SECTION XIII.

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
of malt.		Heat of
effervescence.
119°0
1243½
1297
13410½
13814
14317½
14821
15224½
15728
16231
16735
17138½
17640

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.

Mashes2d3d4th5th
Heat lost8°12°8°8°

For small beer.

Mashes2d3d4th
Heat lost8°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 malt1,56 volume of
1,74 volume at 130° of dryness—— 1 quarter
——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 thismalt to one barrel of water, and consequently the elevenquarters 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 corns1/41/61/81/161/32of the grist
Greater heat of the mash4°3211/2degrees.

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 grist6,32
Water for first mash16,00
——
22,32
6,32Volume of grist6effervescing degrees.
3 3degrees for hard corns.
—— ——
18,96 9degrees equal to 2 inches 1/4 less cooling in for the first mash, (see page 152.)
7Effervescence, per table.
——
22,32) 132,72(6 degrees of heat gained in the first mash by effervescence.
13392
Mashes 1st2d3d4th5th
Deg. of heat, 157°158°162°164°165°See p. 280.
Barrels of water used, 1681299See p. 284.
Quantity ooled in by calculation, 3/422½22See p. 284.
Boiling water by calculation; ——————————
barrels, 15¼69½77
Allowances for incidents,}[32]G. C.L. C.L. C.L. C.
[33]Less 2 inches 1/4.more 2 in.[34]more 3 in.[34]more 2 in.[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.

Grist3,42
Water)14,50
——
17,92
Volume of grist3,42
3
——
10,26 4° for effervescence.
7effervescing 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
7168gained in the mash cooling in.
——by effervescence.
14
Mashes1st2d3d4th
Deg. of heat.154166170174See p. 248.
Whole quantity of water used, barrels14½14½1111See p. 280.
Quantity to be cooled in, barrels3½3¼2½2¼See p. 280.
Boiling water by calculation————————
charged, barrels1111¼8½8¾See p. 280.
Allowances for incidents;
G. C[35]G. C.[36]L. C.[36]L. C.[36]
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.
June. 27.		1760.
June. 30.		1760.
Aug. 3.		1761.
July. 3.		1761.
July. 3.
1st Liquor. Charge great copper,2 inches 1/2 above brass; coolin to 13 inches 1/2 above brass,rake 1/2 hour, mash 1 hour,stand 1 hour 1/2, heat of theextract intended 150 degrees.}151149150153150
2d Liquor. Charge great copper7 inches above brass, cool into 13 inches 1/2 above brass,mash 3/4 hour, stand 3/4 hour,heat intended 162 degrees—1wort came in 33 inches abovebrass, boiled 1 hour 1/2, wentout 28 inches above brass.in to 13 inches 1/2 above brass,}161163163148162
3rd Liquor. Charge little copper3 inches 1/2 above brass, cool in to 13 inches above brass,mash 1/2 hour, stand 1/2 hour, heat expected 166 degrees—2}16616516516715
4d Liquor. Charge little copper10 inches 1/2 above brass, cool in to 13 inches above brass,mash 1/2 hour, stand 1/2 hour, heat expected 170 degrees—2wort came in 39 inches above brass, boiled down to 28 inchesabove brass.}16616516516715
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.
Nov. 20.
43°		1761.
Nov. 3.
35°		1761.
Nov. 3.
40°
1st Liquor. Charge great copper 13 inches above brass, cool in to 17 inches 1/2 above brass, rake 1/2 hour, mash 1 hour, stand 1 hour 1/2, extract expected 153 degrees.}153151154
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 at the tap 154 degrees—1 wort came in great copper 16 inches above brass, boiled 1 hour, went out 13 inches above brass.}155157153
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 come down 158 degrees—2 wort came in great copper 11 inches above brass, boiled 2 hours, went out 5 inches above brass.}157157158
4th 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, to come down 160 degrees. }161160161
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 down at161 degrees—3 wort came in 25inches above brass, went out 13 inches above brass. }160161160