leaven in a manner hereafter
described in the proportion of lb. of maize flour to 1 lb. of grain, and after well
stirring it allow it to stand another twenty minutes.
Simultaneously with the foregoing operations I boil or steam from 20 to 30
per cent. of potatoes, which are afterwards mashed up and added to the
grain and chemicals, and the whole mass is then steamed or allowed to simmer
for about 3 to 5 hours, after which it is allowed to cool down to about 110°
Fahr. At this point I add the mass so obtained gradually to the yeast, all the
time stirring well, and then add about th。 or about 2 ounces of powdered alum
to 100 lbs. of yeast. I then prepare a mixture consisting of one pint of lemon
juice, one pint of cold water, 24 ounces tartaric acid, 24 ozs. citric acid, and
°

page_text: add thereto 2 ozs. bicarbonate of soda and 3½ ozs. powdered ammonia,
and while this mixture is effervescing I add it to the mass of yeast and grain.
I then take about a pint of white wine vinegar, which I dilute with double the
quantity of water, and add thereto 12 oz. white argal, 9 or 10 oz. magnesia, and
when well mixed add it to the mass of yeast and grain, and allow it to stand for
from 24 to 72 hours, according to the temperature of the atmosphere. The mass is
then strained to remove all refuse, and is then cleansed and passed through a filter
press, from which it is taken and made up into packets ready for the market.
The grains which I prefer to use in combination with the potatoe starch flour
are Indian corn and barley malted, and rye and oats unmelted, but I may also use
wheat, buck wheat, beans, peas, or other cereals malted or unmalted.
If unmalted grain be used alone it must first be leavened by pouring thereon hot
water at about 120°, and stirring the mass to the consistency of a very thick paste.
I then add thereto about 20% of common yeast which has been diluted with milk,
warm water, and well stir it, and allow it to stand for from 4 to 6 days, when it
will be ready for mixing with the potatoe starch flour preparatory to the addition
of the chemicals and other mixtures.
If flour of grain be used instead of the crushed grain the per-centage may be
reduced by say from 5 to 10%
I have stated above the materials and chemicals, and the proportions of each
which I prefer to use for my purpose, but I would remark that the proportions
may in some cases be varied, and that other chemicals having similar properties
may also be employed in place of some of those above mentioned. I may further
remark that I have found that by omitting the cereals I can obtain a tolerably
good result, though the leaven or yeast so prepared has not the "duration" of that
prepared with grain,

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Moss Moritz Prager in the Great Seal Patent Office on the 6th
November 1878.
Moss MORITZ PRAGER, of Dalston, in the County of Middlesex. IMPROVE-
MENTS IN THE MANUFACTURE OF LEAVEN OR YEAST."
The object of this Invention is to convert any ordinary brewers' yeast (which has
little or no value) into a good, strong, dry yeast, suitable for baking purposes, and
equal in quality to any imported foreign yeast which hitherto could not be produced
in this country.
In carrying out my Invention I take any ordinary brewers' yeast and press it
If tho
through a filter or common screw press so as to make it as dry as possible.
yeast is dirty, very bitter, or of a dark colour I dissolve it in three times its bulk of
cold water, and let it stand quietly for about four hours, I then draw off the dark
and bitter water from the top, and put the thin yeast water or substance in a clean
suitable receptacle in order to allow it to settle down. After I have removed all
the good and clean yeast which may be yet in the liquor (which is easily
effected by pouring again frosh water on the dark settlement) I throw the dregs
away.
When the thin watery yeast has sottled I draw off all the upper stratum of
water and press the yeast again in order to ascertain the weight of it.
At the commencement of the first pressing of the yeast I add to every one hundred
pounds of brewers' yeast (according to the thickness and duration of fermentation
which I desire to produce) fifteen to twenty-five pounds of grain and potato starch.
The grain which I now prefer to use are Indian corn (maize) and barley malted,
and rye and oats unmalted. I may also use wheat, buckwheat, beans, pease, or
other cereals malted or unmalted.
It is at the discretion of the manufacturer to use more or less of one sort of grain,
also to use only one or two sorts of the above-mentioned grains.
In practice I usually take forty per cent. of malted maize, twenty-five per cent.
of malted barley, twenty per cent. of unmalted rye, ten per cent. of unmalted oats,
and five per cent. of potato starch. To these ingredients I add about the same
weight of potatoes which have been previously boiled and mashed, and I pour over
the mass some cold water, and while stirring it I put in it three-quarters of a pound
of magnesia to every one hundred pounds of grain and of crystalized tartrate of
soda, ten ounces to every one hundred pounds of grain, and allow it to stand,
covered, for twelve hours at least. I then take hot water about one hundred and
seventy degrees to one hundred and eighty degrees Fahrenheit, pour it over the
mass, and while continually stirring I add to every one hundred pounds of grain,
about three pounds of bicarbonate of potash, three pounds of sulphate of potash,
and three pounds of powdered white argol, which I consider somewhat purer than
cream of tartar. The argol I usually dissolve in lukewarm water, and add to it
some white wine vinegar or a smaller quantity of acetic acid or tartaric acid, and
let it again stand, covered, at least one hour. I then put it in a boiler or steamer,
and let it slowly and gradually boil for two to three hours till it attains a tempe-
rature of from two hundred degrees to two hundred and ten degrees Fahrenheit,
after which it is allowed to cool down to one hundred and twenty degrees or one
hundred and ten degrees Fahrenheit, and at this state I mix in it the leavened
stuff, which is always kept previously prepared.
To prepare the leavened stuff I take from ten to fifteen pounds to every one
hundred pounds of brewers' yeast, of maize, flour, or maccaroni, or half of each, or
gluten, or any flour and grain which contains the same properties, and I put the
mass in a vessel, and pour on it cold water, and add to it of crystalized tartrate
of soda one ounce to ten pounds of stuff, stir it very well, and allow it to stand,
covered, twelve to twenty-four hours, after which I add to it some treacle or golden

page_text: syrup and some raisins (the quantity of the sweet stuffs is at the discretion of the
manufacturer, who must know the nature of his brewers' yeast, and whether the
brewer has used sugar stuffs or not, also of what season's brewing the yeast is).
The mass is then put on the fire and allowed gradually to boil or steam to about
two hundred degrees or two hundred and ten degrees Fahrenheit. When it is
cooled down to about one hundred and ten degrees Fahrenheit I add to every one
hundred pounds of stuff three pounds to five pounds of bicarbonate of potash, three
pounds of white argol, which I dissolve, as already mentioned, in water with
vinegar or acetic acid, and after well stirring I allow it to stand quiet for from
twelve to eighteen hours. After that time I pour some hot water at one hundred
and seventy degrees or one hundred and eighty degrees Fahrenheit on it, and
dissolve in lukewarm water common pressed brewers' or some other yeast, about one
ounce to every pound of stuff, and mix it in the mass by stirring it well, and let
it stand uncovered two to six days, by which time it makes a delicious fruity smell
which is so much appreciated in the imported foreign yeast.
Moreover, before I put the above-mentioned leavened stuff to the boiled grain I
dissolve the ready pressed brewers' yeast in lukewarm water at about eighty
degrees to ninety degrees Fahrenheit, and add to it about two ounces of powdered
alum for every one hundred pounds of yeast. I then prepare a mixture of one
pint of lemon juice to every one hundred pounds of yeast and one pint of water,
and dissolve in it two and a half ounces of a mixture of half tartaric acid and
half citric acid, and then add to it about three and a half ounces of powdered
ammonia and about two ounces of bicarbonate of soda, and while offervescing I pour
it into the brewers' yeast. I then make a second mixture of a pint of white
wine vinegar (or a less quantity of acetic acid) and two pints of water, and add to
it ten to twelvo ounces of white argol and six to nine ounces of inagnesia, and
when well mixed together I add the whole to one hundred pounds of yeast.
When the yeast begins somewhat to ferment I add to it the mass of boiled grain
and leavened stuff, and after I have stirred in for about ten to fifteen minutes I allow
it to stand quiet and uncovered for from twenty to seventy hours, according to the
season and temperature of the atmosphere. Then I add cold water to it, stirring it
well, and straining it to remove all refuse, and then let it stand uncovered for about
three hours, till the dark stuff and grain settles on the bottom; I then draw off the
clean substance in another clean vessel, and let it again stand for about an hour,
after which (should some dark stuff or flour still form a settlement) I repeat the
same manipulation as just mentioned. After the clean substance has settled I
throw away the upper water which does not contain any yeast, and I press the
stuff which is now finished in a filter or common screw press, and after leaving it
for about half an hour exposed to the air I make it up in packets or parcels ready
for the market.
I have above stated the materials and chemicals, also the proportion of each
which I have found to answer my purpose best, but I do not intend to confine myself.
to the use of such proportions, or to such materials or chemicals, as there are many.
others having similar properties which can be employed with equally good result.
It is also at the discretion of the manufacturer if he does not so much care for the
peculiar and highly agreeable taste which my yeast gives the bread and cakes to
leave entirely out of the yeast the lemon juice, and the mixture of tartaric and citric
acids, and powdered ammonia, bicarbonate of soda, vinegar, white argol, and
magnesia, as just described, and also the grain and potatoes which I mentioned at
the commencement of the process as I have practically produced a very quick and
strong yeast for the use of pastry cooks and for such bakers as wish to have their.
bread finished from the beginning to the end in about three hours. For instance, I
prepare the brewers' yeast as described at the beginning of the Specification, and
as soon as the yeast is dissolved in lukewarm water I pour some hot water
on the leavened stuff, and stir it into the yeast, and allow it to stand uncovered
for from twelve to eighteen hours, and then I proceed, as described in the latter.
part of the Specification, but in my opinion the yeast prepared in this manner.

page_text: is not of that lasting character which a great majority of English bread bakers
wish for or desire.
I have here to remark that sometimes, according to the bitterness and quality of
the brewers' yeast, I add also some syrup and raisins to the grain and potatoes
before the mass begins to boil. The yeast thus made I term "Victoria Yeast.”
Having now described the nature of the said Invention of "Improvements in
the Manufacture of Leaven or Yeast," and explained the manner of carrying the
same into effect, I wish it to be understood that under the above in part recited
Letters Patent I claim,―
First. The mode or process of manufacturing yeast as above described, whereby I
am enabled to produce a yeast at about half the usual price of foreign yeast, and in
every respect equal thereto.
Second. I claim particularly preparing the grain by the addition thereto of
chemical substances above mentioned, and then boiling the same together with
potatoes before adding the compound to the brewers' yeast, as above set forth.
Third. I also claini preparing the leavened stuff in the manner above described,
and adding the same to the prepared grain and brewers' yeast, as and for the
purpose above set forth.
Fourth. I also claim the employment of sweet grain (such as maize) and potatoes
to improve the quality of the yeast, as above set forth.
Lastly. I claim making a yeast equal to good foreign yeast without the
employment of grain, and without the addition of chemicals to the brewers'
yeast, but simply by the addition of my improved leavened stuff, prepared as
above described.
In witness whereof, I, the said Moss Moritz Prager, have hereunto set my
hand and seal, the Fourth day of November, in the year of our Lord One
thousand eight hundred and seventy-eight.