Parmigiano-Reggiano is a hard, fat granular cheese, cooked but not pressed, named after the producing areas of Parma, Reggio Emilia, Modena, Bologna, in Emilia-Romagna, and Mantova, in Lombardy, Italy.

Parmigiano is simply the Italian adjective for Parma; the French version, Parmesan, is used in the English language. The term Parmesan is also loosely used as a common term for cheeses imitating true Parmesan cheese, especially outside Europe; within Europe, the Parmesan name is classified as a protected designation of origin.

Production

Parmigiano-Reggiano is made from raw cow's milk. The whole milk of the morning milking is mixed with the naturally skimmed milk (it is left in large shallow tanks to allow the cream to separate) of the previous evening's milking, resulting in a part skim mixture. The milk is pumped into copper-lined vats (copper heats and cools quickly). Starter whey is added, and the temperature is raised to 33-35C. Calf rennet is added, and the mixture is left to curdle for 10-12 minutes. The curd is then broken up mechanically (spinitura in Italian) into small pieces (around the size of rice grains). The temperature is then raised to 55 °C with careful control by the cheese-maker. The curd is left to settle for 45-60 minutes. The compacted curd is collected in a piece of muslin before being divided in two and placed in moulds. There are 1100 L of milk per vat, producing two cheeses each. The curd making up each wheel at this point weighs around 45 kg (100 lb). The remaining whey in the vat was traditionally used to feed the pigs from which "Prosciutto di Parma" (cured Parma ham) is produced. The barns for these animals were usually just a few yards away from the cheese production rooms.

The cheese is put into a stainless steel round form that is pulled tight with a spring powered buckle so the cheese retains its wheel shape. After a day or two, the buckle is released and a plastic belt imprinted numerous times with the Parmigiano-Reggiano name, the plant's number, and month and year of production is put around the cheese and the metal form is buckled tight again. The imprints take hold on the rind of the cheese in about a day and the wheel is then put into a brine bath to absorb salt for 20-25 days. After brining, the wheels are then transferred to the aging rooms in the plant for 12 months. Each cheese is placed on wooden shelves that can be 24 cheeses high by 90 cheeses long or about 4,000 total wheels per aisle. Each cheese and the shelf underneath it is then cleaned manually or robotically every 7 days. The cheese is also turned at this time.

At 12 months, the Consorzio Parmigiano-Reggiano inspects each and every cheese. The cheese is tested by a master grader whose only instruments are a hammer and his ear. By tapping the wheel at various points, he can identify undesirable cracks and voids within the wheel. Those cheeses that pass the test are then heat branded on the rind with the Consorzio's logo. Those that don't pass the test used to have their rinds marked with lines or crosses all the way around to inform consumers that they are not getting top-quality Parmigiano-Reggiano; more recent practices simply have these lesser rinds stripped of all markings.