Science Fair Project Encyclopedia
Pickling is the process of preparing a food by soaking and storing it in a brine (salt) or vinegar solution, a process which can preserve otherwise perishable foods for months. The resulting food is called a pickle.
Pickles are made in one of three ways:
- Processed pickles are made the old-fashioned way, by a process of fermentation. The bacteria in the cucumber are allowed to reduce the sugars present. This usually takes about five weeks, and the resulting pickles have a shelf life of many months.
- Fresh-packed pickles are made by pasteurizing cucumbers to kill bacteria or make bacterial spores dormant. Fresh-packed pickles have a shelf life of many months. Many commercially-produced pickles are fresh-packed.
- Refrigerated pickles (sometimes called overnight pickles) are made by placing cucumbers in a vinegar solution and refrigerating them. Compared to processed or fresh-pack pickles, refrigerated pickles have a relatively short shelf life, and even unopened jars should be kept refrigerated.
If the food contains sufficient moisture a pickling brine may be produced simply by adding dry salt. Some pickling forms, most notably Korean Kim Chi, salt the vegetables to draw out excess water, then allow natural fermentation of the vegetable to create a vinegar-like solution. Unlike the canning process, pickling does not require the food to be made completely sterile before it is sealed. The acidity or salinity of the solution makes it an environment in which bacteria or fungi do not easily grow.
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.
It is believed that cucumbers were first pickled 4500 years ago in Mesopotamia. Cleopatra thought pickled cucumbers made her beautiful. The armies of Julius Caesar and Napoleon were fed pickles. During World War II, forty percent of the gherkins produced in the US went to the armed forces.
Pickles popular in different places
The USA pickle market is dominated by cucumber pickles such as gherkins. In the US, the word "pickle" by itself usually refers to a pickled cucumber. Cucumbers may be cooked in spiced sugar syrup (sweet pickles), pickled in brine with dill (dill pickles), or with dill and garlic (kosher dills). Pickle relish, a traditional condiment for hot dogs, is made from sweet pickles.
In the UK, the most common type of pickle in British cuisine is the pickled onion. They are often sold in Fish 'n' Chip shops, as are pickled eggs. Pickled beetroot and condiments such as "Branston pickle" are typically eaten as an accompaniment to pork pies and cold meats or a ploughman's lunch.
Capers are almost invariable served pickled, rather than fresh.
Other foods that are commonly pickled include:
- vegetables: onions, cabbage (to make sauerkraut and kimchi), cauliflower, capers, ginger, peppers (chilli pepper: banana peppers, jalapeņos, etc.), mushrooms, lotus root, garlic, beets, okra, green tomatoes
- fruit: mango, plum, kumquat, lemon, watermelon rind
- meat: beef (to make corned beef and pastrami), pork, ham, pickled snakes
- fish: herring
Other uses of the word "pickle"
Final treatment of iron and steel products before onward sale into manufacturing includes pickling in strong mineral acid to remove rust and prepare the surface for tin or chromium plating or for other surface treatments such as galvanization or painting. The two acids commonly used are hydrochloric acid and sulphuric acid. Wastewaters from pickling include acidic rinse waters together with waste acid. Although many plants operate acid recovery plants, (particularly those using hydrochloric acid), where the mineral acid is boiled away from the iron salts, there remains a large volume of highly acid ferrous sulphate or ferrous chloride to be disposed of.
Pickling may also refer to a metallurgical process in which stainless steel is chemically treated (usually with a solution of nitric acid and hydrofluoric acid) to remove any scale and contaminants from processing, with the goal of improving corrosion resistance.
In Java and Python programming, "Pickling" is the process of creating a serialized representation of objects. A detailed explanation of pickling can be found at http://citeseer.ist.psu.edu/riggs96pickling.html
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