Salami: The Manufacturing Process
Though uncooked, salami are not raw; they have been prepared via curing. The term cotto salame refers to salami cooked or smoked before or after curing. This is done to impart a specific flavor but not to cook the meat. Before curing, a cotto salame is still considered raw and is not ready to be eaten. Most kinds of salami made from donkey or ox are considered "cotto".
Salami are cured in warm, humid conditions in order to encourage growth of the bacteria involved in the fermentation process. Sugar is added as a food source for the bacteria during the curing process, although it tends not to be added to horse meat due to naturally high levels of glycogen. Lactic acid is produced by the bacteria as a waste product, lowering the pH and coagulating and drying the meat. The acid produced by the bacteria makes the meat an inhospitable environment for other, dangerous bacteria and imparts the tangy flavor that separates salami from machine-dried pork. The flavor of a salami relies just as much on how this bacteria is cultivated as it does on quality and variety of other ingredients. Originally, the bacteria were introduced into the meat mixture with wine, which contains other types of beneficial bacteria; now, starter cultures are used.
The curing process is determined by the climate of the curing environment and the size and style of casing. After fermentation, the sausage has to be dried. This changes the casings from being water-permeable to being reasonably airtight. A white covering of either mold or flour helps prevent the photo-oxidation of the meat and rancidity in the fat.
Under some conditions the nitrate probably comes from the breakdown of proteins. Salt, acidity, nitrate levels and dryness of the fully-cured salami combine to make the raw meat safe to consume.