SECTION XVII.
Of the signs generally directing the processes of Brewing, and their comparison with the forgoing Theory and Practice.
We have now brought our barley wines into the casks, and this on principles, it is thought, agreeable and consonant to each other. As the charge of novelty may be alledged, to invalidate what has been offered, it is but just to pay so much regard to a long, and, upon the whole, successful practice, as to recite, if not all, at least the principal maxims and signs in brewing, which hitherto have guided the artist. By comparing these with the present method, they will not only illustrate each other, but perhaps cause both to be better understood; and though, with respect to the art itself, this may be thought rather a curious than an instructive part, yet we may learn, from hence, that such practice, which long experience has proved to be right, will always correspond with true theory.
1. When a white flour settles, either in the underback or copperback, which sometimes is the case of a first extract, it is a sure sign such an extract has not been made sufficiently hot, or, in technical terms, that the liquor has been taken too slack.
Malt, when dried, has its oils made tenacious, in proportion to the power of heat it has been affected with; the grain, though ground, if the water for the extraction is not at least as hot as what occasioned this tenaciousness, must remain in great measure undissolved in the first extract, and deposit itself as just now was mentioned.
2. The first extract should always have some froth or head in the underback.
The oils and salts of the malt, being duly mixed, form a saponaceous body, the character of which is that, on being shook, it bears a froth on its surface.
3. The head or froth in the underback appearing red, blue, purple, or fiery, shews the liquors to have been taken too hot.