When butchers break down a side of pork, they are after the several lean cuts of meat, the bones that can be used in stock or sold as dog treats, and the large pile of trim that can be ground into sausage meat. The only parts that typically go to waste are the head, the glands (particularly prevalent in the jowls, but also in the hind legs), and the skin.
Progressive (or retrogressive?) eaters don’t have a problem with pig head, and the glands represent a very small amount of waste, maybe 100 g on a side of pork. That leaves the skin. While it can be put into a broth or cassoulet, there happens to be a much more dignified use.
I recently came across a recipe for cotechino, a common boiling-sausage from Emilia-Romagna that is traditionally made with a significant amount of pork skin (“cotica” is Italian for “skin”). The following process is based on the cotechino recipe in Paul Bertolli’s Cooking by Hand.
How to Use Pig Skin in Sausages
1: Cut the sheets of skin into manageable squares. The pale squares below are fresh belly skin from my last batch of pancetta. The darker squares are belly skin that was cut from bacon immediately after smoking.
2: Simmer the skin until tender, about one hour, skimming away any greyish foam that develops.
3: Cut away the fat on the back of the pieces of skin. Discard the fat. Chill the skin thoroughly.
4: Grind the skin through a small die.
5. Dice the meat and fat, then mix with the salt and spices (in this case: dried hot peppers, cinnamon, coriander, clove, and black pepper) and the ground skin. Chill the mixture thoroughly.
6: Grind the mixture through a coarse plate.
7: Quenelle test: fry a bit of the forcemeat to check the seasoning. (Optional step: eat quenelle with fried egg, mushrooms, and obscenely large piece of toast.)
8: Stuff the forcemeat into hog middles. You can see some air pockets in the casing below, especially on the bottom curve. Pop those bubbles with a pin.
10: Hang sausages on a dowel to dry out the surfaces.