Cayenne pepper not only offers heat but also subtly enhances other flavors, which helped make it popular in early American cooking. In older spice trade definitions, any pepper that was hotter-than-hot was called "cayenne," after an area of South America which once exported super-hot peppers. Cayenne pepper ranges from 35,000 to 70,000 Scoville heat units. This pepper adds zip to any dish, and when a recipe calls for chile pepper heat, this is the pepper you want.