Cayenne pepper is a hot, red spice made from dried and ground chili peppers. It adds a fiery kick to food: just a pinch can make a bowl of chili or a pot of soup noticeably spicier. The heat comes from a chemical called capsaicin, which makes your tongue feel like it's being burned (even though it's generally safe in normal food amounts).

The pepper gets its name from Cayenne, a city in French Guiana in South America, where these peppers have grown for centuries. Native peoples in the Americas cultivated hot peppers long before European explorers arrived, and cayenne became one of the most popular varieties to spread worldwide.

Cooks measure the heat of peppers using something called the Scoville scale. Cayenne pepper ranks as moderately hot: much spicier than a bell pepper but milder than a habanero. When a recipe calls for cayenne, it usually means the ground powder, though you can also find whole dried cayenne peppers.

If you accidentally get too much cayenne in your mouth, drinking water won't help much because capsaicin doesn't dissolve in water. Milk works better because it contains fats that help wash away the burning sensation.