lupulin

Lupulin is the yellow, powdery substance found in the lupulin glands of hop cones (Humulus lupulus). The glands are located on the hop flower and produce a resinous material that coats the cone’s central portion. Lupulin is composed of resinous compounds and volatile oils that contribute both bitterness and aroma to beer.

The chemical composition of lupulin includes alpha acids (primarily humulone, cohumulone, and adhumulone) and beta acids, along with a range of essential oils such as myrcene, humulene, and farnesene. The alpha acids are responsible for most of the bitterness in beer, which is enhanced when they are isomerized during wort boiling. The essential oils provide hop-derived aroma and flavor, with profiles varying by hop variety. Lupulin also contains other minor compounds that influence the overall character of the hops.

In brewing, lupulin is the source of bitterness and aroma associated with hops. It is extracted into wort through boiling, fermentation, and conditioning, and the quality and balance depend on hop variety, form (whole-cone hops, pellets, or extracts), and processing. Lupulin powder is a refined form of lupulin that can be used to control or study bittering and aroma release.

Historically, lupulin-containing preparations have appeared in traditional medicine as sedatives or sleep aids, but in modern contexts its primary significance lies in beer production. In contemporary brewing, hops and their lupulin-derived compounds remain central to shaping beer bitterness, aroma, and stability.