Page:Encyclopædia Britannica, Ninth Edition, v. 4.djvu/316

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272
BREWING

tions which are most favourable to the conversion of the maximum quantity of the starch it contains into grape- sugar, by the action of the diastase produced in the grain

by the process of malting.

Hops are the catkins or flowers of the Humulus Lupulus, a dioecious plant belonging to tho natural order Urticacew, or the nettle family, and the Linnaean Dicccia pcntandria. It is the female flowers (which grow on different plants from the male flowers) that yield the hop known to com merce. The plant is mentioned by Pliny under the name of lupus salictarius (N. H., xxi. 50). It was cultivated in the 9th century, for we find that in 822 tho millers of Corbey were freed by the abbot from all labours relating to hops ; and hop-gardens are mentioned by Ludovicus Ger- manicus, a few years later. Hops were introduced into England from Flanders about the time of Henry IV. There is a curious edict of Henry VIII., forbidding the mixture of either hops or sulphur with beer; but little attention seems to have been paid to it, for in 1552 hop- plantations were formed. In 1649 the city of London petitioned Parliament against "hoppes" being used, urging that " this wicked weed would spoil the drink, and endanger the lives of the people." It came into common use in Queen Elizabeth s reign.

The hop-clusters are ovoid cones, consisting of scales which are the enlarged persistent bracts enclosing the fruit. They are covered with a tenacious yellow, waxy substance, like powder, called lupulin, and technically " condition." Under the microscope this is seen to consist of minute semi-transparent granules, round in shape; it is the most valuable part of the hop, containing most of its active properties. The amount of powder compared with the total weight of the hop varies from 10 to 15 or even 20 per cent. Amongst the leaves and powder of the hop, we find essential oils, resin with associated bitter principles, and tannin. When distilled with water, the powder gives 2 per cent, of its weight in essential oils (there is none in the leaves); one of these distils at 212 Fahr., but the other requires a much higher temperature for its volatilization. Other products are formed from the lupulin among them valerianic acid, which is the dis agreeable characteristic of old hops. The essential oils not only give the aroma, but are of importance, as through their combination the resins and bitter substances become soluble in water. The resin constitutes 50 per cent, of the powder, and is soluble in alcohol. The importance of tannin consists in its power to precipitate albuminous matter ; of tannin there is only about 2 per cent. It has been suggested to increase this by using the tannic acid of commerce as a partial substitute for hops ; and experi ments have been made in Dresden by Dr Fleck for this purpose. This must, however, be used with caution, as an excess of it would be prejudicial to a successful clarifica tion of the beer.

The most delicate hops are Goldings, grown in East Kent, Farnham and Worcester districts being next best, while good, strong, serviceable hops are grown in the Weald of Kent, Sussex, &c. Large quantities are imported from Germany, Belgium, America, &c., the best being Bohemian, grown near Saaz, which are very excellent in delicacy of flavour and aroma ; Bavarians grown in the district round Spalt are valuable for their cleansing and beer-keeping qualities.

The acreage under hops in England is 65,000, 40,000 being in Kent. This is an increase of more than 15,000 acres since the commutation of the duty in 1862. In that year the duty was taken off hops, and a charge made on brewers of Is. per quarter, being at the rate of 3d. per barrel, on the supposition that four barrels of beer were drawn from every quarter mashed. The old duty was 2d. per lb and 5 per cent, additional. A hop-garden costs from 70 to 100 to start, and from 27 to 30 to farm per annum. A rich, deep soil, rather inclined to moisture, is, on the whole, the best adapted for the crop ; but any soil (stiff clay only excepted) will suit, when properly prepared. It should be enriched with the kind of manure best suited to the land the hops are to be grown on ; stable and cowhouse dung, old rags, shoddy, guano, sprats, and other decomposed matter are used freely ; while on some land peat and lime are required. The land is first rendered fine and mellow by being ploughed and harrowed several times ; then, in the spring, a large hole is made and filled with rich mellow earth; into this "sets" or small pieces of the roots of the kind of hop intended to be grown are planted with the buds uppermost and the earth pressed close about them. These sets take three years to come to perfection. Two or three sets to a pole, three poles to a hill, 1050 hills to an acre, is the usual calculation. The hills should be 6 or 8 feet apart, the latter being best on rich land, as there the bine runs the most. The poles are from 12 to 18 feet high, according 1o the adaptability of the ground for vigorous growth, with the ends that go into the earth charred to preserve then. In America the hop is trained on wires ; this has also been introducced into England, Mr Farmer, of Worcester, having taken out a patent. It is very successful, but the first cost, 75 per acre, has prevented its being used extensively. The hop crop is a most precarious one, and may be said to vary from nothing up to a ton or even 25 cwt. per acre, and in price from 3 to 25 per cwt. In proof of this, at the annual Worcester Fair in 1874, only 74 pockets were on sale, whereas the year before 1000 pockets were in the market, and 2000 more were offered for sale by sample.

The plant is very dependent on the season, and has many enemies in the insect world, in particular, the fly or aphis, which infests the crop early in its growth, feeding upon its juices and leaves, giving the latter the appearance of having been riddled with swan shot. The flies come originally from the sloe bushes, and are produced from eggs deposited in the previous autumn. These, as well as fleas, red spiders, lice, &c., may be destroyed by syringing the plants well with soft soap and water. The mould first betrays itself in yellow and drooping leaves, finally in the hop itself, eating- it up with mildew, the presence of a few half-eaten leaves spoiling a sample. The blight coats the leaves with a thick sooty substance ; and when this appears the hop dwindles away. The fire-blast, as its name implies, sears and scorches the foliage, and withers it up. All these may be seen working mischief at once in the same hop garden.

The catkins of the hop ripen early in September ; they are picked from the bine by thousands of people from London, &c., whose welfare and accommodation have been much neglected ; but great changes in this respect are made by sanitary regulations which come into force this season (1875). Besides these strangers, every man, woman, and child of the resident population is made available for the season, which generally lasts three weeks. The pay is about 2d. per bushel ; and in a good season a family can make 2s. 6d. a day per head.

After picking, the hops are dried on a kiln (oa&t-house,

as its called), the heat never being allowed to rise abovo 90, lest the aroma and volatile oil should be thrown off, A small portion of sulphur is sometimes added to the fire, the appearance of the sample being improved by the sul phurous acid thus formed. This has been generally con siderecl by brewers injurious to the hop, and also to fermentation ; but a commission appointed by the Bavarian Government in 1855 (the late Professor Liebig being one

of its members), after two years of experiments, arrived at