_Of the Incidents, which cause the Heat of the Extract to
vary from the Calculation, the allowances they require,
and the means to obviate their effects._
By incidents, I understand such causes as effect either the malt,
the water, or the mash, during the time the brewing is carrying on,
so as to occasion their heat to differ from what is determined by
calculation. As these might frequently be a reason of disappointment,
an inquiry into their number and effects will not only furnish means to
prevent and rectify the errors they occasion, but also serve to confirm
this practice.
In our researches on the volume of malt, some notice was taken of the
increase of bodies by heat, and the loss occasioned by evaporation.
Water, when on the point of ebullition, occupies the largest space it
is susceptible of; but contracting again, when cold water is added to
it, the true volume of both, when mixed together, remains uncertain,
and may cause a difference between the calculated and real degree
of heat. This cause, however, producing an effect opposite to, and
balanced in part by evaporation, becomes so inconsiderable, as hardly
to deserve any farther consideration.
Water, just on the point of ebullition, may be esteemed heated to
212 degrees. Though, by the continuation of the fire, or by any other
cause[30], the heat never goes beyond this, yet was cold water added to
that, which violently boils, the degree expected from the mixture would
be exceeded; for the cold water absorbing the superfluous quantity of
fire, which otherwise flies off, becomes hot itself, and frustrates the
intent. The time, therefore, of adding the cold water to the hot is
immediately before the ebullition begins, or when it is just ended; and
in proportion as we deviate from this practice, the heat in the extract
will differ from the calculated degree.
The water, for every mash, should, as near as possible, be got ready
to boil, and be cooled in just before it is to be used. A liquor,
which remains a long time after the ebullition is over, and the fire
has been damped up, loses part of its heat, if cold water is applied
to it, the effect cannot be the same as it would have been at first.
On the contrary, if the liquor is got ready too soon, and cold water
immediately added to it, in order to gain the proper degree of
temperature, by leaving the mixture long together, though the fire is
stopped up, more heat than necessary will be received from the copper
and brickwork, especially if the utensils are large. In both cases, the
degree in the extract will not answer the intent.
The effect of effervescence next deserves our consideration, but
this takes place only when the water first comes in contact with the
malt. Germinated grains must, to become malt, be dried so, that their
particles are made to recede from one another, thus deprived of the
parts, to which their union was due, when they come in contact with
other bodies, (as water) they strongly attract the unitive particles
they want, and excite an intestine motion, which generates heat. This
motion and this heat are more active in proportion as the grain has
more strongly been impressed by fire, and the extracting water is
hotter.
A large quantity of liquor applied to the grist is less heated than a
small one, by the power of effervescence. The least quantity of water,
necessary to shew that power, must be just so much as the malt requires
to be saturated, which we have seen to be double the volume of the
grain. When more water than this is applied to the grist, the real
effervescing heat is by so much lessened, being dispersed in more than
a sufficient space.
A table shewing the heat of effervescence for every degree of dryness
in the malt, can only be formed from observations. To apply this table
to practice, and to find out, for any quantity of water used in the
first mash, the degrees of heat produced by effervescence, three times
the volume of the grist must be multiplied by the number expressing
the effervescing heat for malt of such a degree of dryness, and this
produce be divided by the real volume of the whole mash.
A TABLE _shewing the heat occasioned by the effervescing
of malt, for its several degrees of dryness_.
Dryness Heat of
of malt. effervescence.
119° 0
124 3-1/2
129 7
134 10-1/2
138 14
143 17-1/2
148 21
152 24-1/2
157 28
162 31
167 35
171 38-1/2
176 40
Malt dried only to 119 degrees, raises no effervescence, and the
strongest is generated by malt dried to 176 degrees; the heat produced
by this amounts to 40 degrees, but the number of effervescing degrees,
in this or any other case, are reached but from success attending
our endeavours, ultimately to penetrate the malt by heated water, or
not until the grist is perfectly saturated, which, in point of time,
generally takes up the whole space of the first mashing and standing;
the air, therefore, cannot cause any diminution of heat, an incident
which affects considerably every subsequent mash.
The little copper being more distant from the mash tun than the other,
the water there prepared, in its passage to the goods, loses some part
of its heat. And in proportion to the quantity of water used, to the
number of the extracts that have been made, and according as the mashes
have more or less consistency, in the same time do they part with more
or less of their heat. Observations made separately upon strong and
small beer, have shewn the proportions of this loss to be as follows:
_For strong beer._
Mashes 2d 3d 4th 5th
Heat lost 8° 12° 8° 8°
_For small beer._
Mashes 2d 3d 4th
Heat lost 8° 16° 20°
A grist not perfectly malted, or one which contains many hard corns,
disappoints the expectation of the computed degree, as the volume
cannot be such as was estimated from an equal dryness of true
germinated grain. It has been observed, that, in perfect malt, the
shoot is very near pressing through the exterior skin. By so much as
it is deficient in this particular, must it be accounted only as dried
barley, or hard corn. I know no better way of judging what proportion
of the corn is hard to what is malted, than by putting some in water,
the grains not sufficiently grown will sink to the bottom. Were this to
be done in a glass cylinder, the proportion between the hard and malted
corn might be found with exactness.--The unmalted parts being estimated
with regard to their volume, as barley, a quarter of them will be to
the barrel of water as 1,56 to 1[31]. Supposing, therefore, that, in
the brown beer grist, before mentioned, the proportion of hard corns is
of two quarters out of eleven, to discover the true volume of such a
grist, the following rule may be used.
2 quarters of hard malt
9 quarters of true malt 1,56 volume of
1,74 volume at 130° of ---- 1 quarter
----- dryness 3,12
15,66
3,12 volume of 2 quarters of hard corn
Total --------
numb. 11) 18,78 (1,70 true volume of one quarter of this
malt to one barrel of water, and consequently the eleven
quarters will fill a space equal to that of 6,47 barrels.
By means of this rule, we may find what increase of heat any proportion
of hard corns will occasion, as will be seen in the following table.
Proportions of hard corns 1/4 1/6 1/8 1/16 1/32 of the grist
Greater heat of the mash 4° 3 2 1 1/2 degrees.
But the brewing of such malt ought to be avoided as much as possible,
as the hard parts afford no strength to the extract.
If a grist is not well and thoroughly mashed, the heat not being
uniformly distributed in the different parts of the extract, the liquor
of the thermometer, when placed in the running stream of the tap, will
fluctuate, and, at different times, shew different degrees of heat. In
this case, the best way is to take the mean of several observations,
and to estimate that to be the true heat of the mash.
If the gauges of the coppers are not exactly taken, a variation must be
expected.
Though the small and hourly variations in the state of the atmosphere
have but little influence upon our numbers, a difference will be
observed in any considerable and sudden changes either of the heat
or of the weight of the air. Our instruments, and in particular the
thermometer, are supposed to be well constructed and graduated. If the
water cooled in with is more or less hot than estimated, or if the time
of mashing or standing is either more or less than was allowed for, the
computation must be found to vary from the event.
While the malt is new, if the fire it has received from the kiln has
not sufficiently spent itself, this additional heat is not easily
accounted for. This is likewise the case, when malt is laid against the
hot brickwork of coppers; and, on the contrary, a loss of dryness may
be occasioned, if the store rooms are damp.
The artist should be attentive to all these incidents; the not pointing
them out might appear neglectful; enumerating more would exceed the
bounds of use.
Small grists brewed in large utensils lose their heats more readily, by
laying thin, and greatly exposed to the air; and, on the contrary, a
less allowance, for the loss of heat, is required in large grists, and
to which the utensils are in proportion.
This really is the only difference between brewings carried on in
large public brewhouses, and those made in small private places, in
other respects constructed upon the same plan, and with an equal care.
Prejudice has propagated an idea, that where the grists are large, and
the utensils in proportion, stronger extracts could be forced from the
malt, in proportion to the quantity, and that more delicate beers could
be made in smaller vessels less frequently used. These assertions, from
what has been said, will, I hope, need no farther enquiry: the degrees
of heat for the extracts are fixed for every intent, and it cannot be
advantageous, by any means, to deviate from them. Brewings will most
probably succeed in all places, where the grist is not so large as to
exceed the bounds of man’s labour, and not so small as to prevent the
heat from being uniformly maintained. The disadvantages are great on
all sides, when a due proportion is not observed between the utensils
and the works carried on.
It will now be proper to continue the delineation of our two brewings,
and to put all the circumstances relating to them under one point of
view.
A brewing for porter or brown strong beer, computed
for 40 degrees of heat in the air.
11 quarters of malt, dried to 130 degrees, 132 pounds of
hops for 27 barrels 1/2, to go out at 3 worts, 31 Inches
above brass.
Volume of grist 6,32
Water for first mash 16,00
------
22,32
6,32 Volume of grist 6 effervescing degrees.
3 3 degrees for hard corns.
----- ----
18,96 9 degrees equal to 2
7 Effervescence, per inches 1/4 less cooling
table. in for the first mash,
------- (see page 152.)
22,32) 132,72 (6 degrees of heat gained in the first mash
13392 by effervescence.
Mashes 1st 2d 3d 4th 5th
Deg. of heat, 157° 158° 162° 164° 165° See p. 280.
Barrels of
water used, 16 8 12 9 9 See p. 284.
Quantity
cooled in by
calculation, 3/4 2 2-1/2 2 2 See p. 284.
Boiling
water by ------ ------ ------ ----- -----
calculation;
barrels, 15-1/4 6 9-1/2 7 7
Allowances }[32]G. C. L. C. L. C. L. C.
for incidents,}[33]Less 2 inches 1/4. more 2 in. more 3 in. more 2 in.
} L. C. more 2 in. [C] [C] [C]
[34]
A brewing for common small beer, computed for 60 degrees of heat in the
air.
6 quarters of malt dried to 130 degrees; 36 pounds of hops;
30 barrels 3/4 to go out 56 inches above brass.
Grist 3,42
Water )14,50
-------
Volume 17,92
of grist 3,42
3
-----
10,26 4° for effervescence.
7 effervescing degree 1° for hard corns
for malt at 130 3° for new malt hot
----- (see table page 292.) --
8° to be deduced
17,92) 71,82 (4 degrees of heat from the first
7168 gained in the mash cooling in.
----- by effervescence.
14
Mashes 1st 2d 3d 4th
Deg. of heat. 154 166 170 174 See p. 248.
Whole quantity
of water
used, barrels 14-1/2 14-1/2 11 11 See p. 280.
Quantity to
be cooled in,
barrels 3-1/2 3-1/4 2-1/2 2-1/4 See p. 280.
Boiling water
by calculation ------ ------ ------ ------
charged,
barrels 11 11-1/4 8-1/2 8-3/4 See p. 280.
Allowances for [35] [B] [B] [36]
incidents; G. C. G. C. L. C. L. C.
inches; less 2; more 2; more 4; more 5.
These computations, perhaps, will appear more troublesome than they
really are; but, besides the facility which exercise always gives
for operations of this kind, the satisfaction of proceeding upon
known principles, will, I hope, encourage the practitioner to prefer
certitude to doubt. One advantage must greatly recommend it, and at
the same time secure the uniformity of our malt liquors; tables for
each sort and season may be made beforehand, and will serve as often as
the circumstances are the same. The trouble of the computations will
by that means be saved, and by collecting together different brewings
of the same kind, the artist will, at any time, have it in his power
to see what effect the least deviation from his rules had upon his
operations, and to what degree of precision he may hope to arrive.
That nothing may be wanting in this work, to facilitate the
intelligence thereof, I shall insert the method of keeping the account
of actual brewings, made according to the computations I have here
successively traced down. The first column contains the charges of
the coppers, and the numbers computed; the next, the brewings made
from these numbers, with their dates, and the degrees of heat found
by observation; the variations occasioned by unforeseen incidents are
supposed to be allowed for, at cooling in, by the artist, upon the
principle, that each inch of cooling in answers to four degrees of
heat. Noting in this manner the elements of every brewing we make, when
the drink comes into a fit state for use, we are enabled to compare
our practice with the principles which directed it; by this means,
experiments constantly before our eyes will be the most certain and
best foundation for improvement.
_Small Beer. Heat of air 60 Degrees. 6 quarters of Malt, 36lb. of Hops,
for 30 Barrels 3/4, to go out 56 Inches above Brass._
Observations.
| 1760. | 1760. | 1760. | 1761. | 1761. |
| June | June | Aug. | July | July |
| 27. | 30. | 3. | 3. | 5. |
1st Liquor. Charge great copper, }| | | | | |
2 inches 1/2 above brass; cool }| | | | | |
in to 13 inches 1/2 above brass, }| 151 | 149 | 150 | 153 | 150 |
rake 1/2 hour, mash 1 hour, }| | | | | |
stand 1 hour 1/2, heat of the }| | | | | |
extract intended 150 degrees. }| | | | | |
| | | | | |
2d Liquor. Charge great copper }| | | | | |
7 inches above brass, cool in }| | | | | |
to 13 inches 1/2 above brass, }| | | | | |
mash 3/4 hour, stand 3/4 hour, }| 161 | 163 | 163 | 148 | 162 |
heat intended 162 degrees--1 }| | | | | |
wort came in 33 inches above }| | | | | |
brass, boiled 1 hour 1/2, went }| | | | | |
out 28 inches above brass. }| | | | | |
| | | | | |
3d Liquor. Charge little copper }| | | | | |
8 inches 1/2 above brass, cool }|
in to 13 inches above brass, }| 166 | 165 | 165 | 167 | 165 |
mash 1/2 hour, stand 1/2 hour, }| | | | | |
heat expected 166 degrees. }| | | | | |
| | | | | |
4th Liquor. Charge little copper }| | | | | |
10 inches 1/2 above brass, cool }| | | | | |
in to 13 inches above brass, }| | | | | |
mash 1/2 hour, stand 1/2 hour, }| 169 | 172 | 170 | 171 | 173 |
heat expected 170 degrees--2 }| | | | | |
wort came in 39 inches above }| | | | | |
brass, boiled down to 28 inches }| | | | | |
above brass. }| | | | | |
| | | | | |
Length 31 barrels. | | | | | |
_Porter. Heat of the Air 40 Degrees. 11 quarters of Malt, 132lb. of
Hops for 27 Barrels 1/2, to go out at 3 Worts, 31 Inches above Brass._
| 1761, | 1761, | 1761, |
| Nov. 20. | Nov. 22. | Nov. 25. |
| 43° | 35° | 40° |
1st Liquor. Charge great copper }| | | |
13 inches above brass, cool in to }| | | |
17 inches 1/2 above brass, rake }| 153 | 151 | 154 |
1/2 hour, mash 1 hour, stand 1 hour }| | | |
1/2, extract expected 153 degrees. }| | | |
| | | |
2d Liquor. Charge little copper }| | | |
2 inches 1/2 below brass, cool in }| | | |
to 3 inches above brass, mash 3/4 }| | | |
hour, stand 3/4 hour, heat expected }| 155 | 157 | 153 |
at the tap 154 degrees--1 wort came }| | | |
in great copper 16 inches above }| | | |
brass, boiled 1 hour, went out 13 }| | | |
inches above brass. }| | | |
| | | |
3d Liquor. Charge little copper }| | | |
10 inches above brass, cool in to }| | | |
16 inches above brass, mash 1/2 }| | | |
hour, stand 1/2 hour, the tap to }| 157 | 157 | 158 |
come down 158 degrees--2 wort came }| | | |
in great copper 11 inches above }| | | |
brass, boiled 2 hours, went out 5 }| | | |
inches above brass. }| | | |
| | | |
4th Liquor. Charge little copper }| | | |
1 inch 1/2 above brass, cool in to }| | | |
6 inches 1/4 above brass, mash 1/2 }| 160 | 161 | 160 |
hour, stand 1/2 hour, to come down }| | | |
160 degrees. }| | | |
| | | |
5th Liquor. Charge little copper }| | | |
1 inch 1/2 above brass, cool in to }| | | |
6 inches 1/4 above brass, mash 1/2 }| | | |
hour, stand 1/2 hour, tap to come }| 161 | 160 | 161 |
down at161 degrees--3 wort came }| | | |
in 25inches above brass, went out }| | | |
13 inches above brass. }| | | |
| | | |
Length 27 barrels 3/4. | | | |