Traditionally, it uses natural casings made from intestines, a method used since Roman times.
Chorizo may be cooked before eating. In Europe, it is more frequently a fermented, cured, smoked sausage, in which case it is often sliced and eaten without cooking, and can be added as an ingredient to add flavour to other dishes. Spanish chorizo and Portuguese chouriço get their distinctive smokiness and deep red color from dried smoked red peppers (pimentón/pimentão).
Due to culinary tradition and the high cost of imported Spanish smoked paprika, Mexican chorizo is usually made with native chili peppers of the same Capsicum annuum species, used otherwise rarely in Mexican cuisine, however as used extensively in Mexican-American restaurants. Spanish-American cuisine adds vinegar instead of the white wine usually used in Spain.
Chorizo can be eaten sliced in a sandwich, grilled, fried, or simmered in liquid, including apple cider or other strong alcoholic beverage such as aguardiente. It also can be used as a partial replacement for ground (minced) beef or pork.