Humulene, properly alpha-humulene, is a monocyclic sesquiterpene first identified in hops (Humulus lupulus), cannabis's closest cultivated relative. It smells woody, earthy and herbal, the "noble hop" note in beer. Its older name, alpha-caryophyllene, reflects that it is an isomer of beta-caryophyllene; the two are often produced by the same terpene synthase.
In practice
On a terpene panel, humulene typically reads at roughly a third of the beta-caryophyllene figure, around 0.05-0.3% w/w in flower. If a COA shows high caryophyllene with no humulene at all, it's worth asking whether humulene was in the lab's method. As a sesquiterpene it is fairly persistent through drying and storage.
Don't confuse with
- Humulone: a bitter acid from hops, not a terpene and not in cannabis.
- Beta-caryophyllene: its isomer, spicier and peppery.
- Caryophyllene oxide: an oxidation product of beta-caryophyllene, not of humulene (humulene epoxides exist but are seldom reported).
A sesquiterpene is a fifteen-carbon terpene made from farnesyl pyrophosphate, such as beta-caryophyllene, humulene and bisabolol; they are heavier and less volatile than monoterpenes.Beta-caryophyllene is a spicy, peppery sesquiterpene common in cannabis, notable as a dietary terpene that also binds the CB2 receptor in laboratory studies.Terpenes are volatile hydrocarbon compounds built from five-carbon isoprene units; in cannabis they are made in the trichome heads and are a major part of aroma and flavour.A terpene test measures the individual terpenes and total terpene content of a sample, usually by GC-FID or GC-MS, reported in % w/w or mg/g.A COA (certificate of analysis) is a lab's signed report of what it measured in a specific sample, such as cannabinoids, terpenes, moisture and contaminants, with methods and limits.Caryophyllene oxide is the oxidation product of beta-caryophyllene, a less aromatic sesquiterpene epoxide that tends to increase as cannabis ages in air.A terpene profile is the measured mix of terpenes in a sample, reported as each compound's % w/w and the total, used to describe and compare cultivar aroma chemistry.
