The Scoville scale is a measure of the spiciness of chili peppers and other products that contain capsaicin. Capsaicin is a chemical that occurs naturally in chili peppers and is responsible for the spiciness or "hot" sensation you feel when you eat a pepper. Capsaicin is most commonly found in the seeds (the white membranes) of the pepper. Hence, the tip of a pepper is often a lot less hot than the rest of the pepper because there are almost no seeds here.

The Scoville scale was developed in 1912 by American chemist Wilbur Scoville. Capsaicin is measured in Scoville Heat Units (SHU), which indicate how much sugar water is needed to neutralize the heat of the pepper. The scale ranges from zero (no detectable capsaicin) to several million (extremely hot).

The Scoville scale helps people choose peppers that match their taste and tolerance for spiciness. In fact, people who eat spicy food regularly may develop a higher tolerance to capsaicin, meaning they are less likely to experience the burning sensation. Still, some people may remain highly sensitive to the substance, even with milder chilies.