What is the pepper hotness scale?

The Scoville scale is the index for the heatness rating of peppers and ranges from 0 to 2.2 million Scoville heat units. The Scoville scale gets its name from its inventor, Wilbur Scoville, who worked as a pharmacist when he created the pepper index in 1912.

The index was created by getting a group of tasters to taste different chili peppers with sugar water to see how much sugar water was necessary to negate the heat of each pepper. Today, the heat of a pepper is easily measured by finding out how much capsaicin is in it. This chemical is the cause of the spicy heat in the chili peppers.