Which sausage casings or skins should I use?
The choice ranges between collagen, which is a form of dried skin made from the hide of bovine, and the fresh casings from sheep, hog or ox. They range in size from 19mm to about 36mm. The most popular sizes are 22/23 for chipolata type sausages, and 28- 35 for the breakfast and bbq type sausage.
Fresh hog, sheep and ox casings which are made from the intestines of the animal are cleaned, bleached and preserved in salt and these must be soaked in cold water for at least two hours before use (preferably overnight). Fresh casings have a shelf life of about two months if kept in salt and kept refrigerated. The sheep casings are very delicate and require more skill. Nowadays the fresh casings come on tapes or tubes so that they are easier to thread onto the filling nozzle and avoid the arduous task of unravelling a large knotted mass.
The collagen casings do not need any preparation. They are ready to use and are not salted. They have a shelf life of about two years if kept in a cool, clean and dry environment. They do not need to be refrigerated. Once these casings have been filled, it is important that the sausages are left in the refrigerator overnight to rest. The herbs and spices marinate with the meat and the skins rehydrate. These skins look and feel just like normal skins and are often less “chewy” than fresh casings. You may read in places that people mention how tough these casings are. This is NOT true – actually they are very tender indeed! It is the Hog skins (good for bbq’s) that are tougher when eating.
There are other casings on the market however these are not edible. They are used to fill and cook sausages and then need to be peeled. These are known as synthetic or artificial casings and are made from fibre or plastic.