Meat curing is the preservation of meat through the addition of salt, nitrates or nitrites, and sugar. The curing process draws moisture out of the meat, inhibits microbial growth, and produces characteristic flavors and color. Cured meats include bacon, ham, corned beef, pastrami, and salt pork. Curing may be combined with [[Smoking]] and aging for additional preservation and flavor.
Meat curing has been practiced since ancient times. Salt was used to preserve meat in ancient Egypt, Greece, and Rome. The development of saltpeter (potassium nitrate) as a curing agent in the Middle Ages improved the color and safety of cured meats. Modern curing science began in the 19th century with the discovery of nitrite as the active curing agent. The USDA established standards for cured meat production in the 20th century.
Dry curing rubs the meat with a mixture of salt, sugar, and curing salt (pink salt containing sodium nitrite). The meat is placed in a refrigerated environment for 1 to 7 days per centimeter of thickness, allowing the cure to penetrate. The meat is turned and rubbed regularly during the curing period.
Wet curing (brining) submerges the meat in a solution of salt, sugar, and curing salt dissolved in water. The brine concentration is typically 10 to 20 percent salt by weight. The meat is cured for 1 to 5 days per kilogram of weight. Injection curing uses a needle to inject brine directly into the meat, reducing the curing time to 24 to 48 hours.
Curing salt, also called pink salt or Prague powder, contains sodium nitrite that gives cured meat its characteristic pink color and prevents the growth of Clostridium botulinum. Prague powder #1 (6.25 percent sodium nitrite, 93.75 percent salt) is used for short-term cures that are cooked before eating. Prague powder #2 (6.25 percent sodium nitrite, 4 percent sodium nitrate) is used for dry-cured products that are aged for extended periods.