The hop does not come true from seed, so the commercial crop is grown from cuttings of the (really the underground stem) called Planting is done as early in the spring as the soil can be had in mellow condition— in January and February in California, in March in Oregon and Washington, in April in New York. The ((hills* are placed from 6)/2 to 7 feet apart both ways; that is, from 1,031 to 889 hills to the acre. Three cuttings are set to the hill to grow—a fourth is sometimes set to ensure three vines, in case one should he lost. The top bud on the cutting should be placed at two inches below the level of the surface or at the level if the plant is to be hilled up. The price of such sets ranges from $1 per thousand when plentiful , to $10 ner thousand when scarce. The field is thoroughly cultivated from the time the plants start into growth until they are well branched out, weeds being scrupulously kept down. The number of shoots allowed to grow is limited to 9 or 10 to the hill, the other shoots starting being pruned out. The most vigorous ones are left to grow. Some growers cut away the shoots from the top buds (after these have aided the plant to make roots), claiming that a sturdier growth and a larger yield of hops is gained from the deeper buds. The former use of poles has been very largely abandoned in favor of wire trellises. The high trellis is most in favor, the posts being 20 feet high (set two feet into the ground) and six or seven hills apart. A stout wire is carried over the tops of the posts, and to these are fastened strings carried up from pegs set into the ground at each hill. The upper third of each of these strings is of twine strong enough to carry at least 80 pounds. In some hop yards wires are used instead of strings, and are fastened into Shooks at the top, so as to be readily unhooked and thrown down to the pickers at harvest time. The low trellis has posts eight feet high set every third or fourth hill. As the hop vine will not run horizontally, a good deal of extra labor is required with the low trellis in training the vines by hand along the top wire. Where the pole system is still in vogue it is common practice to set a pole at each hill, and to run twine from a' point on each pole five or six feet above the ground across to the tops of the adjacent poles. This is known as the arbor method. To be of first quality hops have to be picked when just ripe. It is customary therefore to grow several vari eties with different periods of ripening, stretch. ing over three or four weeks, so as to work the staff of pickers to the best advantage. Hops generally, but not always, acquire a yellowish hue when ripe. A better test is the texture: when the hops give a crisp rustling sound when crushed in the hand they are "ripe At this time also they give out their characteristic odor. Hops are cured by drying until the 75 per cent of water in the newly gathered hops is reduced to 10 to 14 per cent. This is done in kiln houses where they are submitted to an airblast of from 110° to 140° F. They are then fumed with sulphurous acid gas to improve their color and keeping qualities, and are then cooled and pressed into bales. If not immediately mar keted, they are placed in cold storage where they may remain in perfect condition for 15 to 18 months — perhaps longer. Sulphured hops keep well for a time even if not put in cold storage, and when unsulphured seem to preserve their freshness if so stored, but unsulphured hops not stored in the cold will soon deteriorate and become strong and musty.
In California, the hop will yield the first year the fields are planted; in New York no crop is secured until the second year. For winter pro tection in New York State it is customary to place a large forkful of strawy stable manure over each hill.
The cost of producing hops is about 10 to 12 cents per pound. The price they bring varies enormously, from 12 cents up to 50 or 60 cents, and sometimes over $1 per pound. In times of extreme scarcity the prices have been fabulous.
The hop plant is subject to many diseases, due mostly to parasites, among which are the hop plant-louse (Phordon humuli), the hop grub (Gortyna immanis), the hop-vine snout moth (Hypena humuli), the hop-merchants (Polygonia interrogationis), the zebra cater pillar (Mamestra pitta), the common woolly bear caterpillar (Spilisonma virginica), the saddle-back caterpillar (Empretia stimulea), hop-vine leaf-hopper (Tettienia confluenta); various beetles, the "red spider') or spinning mite, and the needle-nosed hop-bug (Calocoris fulmomaculatus), which mostly produce red smut, etc., and even destroy entire crops. Fun gus pest, blight and mold (black smut), are extremely rare in the United States, although widespread in England and Europe. Within the last few years the hop fields of New York have been devastated by the °powdery mildew" or °blue mould,' a fungus imported from Europe. This pest thrives in rainy weather,
and if allowed to gain headway welly ruins the fields. It has been measurably controlled by spraying dry flowers of sulphur, or finely ground sulphur flour among the plants at in tervals: (1) before any signs of the mildew appear, about the time of the second tying; (2) when the hops are well up on the poles; (3) when the hops are in full bloom; and two sprayings later if needed. The amount of sulphur used for each spraying is about 50 pounds per acre. Should the pest be very severe, 70 pounds are used. The best remedies for the destruction of the animal parasites is the use of bisulphide of lime or a heavy spray ing of soap and tobacco emulsion. Sulphur in any form is a good remedy, and a spray of kerosene soap emulsion, to which a small quantity of flowers of sulphur is added, is gen erally effective. In extreme cases the affected plants are cut down and burned to prevent a spread of the disease.
The elements also play havoc with the de velopment of the tender hop-vine. High winds will tear the vine from its support; drouth will tend to change the color of the light yellow strobile to the objectionable "pole redness'; and too much water will result in a lack of lustre, when the hops are said to be °blind.' This is due to the fact that the entire energy of the plant is spent in the formation of leaves, the strobile being imperfectly developed.
Although it is possible to estimate with a fair degree of accuracy the several constituents of hops, it has not been so' far found possible to establish any definite relation between the value of the hops and the amounts of hop-oil, resins, tannin, etc., which they contain. Con sequently up to the present time, chemistry has not afforded much assistance in this direction. Hence the value of hops is still judged accord ing to its general properties. The color, size and appearance and lustre of the strobile, the quantity and color of the lupulin, the amount of seed, the odor, taste and cleanliness, are the essential points in the valuation of hops.
Fine hops possess a silky lustre which is lacking in inferior grades. The color is green ish yellow, varying with the origin. New York hops have a somewhat paler color of a stronger greenish shade, while the. Pacific coast hops have a more pronounced yellowish color. A reddish tint may indicate pole-redness, or, what is worse, that the hops have become overheated in the bale, which implies a darker coloration of the lupulin and deterioration of quality. The form and size of the strobile is also characteris tic of the origin. Small strobiles are prefer able to big ones, as they contain on an average more lupulin; and the fewer the seeds the bet ter. The bracts ought to lap over one another and hold firmly together, whereby the lupulin is kept in better. The odor and aroma should be strong, fine, free from any off-smell such as odors of fruit, garlic, etc. very slight amounts of stems, foliage or stripped cones should be present, as they impart a coarse taste to the beer. The amount of lupulin present in the strobile is an indicator of the value of the hops, because it contains those resins, volatile oils and bitter substances, which are so essen tially valuable to the brewer. In fresh hops, slight pressure will force out the contents of the strobile in a transparent droplet, but in old hops the contents of the lupulin granule will not flow, due to resinification, and the expressed juice is more syrupy, wax-like and opaque. The largest part of the German crop is merely air dried or sun-dried, and it is claimed that this (natural cure' preserves far more of the essen tial oils and other active principles than is pos sible by the artificial hot-air cure used in the United States and England, and that this at least in part accounts for the peculiarities of Spalt hops that command such extraordinary prices. Hops are easily affected by warmth, moisture, air and light, and for this reason must be protected in storage against these in fluences. For brewing purposes it is almost im possible to pass off a substitute for hops, al though lupulin and hop-extract are now manu factured. The lupulin is separated from the strobile, and inasmuch as it contains the essen tial constituents for which hops are used in brewing, it can be better utilized, although it is impracticOle and impossible to replace the en tire quantity of hops with lupulin alone because it contains very little tannin, which also is es sential. The same remark is applicable to hop extract. The essential oil of hops is another similar preparation. It consists mainly of myrcene and humulene, which constitute from 80 to 90 per cent of the whole, and small pro portions of linalool, linalyl iso-nonoate, some ester or geraniol and a diterpene.