Pickling

Pickling, or corning, is the process of preparing a food by soaking and storing it in a brine containing salt and/or acid (usually vinegar), a process which can preserve perishable foods for months. The resulting food is called a pickle.

Pickling in brine often results in anaerobic fermentation, by either lactic acid bacteria or by yeast.

If the food contains sufficient moisture, a pickling brine may be produced simply by adding dry salt. Some pickling forms, including sauerkraut and Korean kimchi, salt the vegetables to draw out excess water, then allow natural fermentation to create a vinegar-like solution containing lactic acid. Other pickles are made by placing the vegetable in vinegar. 

Unlike the canning process, pickling which includes fermentation requires that the food not be completely sterile before it is sealed. The acidity or salinity of the solution, the temperature of fermentation, and the exclusion of oxygen determine which microorganisms dominate, and determine the flavor of the end product.

When the salt concentration and the temperature is low, Leuconostoc mesenteroides dominates, producing a mix of acids, alcohol, and aroma compounds. When the temperatures are higher, Lactobacillus plantarum dominates, which produces primarily lactic acid. Many pickles start with Leuconostoc, and change to Lactobacillus with higher acidity.

Pickling began as a way to preserve food for out-of-season use and for long journeys, especially by sea. Salt pork and salt beef were common staples for sailors before the days of steam engines. Although the process was originally used to preserve foods, pickling is frequently done because people enjoy the resulting flavor.

Fruits are sometimes pickled in high-sugar solutions or with flavorings such as cinnamon, mustard, or dill seed.