IMPROVEMENTS IN THE MANUFacture OF GERMAN OR DRIED YEAST, PART OF WHICH IMPROVEMENTS IS APPLICABLE TO THE PRODUCTION OF VINEGAR
Year: 1883

page_text: LETTERS PATENT to John Fordred of Tottenham in the County of Middlesex,
Technical Chemist for an Invention of "IMPROVEMENTS IN THE MANUFacture
OF GERMAN OR DRIED YEAST, PART OF WHICH IMPROVEMENTS IS APPLICABLE
TO THE PRODUCTION OF VINEGAR "
PROVISIONAL SPECIFICATION left by the said John Fordred at the Office
of the Commissioners of Patents on the 28th December 1883.
JOHN FORDRED of Tottenham in the County of Middlesex, Technical Chemist
IMPROVEMENTS IN THE MANUFACTURE OF GERMAN OR DRIED YEAST, PART OF
WHICH IMPROVEMENTS IS APPLICABLE TO THE PRODUCTION OF VINEGAR"
Under the name of German or Dried Yeast many varieties of foreign yeast have
for the last fifty years been imported and used in this Country:-the present annual
consumption amounting to 12000 tons, for which foreign producers are paid the
large sum of £600000. These yeasts are known in commerce as Dutch Yeast,
Danish Yeast, Hungarian Yeast and French Yeast; all of these are the product of
the fermentation of worts made without the addition of hops.
Several inventors and patentees have of late years attempted to produce yeast
of the above kind in this Country, but have hitherto failed commercially.
Inventors who have attempted to produce a dried yeast suitable for bakers' use
may be divided into various classes:-1st Those who have taken Brewers' Yeast
and have endeavoured to convert it into German Yeast by various modes of
purification.
.
Another class of inventors have tried to prepare a Dried Yeast either by taking
the yeast produced in Distilleries, and washing and pressing it, or by growing the
yeast plant in a Distiller's wort, as nearly as possible in the manner practised on
the Continent.
A third class of inventors have endeavoured to produce a Dried Yeast by sowing
the yeast seed in a thin paste composed of saccharine and farinaceous matters, in
which the new crop of yeast cells was grown or produced, and afterwards pressing
the whole mass into a dry form.

page_text: Many inventors have failed from a want of knowledge of the kind of article
required, which is not the yeast used for the preparation of the bulk of the bread
baked in this Country (such bread being made by using an extempore or artificial
yeast prepared daily by the baker himself for this purpose and which he calls his
"Ferment"), but a yeast possessing the properties of that imported from the
Continental distilleries, which is of a very special character and is much more
expensive, and is only used for the preparation of Vienna and French bread, buns,
rolls, muffins, crumpets and cakes of various kinds.
Other inventors again have failed through a disregard of the incidence of the
Excise laws of this Country.
In the case of Brewers yeast, the coloring matter and the bitterness of the hops
had to be removed, but even when this was accomplished, the resulting yeast was
devoid of the peculiar and special properties possessed by the true German or
Dried Yeast, as the Brewer's yeast plant (Saccharomyces Cerevisiae) was grown in
a different soil, and under different conditions.
Where it has been sought to produce a dried yeast from Distillers worts, or
worts in which hops have not been infused, it has hitherto been the practice, after
the production of the yeast by fermentation, either to allow the wash to run to
waste, or to distil it for the production of alcohol, and this brought the whole
manufacture under the operation of the Excise laws, which do not permit of the
manufacture being conducted on the Continental system.
Other causes of failure have existed besides those above enumerated, all of which
it is the object of my present invention to remove.
ม
To ensure the successful production in this Country of a Dried or "German
yeast for the special baking purposes above indicated, and equal to that produced
abroad, I prefer to observe the following conditions:-
در
1. The water used must be hard; 2nd Rye grain should form a considerable
proportion of the grist; 3rd to produce a strong and healthy crop of yeast cells,
a wort of high gravity must be employed; 4. The strongest yeast
" seed
obtainable should be used to produce the future crop of yeast cells, such as that
known in commerce as the French or "en avant" yeast; 5. The use of Filter
Presses for the separation and purification of the yeast; and 6. The manufacture
of Vinegar from the resulting wash, instead of either allowing it to run to waste
or distilling it.
In carrying my invention into practice, I proceed as follows:-
1. I take a hard water, such as that found at Burton-on-Trent or Lichfield, or
failing this I harden any good spring water artificially by allowing it to percolate
through a filter bed composed of broken crystalline gypsum, which substance it
will dissolve in considerable quantity, or I harden the water by dissolving in it
what is known as Burton crystals or their equivalent.
2. I employ a grist composed of ground rye, maize, oats and barley malt, and in
which the proportion of rye meal preponderates.
3. The mashing of this grist, which occupies about three hours, is made with a less
proportion of water than is usually employed in preparing a brewer's wort or a
distiller's wort, in order to produce a wort of high specific gravity, and thereby
promote the growth and formation of a very powerful yeast, and to this wort,
when strained and cooled to about 70° Fahrenheit, some strong, vigorous and fresh
yeast "seed" is added. The selection of this seed is a matter to which special
attention should be paid, as the quality of the resulting yeast crop is materially
affected by the nature of the seed employed, and I find that aëration of the worts
materially assists the formation and growth of the new yeast crop.
I may here
remark that a convenient apparatus for preparing the concentrated wort is a mash
tun fitted with what is known as Bucknalls Wort Circulator and Converter (Patent
dated 27th March 1883, N° 1550.).
4. To this concentrated wort I add, in some cases, that is, when there is a deficiency
of yeast food, a proportion of fresh spent wash, which spent wash is known in
France by the name of "Vinasse," and is obtainable from a spirit distillery.

page_text: The goods are now allowed to drain in the usual way, and I then subject the grains
to pressure in any convenient manner, such, for instance, as by passing them through
a perforated conical screw press of the kind known as Burrough's Enterprise Press,
but made proportionately large to deal with the quantity of grains requiring to be
operated on, the object being to recover as much as possible of the rich wort
absorbed by them, which is then conveyed to the fermenting back for subsequent
treatment.
5. After separation of the yeast (as it is formed) from the wort, I strain it through
fine sieves in order to remove any small particles of grist that may be mixed
with it.
The yeast is then pumped through a Filter Press (preferably of the kind known
as Johnson's Filter Press and made of gun metal), from which the resulting cakes
of dried yeast are afterwards removed and packed in the usual coarse canvas bags.
In some cases I prefer to wash the yeast, whilst in the filter press, by pumping
through it cold water, or water containing a small quantity of phosphoric acid or
potassium phosphate; or I mix the yeast with cold water, or with water containing
a small quantity of phosphoric acid or potassium phosphate, previously to pumping
it through the filter press.
As before stated, I employ a wort of high specific gravity, my object being
to effect the two-fold purpose of producing, 1st a strong healthy yeast crop,
2nd a wash of such a character that it can be profitably converted into vinegar of
good quality.
6. In fermenting this heavy wort, I stop its attenuation at the point best adapted
for the double object of yeast making and vinegar making, which point is above
the degree of attenuation usually reached in ordinary distilleries, and after the
separation of the yeast crop I then convert the resulting wash into vinegar in the
usual manner, by passing it over the "Rapes" until the required degree of
acetification is reached.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Fordred in the Patent Office on the 28th June 1884.
JOHN FORDRED of Tottenham in the County of Middlesex Technical Chemist
"IMPROVEMENTS IN THE MANUFACTURE OF GERMAN OR DRIED YEAST, PART OF
WHICH IMPROVEMENTS IS APPLICABLE TO THE PRODUCTION OF VINEGAR"
Under the name of German or Dried Yeast, many varieties of foreign yeasts
have for the last fifty years been imported and used in this Country, the present
annual consumption amounting to 12,000 tons, for which Foreign producers are paid
the large sum of £600,000.-These yeasts are known in commerce as Dutch Yeast,
Danish Yeast, Hungarian Yeast, and French Yeast; all of which are the product
of the fermentation of worts made without the addition of hops. Several Inventors
and Patentees have of late years attempted to produce Yeast of the above kind in
this Country, but have hitherto failed commercially.
Inventors who have attempted to produce a dried Yeast suitable for Bakers' use
may be divided into several classes. First, those who have taken Brewers' Yeast,
and have endeavored to convert it into German Yeast by various modes of
purification.
Another class of inventors has tried to prepare a dried Yeast either by taking
the Yeast produced in Distilleries, and washing and pressing it, or by growing the
Yeast plant in a Distillers' wort, as nearly as possible in the manner practised on
the continent.
A third class of Inventors has endeavoured to produce a dried Yeast by sowing
the seed in a thin paste composed of a saccharine and farinaceous matters, in which
the new crop of yeast cells was grown or produced, and afterwards pressing the
whole mass into a dry form.
Many inventors have failed from a want of knowledge of the kind of article
required, which is not the Yeast used for the preparation of the bulk of the bread
baked in this Country (such Bread being made by using an extempore or artificial
Yeast prepared daily by the baker himself for this purpose, and which he calls his
Ferment"), but a Yeast possessing the properties of that imported from the
continental distilleries, which is of a very special character, and is much more
"expensive, and is only used for the preparation of Vienna and French bread, buns,
rolls, muffins, crumpets, and various kinds of cakes.
"
Other Inventors, again, have failed through a disregard of the incidence of the
Excise laws of this Country.
In the case of Brewers' Yeast, the colouring matter, and the bitterness of the
hops, had to be removed, but even when this was accomplished, the resulting Yeast
was devoid of the peculiar and special properties possessed by the true German or
Dry Yeast, as the Brewers' Yeast plant (saccharomyces cerevisiae) was grown in a
different soil and under different conditions. Where it has been sought to produce
a dried Yeast from Distiller's worts, or worts in which hops have not been infused,
it has hitherto been the practice, after the production of Yeast by fermentation,
either to allow the wash to run to waste, or to distil it for the production of
alcohol, and this brought the whole manufacture under the operation of the Excise
laws of this Country, which do not permit of the manufacture being conducted on 4
the continental system.
Other causes of failure have existed besides those above enumerated, all of which
it is the object of my present invention to remove.
To ensure the economically successful production in this country of a dried or
German Yeast for the special baking purposes above indicated, and equal to those 5
produced abroad, I observe the following conditions
1. The water used must be very hard.
2. Rye Grain should form a very considerable proportion of the grist.

page_text: 3. A wort of high gravity must be employed to produce a strong and healthy
crop of yeast cells.
4. The strongest yeast seed obtainable should be used to produce the future
crop of yeast cells, such as that known in commerce as the French or en avant
yeast (made by Baron Max Springer of Maisons Alfort, Paris.
5. The use of filter presses for the separation and purification of the Yeast.
6. The manufacture of Vinegar from the resulting wash, instead of either
allowing it to run to waste or distilling it.
In carrying my Invention into practice, I proceed as follows:-
1st I take a hard water such as that found at Burton-on-Trent or Lichfield, or
ailing this, I harden any good spring water artificially, by allowing it to percolate
hrough a filter bed composed of broken crystalline gypsum, which substance it will
lissolve in considerable quantity, or I harden the water by agitation with the
rdinary Plaster of Paris of commerce in the proportion of about 1 pound to
very 10 gallons of water, and then, after subsidence, I run off the clear solution.
In making this solution, care must be taken to add the water rapidly to prevent
he ground Plaster of Paris solidifying. The water thus treated should indicate
bout 100 degrees of hardness by Clark's test.
2ndly I employ a mixed grist in which Rye meal preponderates. Such a grist
nav be composed as follows
In making up this grist, the proportions may be varied, always however keeping
the Rye in excess, and other grain or seeds such as Dari, millet, Buckwheat, or the
like, may be substituted for the Maize.
Thirdly: The quantity of water used in mashing this grist (which occupies from
two to three hours) is limited so that a wort of high gravity may be obtained,
this gravity ranging from 1.045 to 1·095 degrees. Such wort promotes the growth
and formation of a very powerful Yeast.
The goods are allowed to drain in the usual way, sparging as little as possible,
and I then separate the residual wort by passing the grains through a centrifugal
machine, or by subjecting them to pressure in any convenient manner, such for
instance as by passing them through a perforated conical screw press of the kind
known as "Burroughs' Enterprize Press," but made proportionately largo to deal
with the quantity of grains required to be operated on, the object being to recover
as much as possible of the rich wort absorbed by them, which after subsidence, is
conveyed to the fermenting tun for subsequent treatment.
To this concentrated wort I add in some cases, that is, when there is a deficiency
of yeast food, a proportion of clear fresh spent wash, which spent wash is known in
France by the name of "Vinasse," and is obtainable from a Spirit Distillery.
To this wort, when strained and cooled to about 70 degrees Fahrenheit, I add
some strong, vigorous, and fresh yeast "seed," in the proportion of say 8 to
10 pounds to every 100 gallons of wort. The selection of this seed is a matter
to which special attention should be paid, as the character of the resulting
yeast crop is materially affected by the nature of the seed employed; a yeast
suitable for such a purpose should possess the following characteristics :-
Under the microscope the cells should appear full, plump and translucent, the
cell wall thin, so that the boundary appears as an almost imperceptible line,
with an absence from the field of empty and shrivelled cells, or any exhibiting
a yellow tint.
I also find that aëration of the worts materially assists the formation and growth

page_text: of the new yeast crop. This aëration I effect by means of any of the Rousers in
ordinary use, such as Sorrell's or Clinch's.
"
I may here remark that a convenient apparatus for preparing the concentrated
wort is a Mash Tun, fitted with what is known as "Bucknall's Wort Circulator
and Converter" (Patent dated 27th March 1883, No 1550). I prefer this mode
of circulation to that effected by means of pumping apparatus, as it has the
effect of not only maintaining, but gradually elevating the temperature of the
Mash, which is of great importance where raw grain constitutes a large proportion
of the grist.
Fourthly: As the yeast is formed, I remove it from the wort in any approved
manner, and after separation, I strain it through fine sieves, in order to remove
any small particles of grist that may be mixed with it. The Yeast is then pumped
through a Filter press (preferably of the kind known as Johnson's Filter Press, and
made of gun metal), from which the resulting cakes of Dried Yeast are afterwards
removed and packed in the usual coarse canvas bags. In some cases I prefer to
wash the Yeast whilst in the Filter Press, by pumping through it cold water, or
water containing a small quantity of a salt of phosphoric acid; or I mix the yeast
with cold water or with water containing a small quantity of a salt of phosphoric acid,
previously to pumping it through the Filter Press. As before stated, I employ a
wort of high specific gravity, my object being to effect the two-fold purpose of
producing, first, a strong healthy yeast crop; and secondly, a wash of such a
character as can be profitably converted into vinegar of good quality.
Fifthly: In fermenting this heavy wort, I stop its attenuation at the point best
adapted for the double purpose of yeast making and vinegar making, that is, when
it has reached a gravity of about 1'008, which point is above the degree of
attenuation usually reached in ordinary distilleries, the object being to avoid, as far
as possible, the production of an acid wash.
After the separation of the Yeast crop, I convert the resulting wash into
vinegar, either by the German quick method, or by stoving, as practised in
England.
Wherever in the above Specification I have prescribed a particular temperature
or proportion of material or time to be employed in the various processes, it must be
understood that I do so merely as indicating that which I have found most
efficacious, but I do not limit myself to such temperatures or proportions or time,
as variations in temperatures or proportions or duration of time, may be introduced,
and results of like character to those which I have described may possibly be
attained.
Having now set forth the nature of my Invention of "Improvements in the
manufacture of German or Dried Yeast, part of which improvements is applicable
to the production of Vinegar," 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 manufacture of German or dried Yeast substantially in the manner
above set forth.
Second: Utilizing the wash resulting from my above described process by
converting the same into vinegar.
In witness whereof I the said John Fordred have hereunto set my hand and
seal the twenty eighth day of June in the year of our Lord One thousand eight
hundred and eighty four.
JOHN FORDRI
ע
(L.S.)