Improvements in the Production of Compressed Bakers' Yeast.
Year: 1896

page_text: Date of Application, 9th May, 1896
1007 Lacanted Oth lulu 1907
PROVISIONAL SPECIFICATION.
Improvements in the Production of Compressed Bakers' Yeast.
I, MORITZ PAUL HATSCHEK of 51 Fulham Park Gardens, in the County of Middlesex,
Chemical Engineer, do hereby declare the nature of this invention to be as
follows:-
The production of compressed baker's yeast has been hitherto carried on in
distilleries by the aid of lactic acid, which was developed in the ferments, or in the
clear spent wash, the latter being added to the wort, before fermentation was started,
or in both ferments and wort.
Baker's yeast prepared in this manner, always contained more or less organic acid,
lactic acid and others, which increased in quantity, if the yeast were kept for some
time, before being used, and often imparted to bread, buns, rolls &c., made from it, an
unpleasant sour or yeasty taste and flavour.
Several attempts have been made to replace the lactic acid by sulphuric or
hydrochloric acid, or by powerful disinfectants, like salicylic and sulphurous acid, but
the yeast, produced by these means, could not be kept and often turned bad in a day
or two.
In about the years 1890 to 1892 Effront attempted to introduce his process of using
hydrofluoric acid and other fluorides, which belong to the most powerful antiseptics,
in the production and for the preservation of baker's yeast, but this also seems to
have failed, because the yeast inust be first by degrees acclimatized to the addition
of hydrofluoric compounds, and when this has been done, it refuses to grow and to
act in a medium free from fluorides, which latter would be most objectionable in a
baker's dough.
I have found that a comparatively weak antiseptic, viz.: boric or boracic acid
(H, BO,, or HBO,, H₂O) is most suitable for the production as well as for the preserva-
tion of baker's yeast, forming a perfect substitute for lactic acid, making the yeast
resistant to infection for a longer period; and preventing the formation of organic
acids in the finished article. The process of making baker's yeast apart from
distilling is based upon the principle, that but small quantities of sugar (maltose etc.)
are required, to forin the walls of the yeast-cells, whilst the albuminous substances,
the phosphates and salts, necessary for the formation of their contents, can be well
supplied by materials, cheaper and more suitable, than grain and malt.
These latter materials are malt-combs, with or without bran, or peas, lupines,
vetches &c., these are mashed like grain with malt or (specially in the case of malt-
combs and bran) only steeped in warm water of from 140° to 200° F. or more, with an
addition of about 1% of sulphuric, or 2% of hydrochloric acid, and 1/10 to 2/10% of
sulphurous or salicylic acid, or with an addition of 1/10 to 4/10% of sulphurous acid
only. The additions of the said acids can be increased or diminished, according to
the amount of infection present in the raw material or in the water, without
influencing the results to any considerable extent, and the said additions are to be
understood as percentages of the weight of the water, used for steeping or mashing,
which amounts to about 10 to 15 times the weight of the materials steeped or

page_text: To the extract drawn off from the said materials or from other materials, sufficiently
rich in albuminous matter, from 1 to 3 lbs. of maltose or other kinds of sugar are
added, to say from 1 to 3 lbs. for each lb. of compressed yeast to be produced. Under
circumstances, specially when the price of the material for making maltose is low
enough, the addition of sugar can be increased to about double the quantity named,
and by doing so the output of yeast will be also increased.
The maltose or other sugar can be mixed with the extract at the beginning of the
operation, or in say from 3 to 6 portions, which method appears more advisable.
The seed-yeast or the ferment is put into the fermenting tub with the first portion
of the whole quantity of extract and sugar, or at any rate at the starting of the
operation, and filtered i.e. purified air is pumped into the fermenting liquid through
roses or pipes, perforated with small holes, close to the bottoms of the vats. The
quantity of air supplied should be sufficient to keep the whole of the wort in a slight
motion, and it should pass into the liquor continuously until the fermentation is
finished, which is indicated by the froth becoming lower, and less in bulk. During
the fermentation or rather the growing of the yeast, a temperature of 85° to87° 1.
should be maintained as the most suitable for the purpose.
Boric (or boracic) acid in the proportion of 1 part (in weight) to between 5000 and
10,000 parts of the fermenting liquor is added to the latter, to make the process
sound, and to prevent the formation of obnoxious organic acid and other infection.
As soon as the fermentation is finished, a quantity of cold water, sufficient for cooling
the wash down to about 72° F., is added to the liquor which is then left standing in a
cool, slightly ventilated locality. At this temperature the young and insufficiently
developed yeast cells will becoine matured in the course of some hours and the whole
outcrop will soon settle down at the bottom of the vat. After 10 or 12 hours the
spent wash is carefully decanted off and the yeast, left at the bottoin of the vessel is
strained through bags or sifting machines, and then well washed in clean cold water,
to which boric or boracic acid is again added in the proportion of 1 part to from 5000
to 10,000 parts of liquor.
Instead of boric acid, its various compounds, such as boric acid with alum, soluble
borates, such as acid magnesium biborate, ammonium and calcium borate, boric
tartrate, further boric acid with borax, boric acid with glycerine, the so-called
boroglyceride &c., could be used in values corresponding with the proportions
indicated above, although it is more advisable, to use pure boracic acid as the inost
suitable substance.
The washing, pressing and packing of the new yeast are effected in the usual
manner.
By means of the improvements herein described it is possible to produce a strong
and vigorous yeast, which keeps better than any other made by the aid of lactic acid,
and does not impart any sour or yeasty flavour to the bread &c. made from it.
I would here remark that the proportions of antiseptics and other acids employed
may be varied according to atmospheric and other conditions.
The invention is also applicable to the manufacture of yeast in connection with
distilling.
In this case the formation i.e. the introduction of lactic acid is also dispensed with,
in the ferments as well as in the wort. Instead of the lactic acid, boracic acid is
added first to the ferments, then to the mash in the large vats, and last to the water
for washing the yeast. The additions of boracic acid to be about the same, as
herein before indicated, but it is advisable, to apply from one and a half to double the
amount for the ferments, than for the mash and for the washing water.
Dated May 9th 1896
HARRIS & MILLS,
23 Southampton Buildings, London, W.C., Agents.

page_text: Improvements in the Production of Compressed Bakers' Yeast.
I, MORITZ PAUL HATSCHEK, of 51 Fulham Park Gardens, in the County of
Middlesex, Chemical Engineer, 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 production of compressed baker's yeast has been hitherto carried on in
distilleries by the aid of lactic acid, which was developed in the ferments or in the
clear spent wash, the latter being added to the wort, before fermentation was started,
or in both ferments and wort.
Bakers' yeast prepared in this manner, always contained more or less organic acid,
lactic acid, and others, which increased in quantity, if the yeast were kept for some
time, before being used, and often imparted to bread, buns, rolls &c., made from it,
an unpleasant sour or yeasty taste and flavour.
Several attempts have been made to replace the lactic acid by sulphuric or
hydrochloric acid, or by powerful disinfectants, like salicylic and sulphurous acid, but
the yeast, produced by these means, could not be kept and often turned bad in a day
or two.
In about the years 1890 to 1892 Effront attempted to introduce his process of using
hydrofluoric acid and other fluorides, which belong to the most powerful antiseptics,
in the production and for the preservation of baker's yeast, but this also seems to
have failed, because the yeast must be first by degrees acclimatized to the addition
of hydrofluoric compounds, and when this has been done, it refuses to grow and to
act in a medium free from fluorides, which latter would be most objectionable in a
baker's dough.
I have found that a comparatively weak antiseptic, viz.: boric or boracic acid,
(H, BO, or HBO,, H₂O) is most suitable for the production as well as for the
preservation of baker's yeast, forming a perfect substitute for lactic acid, making the
yeast resistant to infection for a longer period, and preventing the formation of
organic acids in the finished article.
The process of making baker's yeast apart from distilling is based upon the
principle, that but small quantities of sugar (maltose &c.) are required to form the
walls of the yeast-cells, whilst the albuminous substances, the phosphates and salts,
necessary for the formation of their contents, can be well supplied by materials,
cheaper and more suitable, than grain and malt.
These latter materials are malt combs, with or without bran, or peas, lupines,
vetches &c., these are mashed like grain with malt or (specially in the case of
malt-combs and bran) only steeped in warm water of from 140° to 200° F. or more,
with an addition of about 1% of sulphuric, or 2% of hydrochloric acid, and o
to % of sulphurous or salicylic acid, or with an addition of 1 to 1% of sulphurous
acid only. The additions of the said acids can be increased or diminished, according
to the amount of infection present in the raw material or in the water, without
influencing the results to any considerable extent, and the said additions are to be
understood as percentages of the weight of the water, used for steeping or mashing,
which amounts to about 10 to 15 times the weight of the materials steeped or mashed.
To the extract drawn off from the said materials or from other materials,
sufficiently rich in albuminous matter, from 1 to 3lbs. of maltose or other kinds of
sugar are added to say from 1 to 3lbs. for each pound of compressed yeast to be
produced. Under circumstances, specially when the price of the materials for making
imaltose is low enough, the addition of sugar can be increased to about double the
quantity named, and by doing so the output of yeast will be also increased.

page_text: The maltose or other sugar can be mixed with the extract at the beginning of the
operation, or in say from 3 to 6 portions, which method appears more advisable.
The seed yeast or the ferment is put into the fermenting tub with the first portion
of the whole quantity of extract and sugar, or at any rate at the starting of the
operation, and filtered i.e. purified air is pumped into the fermenting liquid through
roses or pipes perforated with small holes close to the bottoms of the vats. The
quantity of air supplied should be sufficient to keep the whole of the wort in a slight
motion, and it should pass into the liquor continuously until the fermentation is
finished, which is indicated by the froth becoming lower, and less in bulk.
During the fermentation or rather the growing of the yeast, a temperature of 85°
to 87° F. should be maintained as the most suitable for the purpose.
The purified air can also be forced into the fermenting wort by means of a rotating
pipe (rouser) with larger outlets at their outer ends, instead of using fixed pipes or
roses.
Boric (or boracic) acid in the proportion of 1 part (in weight) to between 5000
and 10,000 parts of the fermenting liquor is added to the latter, in aqueous solution
to make the process sound, and to prevent the formation of obnoxious organic acid
and other infection.
As soon as the fermentation is finished a quantity of cold water, sufficient for
cooling the wash down to about 72° F., is added to the liquor which is then left:
standing in a cool, slightly ventilated locality. At this temperature the young and
insufficiently developed yeast cells will become matured in the course of some hours
and the whole outcrop will soon settle down at the bottom of the vat. After 10 or
12 hours the spent wash is carefully decanted off and the yeast, left at the bottom of
the vessel is strained through bags or sifting machines, and then well washed in clean
cold water, to which boric or boracic acid is again added in the proportion of 1 part
to from 5000 to 10,000 parts of liquor.
Instead of boric acid, its various compounds such as boric acid with alum, soluble
borates, such as acid magnesium biborate, ammonium and calcium borate, boric
tartrate, further boric acid with borax, boric acid with glycerine, the so called:
boroglyceride &c., could be used in values corresponding with the proportions indicated
above, although it is more advisable, to use pure boracic acid as the most suitable
substance.
The washing, pressing and packing of the new yeast are effected in the usual
manner.
By means of the improvements herein described it is possible to produce a strong
and vigorous yeast, which keeps better than any other made by the aid of lactic acid,
and does not impart any sour or yeasty flavour to the bread &c. made from it.
I would here remark that the proportions of antiseptics and other acids employed
may be varied according to atmospheric and other conditions.
The invention is also applicable to the manufacture of yeast in connection with
distilling.
In this case the formation i.e. the introduction of lactic acid is also dispensed with,
in the ferments as well as in the wort. Instead of the lactic acid, boracic acid is
added first to the ferments, then to the inash in the large vats, and last to the water
for washing the yeast. The additions of boracic acid to be about the same, as
hereinbefore indicated, but it is advisable, to apply from one and a half to double the
amount for the ferments, than for the mash and for the washing water.
The application of the boracic acid or its compounds might also be omitted in the
ferments, and it might be used in the big fermenting vats and in washing the ready
made yeast only, or even in the latter process alone, in which cases it would have to
some extent a similar effect, although the result would not be equally certain and
reliable.
With reference to Effront's processes, concerning the application of hydrofluoric acid
and other disinfectants to fermentation and yeast making, by first gradually
acclimatizing the seed-yeast to worts containing these acids &c. I remark especially,
that no such gradual acclimatization is required, when using boracic acid or its

page_text: compounds for producing yeast and preserving it in the
described.
way
herein before
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed, I declare that what I claim is:
Improvements in the production of compressed baker's yeast principally consisting
in the application of boracic acid and its compounds or derivatives, excluding the use
of lactic acid, in the manufacture of said yeast as hereinbefore described.
Dated this fith day of March 1897.
HARRIS & MILLS,
23 Southampton Buildings, London, W.C., Agents.
HARRIS & MILLS,
23 Southampton Buildings, London, W.C., Agents.