Hops

Hops (Humulus lupulus) is a climbing plant; for brewing, the female flower clusters, called cones, are used. They contain resins and essential oils. When the wort is boiled, alpha acids provide bitterness and the oils provide aromas of flowers, herbs, citrus or fruit. Hops also act as a preservative and support foam stability.

A distinction is made between bittering hops, used mainly for their alpha acid content, and aroma hops with a delicate scent. The Hallertau in Bavaria is the largest contiguous growing region in the world. Hops are used as cones, pellets or extract. In dry hopping, hops are added after fermentation to gain aroma without extra bitterness.