Ingredients
A sausage consists of meat, cut into pieces or ground, and filled into a casing, with other ingredients. Ingredients may include a cheap starch filler such as breadcrumbs, seasoning and flavourings such as spices, and sometimes others. The meat may be from any animal, but often is pork, beef, or veal. The lean meat-to-fat ratio is dependent upon the style and producer. Speciality sausages with other ingredients such as apple and leek are also made.[3] The meat content as labelled may exceed 100%; this happens when the weight of meat used exceeds the total weight of the sausage after it has been made, sometimes including a drying process which reduces water content.
In some jurisdictions foods described as sausages must meet regulations governing their content. For example, in the United States The Department of Agriculture specifies that the fat content of different defined types of sausage may not exceed 30%, 35% or 50% by weight; some sausages may contain binders or extenders.[4][5]
Many traditional styles of sausage from Europe and Asia use no bread-based filler and include only meat (lean meat and fat) and flavorings.[6] In the United Kingdom and other countries with English cuisine traditions, many sausages contain a significant proportion of bread and starch-based fillers, which may comprise 30% of ingredients. The filler used in many sausages helps them to keep their shape as they are cooked. As the meat contracts in the heat, the filler expands and absorbs moisture and fat from the meat.[7]
When the food processing industry produces sausages to a price, almost any part of the animal can end up in sausages, varying from cheap, fatty specimens stuffed with meat blasted off the carcasses (mechanically recovered meat, MRM) and rusk, while the finest quality contain only meat and seasoning.[3] In Britain "meat" declared on labels could in the past include fat, connective tissue, and MRM; these ingredients may still be used, but must be labelled as such, and up to 10% water may be included without being labelled