Why Are Chili Peppers Hot?

Why Are Chili Peppers Hot? Capsaicin (pronounced “cap-SAY-a-sin”) is the chemical in chili peppers that makes them spicy. Specifically, capsaicin occurs in the fruits of plants in the Capsicum family, including jalapeño peppers, cayenne peppers, and other chili peppers. Why did peppers evolve to be hot? Peppers are plants and those that are spicy use