Who is Wilbur Scoville?
The Scoville scale (invented by Wilbur Scoville), measures the piquancy or "heat" of a chili pepper (sometimes spelled chili with an 'i'). The number of Scoville Heat Units (SHU) indicates the amount of capsaicin(which is what causes the burning heat-sensation) in the hot chile pepper.
The Scoville Heat Scale goes from a 0-rating (a bell pepper) to 16 million (pure capsaicin).
Scoville's method of measurement was called the Scoville Organoleptic Test. In Scoville's test, a measured amount of the capsaicin oil from a dried pepper was extracted with alcohol. This capsaicin extract was added to a solution of water until the "heat" was barely detectable by a panel of taste testers. The degree of dilution gives us the number of Scoville Heat Units or where it falls on the Scoville scale.