Happy 151st birthday to the man who abused his tastebuds in the name of science. Even if you haven’t heard of Wilbur Scoville, you’ve might have heard of the Scoville Organoleptic Test. It’s more commonly known as the Scoville scale today — a standard measure of the perceived heat intensity of chili peppers.
Scoville, a Connecticut-born pharmacist with hair just as cool the Google Doodle above makes it seem, developed his test in 1912 while working at Detroit-based pharmaceutical company Parke-Davis. How it worked: According to ChilliWorld, extract of the pepper being tested was diluted in sugar water until the “heat” of it was no longer perceptible to a panel of testers. Just how much a pepper extract had to be diluted gave it its rating.
If you’re thinking that the methodology sounds imprecise, that’s because it was. Some people are just way more sensitive to heat than others. And what about lingering effects from the last taste test? Or did they wait twenty minutes between each measurement? Maybe they ate Saltines to cleanse the palate?
Of course, the test evolved. Today, capsaicin concentration is typically measured using High Pressure Liquid Chromatography, which separates and measures out the capsaicin in an individual pepper. Sweet peppers have a rating of zero Scoville heat units (SHU), because they aren’t hot at all. On the other end of the scale, pure capsaicin, the compound that gives peppers their burn, has a rating of 6 million SHU. That’s about as hot as it gets.