The Theory and Practice of Brewing

by Michael Combrune

Barley in the mow, though there its utmost heat should not much exceed 100 degrees, may be extracted or brewed without malting. This the distiller’s practice daily evinces; but then the extracts, made from this unchanged corn, are immediately put in the still after the first fermentation, else they would not long remain in a sound state. Nor is this method practicable in summer time, as the extracts would turn sour, before they were sufficiently cooled to ferment. It is true, by this means, all the charge of the malt duty is saved; but our spirits thereby are greatly inferior to those of the French.—Boerhaave recommends the practice of that nation, which is to let the wines ferment, subside, and be drawn off fine from the lees, before they are distilled. Was this rule observed in England, distillation would be attempted only from malted grain, which, if properly extracted for this purpose, the difference in the spirit would soon shew how useful and necessary it is to give wines (either from grapes or corn) time to be softened, and to gain some degree of vinosity before they are used to this intent.

But might not barleys be dried without being germinated? Undoubtedly they might; but as they abound with many acids and strong oils, they would require a heat more intense than malt does, before they were sufficiently penetrated, and then the oleaginous parts would become so compact, and so resinous, as nearly to acquire the consistence of a varnish, scarcely to be mollified by the hottest water, and hardly ever to be entirely dissolved by that element.

Barley then ungerminated, either in its natural state or when dried, is not fit for the purpose of making wines; but when, by germination, the coarser oils are expelled, and the mealy parts of the grain become saccharine, might not this suffice, and where is the necessity of the grain being dried by fire? I shall not dwell on the impossibility of stopping germination at a proper period, without the assistance of fire, so that sufficient quantities of the grain, thus prepared, may always be provided for the purposes of brewing; nor even insist upon the difficulty of grinding such grain, as, in this case, it would be spongy and tough. I think it sufficient to mention solely the unfitness of this imperfect malt, for the purpose it is to be applied to, that of forming beers and ales capable of preserving themselves for some time. We should find so many acids blended with the water still remaining in the grain, that, in the most favorable seasons for brewing, they would often render all our endeavors abortive, and, in summer time, make it impracticable to obtain from them sound extracts in any manner whatever.

I have heard of a project of germinating grain, and drying it by the heat of the sun, in summer time, in order, by this means, to save the expence of fuel. Though the hottest days in England may be thought sufficient for this act, as well as for making hay, yet, as barley and grass are not of equal densities, the effects would not be the same. This, however, is not the only objection: as the corn, after a sufficient germination, should be made inactive, this very hot season, favorable, in appearance, to one part of the process, would rather forward, than stop or retard, vegetation; for the barley, by this heat, would shoot and come forward so fast as to entangle too much the constituent principles of the grain with one another, and drive the coarser ill-tasted oils among the finer sweet mealy parts, which alone, in their utmost purity, are the subject required for such as would obtain good drinks.

There often appears in mankind a strange disposition to wish for the gifts of Providence, in a different manner than they have been allotted to us. The various schemes I have just now mentioned, if I mistake not, have sprung from the desire of having beers and ales of the same appearance with white wines. But as they are naturally more yellow or brown, when brewed from malts dried by heats equal or superior to that which constitutes them such, all such projects, by which we endeavour to force some subjects to be of a like color with others, are but so many attempts against nature, and the prosecution of them must commonly be attended with disappointments. It is true, that though the germinated grain be dried slack, yet; if they are speedily used, and brewed in the most proper season, they may make a tolerable drink, which will preserve itself sound for some time: but the proportion, which should be kept between the heat which dried the malt, and that which is to extract it, cannot, in this case, be truly ascertained; and, as the grain will be more replete with air, water, and acids, than it ought to be, the drink, even supposing the most fortunate success, and that it does not soon turn acid, will still be frothy, and therefore greatly wanting in salubrity; for an excess in any of the fermentable principles must always be hurtful.

Barley then, to be made fit for the purpose of brewing, must be malted; that is, it must be made to sprout or germinate with degrees of heat nearly equal to those which the seed should be impressed with when sown in the ground; and it must be dried with a heat superior to that of vegetation, and capable of checking it. How far germination should be carried on, we have already seen; the law seems to be fixed universally, as to the extent of the acrospire: the degree of dryness admits of a larger latitude, the limits of which shall be the subject of our next enquiry.

Malt dried in so low a degree, as that the vegetative power is not entirely destroyed, on laying together in a heap, will generate a considerable degree of heat, germinate afresh, and send forth its plume or acrospire quite green. The ultimate parts of the nourishing principles are then within each other’s power of acting, else this regermination could not take place; and such grain cannot be said to be malted, or in a preservative state. Bodies, whose particles are removed, by heat, beyond their sphere of attraction, can no more germinate; but, coming in contact with other bodies, as malt with water, they effervesce. The grain we are now speaking of first shews this act of effervescence, when it has been thoroughly impressed with a heat of 120 degrees, and a little before its color, from a white, begins to incline to the yellow. Such are the malts, which are cured in a manner to be able to maintain themselves sound, though in this state, and at this degree of dryness, they possess as much air, and as many acid and watery particles, as their present denomination can admit of. This therefore may be termed the first or lowest degree of drying this grain for malt.

To discover the last or greatest degree of heat it is capable of enduring, the circumstance to guide us to it, though equally true, is not so near at hand as effervescence, which helped us to the first. We must therefore have recourse to the observation of that heat, which wholly deprives the grain of its principal virtues. Dr. Shaw observes, alcohol is one of the most essential parts of wine; when absent, the wine loses its nature, and, when properly diffused, it is a certain remedy for most diseases incident to wines, and keeps them sound and free from corruption; from whence was derived the method of preserving vegetable and animal substances.—The same excellent author had before this observed, that no subjects but those of the vegetable kingdom are found to produce this preserving spirit. Is alcohol, then, a new body, created by fermentation and distillation; or did it originally, though latently, reside in the vegetable? I have for a good while been satisfied, by experiments, says Boerhaave, that all other inflammable bodies are so only as they contain alcohol in them, or, at least, something that, on account of its fineness, is exceedingly like it; the grosser parts thereof, that are left behind, after a separation of this subtile one, being no longer combustible.

Now, as the same author has clearly proved[9] that fire, by burning combustible bodies, as well as by distilling them, separates their different inflammable principles, according to their various degrees of subtilty, the alcohol residing in the barley, when exposed to such a degree of heat as would cause it to boil, i. e. 175 degrees, must make great efforts to disengage itself from the grain. Is it not, therefore, natural to conclude, that, in a body like malt, whose parts have been made to recede from one another, (from whence it is porous, and easily affected by fire,) prepared for fermentation, or the making a vinous liquor, this event will probably happen at the same time when the body of the grain has been ultimately divided by fire, or that malt charrs? and if this is true, may not charring be termed the last degree of dryness, when, even somewhat before it takes place, the acid parts and finest oils, which are necessary for forming a fermentable must, fly off, and cannot be recovered.—Charring seems to be a crisis in solid bodies, somewhat analogous to ebullition in fluids; both being thereby perfectly saturated with fire, their volatile and spiritous parts tend to fly off. In charring, the subject being ultimately divided by fire, the constituent principles are set at liberty, and escape in the atmosphere, in proportion to their several degrees of subtilty, and to the fire which urged them. In boiling they are equally divided, and incline to disperse; but, even the more volatile, being surrounded with water, a medium much denser than themselves, they are caught up therein, and, by the violent motion caused in boiling, entangled with it, and with other parts it contains, so as not to be extricated or divided therefrom except by the act of fermentation. Now, as liquors boil with a greater or less fire in proportion to their tenacity and gravity, solid bodies may likewise be charred by various proportions of heat. The whole body of the barley, as its different parts are of different texture, cannot, at the same instant, become black, nor, where any quantity of the grain is under similar circumstances, if not equally germinated, can the whole charr with the same degree.