The constituent parts of malt, like those of all vegetable sweets, are so inclined to fermentation, that, when once put in motion, it is difficult to retard their progress, retain their preservative qualities, and prevent their becoming acid. Among the many means put in practice, to check this forwardness of the malt, none promised so much success as blending with the extracts, the juices of such vegetables as, of themselves, are not easily brought to fermentation. Hops were selected for this purpose, and experience has confirmed their wholesomeness and efficacy.

Hops are an aromatic, grateful bitter, endued with an austere and astringent quality, and guarded by a strong resinous oil. The aromatic parts are volatile, and disengage themselves from the plant with a small heat. To preserve them, in the processes of brewing, the hops should be put into the copper as soon as possible, and be thoroughly wetted with the first extract, while the heat of the wort is at the least, and the fire under the copper has little or no effect thereon. Whoever will be at the trouble to see this performed, by the means of rakes, or otherwise, will be made sensible, that flavor is retained, which, when the wort comes to boil, is otherwise constantly dissipated in the air.

The bitter is of a middle nature, or semivolatile: it requires more fire to extract it, than the aromatic part, but not so much as the austere or astringent. Hence it is plain, that the principal virtues of this plant are best obtained by decoction, the austere parts not exhibiting themselves, but when urged by so violent and long continued boiling, as is seldom, or never practised in the brewery. It would be greatly satisfactory to fix, from experiments, the degrees of heat, that first disperse the aromatic, next the bitter, and lastly the austere parts; as it is likely, by this means, a more easy and certain method of judging of the true value and condition of hops, than any yet known, might be discovered.

This vegetable is so far from being, by itself, capable of a regular and perfect fermentation, that, on the contrary, its resinous parts retard the aptness which malt has to this act. Hops, from hence, keep barley-wines sound a longer space of time, and, by repeated and slow frettings, give an opportunity to the particles of the liquor to be more separated and comminuted. Fermented liquors acquire, by this means, a greater pungency, even though it was admitted they received no additional strength from this mixture, the direct contrary of which might easily be made to appear. Hops, then, are not only the occasion of an improvement of taste, but an increase of strength.

Dr. Grew seems to think the bitter of the hops may be increased by a greater degree of dryness; but, perhaps, this is only one of the means of their retaining longer this quality, which undoubtedly decreases through age, in a proportion, as near as can be guessed, of from 10 to 15 per cent. yearly.

The varieties of the soils in which hops are planted, may have some share in the inequality we perceive in them. They seem to be much benefited by the sea air. Whoever will try similar processes with the19 Worcestershire and Kentish hops, will soon perceive the difference, and the general opinion strengthens this assertion, as the county of Kent alone produces nearly half the quantity of hops used in this kingdom.

The sooner and the tighter hops are strained, after having been bagged, the better will they preserve themselves. The opinion that they increase in weight, if not strained until after Christmas, may be true, but will not recommend the practice; the hops imbibe the moisture of the winter air, which, when the weather grows drier, is lost again, together with some of the more spiritous parts. Nor is this the greatest damage occasioned by this delay, as hops, by being kept slack bagged in a damp season, too often become mouldy.

Hops may be divided into ordinary and strong, and into old and new. The denomination of old is first given to them, one year after they have been bagged. New ordinary hops, when of equal dryness, are supposed to be nearly alike in quality, with old strong ones.

The different teints, with which hops are affected from the fire of the kiln, afford in brewing the best rule for adapting their color to that of the malt; in general the finest hops are the least, but the most carefully, dried.

To extract the resinous parts of the hops, it is necessary they should be boiled. The method of disposing them is generally to put the whole quantity, in the first wort, which, being always made with waters less hot than the succeeding extracts, possesses the greatest share of acids, and is in want of the largest proportion of resins and bitters to defend it. The virtue of the hops is not entirely lost by once boiling, there remains still enough to bitter and preserve the second wort. But where the first wort is short of itself, and a large quantity of hops are required for the whole, it is needless and wasteful to put more in at once than it can absorb, the overplus of which appears by a thin bitter pellicle floating on the wort when laid to cool in the backs. No particular rules can be given to avoid this inconveniency, as the nature and quantity of the worts on one side, and the strength of the hops on the other, must occasion a difference in the management, easily determinable by experience.

When waters, not sufficiently hot, have been used, the wort, for want of the proper quantity of oils, readily admits of the external impressions of the air, and is easily excited to a strong and tumultuous fermentation, which disperses the bitter particles, and diminishes the effects of the hops. The virtue of this plant is therefore retained in the drinks, in proportion to the heat of the extracts, and the slowness of the fermentation.

But beers being a composition of malt, hops, and water, united by heat, and the properties of this combination being judged of by the medium of the whole number of degrees of fire made use of in the process, as we brought the virtues of malt to this denomination, it is also essential to reduce those of hops. After many tedious calculations and experiments, made with this view, and unnecessary here to mention, we were obliged to have recourse to a more simple and probable hypothesis, and confirm the truth thereof by repeated experiments, the relation of which, as it becomes here necessary, will shew the necessity we were under to take a general view of the whole process before we attempted to ascertain this point.

In the table shewing the mean heat of the air applicable to practice, the greatest cold is 35 degrees, and in this season we observed, (page 156) the repositories of beers were more warm than this by 10 degrees, which makes the greatest cold of cellars to be 45 degrees; in the same table the highest heat is 60, when cellars are 5 degrees colder than the external airs, the utmost difference then in the temperature of cellars is 10 degrees, and this takes place in 6 months, so that the whole variety of heat beers deposited for keeping undergo in one twelvemonth is 20 degrees.

There is no specie of beer, in brewing of which it is requisite the artist should be more attentive to alter his process in proportion to the change of heat in the air, than common small beer, which, though brewed in every season, is constantly expected to be in an uniform order for use. In the preceding section, in the table directing this variety, we find a difference of five degrees of heat in the air, requires an alteration in medium heat of the whole process of 3 degrees, and as it is from the mean heat of the dryness of the malt, of the heat of the extracts, and of the value of hops in degrees, that we are to discover the quantity of fire to be given to the extracts, this can be done only by deducting from such medium so much as it is affected by the properties of the hops. Just before we have seen, that the whole of the variety of heat beers deposited in cellars to keep twelve months undergo, amounts to 20 degrees, these, in a proportion of 5 to 3, would be 12, without being scrupulously exact. Hops, with regard to their proportion in the whole process, must be admitted to be one third part thereof, and, in this case, of the proportion, 12, now found, only 4 degrees would be what they contribute towards preserving the drink 12 months: the quantity of hops necessary to maintain beers in a sound state this space of time, we have found to be twelve pounds; this quantity then is equal to 4 degrees of the medium heat of the whole process. On these grounds we repeatedly tried the experiment in a variety of brewings made for different purposes, and never found any inconveniencies from the estimating hops in such like proportion.

Hops should be used in proportion to the time the liquors are intended to be kept, and to the heat of the air in which they are fermented. The quantity requisite to preserve beers twelve months, experience has shewn to be20twelve pounds, of a good quality, joined to one quarter of malt, and when the heat of the air is at 40 degrees, three pounds to every quarter has been found sufficient to preserve drinks from four to six weeks, as six pounds are to keep them the same term when the thermometer is so high as 60 degrees. From these facts, founded on informations obtained from long practice, we shall hereafter ascertain the proper quantities to be used in all cases.

Having premised these observations, sufficiently accurate for the government of this art, the construction as well as utility of the following tables will be obvious.

A TABLE of the value of the hops, expressed in degrees, to be added to the medium of the dryness of the malt, and of the heat of the extracts.

A TABLE of the quantity of hops requisite for every quarter of Malt brewed for porter, supposed to be fit for use from eight to twelve months.

N.B. The quantity of old beer to be blended with new is here supposed never to exceed one eighth part of the whole.

A TABLE of the quantity of hops requisite for common small beer, for each quarter of malt, in every season.

The medium heat of the hottest days in England, in the shade, seldom, at any time, exceeds 60 degrees, but I continued the table proportionably, as what is here set down is from repeated experiments, and from thence it appears, at the lowest fermentable degree of heat, three pounds of hops are required for each quarter of malt; at the highest, nine pounds of hops should be allowed for the same quantity; this, in some measure, determines the effect of a greater activity in fermentation.

A TABLE of the quantity of hops necessary to each quarter of malt, in brewing amber or two-penny.

Amber is a liquor which, by repeated periodical fermentations, is so attenuated, as to be soon fit for use, and, by its strength, is supposed to resist the impressions of the air longer than common small beer, especially in winter; for this reason, it wants fewer hops than that drink does, and in the summer both require equal quantities, on account of the fermentation of amber being carried to a greater degree.

The hops once boiled in amber, but used afterwards for small beer, may be estimated equal to one fourth of their original quality.

When twelve shilling small beer is made after amber, the quality of the hops used should at least be equal in value to the quantity of ten pounds fresh hops to every five barrels of beer, when brewed from entire grists of malt for this purpose.

A TABLE of the quantity of hops necessary for each quarter of malt, in brewing Burton ale.

This liquor requires fewer hops than such ales as are more diluted by water: as it is always brewed in the winter, the quantities here set down are for the number of months it is supposed to be kept, before it is drank or bottled.

Though common amber, keeping amber, and Burton ales require the same degree of heat to govern the whole of their processes, yet some small difference will be found in the heats of their extracts, on account of the different quantity of hops used.

Besides the use of hops for keeping the musts of malt, they may also, with great propriety, be employed both to strengthen and preserve sound the extracts. One or two pounds, in a net suspended in the water the mash is to be formed with, are sufficient for this purpose.

Though the purchasing the materials, used in manufacture, does not immediately relate to its practical part, yet as, in this case, it is of great importance to the brewer to know what stock it is prudent for him to keep, of an ingredient equally necessary and variable in its value, I hope the attempt of a calculation on this subject, will easily be pardoned.

The amount of the duty upon hops, for sixteen years, from 1748 to 1765, was £.1,171,227, which sum, estimating the duty at 21s. per bag, gives 1,115,454 bags, used in that time. At the beginning and expiration of this interval, hops sold at such high prices, as no considerable stock can be supposed to have remained in hand, viz. from £.8 to £.10 per hundred. If, therefore, to the aforesaid quantity of 1,115,454 bags, which may be supposed to have served for the whole consumption during this period, we add what may have escaped paying duty21, the annual consumption of hops may be estimated at 70,000 bags, including what is exported to Ireland or elsewhere. From these premises, the following table was constructed, which, though not capable of absolute certainty, may be of some service to the brewers, in informing them of the quantities, that probably remain in hand at any time, and the stock which prudence will suggest to them to lay in.

A TABLE, shewing the medium price Hops should bear, in proportion to the growth, and determining the quantity to be purchased, in proportion to the stock in hand.

This chapter should not be dismissed without reminding the brewery, of the gross imposition they submit to in purchasing hops. The tare which justice requires to be allowed in the sale of all packed merchandize, by the hop-factors is refused, who exact payment for the bagging, at the same price as for the commodity itself. If the consumption of hops, in England, is yearly 172,268 cwt. and these be packed one half in bags and the other half in pockets, taking the mean price of hops to be 3l. 14s. per cwt. in this case the consumers are defrauded at least of 39,834l. per annum; that, on a just regulation of this matter, the commodity itself would rise in price, there is not the least foundation for. The present practice of monopolizing hops, by much too frequent, is a farther reason to induce the brewery to exert the influence they ought to have with superior power, to obtain a right so justly due to them.