Scoville scale

The Scoville scale is a measurement of pungency (spiciness or "heat") of chili peppers and other substances, recorded in Scoville heat units (SHU). It is based on the concentration of capsaicinoids, among which capsaicin is the predominant component.

The scale is named after its creator, American pharmacist Wilbur Scoville, whose 1912 method is known as the Scoville organoleptic test. The Scoville organoleptic test is a subjective assessment derived from the capsaicinoid sensitivity by people experienced with eating hot chilis.

An alternative method, high-performance liquid chromatography (HPLC), can be used to analytically quantify the capsaicinoid content as an indicator of pungency. Provided by Wikipedia