enabling the revenue
officers to assess the duty) to the _Collecting Vessel_,[4] and finally to
the _Fermenting Vessels_, in which the wort is transformed into "green"
beer. The latter is then cleansed, and finally racked and stored.

It will be seen from the above that brewing consists of seven distinct main
processes, which may be classed as follows: (1) Grinding; (2) Mashing; (3)
Boiling; (4) Cooling; (5) Fermenting; (6) Cleansing; (7) Racking and
Storing.

_Grinding_.--In most modern breweries the malt passes, on its way [v.04
p.0509] from the bins to the mill, through a cleaning and grading
apparatus, and then through an automatic measuring machine. The mills,
which exist in a variety of designs, are of the smooth roller type, and are
so arranged that the malt is _crushed_ rather than ground. If the malt is
ground too fine, difficulties arise in regard to efficient drainage in the
mash-tun and subsequent clarification. On the other hand, if the crushing
is too coarse the subsequent extraction of soluble matter in the mash-tun
is incomplete, and an inadequate yield results.

[Illustration: FIG. 1.--An 8-quarter Brewery (Messrs. L. Lumley & Co.,
Ltd.).]

[Illustration: FIG. 2.--Mash-tun with mashing machine.]

_Mashing_ is a process which consists mainly in extracting, by means of
water at an adequate temperature, the soluble matters pre-existent in the
malt, and in converting the insoluble starch and a great part of the
insoluble nitrogenous compounds into soluble and partly fermentable
products. Mashing is, without a doubt, the most important of the brewing
processes, for it is largely in the mash-tun that the character of the beer
to be brewed is determined. In modern practice the malt and the mashing
"liquor" (_i.e._ water) are introduced into the mash-tun simultaneously, by
means of the mashing machine (fig. 2, A). This is generally a cylindrical
metal vessel, commanding the mash-tun and provided with a central shaft and
screw. The grist (as the crushed malt is called) enters the mashing machine
from the grist case above, and the liquor is introduced at the back. The
screw is rotated rapidly, and so a thorough mixture of the grist and liquor
takes place as they travel along the mashing machine. The mash-tun (fig. 2)
is a large metal or wooden vessel, fitted with a false bottom composed of
plates perforated with numerous small holes or slits (C). This arrangement
is necessary in order to obtain a proper sepa