Prosciutto di Parma

A ham that is cured, not fermented

Prosciutto di Parma is a whole pork hind leg that is salted, rested, dried and matured until the muscle is firm and the flavour is developed. It is not smoked, and in the protected version no nitrites or nitrates are used: salt is the only preservative. The Consortium says that, and that the process takes at least 14 months from the first salting.

The changes that matter are salt diffusion and water loss, followed by slow enzymatic change in the muscle during maturation. The sources reviewed for this page describe the process and the protected conditions, not the microbiology. Nothing in them shows a starter culture, so this record does not classify the ham as a fermented food.

The protected specification

The European Commission’s summary of the protected name sets out the production rules. The traditional breeds are Large White, Landrace or Duroc, with other breeds allowed if they are compatible with the Italian Herd Book. The pigs must be at least nine months old and weigh about 160 kg live weight. The legs are salted, rested for 15 to 18 days after the second salting, and hung for about 80 days in a ventilated, temperature-controlled room, and the curing lasts a minimum of 14 months.

Production, packaging and slicing must take place in the Province of Parma. The raw legs may come from a wider list of regions, which the EC summary names. The Consortium’s own page gives the day counts differently in places, so the legal specification should be checked for any commercial claim.

Salt, cold and the first weeks

The salting stage is the core of the method. The consortium describes a humid sea salt on the pigskin and a dry salt on the muscle, followed by about a week at 1 to 4 C and about 80 per cent humidity. A second, thinner salt coating then rests for 15 to 18 days, depending on the weight of the leg. The cold keeps the meat from spoiling while salt moves into it.

Resting follows at about 75 per cent humidity for 60 to 90 days in the consortium’s account. The meat darkens during this time and returns to a rosy colour in the last days. The ham is then washed in warm water, brushed to remove excess salt, and hung to dry for a few days before the first long cure.

Curing in windows, then in cellars

The initial cure lasts about three months in well-ventilated rooms with large windows, opened when the outside air is suitable. The exposed surface dries and hardens. A paste of minced lard and salt is then applied to the exposed surfaces to slow the outside drying.

From about the seventh month the hams move to low-air, low-light cellars to finish. Weight falls by about 5 per cent during curing, and a trimmed ham loses more than a quarter of its weight in total. The ham is tested after at least 14 months with a horse-bone needle that shows the aroma; some hams age up to three years.

Serving the ham

Prosciutto is served uncooked and thinly sliced, as the image of a board of slices shows. The sources reviewed do not give pairings or serving temperatures, so none are recorded here.

Unknowns and limits

No source reviewed gives a home method that meets the protected specification. The sources also do not give a salt quantity, a room size, a safe hanging humidity for a small cabinet or a parasite control step. The Wikipedia article describes the pork history of Friuli and the Romans, but it does not date Parma ham itself, so that history is not used here as the origin of this product.

Curing a leg in a domestic cabinet is a different process from the protected one. This page keeps the specification as the reference and does not present a home version as Prosciutto di Parma.