Salting and pickling are food preservation methods that have been used for centuries. Food is preserved so that it can be available even when these foods are out of season. Various meats, fruits and vegetables can be preserved using salting and pickling methods of preservation.
Salting is also known as curing and this process draws moisture from the meat through osmosis. Table salt, which consists primarily of sodium chloride, is the most common ingredient for curing food and is used in relatively large quantities. Salt kills and inhibits the growth ofmicroorganisms by drawing water out of the cells of both the microbe and the food through osmosis. Concentrations of salt up to twenty percent are required to kill most species of unwanted bacteria.
When food is preserved using wet methods it is called a pickle. Pickling is also known as corning or brining and this process preserves food by anaerobic fermentation in brine (salt and water solution) to produce lactic acid. Food can also be marinated and stored in an acid solution which is usually vinegar (acetic acid) and these procedures give the food a salty or sour taste. In South Asia edible oils are used as the pickling medium instead of vinegar.
Process of salting
There are two methods used to salt meats, fish and pork and these are dry salting and wet salting (pickling). Though use of salt is most common but saltpetre is also used in salting non-vegetarian foods. Sugar or a combination of salt and sugar is sometimes also used to cure meats. Nitrates and nitrites can also be used as curing medium and these chemicals give meat a pink colour and also help to inhibit Clostridium botulinum bacteria. Sauerkraut (finely cut cabbage) and Korean kimchi (fermented vegetables with seasoning) are also produced by salting the vegetables to draw out excess water. With dry salting meat is packed in dry salt or salt is rubbed with a coating of salt but this method does not preserve the meat as long as wet salting. In wet salting meat is first rubbed with salt and salt is also placed between the layers of meat; then brine is poured over the packed salted meat and kept submerged in brine solution. Pickling does not leave the meat as salty as in dry salting but it still needs to be pre-soaked, which removes excess salt, before cooking.
Process of pickling
Pickling is a method of preserving food in an edible anti-microbial liquid. Pickling is of two types
- chemical pickling (brining)
- fermentation pickling
In chemical pickling, food is placed in an edible liquid that inhibits or kills bacteria and other micro-organisms. A number of pickling agents can be used like brine, vinegar, alcohol, and vegetable oil (olive or mustard oil). The chemical pickling process could also involve heating or boiling so that the food being preserved becomes saturated with the pickling agent. Common chemically pickled foods include cucumbers, peppers, corned beef, herring, and eggs, chow-chow (chayote and Hindi chocho) as well mixed vegetables such as piccalilli and giardiniera (chopped pickled vegetables and spices) and also Indian achar.
In fermented pickling, the food itself produces the preservation agent, typically by a process that produces lactic acid. Fermented pickles include sauerkraut, nukazuke (Japanese pickle made by fermenting vegetables in rice bran) kimchi, surströmming (Swedish food- fermented Baltic Sea herring) and curtido (fermented cabbage, onions, carrots, oregano- Central American cuisine). Some chemically pickled cucumbers are also fermented. In commercial pickles, a preservative like sodium benzoate or EDTA may also be added to increase shelf life.