In the table[12] shewing the different effects produced in the grain by the different degrees of heat, the numbers, with respect to beers, express, not only the mean of the degrees of dryness the malt had, with those also of heat in the extracting liquors, but also is implied the power communicated by the hops, that is, it imparts to us, the idea of the whole combination.
As malt liquors are made with different views, so must the principles on which they are formed be varied. Beers intended long to be kept, require more heat in their extracts, in order to produce such oils, or so many in quantity from the grain, as shall retard and delay the quick effects of fermentation; and malt liquors, which are soon to be brought into use, claim an opposite management. This is imitating nature, for we have before observed[13], the hotter the autumnal, the vernal and maturating heats are, with more power do the wines resist the impressions of time and the air; and we traced the rule which governed this variety, by an enquiry into the number of degrees required to form the juices of grapes, and applied their number to discover the first and last heats they were impressed with. In calculations to find out the heat to be given to water properly to resolve the malt, the same method must be followed, it being equally necessary here to employ only such a proportion of the number of degrees which constitute the whole of the fermentable principles in malt that are needful to the purpose we would answer. We have said malts continue in possession of all their constituent parts from their first degree of dryness, 119 to 129. By age alone beers obtain spontaneous pellucidity, when urged in the whole of their process with a heat so great as 138 degrees, precipitation or art extends it to near 157 degrees, after which neither the acid parts furnished by the air, nor art avails: an obstinate foulness is the result; from whence it may be concluded, that at or beyond this heat, so great a part of the fermentable principles is dispersed, as what remains in the grain has not power sufficient to produce transparency. The following table, founded on these principles, will hereafter be found directive to fix the first and last heats to be given to the extracts of malt.
A TABLE, shewing the quantity of fermentable principles residing in malts at their several degrees of dryness, or, the number of constituent parts which form beers in proportion to their properties[14], specified in degrees, and to be used in calculations, made to ascertain the proper heats to be given to the first and last extracts of malt.
| Mean degrees of heat affecting malt. | Constituent parts. |
| 119 | 10 |
| 124 | 9 |
| 129 | 8 |
| 134 | 7 |
| 138 | 7 |
| 143 | 6 |
| 148 | 5 |
| 152 | 5 |
| 157 | 4 |
| 162 | 3 |
| 167 | 2 |
| 171 | 1 |
| 175 | 0 |
Though beers and ales are divided into strong and small, this division regards only the proportion of the vehicle, and not that of the constituent parts. The same means, as to the heat of the extracts, must be employed, to form small beers, capable of preserving themselves sound for some time, as are used to make strong drinks: for though a small liquor possesses more aqueous parts, the oils and salts of the malt are only more diluted, not altered in their proportions, and this causes but a very small difference in the duration of the liquor.
It now remains to apply these rules, deduced from the theory, to the several sorts of malt liquors, which answer to the four modes of extraction, just before laid down.
The first and most perfect is, when the malt is chosen of such dryness, and the extracts made with such heats, as give the beers an opportunity of being improved by time, and slow fermentations, to become spontaneously bright and transparent. Under this head, may be comprehended all pale keeping strong, and all pale keeping small beers.