_Of the disposition of the Worts when turned out of
the Copper, the thickness they should be laid at in
the Backs to cool, and the heat they should retain for
fermentation, under the several circumstances._
When a process of brewing is regularly carried on with two coppers, the
worts come in course to boil, as the extracts which formed them are
produced. It would be tedious and unnecessary to describe the minutest
parts of the practice; which, in some small degree, varies as brewing
offices are differently constructed, or the utensils are differently
arranged. Without the assistance of a brewhouse, it is perhaps
impossible to convey to the imagination the entire application of the
rules before laid down, but with one, I hope they need little, if any,
farther explanation.
The worts, when boiled, are musts possessing an intended proportion of
all the fermentable principles, except air; this was expelled by fire,
and until their too great heat is removed, cannot be administered to
them.
In musts, which spontaneously ferment, the external air excites in
their oils an agitation, which, heating and opening the pores of the
liquor, expands and puts in action the internal air they possess.
The case is not exactly the same with regard to those musts which
require ferments. The air wanted in boiled worts must be supplied by
the means of yeast. Was the heat of the wort such, as to occasion the
immediate bursting of all the air bubbles contained in the yeast,
an effervescence rather than a fermentation would ensue. Now a heat
superior to 80 degrees has this effect, and is therefore one of the
boundaries in artificial fermentation; 40 degrees of heat, for want of
being sufficient to free the air inclosed in the yeast bubbles, and to
excite their action, is the other. Within these limits, must the wort
be cooled to; and the precise degree, which varies according to the
different circumstances they are in, and to the intent they are to be
applied to, is, together with the means of procuring this heat, the
purport of this section.
Worts, when in the copper, boil at a heat somewhat superior to that of
212 degrees; the more this is exceeded, the stronger the liquor is. The
instant the wort is suffered to go out of the copper, it loses more
heat than in any other equal space of time after it has been exposed to
the air. In the course of the natural day, or in 24 hours, the heat of
the air varies sometimes, (especially in summer) as much as 20 degrees.
If the wort, after having reached the lowest heat in this interval,
was suffered to remain in the coolers, till the return of a greater in
the air, it would be influenced by this increase, expand, and be put
in action; and, should there be at this time any elastic air in any
part of the coolers, which sometimes happens, either from the sediment
of former worts, from the backs not being clean swept, or from the
wood being old and spungy, the wort supposed to be left to cool, will,
by receiving the additional heat from the air, and blending with the
incidental elastic air adhering to the coolers, bring on, in a lower
degree, the act of fermentation; an accident by the artist called the
_backs being set_.
For this reason, a wort should never be suffered to lay so long as to
be exposed to the hazard of this injury, which generally may happen
in somewhat more than twelve hours. Thus are we directed to spread
or lay our worts so thin in the backs, as they may come to their due
temperature within this space; in summer it is sufficient if the backs
be covered; in winter a depth of two inches may oftentimes be allowed
with safety.
From the inclination of the coolers or backs to the place, where the
worts run off, from their largeness, or from the wind and air warping
them, a wort seldom, perhaps never, lays every where at an equal
depth, and cannot therefore become uniformly cold in the same space
of time. This renders the use of the thermometer difficult, though
not impracticable. To supply the want of this instrument with some
degree of certainty, the hand intended to feel the worts, is brought
to the heat of the body, by placing it in the bosom, until it has
fully received it. Then dipping the fingers into the liquor, we judge,
by the sensation it occasions, whether it is come to a proper degree
of coolness to be fermented. As the external parts of our bodies are
generally of about 90 degrees of heat, some degree of cold must be
felt, before the worts are ready for the purpose of fermentation. But
that degree varies for different drinks, and in different seasons. I
will endeavour to point out the rules to form a judgment for the heat
of small beer worts. A greater precision, both for that and for other
drinks, will be found in the following table.
In July and August, no other rule can be given, than that the worts
be got as cold as possible. The same rule holds good in June and
September, except the season is unnaturally cold. In May and October,
worts should be let down nearly thirty degrees colder than the hand; in
April, November, and March, the worts should be about twenty degrees
colder than the hand, and only ten in January, February and December.
It may perhaps be thought that the heats here specified are great, but
worts cool as they run from the backs to the working tuns, they are
also affected by the coldness of the tuns themselves, and perhaps these
circumstances are not so trivial, but that an allowance should be made
for them. In general, the heat of no must should exceed 60 degrees,
because fermentation increases this or any other degree, in proportion
to that, under which this particular part of the process begins. To
render the thermometer more useful, and to suit it to our conveniency,
we have before supposed every first mash for common small beer to be
made at four o’clock in the morning: in this case, and where the worts
are not laid to cool at more than one inch in depth, the following
table may be said to be a measure of time, the first and last worts for
this drink should be let down at.
A TABLE, _shewing nearly the times the first and last worts of common
small beers should be let down in the working tuns, supposing the first
mash of the brewing to be made at four o’clock in the morning, and no
uncommon change happens in the heat of the air_.
Vertical headings--
A: Heat of the air at 8 o’clock in the morning.
B: Hours in the afternoon, same day as brewing began.
C: Hours in the afternoon.
D: Hours of the next morning.
[A] Air. 1st Wort. [B] 2nd Wort. [C]
30 3 o’clock. } 5 o’clock }
35 3-1/2 } 6-1/2 }
40 4-1/4 } 8 }
45 4-3/4 } 9-1/4 }
50 5-1/2 } 11-1/2 }
55 6-1/2 } 1-1/2 } [D]
60 7-1/2 } 2-1/2 }
65 8 } 2-1/2 }
70 8-1/2 } 3 }
75 9 } 3 }
80 9 } 4 }
Small beer worts being nearly alike in consistency, the necessary
variations from this table must be less frequent. It is true, some
difference may happen from the exposition of a brewhouse, or from
other circumstances, admitting more or less freely the intercourse of
the air, and be such as might alter, upon the whole, the times set
down in the preceding page. Brown beer worts, which are more thick and
glutinous, and especially amber worts, which are stronger still, will
require other and longer terms to come to their due temperature, to be
fermented at; but when once observed and noted, according to various
degrees of heat in the air, at 8 o’clock each morning, the conveniency
of these observations must be such, in this business, which requires
long watchings and attendance, that no arguments are necessary to
recommend what is rather indulgence than industry.
A TABLE _shewing the degrees of heat worts should be at,
to be let down from the coolers into the working tuns,
according to the several degrees of heat in the air_.
Heat of the air. Common small. All-keeping beers. Amber or ales.
25 75 59 55
30 70 56 54
35 65 53 53
40 60 50 52
45 55 50 51
50 50 50 50
55 } In these cases, when the medium heat of the air
60 } is greater than that which the worts should ferment
at, the cold of the night must be made use of, to
bring them as near as possible to their temperature. It
has been observed, that the coldest part of the natural
day is about one hour before sun rising.
The consequences of worts being set to ferment at, in
an undue heat, are the following. In strong beers, or
such as are intended for long keeping, if the worts be
too cold, a longer time is required for their fermentation,
and the drinks grow fine with more difficulty; if, on the
contrary, they are too hot, acidity, and a waste of some
of the spiritous parts must ensue. Either of these disadvantages
appears more conspicuous in common small
beer, as, in winter, this drink is seldom kept a sufficient
time to correct the defect, and in summer, from being
too hot, it becomes putrid, or, in the terms of the brewery,
is hereby _foxed_.