IMPROVEMENTS IN THE MANU- FACTURE OF YEAST
Year: 1877

page_text: LETTERS PATENT to Julius Augustus Liebert, of Portsmouth, in the County
of Hants, Gentleman, for the Invention of "IMPROVEMENTS IN THE MANU-
FACTURE OF YEAST." (Partly a communication from abroad by Siegesfred
Adolphus Liebert, of Berlin, Prussia.)
Sealed the 11th January 1878, and dated the 16th July 1877.
PROVISIONAL SPECIFICATION left by the said Julius Augustus Liebert at
the Office of the Commissioners of Patents on the 16th July 1877.
<<
JULIUS AUGUSTUS LIEBERT, of Portsmouth, in the County of Hants, Gentleman.
IMPROVEMENTS IN THE MANUFACTURE OF YEAST." (Partly a communication from
abroad by Siegesfred Adolphus Liebert, of Berlin, Prussia.)
This Invention, which relates to improvements in the manufacture of yeast, has
reference to the conversion of brewers' yeast into what I term "Alexandra yeast,"
at a nominal cost and without the use of chemicals, the resulting "Alexandra
yeast" being of good quality, powerful action, and great durability, and being
equal to yeast of foreign manufacture, which it has hitherto been very difficult to
produce.
According to the process of conversion embraced in the present Invention I take
ale, beer, or porter yeast, fresh from the tun, press the liquor from it, mix it with
fresh cold water, strain it through a silk cloth sieve (as used by millers and obtain-
able at millwrights') into the yeast-back. I add a large volume of fresh, stir
well, and allow it to settle. When the yeast has fallen to the bottom I emit the
dirty bitter water through a tap placed underneath at the end of the yeast-back; I
replenish with pure cold water, and repeat the above process until the bitterness is
nearly or wholly removed. I then add from 5 to 15 per cent. of cereals, according
to the strength and quality of the yeast, which can be easily ascertained by experi-
ments on a small scale. For an average quality of yeast I add about 10 per cent. of
cereals, the mixture of which I prefer to use consisting rd. of finely ground rye
flour, rd. of buckwheat flour, and 3rd. of Hungarian or Californian wheat flour. I
then dilute with warm water with a sufficient quantity (for an average quality of
yeast, about 10 per cent.) of common white soft sugar, or similar white saccharine

page_text: matter, to make an active ferment, and I put the whole into large barrels and
gradually raise the temperature to 75° Fahrenheit (or to a less degree, as herein-
after more particularly referred to) by adding hot water, and I let it ferment. I
thus obtain the necessary germ power and nitrogeneous matter through a vinous
fermentation, and the conversion of the sugar and cereals into alcohol and carbonic
acid, without which no pressed yeast (in which state the present process of con-
version leaves the "Alexandra yeast,") can be either powerful or lasting. When
the yeast begins to thicken I skim it from the top, and continue doing so until it is
exhausted; I then dilute it with cold water to the proper consistency (preferably a
little thick than thin) for pumping or pressing through. But before pressing I add
about 10 per cent. of potato starch, and optionally, about 1 quart of butter-milk to
every 100 pounds of yeast, the latter producing the milk-acid taste peculiar to yeast
of Dutch manufacture, and appreciated by many. I then strain the whole again
through a sieve, stir intimately with a whisk, and press dry with either a filter,
screw, or hydraulic press, with a gradually increasing but not excessive pressure.
Should the yeast however come too dry from the press, I knead it with a little cold
water until it breaks in flakes with a rough surface. When pressed I spread the
yeast on cold floors for several hours to allow the gas to escape. I then knead it into
a mass and pack it into linen bags, or cut it by any suitable mechanical means into
blocks of convenient size, or compactly knead it into buckets, and scoop it out as I
require it; and in order to keep it sweet, powerful, and in good quality for a long
time, I keep it always in a cool dry place.
The good quality of the yeast is recognized by a delicious fruity smell when it
comes from the press.
I would remark that in such qualities of yeast where the fermentation under a
temperature of about 75° Fahrenheit is found not to answer owing to its quickness,
I prefer to use a slow and gradual fermentation under a temperature of about 40°
to 50° Fahrenheit, and I subject the yeast to experiments on a small scale previous
to producing it in bulk, as owing to the various ingredients used in brewing the
quality of brewers' yeast varies greatly.
In conclusion, I would remark that I consider the most important advantages
obtained by the above-described treatment of brewers' yeast, in addition to those
previously enumerated, to be,-
The strength obtained from refermentation in about the temperatures stated.
The nitrogenous and alcoholic principles obtained by the destruction of the added
sugar and cereals by fermentation, and their conversion into alcohol and carbonic
acid.
The production of a white color in the yeast, and the absorption of bitterness by
the process generally; and the production of the milk-acid taste by the addition of
butter-milk or fermented milk.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Julius Augustus Liebert in the Great Seal Patent Office on the
16th January 1878.
JULIUS AUGUSTUS LIEBERT, of Portsmouth, in the County of Hants, Gentleman.
"IMPROVEMENTS IN THE MANUFACTURE OF YEAST." (Partly a communication from
abroad by Siegesfred Adolphus Liebert, of Berlin, Prussia.)
This Invention, which relates to certain new and useful improvements in the
manufacture of yeast, has reference to the conversion of brewers', distillers', or other
yeast into a substitute for foreign or German yeast.
My improved yeast is produced at a nominal cost, and without the use of
chemicals; it will be found of good quality, powerful in action, and of great
durability, and it is equal, if not superior, to the yeast of foreign manufacture, which
has not hitherto been produced in this country.
According to the process adopted in carrying out this Invention I take brewers',
distillers', or other yeast fresh from the tun, I strain it through a fine hair sieve,
then I press the liquor from it by means of an ordinary screw or filter press, and I
put it under a large volume of pure cold water in a large yeast-back or other similar
large vessel. I then stir it well and allow it to settle. About every eight hours,
when the yeast has fallen to the bottom, I emit or let out the dirty bitter water
through a tap, or bung holes, or other similar contrivance placed underneath at the
end of the yeast-back. I stir it and replenish with fresh pure cold water, and repeat
the above process as often as necessary, until it is found that the bitterness and
color are removed; this is generally effected in two or three washings. I next
referment the disembittered yeast in unheaded casks or similar open vessels under
a low temperature of (say) from about 42 to 45 degrees Fahrenheit, which I obtain
by placing the fermenting cask or vessel in an outer vessel, or a refrigerator filled
partly with cold water which can be cooled in any approved manner, either by the
addition of ice or by the use of an ordinary cooling apparatus; 2 to 5 per cent. of
pure alcohol is added thereto and the extracted liquor from cereals, according to the
following proportions (which proportions I have found most suitable in practice),
that is to say, about 10 per cent. of cereals, such as the flour of wheat, rye, buck-
wheat, malt, and similar cereals. To these ingredients I add (say), about two
gallons of hot water for every 100 pounds in weight of the compressed yeast (that
being sufficient to break up the yeast), the temperature being from 170 to 180
degrees Fahrenheit. I stir the whole into a thin mash, and then I allow it to stand
in a covered vessel for half an hour so as to effect the formation of grape sugar,
which after cooling I add to the yeast. I then let the same ferment slowly over-
night, and before pressing I add about 20 per cent. of thick butter-milk or other
similar albuminous, or gelatinous or glutinous substance or matter, and also 2 to 5
per cent. of gluten to give the yeast a proper consistency, and about 10 per cent. of
farinaceous material or substance, by preference potato starch (or other farinaceous
substances may be used); and I would here remark that the proportions of such
materials or ingredients will necessarily vary according to the seasons of the year.
I then press the yeast again by the same press in order to obtain the proper consistency.
I then roll the yeast with a common wooden roller, pin, or other suitable implement
to procure a sameness of color throughout; it should then be spread out in a dry
cool place as long as necessary to allow the gas to evaporate; and finally it is pressed
hard into strong bags made of canvas or other suitable material, which are then
sewn up, and they must invariably be kept in a cool dry place or places. The yeast
will then be ready for use.
In conclusion, I would remark that I consider the most important advantages
obtained by the above-described treatment of brewers', distillers', or other yeast, in
addition to those previously enumerated, are,-
The strength obtained from the refermentation with alcohol and cereals in (or
about in) the temperature stated.

page_text: The production of a white color in the yeast and the removal of bitterness.
Having now particularly described the nature and object of the said Invention,
and the best means that I am acquainted with for successfully carrying out the
Invention in practice, I have to state that I do not confine myself to the precise
porportions or quantities of the ingredients used in my improved manufacture of
yeast, nor to the exact degrees of temperature named in the herein-before described
process of manufacture, as such proportions and degrees will necessarily vary
according to circumstances, and variations or modifications might be made in the
details of the improved manufacture without deviating from the main principles of
the Invention, but what I claim as new and the Invention secured under the herein-
before in part recited Letters Patent is,―
.
The improved manufacture of yeast, substantially as herein-before described, in
which is more particularly comprised the production of strength and germ power
in the yeast caused by the slow refermentation thereof with cereals and alcohol at a
low or suitable temperature.
Also, the introduction and combination of albuminous, gelatinous, or glutinous
materials in the manufacture, whereby the better keeping quality and consistency of
the yeast is secured.
Also, the rolling and packing the yeast, whereby it is kept in proper and good
condition ready for use.
In witness whereof, I, the said Julius Augustus Liebert, have hereunto set my
hand and seal this Fourteenth day of January in the year of our Lord
J. A. LIEBERT. (L.S.)