A sausage consists of ground meat, animal fat, herbs and spices, and sometimes other ingredients, usually packed in a casing (historically the intestines of the animal, though now generally synthetic), and sometimes preserved in some way, often by curing or smoking. Sausage making is a very old food preservation technique. There is no consensus whether similar products that are not packed in casings, such as pâté, meatloaf, scrapple and head cheese should be considered sausages.