A New or Improved Process for the Recovery and Utilization of Yeast.
Year: 1890

page_text: Date of Application, 8th May, 1890
Complete Specification Left, 5th Dec. 1890-Accepted, 24th Jan., 1891
PROVISIONAL SPECIFICATION.
A New or Improved Process for the Recovery and Utilization of
Yeast.
I, JAMES CAMPBELL, of 36, Roslea Drive. Glasgow, Lanarkshire, Distillery
Manager, do hereby declare the nature of my invention to be as follows:–
1
This invention has reference to and comprises a new or improved process for the
recovery as a bye product of that class of yeast known as "ordinary brewers yeast,"
used either in liquid or compressed form, in malt and in grain distilleries, so that it
can be utilized or used over again, instead of as heretofore becoming a waste or
unrecovered product.
In carrying my invention into practice the ordinary fermenting wort tuns from
which it is intended to recover the hitherto waste product of yeast, are set to ferment
at a temperature preferably of about from 73 to 76 degrees Fahrenheit. The
specific gravity of the worts when set to ferment is preferably hetween 38 and 45
degrees. By my improvements the yeast is skimmed, tapped or removed from the
top of the fermenting tuns, preferably when from about 8 to 10 degrees of gravity
remain unattenuated, and conveyed to a shallow vessel or other suitable receiver
fitted with an "attemperator" for the purpose of maturing and preserving it in a
liquid state. Cold water is run through the pipes or tubes of the attemperator so as
to first lower the temperature of the yeast as quickly as possible to about 6 degrees
Fahrenheit, and then gradually reduce it over a period of about two days until it
reaches any stage from hetween say 53 to 45 degrees Fahrenheit more or less; and
in hot weather ice may also be used as well as water for the cooling medium. A day
or two before the yeast is required for use, the liquid which lies between the top and
bottom. layers of yeast in the vessel in which it is collected, is drained away preferably
by means of an adjustable telescopic drainer, which removes the liquid only, leaving
the yeast in the vessel free; and when the liquid has been thus removed, the yeast is
then collected and placed in casks for re-use as "ordinary brewers yeat." The liquid
drained from the vessel in which the yeast was collected is removed to the fermenting
tuns (after fermentation has ceased) or to the "wash charger" for distillation so that
there is no loss of material, by this new yeast. recovery process. In practice common
salt, in proportion of about one pound to each two thousand gallons wort is dissolved
in bot water, and added to the fermenting tuns when the worts cominence to run in,
and at the same time there is added wheaten flour in the proportion of about one
ounce to each thirty six gallons after being well mixed with twelve gallons of cold
water and passed through a fine hair sieve. In starting the fermenting tuns from
which the yeast is subsequently recovered they would preferably be set to ferment
with fresh brewers yeast taken direct from the brewery.
11
135
1000

page_text: COMPLETE SPECIFICATION (AMENDED).
A New or Improved Process for the Recovery and Utilization of
Yeast.
I. JAMES CAMPBELL, of 36 Roslea Drive, Glasgow, Lanarkshire, Distillery
Manager, do hereby declare the unture of my invention, and in what manner the
same is to be performed to ho particularly described and ascertained in and by the
following statement in writing, flat is to say :-
My invention has reference to and comprises a new or improvel process applicable
only to mult and grain distilleries for the recovery as a bye product of that class or
type of yeast known as "ordinary brewers yeast," sueli as is used in English and
Scotch breweries, and supplied to malt and grain distilleries either in compressed or
liquid form. This is a separate and distinct type of yeast from what is known as
"German yeast." or "bakers yeast."
By my improvements this yeast is enabled to be used over again, either in
distilleries or breweries, instead of as heretofore becoming a waste or unrecovered
product in distilleries.
In carrying my invention into practice the ordinary fermenting wort tuns of malt
and grain distilleries from which it is intended to recover the hitherto waste product of
yen-t, are set to ferment preferably at about from 73 to 76 degrees Fahrenheit. The
specific gravity of the worts when set to ferment is preferably between 38 and 45 degres,
as indicated by the saccharometer used by the Inland Revenue officials. By my
improvements the yeast is skimmed, tapped, or removed by other me ins, from the top
of the fermenting tuns, the operation commencing preferably when from 8 to 12 degrees
of gravity remain unattenuated, till all the yeast required or obtainable is removed,
after which it is conveyed by pipes, spouts, or other means into a shallow vessel or
other suitable receiver, for the purpose of maturing, settling, and preserving it in a
liquid state. This vessel is fitted with an attemperator," or arrangement of pipes,
or tubes through which cold water is run to lower the temperature of the yeast.” The
cooling may also be effected by a refrigerator, a jacketed or false bottomed yeast
receiver through which cold water is run, or by other equivalent means. The
temperature of the yeast in reveiver is reduced preferably to about 60 degrees
Fahrenheit, and then further gradually lowered to any convenient point between 55
and 45 degrees Fahrenheit, more or less, and in hot weather fer may also be used for
the cooling medium. The yeast should be allowed to romain sufficiently long in the
receiver in order that it may "settle" or separate itself from the "wash" or liquid.
A day or two, more or less, before the yeast is require for use the liquid which lies
between the top and bottom layers of yeast in the vessel in which it is collected, is
drained away, preferably by means of an adjustable tele-cope drainer, which removes
the liquid with a small portion of thin yeast, leaving the solid or thicker yeast in the
vessel free and when the liquid has been thus removed, the yeast is then collected
and placed in casks for re-use as ordinary browers' yenst." The liquid or wash
drained from the vessel in which the yeast was collected is removed to the fermenting
Inns (after fermentation las ceased) or to the wash charger" for distillation, so tint
there is little or no loss of material by this new yoast recovery process, and no injury
done to fermentation in the "backs from which the yeast was removed. In practice
common wheaten flour added as a dressing in the fermenting tuns baforo fermentation
his commenced can be used to advantage in producing a larger crop or quantity of
yeast, the proportion being about one ounce of flour to each 36 gallons of worts set to
ferment. The flour should be first mixed with 12 or 15 gallons of cold water and
passed through a fine hair sieve before being added to the worls. In some casos salt
may be added as a preservative agent. In starting fermentation in the fermenting
tums from which the yeast is subsequently recovered they would preferably bo sot to
ferment with fresh brewers' yeast inkon direct from the brewery.
To obtain greater increase in quantity of fine yeast 3 or 4 per cent. of ryu grist

page_text: may be added to the mash from which the worts are taken to produce the yeast,
without perceptibly affecting the flavour of the spirit, in malt distilleries.
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 :-
First. The herein described process for the recovery and utilization of brewers
yeast consisting in skimming tapping or otherwise recovering it from the top of the
fermenting tuns, and cooling and subsequently treating and separating it from the
wash or liquor, substantially as set forth.
Second. In a process for the recovery and use of brewers' yoast the skimming
tapping or removing of the yeast from the top of the fermenting tuns, and cooling
same in with an "attemperator" or equivalent imedium, substantially as set forth.
DL on 1800
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.