Halal sausages are those which are prepared in accordance with Islamic dietary law. In Islam, the term halal, or "lawful," describes any religiously permissible action, but it often specifically refers to food. To be halal, a sausage must not include prohibited meats. The meat content must also come from animals slaughtered in accordance with Islamic tradition.
Islamic dietary law is part of a larger body of Islamic law called sharia. This set of laws divides actions into things which are halal and things which are haraam or "forbidden." In the case of food, Islamic dietary law prohibits intoxicants as well as foods considered unclean. Some of these foods are common sausage ingredients, meaning that most sausages are not halal unless specifically intended to be.
Halal sausages usually contain lamb, beef or chicken. Islamic dietary law strictly forbids the consumption of pork and pork products, which are the main ingredient of many sausages. In addition to ground pork as a sausage filling, pork intestines are also sometimes used as sausage casings. Neither of these are acceptable to observant Muslims. The risk of contamination means that halal sausages are usually not prepared in facilities that also prepare pork products.
In addition to pork, Islamic law also forbids food made from blood, which is an ingredient in some types of sausage. Traditional Islamic slaughtering practices, called dhabiha, are designed to drain the carcass completely of blood before butchering. Meat in halal sausages comes from animals slaughtered according to this practice.
Although the presence of explicitly-packaged halal sausages on supermarket shelves has increased in recent years, sausages marketed as halal are not the only halal sausages. Vegetarian sausages, for example, are almost always halal, since they contain no animal products at all. Although other types of chicken, beef and lamb sausages may not contain pork, their halal status may be uncertain because the slaughtering methods have not been verified. In some regions, a halal certification authority inspects production facilities and labels products which satisfy dietary law.
A wide variety of different types of halal sausage exist. In some cases, these are halal substitutes for sausages that contain pork, such as halal versions of traditional British sausages. In other cases, they are part of the native cuisine of Islamic cultures, such as merguez. These long, thin spicy sausages contain either lamb, beef or a mixture of both in a casing made from lamb intestine. They originate in the cuisine of North Africa.