Improvements in the Manufacture of Yeast.
Year: 1893

page_text: Date of Application, 27th Jan., 1893
Complete Specification Left, 27th Nov., 1893-Accepted, 20th Jan., 1894
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Yeast.
I, FLÉGONT MIKAÏLOVITCH POLSKY, of 65, Rue Emóriau, Paris, in the
Republic of France, Architect, do hereby declare the nature of this invention to
be as follows:-
My invention relates to improvements in the manufacture of yeast from rico
without the production of alcohol.
"
Hitherto the manufacture of yeast has usually been followed by the manufacture
of alcohol. There are in fact in existence many manufacturers who work in this
manner and who obtain from ten to twelve per cent. of yeast (the alcohol being
lost) which they sell as "pressed yeast." But the quantity of yeast thus obtained
is quite insufficient to meet the demand besides which its relatively high price
places it beyond the reach of the consumers, such for example, as certain bakors
who are obliged to make their broad without yeast.
In view of these considerations I endeavoured to discover a process which would
allow of manufacturing yeast economically, that is to say, which would enable mo
to obtain a yeast containing the whole of the material originally employed.
According to my process I make use of rice as such original material, that is to
Bay, the product which contains more than any other cereal, the primary materials
capable of being converted into yeast, and which yields, by my new method of
manufacture, beer of the finest quality.
I prefer to employ uncrushed rice; nevertheless if I am unable to obtain it in
this condition I employ crushed rice. In this case before any operation I soak it
until it will easily become crushed in its repeated passages between the cylinders of
a crushing machine.
If I treat rice flour, I soften it by preparing the paste by means of steam at a
high temperature.
For a given quantity of rice I take an equivalent quantity of green barley
malt and an equivalent quantity of wheat malt which has been previously slightly
dried.
Before mixing these substances I propare the water necessary for the mixture in
the following manner.
I take a quantity of water say about half that of the weight of the two malts
employed.
In this volume of water I dissolve six grammes of tribasic phosphate of lime
(3 CaO Pho) for one kilogramme of dried material. I heat this solution to
70 to 75 degrees and I then mix the rice with double tho weight of this water; I
stir for a long time and with great care until a paste or dough is formed which
1 then leave to rest for about two hours, stirring it once again during this
interval.
At the end of this time I commence to add thereto the mixture of the two
malts proviously prepared, and to pour therein the remainder of the solution.
While kneading this new paste or dough I arrango that it shall have at the end
of the operation a temperature not lower than 42 degrees; I afterwards leave it to
rest again for one or two hours, kneading it again during this interval.
These various operations constitute the first part of my process. The second
part consists in converting the starch of the paste or dough into sugar, which
result I obtain by adding to the paste or dough, water heated to 90 to 95 degrees
until the temperature of the mixture reaches 62 to 65 degrees, I then carefully
cover the vessel and leave the mixture to rest for from 1 to 2 hours according to

page_text: the temperature of the surrounding atmosphere, after which I uncover the vessel
and lower the temperature of the mixture to 30 to 32 degrees.
During this time I prepare the yeast in the following manner in order to add it
to the preceding mixture in which the sugar has just been formed.
1 take pressed or liquid yeast remaining from the former operation in the
proportion of fifteen per cent. by weight of the materials employed. I dissolve it
in water or preferably in liquid taken from the vessel containing the preceding
mixture; I stir it and leave it covered over for half an hour and I add the product
to the mixture in the vessel when it has reached an indicated temperature of 30 to
32 degrees.
At the end of this operation I dissolve in water for each kilogramme of yeast
8 centigrammes of tartaric acid (CHO) which I pour into the mixture
immediately after having added thereto the dissolved yeast, I add a solution of
bi-carbonate of soda (NaO, 2 CO,) in the same proportion as the first, that
is to say, 0 gr. '08 of bicarbonate of soda for 1 kilogramme of yeast. I stir the
mixture.
After a quarter of an hour has elapsed I again add the same quantity of tartario
neid solution, and a quarter of an hour aftor another bi-carbonate of soda solution
and so on for every quartor of an hour. 6 to 6 times following.
When these succussive additions have been made I mix this stoop with a
similar steop previously prepared in exactly the same manner as the first and
employing the same materials but in the proportions of about half those before
stated.
I mix the two steeps directly I have poured bi-carbonate of soda into the first
for the last time, and added yeast to the second. I stir with care and add carbonate
of ammonia (CONH), or sal ammoniac (NHCl) dissolved in a small quantity
of water in the proportion of 8 grammes to one kilogramme of pressed yeast or
an equivalent quantity of liquid yeast.
After this fattor oporation I leave the mixture to ferment for 6 to 8 hours,
stirring it from time to time.
At the end of this time the fermentation is almost completed and the yeast sinks
into the bottom of the vessel.
Now I commence the mechanical part of the work, that is to say, the blenching
and pressing of the yeast.
Sometimes, it is necessary to add to the water during one of the washings of the
yeast a small quantity of phosphate of lime (3 CaO, Pho,).
My process carried out as hereinbefore described gives a very white yeast of
the finest quality exactly the samo in quantity as the substances employed. In
cases whore the colour is of no importance, for example, when the yeast is to be
used for the manufacture of alcohol from pure sugar, in order to lower the cost
price I add to the rice a certain of maize flour or bruised maize malt.
Dated this 27th day of January 1893.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Yeast.
1, FLÉGONT MIKAÏLOVITCH POLSKY, of 65, Rue Emérinu, Paris, in the
Republic of France, Architect, 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 :-
My invention relates to improvements in the manufacture of yeast from rice
without the production of alcohol.

page_text: vessel; c indicates a space between the two vessels for cooling the fermented
mass or for maintaining it at an uniform degree of temperature; d, d are the
covers, e, e the floor, the feet of cast iron or wood, 9, 9 the open cross pieces
for supporting the vessel a; is a cock for admitting hot or cold water and z is a
cock for the discharge of the water; each compartment of the vessel a cun serve
for the formation of 20 to 25 kilos. of yeast.
The object of this vessel is to prevent the vexatious causes which might act on
the fermentation in the entire mass and give it a character detrimental to the
formation of the yeast; I have besides observed that the process of multiplication
of yeast in a small quantity of fermented liquid generally gives better results
and consequently easily allows of controlling the separate fermentation.
In transferring the liquid, in which the formation of the sugar has been already
completed from the general vessel into the divided vessel a by means of a pump or
by other suitable means I manage so that the temperature of the liquid falls rapidly
but not below 30° to 32°.
While the temperature is decreasing I prepare the yeast in the following manner
in order to add it to the preceding mixture (wort).
I take pressed or liquid venst remaining from the former operation in the pro-
portion of fifteen per cent. by weight of the materials employed. I dissolve it in
water or preferably in liquid taken from the vessel, I stir it and leave it covered
over for half an hour and I add this stirred yeast to the mixture in the divided
vessel, distributing the whole in the different parts of the vessel when it has reached
an indicated temperature of 30 to 32 degrees.
At the end of this operation I dissolve in water for each kilogramme of yeast
8 centigramines of tartaric acid (CHO) which I pour into the mixture
immediately after having added thereto the dissolved yeast in the divided vessel.
A quarter of an hour after I add a solution of bi-carbonate of potash (KHCO₂)
or of bi-carbonate of soda (NaHCO₂) in the same proportion as the first, that is
to say, 8 centigrammes of bicarbonate of soda for 1 kilogramme of yeast, I stir
the mixture.
Without departing from the principle of the chemical and successive combinations
of the above mentioned, substances the employment of these substances can be
modified, that is to say, after having poured the whole of the tartaric acid solution
at once into the formented mass and having after then added thereto in 5 or
6 portions the bi-carbonate of potash or soda solution, I stir the mixture.
After a quarter of an hour has clapsed I pour into each compartiment of the
divided vessel a the same quantity of tartaric acid solution, and a quarter of an hour
after another bi-carbonate of potash or soda solution and so on for every quarter of
an hour, 5 to 6 times in succession.
When these successive additions have been made the second steep is ready to be
added to the first, this stoep having been previously prepared in exactly the same
manner as the first but the dry materials, that is to say, the rice and the malta are
in the proportions of half those before stated and poured into the general vessel in
which the saccharification took place. I add the second steep to the first in each
compartment of the divided vessel. Finally after having well stirred them I add
carbonate of ammonia (NH),CO, or sal ammoniac (NCI) dissolved in a small
quantity of water in the proportion of 8 grammes to one kilogramme of pressed
Feast or an equivalent quantity of liquid yenst.
After this latter operation I leave the mixture to ferment for 6 to 8 hours,
stirring it from time to time.
At the end of this time the fermentation is almost completed and the yeast sinks
into the bottom of the vessel where it becomes mixed with the particles of malt.
I leave it to rest until the next day (8 to 10 hours).
Now I commence the mechanical part of the work, that is to say, the bleaching
and pressing of the yeast.
Sometimes, it is necessary to add to the water during one of the washings of the
yenst a small quantity of phosphate of lime Ca(PO),.

page_text: of alcohol. There are in fact in existence many manufacturers who work in this
manner and who obtain from teu to twelve per cent. of yeast (the alcohol boing
lost) which they sell as "pressed yeast." But the quantity of yeast thus obtained
is quito insufficient to meet the demand besides which its relatively high price
places it beyond the reach of the consumers, such for example, as certain bakers
who are obliged to make their bread without yeast.
In view of these considerations I endeavoured to discover n process which would
allow of manufacturing yeast economically, that is to say, which would enable me
to obtain a yeast containing the whole of the material originally employed.
According to my process I make use of rice as such original material, tlint is
to say, the product which contains more than any other cereal, the primary
materials capable of being converted into yeast, and which yields, by my new
method of manufacture, yeast of the finest quality.
I prefer to employ unhusked rice; nevertheless if I am unable to obtain it in
this condition I employ husked rice. In this case before any operation I soak it
frequently changing the water, until it will easily become crushed if repeatedly.
passed between the cylinders of a crushing machine.
If I treat rice flour; I soften it by preparing the paste by means of steam or
by the addition of water at a high temperature.
For a given quantity of rice I take an equivalent quantity of green barley malt
sometimes replacing a part of the latter by an equivalent quantity of wheat malt
which has been previously slightly dried.
Before mixing these substances I prepare the water necessary for the mixture
in the following manner.
I take a quantity of water say about twice as large as the weight of rice plus
a quantity of water half that of the weight of the two malts employed.
In this volume of water I dissolve six grammes of phosphate of lime preferably
that which will most easily dissolve in wator, that is to say, acid phosphate of
lime Ca,H,(PO), for one kilogramme of dried material. The employment of
this phosphate assists the development of the globules of yeast, makes them more
elastic, assists the growth of yeast and their branches and prolongs their activity
so that the yeast produced lasts for a longer time and is less affected by change
of temperature.
I heat this solution to 70 to 75 degrees centigrade and I then mix the rice
with double the weight of this water; I stir for a long time and with great care
until a paste or dough is formed which I then leave to rest for about two hours,
stirring it once again during this interval.
At the end of this time I commence to add thereto the mixture of the two
barley and wheat malts previously mixed or prepared, and to pour therein the
remainder of the solution.
While kneading this new paste or dough I arrange that it shall have at the
end of the operation a temperature not lower than 42 degrees; 1 afterwards
leave it to rest again for one to two hours, kneading it again during this interval.
These various operations constitute the first part of my process. The second
part consists in converting the starch of the paste or dough into sugar; this
saccharification I obtain by adding to the paste or dough, water heated to 90 to
95 degrees until the temperature of the mixture reaches 62 to 65 degrees; I then
carefully cover the vessel and leave the mixture to rest for from 1 to 2 hours
according to the temperature of the surrounding atmosphere, after which I uncover
the vessel and commence the operation of transferring the liquid (wort) into a
special vessel provided with partitions or divisions and which is constructed as
shown in the accompanying drawing in the following manner :-Figure being
a longitudinal elevation of the said vessel: Figuro 2 an end view. Figure 3 a
plan and Figure 4 a transverse section of the same, and Figure 5 a transvorso
section of a detail.
a is the interior copper vessel for the fermentation, and a', a¹ are the fixed or
movable partitions or divisions dividing it into compartments; b is an outer metal

page_text: My process carried out as hereinbefore described gives a very white yeast of the
finest quality exactly the same. in quantity as the substances employed. In cases
where the colour is of no importance, for example, when the yeast is to be used for
the manufacture of alcohol from pure sugar, in order to lower the cost price I add
to the rice a certain quantity of maize Hour or maize malt and also other cereals
containing starch.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is :-
1. The herein described process of manufacture of yeast, consisting in the employ-
ment of rice, préferably unhusked, by carrying out the two following operatious :-
(a) Mixing the rice, barley-malt or barley and wheat malts, with a heated
solution of phosphate of lime and by preference acid phosphate of lime.
(b) Saccharifying the paste obtained by dividing it into separate portions or
quantities placed in the compartments of a divided ressol arranged in an
outer supporting vessel, a space being left between the two vessels, the said
space being utilised for obtaining or maintaining the required degree of heat;
mixing the paste in each compartment with the yeast of the preceding
preparation; adding successively and with suitable stirring solutions of
tartaric acid and of bi-carbonate of potash or soda; and allowing the
mixture to ferment during the required time, thereby obtaining the
maximum of yeast which is, if required, bleachod, sifted and pressed.
2. As a new article of manufacture the yeast resulting from the application of
the herein described process and from the employment of rice in various conditions,
such as husked and unhusked rice, barley-malt or barley and wheat malts, mixed or
not with maize or other cereals.
3. The apparatus having divisions or compartments allowing of operating on a
large mass of yeast, but by simultaneous, isolated or separate fermentations,
substantially as heroinbefore described and illustrated in the accompanying
drawing.
Dated this 27th day of Namba 1902