Pickling Spice is used in the process of preserving or expanding the lifespan of food by either anaerobic fermentation in brine or immersion in vinegar. The resulting food is called a pickle, or, to prevent ambiguity, prefaced with the adjective pickled. The pickling procedure will typically affect the food’s texture and flavor. In East Asia, vinaigrette (vegetable oil and vinegar) is also used as a pickling medium. Foods that are pickled include meats, fruits, eggs, and vegetables.
Another distinguishing characteristic is a pH 4.6 or lower, which is sufficient to kill most bacteria. Pickling can preserve perishable foods for months. Antimicrobial herbs and spices, such as mustard seed, garlic, cinnamon or cloves, are often added. If the food contains sufficient moisture, a pickling brine may be produced simply by adding dry salt. For example, German sauerkraut and Korean kimchi are produced by salting the vegetables to draw out excess water. Natural fermentation at room temperature, by lactic acid bacteria, produces the required acidity. Other pickles are made by placing vegetables in vinegar. Unlike the canning process, pickling (which includes fermentation) does not require that the food 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 both salt concentration and temperature are low, Leuconostoc mesenteroides dominates, producing a mix of acids, alcohol, and aroma compounds. At higher temperatures Lactobacillus plantarum dominates, which produces primarily lactic acid. Many pickles start with Leuconostoc, and change to Lactobacillus with higher acidity.
Pickling began 4000 years ago using cucumbers native to India. This was used 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 invented to preserve foods, pickles are also made and eaten because people enjoy the resulting flavors. Pickling may also improve the nutritional value of food by introducing B vitamins produced by bacteria.
The term pickle is derived from the Dutch word pekel, meaning brine. In the U.S. and Canada, and sometimes Australia and New Zealand, the word pickle alone almost always refers to a pickled cucumber, except when it is used figuratively. It may also refer to other types of pickles such as “pickled onion”, “pickled cauliflower”, etc. In the UK, pickle, as in a “cheese and pickle sandwich”, may also refer to Ploughman’s pickle, a kind of chutney.
In traditional pickling fruit or vegetables are submerged in a brine (20-40 grams/l of salt (3.2–6.4 oz/imp gal or 2.7–5.3 oz/US gal)) or shredded and salted as in sauerkraut preparation and held underwater by flat stones layered on top. Alternatively a lid with an airtrap or a tight lid could be used if the lid is able to release pressure which might result from carbon dioxide build up. When using an open container it should be covered with cloth to keep insects away. Mold or (white) kahm yeast may form on the surface and should be removed. Kahm yeast is mostly harmless but can impart an off-taste.
In chemical pickling, the jar and lid are first boiled in order to sterilize them. The fruits or vegetables to be pickled are then added to the jar along with brine, vinegar, or both, as well as spices, and are then allowed to mature until the desired taste is obtained.
The food can be pre-soaked in brine before transferring to vinegar. This reduces the water content of the food which would otherwise dilute the vinegar. This method is particularly useful for fruit and vegetables with a high natural water content.
In commercial pickling, a preservative like sodium benzoate or EDTA may also be added to enhance shelf life. In fermentation pickling, the food itself produces the preservation agent, typically by a process involving Lactobacillus bacteria that produce lactic acid as the preservative agent.
Alum is used in pickling to promote crisp texture and approved as a food additive by the United States Food and Drug Administration.
“Refrigerator pickles” are unfermented pickles made by marinating fruit or vegetables in a seasoned vinegar solution. They must be stored under refrigeration or undergo canning to achieve long-term storage.