Germany, England, and the United States are leading hop producers. Cultivation of American hop is common only in the Pacific states. Hop must be grown in areas having an abundant rainfall during the growth period and abundant sunlight during the fruiting period. Only female plants produce fruit, but a few male plants are included in each hop field because fertilized catkins grow larger and more rapidly than unfertilized catkins. Hop plants are trained to, or guided by, strings suspended above the rows.
Catkins become aromatic in late summer and are then harvested.
The common hop is classified as Humulus lupulus, the American hop as humulus lupulus variety lupuloides. All rights reserved. Learn about Encarta's editorial process. All rights reserved. Get the latest edition of Encarta Reference Suite now.