Sausage casing
[3] Natural casings have been used in the production of meat specialties for centuries and have remained virtually unchanged in function, appearance, and composition.
The size and usage of natural casings are impacted by the animal they are derived from, the narrowest being lamb followed by sheep followed by pig followed by beef.
The cleaned runners are then tied in bundles and packed in plastic drums and filled with a saturated salt brine for preservation.
The runners are then sold to a company which processes natural casings by grading and packaging them to create finished units called hanks.
Sheep/lamb and hog are available in all packaging types due to the high demand and long length of pieces; due to the shorter length and much lower demand for beef casings they are primarily only available loose or in net packs either salted or in brine.
These are available in all diameters and in lengths greater than 3 meters (as 2-meter or shorter pieces are cost prohibitive to tube).
It is formed by extrusion through a die to the desired diameter, dried and shirred into short sticks up to 41 cm (16 in) long that contain as much as 50 m (160 ft) of casing.
Some innovative coextrusion processes have been developed in recent years, allowing 100% plant-based vegetarian casings to be created.
[citation needed] Casings made from cellulose and plastics are peeled off food products and are not eaten.
Cellulosic viscose solutions are combined with wood or for example abaca pulp to make large diameter fibrous casings for bologna, cotto salami, smoked ham and other products sliced for sandwiches.
They can be flat or shirred, depending on application, and can be pretreated with smoke, caramel color, or other surface treatments.
Generally, smoke and water cannot pass through the casing, so plastic is used for non-smoked products where high yields are expected.
Polyamide (Nylon) plastic casings are the most commonly used in production of cooked sausages and hams such as luncheon meat and bologna.
The oriented polyamide[6] are shrinkable casings and will shrink during the cooking process thereby reducing the water loss.
