Hog casings are made from the submucosa of the small intestine of the hog. They are stripped, emptied of their content and the fat and inner lining is removed leaving behind a mostly collagen material.
Hog casings are usually sold in bundles or "Hanks" of 100 yards.
Hog casings are mainly used for fresh, smoked, and cooked sausage varieties but are also used for some fermented and dried sausages.
Natural hog casings readily permit smoke penetration and do not contribute any undesirable flavors.
Pre-flushed hog casings are vacuum packed in a heavy salt brine. This keeps them perfectly safe for the short amount of time involved in unrefrigerated shipping. When you receive your casings store them in the original bag in the refrigerator until time for use. Hog casings stored in the original un-opened bag have been shown to keep up to four years under refrigeration. Some odor is normal with natural casings especially in warm weather and this should disappear after a rinse or two in fresh, clean water.
Hog casings should be rinsed in clean water at least once to remove excess salt and then soaked in luke warm water for 1 hour before use. This helps to open the pores of the casing and makes them easier to handle. You can do this a day ahead of time to maximize the ease of handling effect. Place the casings in the warm water let the water cool to room temperature, drain and replace with fresh, clean, cold water and refrigerate. When you are ready to begin the stuffing operation, drain and replace the cold water with fresh, clean warm water and the casings are ready to stuff.
NEVER USE HOT WATER ON NATURAL CASINGS as this may actually cook the casing rendering them useless.
Use natural hog casings for fresh or smoked sausage. Bratwurst, Polish sausage, and Italian sausage. Natural pork casings are also used to stuff pepperoni and dried chorizo.