lupulus

Lupulus is the Latin epithet used in the scientific name Humulus lupulus, the common hop plant. In modern taxonomy, hops belong to the Cannabaceae family and are cultivated primarily for their aerial inflorescences, the hop cones, which are used in brewing to impart bitterness and aroma.

Humulus lupulus is a vigorous perennial climber that grows from rhizomes. It has twining stems, lobed leaves, and dioecious flowers: female plants produce dense, cone-shaped inflorescences packed with resin glands. The cones are harvested for processing and storage, while male plants are generally not used in brewing.

Native to Europe and western Asia, hops are now cultivated in temperate regions worldwide, with historic centers such as Hallertau and Tettnang in Germany and Saaz in the Czech Republic, and modern production in the Pacific Northwest of the United States and other regions. They require well-drained soil, full sun, and support structures for climbing. Harvest occurs in late summer to early autumn when cones reach peak essential oil content.

Chemically, hop cones contain alpha acids (humulones) and beta acids, which contribute bitterness, and a range of essential oils (including myrcene, humulene, and farnesene) that provide aroma. In brewing, alpha acids are isomerized during boiling to form iso-alpha acids, contributing stability and bitterness. Hop varieties are categorized as bittering, aroma, or dual-purpose, reflecting their primary use in beer production.