Curing is a traditional method of preserving and flavouring food, usually meats or fish ( think ham and smoked salmon ), using different chemical salts and sugars with adds spices and aromatics. The meat is then quite often cold smoked, which adds more flavour and dried, which are both also methods of preserving. The use of nitrite salts * ( saltpetre or nitre ) pioneered in the eighteen hundreds helps prevent bacteria from multiplying in the meat cells and keeps the cured meat its distinctive pink colour. Brining uses only normal salt ( sodium chloride ), sugars and flavourings and is used to enhance the flavours of and add moisture to meat. While each technique was primarily concerned with stretching out the length of time slaughtered meat could be kept without refrigeration people began to cure, smoke and dry meat because of the agreeable changes in texture and flavour.
There are two methods of curing; dry curing and sweet pickle curing. Each uses salts; sodium chloride, nitrite and nitrate and sugars ( from honey, cane molasses or maple syrup ) and in a sweet pickle the mixture is made like a brine solution. Some producers use spice mixtures to add extra flavour to the cure. Sodium Nitrate helps inhibit bacterial growth while the curing process takes place. During curing a chemical reaction takes place at a cellular level in the meat drawing out water and introducing salt. This process further inhibits bacterial growth which causes food spoilage and can be poisonous. Bacteria does not grow in salty conditions and requires high levels of moisture. This is particularly important if the meat is to be smoked as this raises the temperature of the meat which encourages bacteria to grow. The salt also prevents the meats from spoiling through oxidisation and going rancid.
There are strict legal guidelines on the levels of nitrates in curing please follow any recipe precisely.