In carrying out my improved process in and with the apparatus employed
in ordinary commercial distilleries, says Mr. Alfred Springer, of
Cincinnati, O., I preferably employ separate vats or tubs for the nitric
acid solution and the material to be treated, and a convenient
arrangement is to locate the nitric acid tub directly under the grain
tub, so that one may discharge into the other. In the upper vat is
placed the farinaceous material, preferably ground, thoroughly steeped
in three times its weight of water, and, where whole grain is used,
preferably "cooked" in the ordinary manner. The vat into which the
dilute acid is placed is an ordinary cooking tub of suitable material to
resist the acid, provided with closed steam coils and also nozzles for
the discharge of steam into the contained mass. Into this vat is placed
for each one hundred parts of the grain to be treated one part of
commercial nitric acid diluted with fifty parts of water and brought to
a state of ebullition and agitation by the steam coils and the discharge
through the nozzles, the latter being regulated so that the gain by
condensation of steam approximately equals the loss by evaporation. The
farinaceous contents of the upper vat are allowed to flow slowly into
the nitric acid solution while the ebullition and agitation of the mass
is continued. This condition is then maintained for six to eight hours,
after which the mass is allowed to stand for one day or until the
saccharification becomes complete. The conversion can be followed by the
"iodine test" for intermediary dextrins and the "alcohol test" for
dextrin. After the saccharification is complete I may partially or
wholly neutralize the nitric acid, preferably with potassium or Ammonium
carbonate, preferably employing only one-half the amount necessary to
neutralize the original quantity of nitric acid used, so that the mass
now ready to undergo fermentation has an acid reaction. The purpose in
view here is to keep the peptones in solution also, because an acid
medium is best adapted to the propagation of the yeast cells. It is not
absolutely necessary to even partially neutralize the nitric acid, but
it is preferable. Yeast is now added, and the remaining processes are
similar to those generally employed in distilleries, excepting that just
prior to distillation potassium carbonate sufficient to neutralize the
remaining nitric acid is added, in order to avoid corrosion of the still
and correct the acid reaction of the slop.
As a variant of the process I sometimes add to the usual amount of
nitric acid an additional one one-hundredth part of phosphoric acid on
account of its beneficial nutritive powers--that is to say, to one
hundred parts of grain one part of nitric acid and one one-hundredth
part of phosphoric acid.
While my improved process is based on the well-known converting power of
acids on starch, I am not aware that it has ever been applied in the
manner and for the purposes I have described. For example, sulphuric and
hydrochloric, also sulphuric and nitric, acids have been employed in the
manufacture of glucose; but in every such case the resulting products
were not capable of superseding those obtained by the existing methods
of saccharification used in distilleries. In my process, on the other
hand, the product is so capable. Not only may malted grain be entirely
omitted, but more fermentable products are formed and the products of
fermentation are purer. The saccharification being more complete, there
are less intermediary and nonfermentable dextrins, and the yield of
spirits is therefore increased. Malted grain being omitted or used in
reduced quantity, there is less lactic acid and few or foreign ferments
to contaminate the fermenting mass; also, the formation of higher
alcohols than the ethyl alcohol is almost totally suppressed.
Consequently the final yield of spirits is purer in quality and requires
little or no further purification. Also, further, the nitrates
themselves acting as nutrients to the yeast cells, these become more
active and require less nutrition to be taken from the grain.
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