Improvements relating to the Production of Yeast, and to Apparatus therefor.
Year: 1897

page_text: Improvements relating to the Production of Yeast, and to Apparatus
therefor.
I, JOHAN HENRI FOLKERTS, of 15, South Street, Finsbury, London, E.C.,
Commercial Agent, do hereby declare the nature of this invention to be as
follows:-
My invention relates to the manufacture of yeast and to apparatus therefor.
In the Specification of former Letters Patent granted to me and dated 1st
October 1895, No. 18296, I have described a process of manufacturing yeast wherein
the albuminous substances are peptonized by first preparing a mash in the usual
manner and allowing this mash to saccharify, and then adding spent wash to the
saccharified materials.
As mother wort for the manufacture of yeast, unmixed clear wort, such as is
obtained in the mashing vat after complete saccharification, can also be advan-
tageously employed for peptonising the albuminous matter, instead of wort mixed
with distiller's wash; since, by reason of the higher concentration of the wort, a
purer course of the fermentation process can be obtained. For removing the
necessary small quantity of still unmixed clear wort from the mash, one or more
cloth filters preferably bucket-shaped are employed, each of which preferably com-
prises a frame of iron or other suitable material, conical at the bottom; over this
frame is stretched a bag or sack of filtering cloth, so that, in this manner, bucket-
shaped receptacles with permeable walls are obtained. These receptacles, the
form of which can however be modified as desired, are simply suspended in the mash
in the mashing vat; the clear wort soon forces its way through the filtering cloth
into the interior of the cloth-bucket; whilst the solid constituents remain in the
mashing vat outside the bucket or receptacle. The clear wort, forced into the
bucket, can be removed from the suspended receptacle by means of a small hand-
pump or in any other suitable manner, in order to be set in fermentation by means
of yeast and then added to the first wort, or with this, to the main wort. If desired,
however, before the yeast is added, a lactic-acid fermentation can be first set up in
the clear wort.
As regards the improved process for the production of yeast herein considered,
I effect an essential improvement or simplification, as compared with the method
exclusively observed, in the processes heretofore usual, wherein the separation of
the solid constituents (grains) of the mash peptonized by means of distiller's wash
from the wort to be attenuated, is carried out by means of filter-presses or clearing
or settling vats, as, in the present process, the performance of the said operation of
separation requires no expensive plant, which latter renders the production of yeast
generally unprofitable in small distilleries. In this new process of separation of
the grains and wort, the mixing of the mash with the distiller's wash takes place

page_text: in a mixing vat, from which short pipes provided with stop-cocks, plugs or the
like, open into another vat, called the first collecting vat.
To these pipes are secured filter-bags which are suspended in the collecting vat
down to the bottom.
When the mash, mixed with distiller's wash, has been subjected to the peptonisa-
tion for a sufficient length of time, the whole mixture is again thoroughly stirred
and then allowed to run through the said pipes into the bags by opening the cocks.
The wort runs quite clear through the pores of the bags into the first collecting
vat, and from there into the aerating vat.
In half an hour, in most cases, with this filtering process, the grains are dry.
The wort having now entirely trickled out of the mash, the lower end of the bag,
which was closed by a clamp, is opened, and the dry solid constituents then fall
into the first collecting vat, the opening through which the wort ran off into the
aerating vat, being previously closed; this material is now mixed with an equal
quantity of water of about 35° Celsius or even with clear distiller's wash and
allowed to run through the pipes in the bottom of the first collecting vat, into the
bags, from which the wort is filtered into a second collecting vat and from thence
flows into the aerating vat. If this appears desirable, a third filtration can be
effected after water has been again added to the solid matter, but in practice this
is very seldom necessary..
The solid matter remaining in the bags after the last filtration, is now emptied
therefrom into the second collecting vat, and from thence transferred to the fer-
menting vat where it is further treated as previously described
Where different kinds of grain are employed, or in general where mashes are
made from which the wort does not readily separate, the bags, as soon as the wort
no longer runs through quickly enough, are tightly tied a little higher than where
the contents are, and at this place a stout rod is secured which is now rotated whilst
the bottom of the bag is pressed fairly closely against the bottom of the collecting
vat, so that it remains lying closely thereto. Or, if desired, the clamp above referred
to may be of such form as to permit of the bag being easily twisted so as to squeeze
its contents. By the rotation, the mash in the bag is tightly pressed and all the
wort thereby rapidly filtered through, just as rapidly as if an easily-filtering mash
were being dealt with.
The arrangements for obtaining the wort by filtering through bags can obviously
be varied in many ways.
In smaller distilleries, for example, the mash mixed with the distiller's wash
can be drawn or pumped from a vat into the bag of an empty vat near it, in which
the bag is suspended, and then, for the second filtration, the bag is again suspended
in the first vat and the material transferred therein, and, after the filtration, allowed
to fall down out of the bag so that the grains can be brought into fermentation in
the vat in which the mash is mixed; the filtered wort runs through a pipe in the
_bottom of the vat to the aerating_vat..
Instead of adding distiller's wash directly to the mash in the mashing vat, the
mash can also be filtered after peptonisation directly through the bag, and the
filtered sweet wort immediately conducted out of the collecting vat into the aerating
vat, where it is cooled and brought into fermentation with or without the addition
of distiller's wash. The grains are then, as above mentioned, brought into the
collecting vat, mixed with clear distiller's wash and this mixture allowed to stand
for several hours so that the wash can act on the grains. After this, the material
is again filtered through the bag suspended in the collecting vat and the wort so
obtained transferred to the wort already in fermentation in the aerating vat.
After this filtration, the grains can be again leached, but the small quantity of
sugar which still remains in the grains is not worth the labour.
Instead of immediately cooling off the sweet wort in the aerating vat as above
mentioned and adding yeast, a lactic-acid fermentation can be first set up therein
and the wort cooled, when it is added to the mash mixed with distiller's wash.
All these operations are, however, as will be seen, based on the same fundamental

page_text: idea, and in most cases the first-mentioned method of operation will be the most
convenient to carry out.
In the first-mentioned process, I employ bags which can filter 250 kilogrammes
of grain at a time, and thus, with four bags, 1000 kilogrammes can be dealt with
together; with the simple apparatus described, ten mashes of 1000 kilogrammes can
be quite easily filtered in 24 hours. The principal advantages which this process
for the separation of grains and wort offers, are the following:-
1. No expensive apparatus, such as filter-presses, clearing or settling vats, or
centrifugal separators are required in the manufacture of wort yeast.
2. The time required for obtaining the wort is reduced to a minimum, since
about 2 hours altogether are sufficient.
3. A safer and better leaching is effected and thus a greater yield of yeast.
4. The labour involved is of an extremely simple and easy nature and requires
no, or very little, practice and attention.
5. The wort is clearer than after any other processes of working, so that a finer
product is obtained.
6. The cleansing is easier and can be carried out in a more certain manner than
with the other known processes.
7. The wear of the bags is much less than in filter-presses and the labour in wash-
ing and reversing them is also much easier.
8. The process is applicable as well for the smallest as for the largest manu-
factories.
011 1
100%
D. YOUNG & Co.,
11 and 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.
Improvements relating to the Production of Yeast, and to Apparatus
therefor.
I, JOHAN HENRI FOLKERTS, of 15, South Street, Finsbury, London, E.C.,
Commercial Agent, 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 the manufacture of yeast and to apparatus therefor.
In the Specification of former Letters Patent granted to me and dated 1st
October 1895, No. 18296, I have described a process of manufacturing yeast wherein
the albuminous substances are peptonized by first preparing a mash in the usual
manner and allowing this mash to saccharify and then adding spent wash to the
saccharified materials.
As mother wort for the manufacture of yeast, unmixed clear wort, such as is
obtained in the mashing vat after complete saccharification, can also be advan-
tageously employed, instead of wort mixed with distiller's wash, for peptonising
the albuminous matter; since, by reason of the higher concentration of the wort,
a purer course of the fermentation process can be obtained. The necessary small
quantity of still unmixed clear wort is removed from the mash by means of my
improved filtering apparatus to be hereinafter described, in order to be set in fer-
mentation by means of yeast and then added to the first wort (i.e. one of the separated
parts of the wort) or with this, to the main body of the wort. .If.desired, however,
before the yeast is added, a lactic-acid fermentation can be first set up in the clear
wort.

page_text: Or, instead of adding distiller's wash directly to the mash in the mashing vat,
the mash can also be filtered after peptonisation directly through my improved
filtering apparatus to be hereinafter described, and the filtered sweet wort immedi-
ately conducted out of the collecting vat into the aerating vat where it is cooled
and brought into fermentation with or without the addition of distiller's wash. The
grains are then brought into the collecting vat, mixed with clear distiller's wash
and this mixture allowed to stand for several hours so that the wash can act on
the grains. After this, the material is again filtered and the wort so obtained
transferred to the wort already in fermentation in the aerating vat.
After this filtration the grains can be leached, but the small quantity of sugar
which still remains in the grains is not worth the labour.
Instead of immediately cooling off the sweet wort in the aerating vat as above
mentioned and adding yeast, a lactic-acid fermentation can be first set up therein
and the wort cooled, when it is added to the mash mixed with distiller's wash.
My said invention, moreover, comprises an improved filter for separating the
clear wort from the completely saccharified mash, wherein cloth-filters, stretched
over iron or other frames, are simply-suspended in the mash in the mashing vat
so that the clear wort forces its way into the interior of the filter and can be removed
therefrom in any suitable manner.
For separating the solid constituents of the mash mixed with wash from the
clear wort, I employ bags made of filter-cloth and secured beneath the mixing vat
or suspended in an adjacent vat and so fitted and arranged that the filtration can
be promoted by pressing the mash by turning round one end of or twisting the bag,
and the solid matter therein can be afterwards discharged into a vat beneath by
opening the bottom of the said bag.
In my improved process for the production of yeast I effect an essential simplifica-
tion, as compared with the method exclusively observed, in the processes heretofore
usual, wherein the separation of the solid constituents (grains) of the mash
peptonized by means of distiller's mash from the wort to be attenuated, is carried
out by means of filter-presses or clearing or settling vats, since, in the present
process, the performance of the said operation of separation requires no expensive
plant, which latter renders the production of yeast generally unprofitable in small
distilleries.
In the accompanying drawings I have shown various forms of the apparatus which
I employ in carrying my said invention into practice:-
Figure 1 is a side elevation, partly in vertical central section, and
Figure 2 a plan showing my improved bucket-shaped filter.
Figure 3 is a vertical section, showing a filtering-plant constructed according to
my said invention with bag-shaped filters.
Figure 4 shows a portion of the filtering apparatus illustrated in Figure 3, drawn
to an enlarged scale.
--Figures 5, 6 and 7 are side elevations_illustrating clamping devices for use in
connection with my improved apparatus.
Figure 8 is a diagrammatic view, illustrating a modified form of the apparatus
shown in Figure 3, some of the parts being removed."
.
Like letters indicate corresponding parts throughout the drawing.
In the arrangement shown in Figures 1 and 2, M is a bucket-shaped bag of
filter-cloth which is stretched over a frame N of iron or other suitable material,
this frame being made conical at the bottom as shown. An adjustable clamping
ring M¹ is also provided around the upper edge of each bag M so as to retain it in
position on the frame N, the said frame N being also provided with a loop Nor
other suitable means whereby it may be supported in position for use.
receptacles, the form of which can, however, be modified as desired, are simply
These
suspended in the mash in the mashing vat: the clear wort soon forces its way
through the filtering cloth into the interior of the cloth-bucket; whilst the solid
constituents remain in the mashing vat outside the bucket or receptacle. The clear
5

page_text: wort, forced into the bucket, can be removed from the suspended receptacle by
means of a small hand-pump or in any other suitable manner.
In Figures 3 to 7 I have shown, by way of example, an arrangement whereby
the clear wort can be separated from the solid constituents (grains) of the mash
in a more complete and less expensive manner than has heretofore been practised
with filter-presses, clearing-vat centrifugal apparatus, etc. This arrangement,
which is suitable for larger plants, comprises tanks or vats A, B, C, arranged one
above another. In the bottom of the vats A and B are secured outlet-tubes b ta
which filter bags S and S¹ of filtering cloth are suspended, the lower open ends of
which lie over or extend into the vats B and C respectively.
Figure 4 shows how the bags can be secured at their upper ends (which are like-
wise open) to the supporting tubes. In the upper edge of each bag is sewed a
severed ring or bow a, whereby the bag is placed over the supporting tube, which
tube is provided at its lower end with a projecting flange or bead; the bag is then
tightly clamped beneath the said ring or bow onto the supporting tube by means
of a clamping ring D, Figure 5. The bow thus effectually prevents slipping-off
of the bag.
The lower end of the bag can be held together by means of tongs E, Figure 6,
provided with an adjusting ring e.
Figure 7 shows a pair of tongs F formed with an arm f, which, in addition to
holding together the lower end of the bag, also serves for wringing-out the bag to
accelerate filtration. The vat B is, moreover, provided with an outlet-pipe o, and
the vat C with two outlet-pipes o¹ and p.
The various outlet-pipes are provided with suitable closing devices such as pins
or plugs d, etc.
The arrangement shown in Figure 3 can be used as follows for the purposes
stated, viz.
The mash is brought into the vat A, or is prepared therein, either with or without
the addition of spent wash, and, after being thoroughly stirred, is let or drawn off
into the bags closed beneath by the tongs E or F. The filtered wort drops
into the collecting vat B and flows through the outlet-pipe o into an aeration vat.
When the wort has ceased trickling from the bags S, say, after half-an-hour from
the commencement of the operation, the tongs E or F are opened and the outlet a
closed. The solid constituents then fall into the collecting vat B. This residue
in the vat B is now mixed with water or clear wash at a temperature of about 35° C.
and filtered through the bags S₁ which hang beneath the mixing vat B. The wort
filters into the vat C and passes from there into the aeration-vat through the
pipe o¹.
As soon as the filtration has ceased, the outlet o¹ is closed and the tongs
removed from the bags S¹, so that the solid constituents fall into the vat C, from
whence they are transferred into the fermenting vat through the pipe p.
It is possible, if it appears desirable, to effect a third filtration, after again adding
water to the solid constituents; however in practice this will seldom be necessary.
The solid matter remaining in the bags after the last filtration is now emptied
therefrom and transferred to the fermenting vat where it is further treated as
previously described.
Where different kinds of grain are employed, or in general where mashes are
made from which the wort does not readily separate, the bags, as soon as the wort
no longer runs through quickly enough, are tightly tied a little higher than where
the contents are, and at this place a stout rod is secured which is now rotated whilst
the bottom of the bag is pressed closely against the bottom of the collecting vat,
so that it remains lying closely thereto. Or the bags may be twisted by means
of the tongs F above described.
Figure 8 shows the arrangement in a simpler form, for cases in which space is
limited in an upward direction, and for small plants.
A¹ and B¹ are two adjacent vats provided with outlet pipes o and o' that can be
closed as above described. Over these vats is arranged a filter-bag S in such a

page_text: +
manner that it can be suspended at one time over one, and at another time over
the other vat.
In this arrangement, for example, the mash can be prepared in the vat A', which
mash is then pumped or otherwise transferred into the filter-bag S hanging over
the vat B which bag is closed at the bottom with a pair of tongs E or F. The
wort filters into the vat B and runs through the pipe o into the aerating vat. After-
wards the pipe o is closed, and the bag S opened at the bottom. The solid con-
stituents that fall into the vat are mixed with water or clear wash and then again
transferred into the filter-bag whilst the same is hanging over the vat A. The
filtered wort drops into the vat A¹ and runs through the pipe o' to the aerating vat,
after which the pipe o¹ is closed and the bag emptied into the vat A¹ where the
grains can be brought into fermentation.
In the process described with reference to Figures 3 to 7 I employ bags which
can filter 250 kilogrammes of grain at a time and thus, with four bags 1000 kilo-
grammes can be dealt with together; with the simple apparatus described ten mashes
of 1000 kilogrammes can be quite easily filtered in 24 hours. The principal advan-
tage which this process for the separation of grains and wort offers, are the
following:-
1. No expensive apparatus, such as filter-presses, clearing or settling vats, or
centrifugal separators are required in the manufacture of wort yeast.
2. The time required for obtaining the wort is reduced to a minimum since about
2 hours altogether are sufficient.
3. A safer and better leaching is effected and thus a greater yield of yeast.
4. The labour involved is of an extremely simple and easy nature and requires
no or very little practice and attention.
5. The wort is clearer than after any other processes of working so that a finer
product is obtained.
6. The cleansing is easier and can be carried out in a more certain manner than
with the other known processes.
7. The wear of the bags is much less than in filter-presses and the labour in wash-
ing and reversing them is also much easier.
8. The process is applicable as well for the smallest as for the largest manu-
.factories.
· 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
First. A process for the manufacture of yeast, in which unmixed clear wort, such
as is obtained in the mashing vat after complete saccharification of the mash, is
set in fermentation and then added to the first wort, or with this, to the main wort,
substantially as hereinbefore described.
Second. The removal of the mother. wort from the mashing vat by means of
bucket-shaped cloth filters which consist of perforated bucket-frames of iron or
other suitable material covered with filter-cloth and which are suspended in the
saccharified mash so that the clear wort collects in their interior and can be removed
therefrom in any desired known manner, substantially as herein before described.
Third. The modification of my improved process in which the mash, without
addition of wash, is filtered in the manner herein before described and the filtered
sweet wort is brought into fermentation in the aerating vessel, whilst the grains,
after being mixed with clear wash, are again filtered and the wort conducted to the
already fermenting wort in the aerating vessel.
Fourth. For effecting the separation of the solid constituents of the mash mixed
with wash, from the clear wort, without the employment of filter-presses, centri-
fugal apparatus or clearing-vats, the filtration of the peptonised combined mash
through bags made of filter-cloth and secured beneath the mixing-vat or suspended
in an adjacent vat, the filtration, if desired, being further promoted by pressing
the mash by twisting the bag, substantially as herein before described.

page_text: Fifth. The filtration of the mash in the manufacture of yeast, by introducing
the mash to be filtered into open bags of filtering cloth provided at their lower
ends with easily detachable fastening or closing devices, and arranging these bags
over one or more collecting vats, then running the filtered wort into the said vats,
and, after running-off this wort, allowing the solid constituents of the mash to fall
into the said vats by loosening the fastenings of the bags, substantially as herein-
before described.
Sixth. A filtering device for effecting a complete filtration so as to entirely use
up the grains, wherein one or more filter-bags are suspended beneath a mixing
vat and above a collecting-vat having an outlet-pipe for the filtered wort, to the
bottom of which collecting-vat are also suspended filter-bags for the filtration of
the residue, after treatment of the grains shot out into the said collecting-vat with
water or clear wash, a running-off vat for these bags being also provided, if desired,
with suspended filter-bags for further filtration of the residue, substantially aa
hereinbefore described.
Lot
הד
1000
D. YOUNG & Co.,
11 and 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.