IMPROVEMENTS IN THE MANUFACTURE OF SPIRIT
Year: 1880

page_text: LETTERS PATENT to John McGaan and William Oliphant Glassford, both of
38, Dale Street, Liverpool, for an Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF SPIRIT."
PROVISIONAL SPECIFICATION left by the said John McGaan and William
Oliphant Glassford at the Office of the Commissioners of Patents on the 24th
July 1880.
JOHN MCGAAN and WILLIAM OLIPHANT GLASSFORD, both of 38, Dale Street,
Liverpool. IMPROVEMENTS IN THE MANUFACTURE OF SPIRIT."
"
This Invention has for its object improvements in the manufacture of spirit.
In a Provisional Specification filed by one of us, namely, by me, John McGaan,
on the 5th day of February in the present year, No. 512, a process is described a
main of which is to save to the distiller the inconveniences which he now suffers
owing to the residues of the grain from which he prepares the wash for distilling.
According to the said process a finished glucose is first prepared from the grain, and
the difficulty in ferimenting the glucose by yeast or like ferment is overcome by
the addition of a suitable yeast food.
There are however many distillers so situate that they can dispose of their
residues without serious trouble. In such cases the following process which we
have invented is conveniently and advantageously applied, and an increased yield
and improved quality of spirit is obtained. The grain in the form of meal is
digested under pressure in sulphuric acid diluted with water, in the manner well
understood, for the conversion of the starch of the grain into glucose. The contents
of the boiler are run out and the acid is neutralized with lime. The residue is
separated and the liquor is at once fermented by the addition of yeast, or it might
be wine ferment, and by the addition also of a material upon which the ferment
can feed; malt, or extract of malt, or suitable mineral salts may be employed.
When the fermentation is complete the distillation of the wash is conducted in the
usual manner.
In place of converting the whole of the starch of the grain into glucose by
digesting under pressure with acid this process may be stopped short whilst some

page_text: starch still remains unconverted, and after coming out of the boiler and heing
neutralized the product may be submitted to a mashing process with malt. The
effect of the mashing will be to convert the remaining starch into maltose and
dextrine, of which the former will afterwards yield spirit, but the latter is
unfermentable and is ultimately wasted; therefore the highest yield of spirit will
be obtained when the whole, or practically the whole, of the starch is converted
into glucose. We would remark that at present meal is used in some distilleries,
and it is digested with sulphuric acid and water, but the digestion is always carried
on without pressure, under which condition only a few per cent. at the most of the
starch is converted into glucose, and the great bulk of the starch of the meal is left
to be converted into maltose and dextrine by a subsequent mashing operation; this
is a wasteful process as compared with the conversion of the starch into glucose.
The essential feature of our improvement is the digestion with dilute acid under
pressure, and subsequently the fermentation of the product or liquor drawn from
the boiler so as to convert it direct into wash for distilling. If the digestion under
pressure be arrested whilst a notable quantity of starch remains unconverted a
mashing process is necessary before the fermentation, but if practically the whole of
the starch has been converted into glucose then after neutralization the liquor has
only to be reduced to a proper gravity to be ready for the addition of the yeast and
yeast food.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John McGaan and William Oliphant Glassford in the Great
Seal Patent Office on the 21st January 1881.
JOHN MOGAAN and WILLIAM OLIPHANT GLASSFORD, both of 38, Dale Street,
Liverpool. "IMPROVEMENTS IN THE MANUFACTURE OF SPIRIT."
This Invention has for its object improvements in the manufacture of spirit.
In a Provisional Specification filed by one of us, namely, by me, John McGaan,
on the 5th day of February in the present year, No. 512, and upon which a Patent
has since been granted, a process is described a main object of which is to save to
the distiller the inconveniences which he now suffers owing to the residues of the
grain from which he prepares the wash for distilling. According to the said process
a finished glucose is first prepared from grain, and the difficulty in fermenting the
glucose by yeast or like ferment is overcome by the addition of a suitable yeast
food.
There are however many distillers so situate that they can dispose of their
residues without serious trouble. In such cases the following process which we
have invented is conveniently and advantageously applied, and an increased yield
and improved quality of spirit is obtained. The grain previously crushed is digested
under pressure with sulphuric or other acids diluted with water, in the manner well
understood, for the conversion of the starch of the grain into glucose, for example,
that is to say, the crushed grain is mixed with about three times its weight of
water and three parts of real sulphuric acid to 100 parts of corn, and having
digested for some time the mixture is transferred to a strong metal convertor,
where it is subjected to a high temperature by injecting steam of a pressure of
about 80lbs. to the square inch, and the pressure is maintained for about six
minutes. The contents of the boiler are run out and the acid is neutralized with
lime. The residue is separated, for which purpose a filter press may be employed,
and the liquor, having been brought to a proper specific gravity and temperature is
at once fermented by the addition of yeast or ferment, and by the addition also of
a material upon which the ferment can feed; malt, or extract of malt, or suitable
mineral salts may be employed, as is described in the Specification of the Patent,
No. 512, in the year 1880, to which reference has already been made. Malt extract
is the yeast food which we generally find to be the best. We add three quarters
of a part by weight of well drained yeast for every hundred parts of actual glucose
in solution. Also as a yeast food we add the clear extract or wort obtained by
mashing from 5 to 10 parts of malt per hundred parts of glucose. The liquor
should be set for fermentation at a temperature of about 25° C. and at a specific
gravity of 1055 (water being 1.000). When the fermentation is complete the
distillation of the wash is conducted in the usual manner.
If it should be preferred to use as yeast food the mineral salts already referred
to the cost of neutralizing sulphuric acid with lime and filtering off the sulphate
of lime may be avoided by the substitution for sulphuric acid of other acids as
follows:-
Tribasic phosphoric acid, about 5 parts per 100 parts of corn.
Tartaric acid
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In this case the pressure is maintained at about 80lbs. per square inch for about
10 minutes, the liquor is run out, brought to the proper specific gravity and
temperature, and the following salts added:-
Potassium carbonate, about 1.3 parts per 100 of grain used.
silicate
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Aminonium carbonate
Ferrous sulphate
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page_text: In place of converting the whole of the starch of the grain, or it might be other
starchy material, into glucose by digesting under pressure with acid, this process
may he stopped short whilst some starch still remains unconverted; and after
coming out of the boiler and being neutralized the product may be submitted to a
mashing process with malt. The effect of the mashing will be to convert the
remaining starch into maltose and dextrine, of which the former will afterwards
yield spirit, but the latter is unfermentable and is ultimately wasted; therefore the
highest yield of spirit will be obtained when the whole, or practically the whole, of
the starch is converted into glucose.
We would remark that at present meal is used in some distilleries, and it is
digested with sulphuric acid and water, but the digestion is always carried on
without pressure, under which condition only a few per cent. at the most of the
starch is converted into glucose, and the great bulk of the starch of the meal is left
to be converted into maltose and dextrine by a subsequent mashing operation ;
this is a wasteful process as compared with the conversion of the starch into
glucose.
The essential feature of our improvement is the digestion with dilute acid under
pressure, and subsequently the fermentation by the aid of an added yeast food and
yeast of the product or liquor drawn from the boiler so as to convert it direct into
wash for distilling. If the digestion under pressure be arrested whilst a notable
quantity of starch remains unconverted a mashing process is necessary before the
fermentation, but if practically the whole of the starch has been converted into
glucose then after neutralization the liquor has only to be reduced to a proper
gravity to be ready for the addition of the yeast and yeast food.
In place of yeast a wine ferment may be employed where this is more readily
obtainable.
Having thus described the nature of our said Invention, and the manner of
performing the saine, we would have it understood that we claim,-
The manufacture of spirit by treating under pressure in a closed boiler crushed
maize or other grain or other starch containing material with dilute acid and water
so as to obtain a solution of glucose, which solution (after suitable preparatory
treatment) is fermented by the aid of yeast food and yeast or like ferment and then
distilled, substantially as described.
In witness whereof, I, the said John McGaan, have hereunto set my hand
and seal, this Twentieth day of January, in the year of our Lord One
thousand eight hundred and eighty one.
JNO. MGAAN. (L.S.)