A Scoville unit is basically a unit of measurement indicating the heat level in chili peppers. The person responsible for creating this method was none other that Wilbur Scoville. Back in 1912, "Willy" was working for Parke Davis, the drug company, to develop a muscle cream called "HEET." Heet used capsaicin, a substance derived from chili peppers, as a main ingredient. The problem that "Willy" faced was that the peppers he used had inconsistent heat levels, which made it difficult to judge amounts needed. After trying several different laboratory tests, Wilbur decided that the best heat-o-meter was the human tongue, which could detect capsaicin dissolved in solution a million times it's volume. Because capsaicin is soluble in alcohol, Wilbur would soak the peppers overnight, then take a precise measurement of the exact number of portions or "units" of sweetened water it took to dissipate the heat of the extract determined the heat level or "Scoville Units" for that particular pepper. With progress and the advent of High Pressure Liquid Chromatography(HPLC), the tongue has become an antiquated way to rate pepper heat, but it's still the best and only true way to test your tolerance of Scoville units.