Much has been written on the injurious effects of sulphuring, both to the fermentation and the health of beer-drinkers, and some people have very strong views on the subject. In 1855 a commission, which included Liebig among its members, was appointed by the Bavarian Government to inquire into the matter. After experiments which lasted over a period of two years, a report was issued in which it was stated that in the opinion of the commissioners, sulphuring was beneficial to the hops, and in no way prejudicial to the fermentation. In 1877, a method was made known of preserving hops without sulphur. The oil which prevents the hops from keeping was separated from them by a chemical process, and bottled. The hops were then pressed and kept in the usual way. When required for brewing, the hops and oil could again be united by adding ten or twelve drops of the latter to every twenty-two gallons of beer. This system does not seem to have found favour with hop merchants.
Aloes have occasionally been used to restore decayed hops, though with such poor success that we should hardly think the experiment was often repeated. Professor Bradly, a Cambridge professor of botany, wrote as follows:—“I cannot help taking notice here of a method which has been used to stale and decayed hops, to make them recover their bitterness, which is to unbag them, and sprinkle them with aloes and water, which, I have known, has spoiled great quantities of drink about London; for even where the water, the malt, the brewer, { 82} and the cellars are each good, a bad hop will spoil all: so that every one of these particulars should be well chosen before brewing, or else we must expect a bad account of our labour.”
The age of hops is known by their appearance, odour, and feel. New unsulphured hops, for instance, when rubbed through the hand feel oily. In their first year they are of a bright green colour, have an aromatic smell and the lupuline is a bright yellow. In the second year they get darker, have a slightly cheesy odour, and the lupuline becomes a golden yellow. In the third year the lupuline is a dark yellow, the smell being about the same as in the second year.
In the hedges about Canton is found a variety of hop growing wild. It has been named the _Humulus Japonicus_. “Although this species,” says Seemann, in his _Botany of the Voyage of H.M.S. Herald_, “was published many years ago by Von Siebold and Zuccarini, we still find nearly all our systematic works asserting that there is only _one_ species of Humulus, as there seems to be only one species of Cannabis. This, however, is a very good species, at once distinguished from the common Hop by the entire absence of those resinous spherical glands, with which the scales of the imbricated heads of the latter are scattered, and to which they owe their value in the preparation of beer, making the substitution of the one for the other for economical purposes an impossibility.”