_OF MASHING._
Of late years, great progress has been made towards perfecting the
construction and disposition of brew-house utensils, which seem to
admit of very little farther improvement. The great copper, in which
the waters for two of the extracts receive their temperature, is built
very near the mash tun, so that the liquid may readily be conveyed to
the ground malt, without losing any considerable heat. A cock is placed
at the bottom of the copper, which being opened, lets the water have
its course, through a trunk, to the real bottom of the mash tun. It
soon fills the vacant space, forces itself a passage through many holes
made in a false bottom, which supports the grist, and, as the water
increases in quantity, it buoys up the whole body of the corn.
In order to blend together the water and the malt, rakes are first
employed. By their horizontal motion, less violent than that of
mashing, the finest parts of the flower are wetted, and prevented from
being scattered about, or lost in the air.
But as a more intimate penetration and mixture are necessary, oars
are afterwards made use of. They move nearly perpendicularly, and by
their beating, or mashing, the grains of the malt are bruised, and a
thorough imbibition of the water procured.
The time employed in this operation cannot be settled with an absolute
precision. It ought to be continued, till the malt is sufficiently
incorporated with the water, but not so long as till the heat necessary
to the grist be lessened. As bodies cool more or less speedily, in
proportion to their volume, and the cohesion of their parts, a mash
which has but little water, commonly called a _stiff mash_, requires a
longer mashing to be sufficiently divided, and, from its tenacity, is
less liable to lose its heat. This accounts for the general rule, that
the first mash ought always to be the longest.
After mashing, the malt and water are suffered to stand together
unmoved, generally for a space of time equal to that they were mashed
in. Was the extract drawn from the grain as soon as the mashing
is over, many of the particles of the malt would be brought away
undissolved, and the liquor be turbid, though not rich. But, by leaving
it some time in contact with the grain, without any external motion,
many advantages are gained. The different parts of the extract acquire
an uniform heat, the heaviest and most terrestrial subside, the pores
being opened, by heat, imbibe more readily the water, and give way
to the attenuation and dissolution of the oils. When the tap comes
to be set, or the extract to be drawn from the grist, as the bottom
of the mash is become more compact, the liquor is a longer time in
its passage through it, is in a manner strained, and consequently
extracts more strength from the malt, and becomes more homogeneous and
transparent.
Such are the reasons why the grist should not only be mashed pretty
long, but likewise be suffered to rest an equal time. It is the
practice of most brewers, and experience shews it is best, to rake the
first mash half an hour, to mash it one hour more, and to suffer it to
stand one hour and a half. The next extract is commonly mashed three
quarters of an hour, and stands the same space of time; the third, and
all that follow, are allowed one half hour each, both for mashing and
standing.
The heat of the grist being in this manner equally spread, and the
infusion, having received all the strength from the malt, which such
a heat could give it, after every mashing and standing, is let out of
the tun. This, undoubtedly, is the fittest time to observe whether our
expectations have been answered. The thermometer is the only instrument
proper for this purpose, and ought to be placed, or held, where the tap
is set, adjoining to the mouth of the underback cock. The observation
is best made, when the extract has run nearly half; and as, by it,
we are to judge with what success the process is carried on, it is
necessary to examine every incident, which may cause a deviation from
the calculated heat.