The Theory and Practice of Brewing

by Michael Combrune

SECTION XI.

Of the Proportion of cold Water to be added to that which is on the point of Boiling, in Order to obtain the desired heat in the Extract.

The degree of heat, which causes water to boil is determined, by Farenheit’s scale, to 212. It is in our power to give to any part of the extracting water this degree of heat; and by adding to it a sufficient proportion of water of an equal heat with that of the air, and blending these two quantities with the grist, to bring the whole to the required temperature. The rules for obtaining this end are extremely simple, and cannot be unknown to those, who are skilled in arithmetical operations. But as our view is to render this part of our work generally useful, we think it will be proper briefly to lay down these rules, and to illustrate them by the examples of our two brewings.

Rule to ascertain the heat of the first Mash.

Let a express the degree of boiling water, b the actual heat of the air, c the required degree for the extract, m the whole quantity of water to be used, n the volume of the malt; x, that part of the water, which is to be made to boil, will be determined by the following equation.

	———		———
	c - b	×	m + n
x =	—————————
	a - b

The quantity of water used, added (+) to the volume of the grist.

Their sum (z) multiplied (×) by the heat required, less (-) the heat of the air.

This produce divided (÷) by the heat of boiling water (212) less (-) the heat of the air will quote how much is to be made to boil or brought through (212) that is how high the copper is to be charged, the remainder of the length of the whole liquor for this mash, is the quantity to be cooled in.

The first example is that of a brewing of small beer, when the heat of the air is at 60, (see page 232.) The volume of the 6 quarters of malt was estimated at 3,42 barrels, (see page 268;) the first liquor is 14½ barrels, (see page 247) and the heat required for the first mash 154 degrees, (see page 247.)

First Mash.

m =	14,50	Barrels of water
n =	3,42	Volume of grist
	——
m + n =	17,92	c = 154 Heat of the first mash,
	94	b = 60 Heat of the air,
	——	——
(a) heat of		c - b = 94
boiling water, 212	7168
b heat of the air, 60	16128
——	——
a - b = 152	)168448	(1108 barrels of water, tobe made to boil out of the 14 + 1/2 barrels whichare allotted for the first mash. The incidents to be mentioned, are not considered in this calculation.
	152
	——
	164
	152
	——
	1248
	1216
	——

The next example of a brewing is that of a grist of eleven quarters of malt for porter or brown beer; the medium heat of the air is forty degrees, the volume of the grist, 6,32 barrels, (see page 268) the first liquor to mash with sixteen barrels, (see page 245) and the heat expected in the mash, one hundred and fifty-seven and a half[29] degrees. (See page 245).

First Mash of brown strong beer.

	16,00	Barrels of water
	6,32	Volume of malt
	——	157 Heat required in the
	22,32	mash, vide page 247.
	117	40 Heat of the air.
	——	——
Heat of boiling	15624	117
water, 212	2232	——
Heat of air, 40	2232
——	——
172	)261144	(15,18 barrels of water, to be
	172	made to boil out of the
	——	16 barrels.
	891
	860
	——
	314
	1324
	——

I will give one proof of the certainty of this rule, by setting down the state of this first mash from it.

	15,18
	212
	———
	3036
	1518
	3036
	———
A.	3218,16	Number of degrees of heat in 14,66 barrels of boiling water.
	16,00	Barrels of water to first mash.
	15,18	Barrels made to boil.
	———
	,82	Barrel to cool in.
	40	Heat of cold water.
	40	Heat of cold water.
B.	32,80	Number of degrees of heat in 1,34 barrels of cold water.
	15,18	Boiling water.
	,82	Cold water.
	6,32	Volume of grist.
	———
C.	22,32	Barrels, volume of the whole mash.
	6,32	Barrels, volume of the 11 quarters of malt.
	,40	Heat of the grist.
	———
	252,80	Number of degrees of heat in the grist.
	32,80	B.
	3218,16	A.
	———
C.	22,32 )350376	(157 degrees of heat required in thefirst mash, as above.
	2232
	———
	12717
	11160
	———
	15576
	15624
	———

So long as the mixture consists only of two quantities of different heat, as is always the case of the first mash, the preceding solution takes place. But in the second and other mashes, where three bodies are concerned, each of different heat, viz. the boiling water, the cold water, and the mash, are to be mixed, and brought to a determinate degree, the rule must be different; yet, like the former, it is the same with what is used in similar cases of allaying, when different metals are to be melted down into a compound of a certain standard, or different ingredients of different value to be blended, in order to make a mixture of a determinate price. What the different density of the metals, or the different value of the ingredients are, in these cases, the different degrees of heat of the boiling water, the grist, and the air, are in this.

Rule to ascertain the heat of the second mash, and of the subsequent ones.

Let the same letters stand for the things they signified before, and d express the actual heat of the grist, then will

	——		——
x =	c — b	× m +	c — d	× n
——————————
a — b

or in plain terms, the heat required less (-) the heat of the air, multiplied (×) by the quantity of water used.

The heat required less (-) the heat of the goods, multiplied (×) by the volume of the goods.

Their sum (z) divided (÷) by the heat of boiling water, (212) less (-) the heat of the air.

Will quote the quantity to be made to boil, or to be brought through (212) the remainder part of the whole liquor for the mash is consequently the quantity to be cooled in.

We may now collect the circumstances of the two brewings, and find the quantity of boiling water, required for their second and subsequent mashes, exclusively of the incidents which will hereafter be mentioned.

The first mash for the six quarters of small beer, had 154 degrees of heat, but this and every mash loses, in the time the extract is parting from it, 4 degrees, which reduces the heat to 150 degrees. The volume of this grist, in its dry state, was 3,42 barrels, but now, by being expanded, and having imbibed much water, it occupies three times that space, or 10,26 barrels; the air is supposed to continue in the same state of 60 degrees of heat. The length and heat to be given to the three remaining mashes, are as follows. (See page 247.)

Degrees of heat,	154	166	170	174
Barrels of water,	14½	14½	11	11
Liquors,	1st	2d	3d	4th
	╰━━⌄━━╯		╰━━⌄━━╯
	1 wort.		2 wort.

Second Mash for Small Beer.

c =	166	Heat required in the mash.
d =	150	Heat of the goods.
	——
c - d =	16
n =	1026	Volume of the goods.
	——
	96
	32
	160
	——
c - d × n =	16416
c =	166	Heat required in the mash.
b =	60	Heat of the air.
	——
c - b =	106
m =	1450	Barrels of water.
	——
	5300
	424
	106
	——
c - b × m =	153700
c - d × n =	16416
	——
a - b = 152)	170116	(11,19 Barrels of water to be made to
	152	boil out of the quantity allotted
a = 212	——	for the second mash.
b = 60	181
——	152
152	——
	291
	152
	——
	1396
	1368

Third Mash.

170	Heat of mash.	170	Heat of 3rd mash.
60	Heat of air.	162	Heat of goods.
——		——
110		8
1100	Barrels of water	1026	Volume of grist.
——	3d mash.	——
11000		8208
110
——
121000
8208
——
152)129208	(8,50 Barrels to be made to boil out of thequantity of water allowed for the third mash.
1216
——
760
760
——
8

Fourth Mash.

174	Heat of 4th mash.	174	Heat of 4th mash.
60	Heat of air.	166	Heat of goods.
——		——
114		8
11,00	Barrels of water	1026	Volume of goods.
——	for 4th mash.	——
11400		48
114		16
——		80
125400		——
8208		8208
——
152)133608	(879 Barrels to be made to boil out of thequantity of water allowed for the fourth mash.
1216
——
1200
1064
——
1368
1368
——

The liquors of this brewing of common small beer, when the mean heat of the air is 60 degrees, must therefore be ordered in the following manner (the incidents hereafter to be noticed, excepted.)

	1 Liqr.	2 Liqr.	3 Liqr.	4 Liqr.
Lengths of liquors,	14½	14½	11	11
	——	——	——	——
Boiling water; barrels,	11	11½	8½	8¾
Cold water; barrels,	3½	3¼	2½	2¼
	——	——	——	——
	14½	14¼	11	11
	——	——	——	——

The heat of the first mash for the 11 quarters of brown beer, was 157 degrees, (see page 245) and after the parting of the extract from it, 153; the volume of the grist, in its dry state, was valued at 6,32 barrels of water, (see page 268) but, for the reasons before mentioned, it now occupies three times that space, or 18,96 barrels. The air is supposed to continue at 40 degrees, and the length and heat to be given to the different mashes, were determined as follows: (see page 245.)

Degree of heat,	157	158	162	164	165
Barrels of water,	16	8	12	9	9
Liquors;	1st	2d	3d	4th	5th
	╰━━━⌄━━━╯		╰━⌄━╯	╰━━━⌄━━━╯
	1 wort.		2 wort.	3 wort.

Second Mash of Porter, or brown strong.

212	Boiling water.
40	Heat of air.
——
72
		158	Heat of 2nd mash.
		158	Heat of the grist or goods.
		——
		5
		1896	Volume of goods.
		——
158	Heat of 2nd mash	30
40	Heat of air	45
——		40
118		5
8,00	Barrels of	——
——	water.	9480
94400		——
9480
——
172)103880	(6,03 Barrels of water to be made to boil for the second mash.
1032
——
680
516
——

Third Mash.

212	Heat of boiling water.
40	Heat of air.
——	Heat of air.
172
		162	Heat of 3rd mash.
		154	Heat of goods.
		——
162	Heat of 3rd mash.	8
40	Heat of air.	18,96
——		——
122		48
12,00	Bar. of water.	72
——		64
146400		8
15168		——
——		15168
172)161568	(9,45 Barrels of water to be made to boil for third mash.
1548
——
776
688
——
888
860
——

Fourth Mash.

		164	Heat of 4th mash.
		158	Heat of goods.
		——
		6
		18,96	Volume of grist wetted.
164	Heat of 4th mash.	——
40	Heat of air.	36
——		54
124		48
9,00	Bars. of water.	6
——		——
111600		11376
11376		——
——
172)122976	(7,14 Barrels of water to be made to boil for the fourth mash.
1204
——
257
172
——
856
688
——
168

Fifth Mash.

		165	Heat of 5th mash.
		160	Heat of Goods.
		——
		5
		18,96
165	Heat of 5th mash.	——
40	Heat of air.	30
——		45
125		40
9,00	Barrels of water.	5
——		——
114500		9480
9480
——
172)123980	(7,20 Barrels of water to be made to boil for the 5th mash.
1204
——
358
344
——
140

The liquors of this brewing of brown beer must therefore be ordered in the following manner:

Barrels of boiling water,	15¼	6	9½	7	7
Barrels of cold water,	¾	2	2½	2	2
	——	——	——	——	——
	16	8	12	9	9
Liquors,	1st.	2nd.	3rd.	4th.	5th.

What in the brewery is generally called cooling in, must be settled for this brewing according to the number of barrels of cold water specified as above, the incidents hereafter to be noticed excepted.

Each of these calculations may be proved in the same manner as was done before. This method of discovering the proportion of water to be cooled in, deserves, on account of its plainness and utility, to be preferred to any other, which depend only upon the uncertain determination of our senses.

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SECTION XII.
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.

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