Perennial climbing vine that grows wild and also is cultivated
extensively in several central European countries, North America,
Brazil, and Australia. It has shoots up to 10 m (33 ft.) in length,
opposite leaves, greenish-yellow flowers (June to September), and
ovoidal fruits surrounded by a calix. The part used is the female
flower catkins from the climbing vine and the (lupulin) glandular
trichomes dried at 38°C maximum. Hops has a bitter, tonic, aromatic flavor.
The essential oil is present in hops in amounts of approximately
0.5%; yields after distillation range around 0.25%. The oil exhibits
different physical-chemical constants depending on the source.
The oil contains P-myrcene, dipentene, α- and p-caryophyllene,
humulone, linalool, methyl nonyl ketone, and other substances.
Beef flavor is associated with hops; the bitter flavor is given by
the resin, the flavor complex of the essential oil.
The derivatives are infusion (1.5%), fluid extract, tincture (20%
in 40% ethanol), concrete, and absolute. The main constituents of
lupulin are a bitter resin containing humulone, lupulone, lactaric
acid, cerotic acid, and ceryl alcohol.
