Crushed Red Pepper flakes are a must have for your kitchen pantry, and are usually found on every pizzeria table in the country to add some spice to your favorite slice of pizza. Dried red pepper flakes are usually made up of a combination of chile flakes, and could contain any combo of ancho, bell, cayenne, and other red peppers. These chiles are about a 3-4 on a heat scale, and add a pleasant note of heat to any dish.