In the first place, it
was not until the malt tax was repealed that the brewer was able to avail
himself of the surplus diastatic energy present in malt, for the purpose of
transforming starch (other than that in malted grain) into sugar. The
diastatic enzyme or ferment (see below, under _Mashing_) of malted barley
is present in that material in great excess, and a part of this surplus
energy may be usefully employed in converting the starch of unmalted grain
into sugar. The brewer has found also that brewing operations are
simplified and accelerated by the use of a certain proportion of
substitutes, and that he is thereby enabled appreciably to increase his
turn-over, _i.e._ he can make more beer in a given time from the same
plant. Certain classes of substitutes, too, are somewhat cheaper than malt,
and in view of the keenness of modern competition it is not to be wondered
at that the brewer should resort to every legitimate means at his disposal
to keep down costs. It has been contended, and apparently with much reason,
that if the use of substitutes were prohibited this would not lead to an
increased use of domestic barley, inasmuch as the supply of home barley
suitable for malting purposes is of a limited nature. A return to the
policy of "malt and hops only" would therefore lead to an increased use of
foreign barley, and to a diminution in the demand for home barley, inasmuch
as sugar and prepared cereals, containing as they do less nitrogen, &c.
than even the well-cured, sun-dried foreign barleys, are better diluents
than the latter. At the same time, it is an undoubted fact that an
excessive use of substitutes leads to the production of beer of poor
quality. The better class of brewer rarely uses more than 15-20%, knowing
that beyond that point the loss of flavour and quality will in the long run
become a more serious item than any increased profits which he might
temporarily gain.

With regard to the nature of the substitutes or adjuncts for barley malt
more generally employed, raw grain (unmalted barley, wheat, rice, maize,
&c.) is not used extensively in Great Britain, but in America brewers
employ as much as 50%, and even more, of maize, rice or similar materials.
The maize and rice preparations mostly used in England are practically
starch pure and simple, substantially the whole of the oil, water, and
other subsidiary constituents of the grain being removed. The germ of maize
contains a considerable proport