ion of an oil of somewhat unpleasant
flavour, which has to be eliminated before the material is fit for use in
the mash-tun. After degerming, the maize is unhusked, wetted, submitted to
a temperature sufficient to rupture the starch cells, dried, and finally
rolled out in a flaky condition. Rice is similarly treated.

The _sugars_ used are chiefly cane sugar, glucose and invert sugar--the
latter commonly known as "saccharum." Cane sugar is mostly used for the
preparation of heavy mild ales and stouts, as it gives a peculiarly sweet
and full flavour to the beer, to which, no doubt, the popularity of this
class of beverage is largely due. _Invert sugar_ is prepared by the action
either of acid or of yeast on cane sugar. The chemical equation
representing the conversion (or inversion) of cane sugar is:--

C12H22O11 + H2O = C6H12O6 + C6H12O6.
cane sugar water glucose fructose
----invert sugar----

Invert sugar is so called because the mixture of glucose and fructose which
forms the "invert" is laevo-rotatory, whereas cane sugar is dextro-rotatory
to the plane of polarized light. The preparation of invert sugar by the
acid process consists in treating the cane sugar in solution with a little
mineral acid, removing the excess of the latter by means of chalk, and
concentrating to a thick syrup. The yeast process (Tompson's), which makes
use of the inverting power of one of the enzymes (invertase) contained in
ordinary yeast, is interesting. The cane sugar solution is pitched with
yeast at about 55 deg. C., and at this comparatively high temperature the
inversion proceeds rapidly, and fermentation is practically impossible.
When this operation is completed, the whole liquid (including the yeast) is
run into the boiling contents of the copper. This method is more suited to
the preparation of invert in the brewery itself than the acid process,
which is almost exclusively used in special sugar works. Glucose, which is
one of the constituents of invert sugar, is largely used by itself in
brewing. It is, however, never prepared from invert sugar for this purpose,
but directly from starch by means of acid. By the action of dilute boiling
acid on starch the latter is rapidly converted first into a mixture of
dextrine and maltose and then into glucose. The proportions of glucose,
dextrine and maltose present in a commercial glucose depend very much on
the duration of the boiling, the streng