If bell peppers have the same scientific classification as cayenne pepper, are bell peppers not spicy? This compound goes to a chemical compound capsaicin. This chemical is thought to be the sole reason why jalapeños are hot and bell peppers are not. Bell peppers do not have capsaicin. Capsaicin attaches itself to the mucous membranes in our mouth, which in turn produces the sensation of hot flashes. The amount of heat in your mouth will vary greatly depending on the type of chili you have eaten. Peppers are ranked according to their heat, or the amount of capsaicin they contain, on a scale known as the Scoville Scale. Capsaicin concentrations are given a number on the Scoville heat unit scale. Bell peppers have no capsaicin, so they don't have a Scoville heat unit, so they're at the bottom of the Scoville scale.
