Crushed red pepper, also known as red pepper flakes, is a condiment consisting of dried and crushed (as opposed to ground) red chili peppers. Crushed red pepper flakes are used in pickling, chowders, gumbos, spaghetti sauce, pizza sauce and sausage.
Crushed red pepper flakes are made from hot dried red peppers. Crushed red pepper shakers have become as standard as salt and pepper on tables at Italian restaurants and especially pizza parlors in the United States. Red pepper flakes are not made of one type of chili, but from various combinations of ancho, bell, cayenne and more. Often there is a high ratio of seeds, which intensifies the heat of the pepper.
As chilis have become more popular the styles and varieties of peppers used to make crushed red pepper has also increased.