Improved Process for the Manufacture of Yeast without Alcohol.
Year: 1892

page_text: COMPLETE SPECIFICATION.
Improved Process for the Manufacture of Yeast without Alcohol.
I, MICHEL KROUCHKOLL, of 17 Rue du Faubourg St. Jacques Paris, France,
Doctor of Science, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement :-
The object of this invention is the manufacture of yeast without simultaneous
production of a notable quantity of alcohol.
In the process about to be described, yeast sewn on a suitably prepared soil for
its cultivation, becomes developed and grows at the expense of the material
constituting the soil, occasioning disengagement of only traces of alcohol. The
process is as follows:-
Germinated barley not deprived of its rootlets, sometimes called green malt, is
crushed by an ordinary malt mill. To this crushed malt is added about its weight
of flour or some starchy substance, the whole is well mixed and has added to it
at 54° to 56° C. a quantity of water weighing about three quarters of the weight
of the above mixture; the whole is stirred for 5 minutes and then left to settle for
1 to 3 hours, according to the quality of the material employed. At the end of
this time there is added to the mass produced as above a quantity of water
at 95° C. sufficient to produce a temperature of the whole mixture of 62° to 64°,
which is then stirred for 2 to 3 minutes; the steeping vessel is then carefully
covered and kept so for about 1 hour. At the end of this time the vessel is
opened and allowed to cool slowly until the temperature of the mash reaches 32°.
During this time there is diluted with water at 32° a quantity of yeast equivalent
in weight to about 10 per cent. of the solid matter employed, to which is added
about 2 parts per thousand of tartaric acid (CHO) dissolved in warm water and
poured into the mash at 32°. The whole is stirred for several minutes and left to
settle. At the end of 2 hours there are added to the mash 2 parts per thousand of
bicarbonate of soda (CO³NaH) or carbonate of potash (CO³K) the whole is mixed
and left to settle.
About 5 hours after the preparation of the first mash, another is prepared but
with half the weight of the materials used in the first. This is subjected to exactly
the same operations as the first, but instead of the tartaric acid, a like weight of
hydrochlorate or carbonate of ammonia is added to the yeast.
When the second mash has cooled down to 32° there is added to it the diluted
yeast containing the ammonia salt, the whole is agitated; and then the two mashes
are mixed and left to settle for 12 hours. At the end of this time the yeast is seen
to form a layer at the bottom of the vessel where it is mixed with the pellicules of
barley. The whole is pressed through a sieve to separate the impurities, especially
the pellicules, the yeast passing through the sieve. It is left to settle, the yeast
collects at the bottom of the vessel; it is washed several times by successive
pourings of water into the vessel and decanting every time after 5 or 6 hours
of rest.

page_text: In the first mash, germinated barley not crushed may be employed, only that in
this case it must be left to soak in warm water before adding the flour.
Although I have stated certain temperatures and proportions of the materials
and reagents employed in the process above set forth, these temperatures and
proportions may be varied within narrow limits.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-