Ham is produced by curing raw pork by
salting, also known as dry curing, or
brining, also known as wet curing. Additionally, smoking may be employed, and seasonings may be added.
Dry-cured Traditional dry cure hams may use only salt as the curative agent, although this is comparatively rare. This process involves cleaning the raw meat, covering it in salt while it is gradually pressed to squeeze out fluid. Specific herbs and spices may be used to add flavour during this step. The hams are then washed and hung in a dark, temperature-regulated place until dry. It is then hung to air for another period of time. The duration of the curing process varies by the type of ham. For example,
Jinhua ham takes approximately 8 to 10 months to complete,
jamón serrano cures in 9–12 months, prosciutto di Parma takes more than 12 months, and
Iberian ham can take up to 2 years to reach the desired flavour characteristics. Many dry-cured hams, such as
prosciutto, are eaten without being cooked. Most modern dry cure hams also use
nitrites (either
sodium nitrite or
potassium nitrite), which are added along with the salt. Nitrites are used because they prevent bacterial growth and, in a reaction with the meat's
myoglobin, give the product a desirable dark red colour. The amount and mixture of salt and nitrites used have an effect on the shrinkage of the meat. Because of the toxicity of nitrite, some areas specify a maximum allowable content of nitrite in the final product. Under certain conditions, especially during cooking, nitrites in meat can react with degradation products of
amino acids, forming
nitrosamines, which are known
carcinogens. The dry curing of ham involves a number of
enzymatic reactions. The enzymes involved are
proteinases (
cathepsins—
B,
D,
H &
L, and
calpains) and
exopeptidases (
peptidase and
aminopeptidase). These enzymes cause
proteolysis of muscle tissue, which creates large numbers of small
peptides and free amino acids, while the
adipose tissue undergoes
lipolysis to create free fatty acids. Animal factors influencing enzymatic activity include age, weight, and breed. During the process itself, conditions such as temperature, duration, water content,
redox potential, and salt content all have an effect on the meat.
Wet-cured Wet-cured hams are brined, which involves the immersion of the meat in a
brine, sometimes with other ingredients such as sugar also added for flavour. The meat is typically kept in the brine for around 3 to 14 days. Wet-cured ham is usually cooked, either during processing, or after ageing. A typical example of wet-cured ham made this way is
Italian . It is first brined, then cooked in a container and finally surface pasteurised. Italian regulations allow it to contain salt, nitrites, sugar, dextrose, fructose, lactose, maltodextrin, milk protein, soy protein, natural or modified starches, spices,
gelatine, and flavourings.
Smoking Ham can also be additionally preserved through smoking, in which the meat is placed in a
smokehouse (or equivalent) to be cured by the action of smoke. The main flavour compounds of smoked ham are
guaiacol, and its 4-, 5-, and 6-methyl derivatives as well as
2,6-dimethylphenol. These compounds are produced by combustion of lignin, a major constituent of wood used in the smokehouse. == Labeling ==