It is made from the hind legs of Casertano pigs slaughtered on milder days in winter. Castrated pigs are not used.
A day after slaughter, the ham is placed on a concave, tilted piece of wood to drain. It is lightly salted and let cure for 15 to 20 days. When it has lost a good deal of its moisture, the residual salt is cleaned off, then the ham is placed in a wood press. The press is made of large heavy boards. Each board has 2 to 4 holes in it, that line up with the holes in the other boards. You put some hams on the bottom board, put the dowels in the board, slide another board down along the dowels, and either finish there, or you can make additional layers. It is pressed for four days, then hung in a smoky room for a week, then pressed again for another 4 weeks, then (sometimes) rubbed with black pepper and ground dried chile peppers (pepperoncini) then hung for further drying in a well-ventilated room for 18 to 36 months.
The finished product averages around 26 pounds (12 kg), but often weighs as much as 33 pounds (15 kg), with the minimum weight being about 20 (9 kg.)
In 1917, Antonio Iamalio, a professor, wrote about Pietraroja: “Fiorente vi è principalmente l’allevamento dei suini, donde i rinomati prosciutti di Pietraroja” (“the main industry there is raising pigs, from which comes the renowned Prosciutto di Pietraroja” (from his “Rivista Storica del Sannio”)
Prosciutto di Pietraroja has almost died out. At one point in the 1990s, only one person in Pietraroja — a man named Giovanni Cusanelli — still made it, and only about 40 to 50 of them a year.
Serve in very thin slices.