Scoville scale

The Scoville scale is a measurement of the pungency (spicy heat) of chili peppers, such as the jalapeño, the ghost pepper, and the world's (current) hottest pepper—the Carolina Reaper, or other spicy foods as reported in Scoville heat units (SHU), a function of capsaicin concentration. Capsaicin is one of many related chemicals, collectively called capsaicinoids. The scale is named after its creator, American pharmacist Wilbur Scoville. His method, devised in 1912, is known as the Scoville Organoleptic Test.

Unlike methods based on high-performance liquid chromatography, the Scoville scale is an empirical measurement dependent on the capsaicin sensitivity of testers and so is not a precise or accurate method to measure capsaicinoid concentration.

Scoville organoleptic test

In Scoville's method, an exact weight of dried pepper is dissolved in alcohol to extract the heat components (capsinoids), then diluted in a solution of sugar water. Decreasing concentrations of the extracted capsinoids are given to a panel of five trained tasters, until a majority (at least three) can no longer detect the heat in a dilution. The heat level is based on this dilution, rated in multiples of 100 SHU.