Souring is a food preparation technique that causes a physical and chemical change in food by exposing it to an

acid An acid is a molecule or ion capable of either donating a proton (i.e. Hydron, hydrogen cation, H+), known as a Brønsted–Lowry acid–base theory, Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis ...

. This acid can be added explicitly (e.g.,

vinegar Vinegar () is an aqueous solution of diluted acetic acid and trace compounds that may include flavorings. Vinegar typically contains from 5% to 18% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting ...

lemon juice The lemon (''Citrus'' × ''limon'') is a species of small evergreen tree in the ''Citrus'' genus of the flowering plant family Rutaceae. A true lemon is a hybrid of the citron and the bitter orange. Its origins are uncertain, but some ...

, lime juice, etc.), or can be produced within the food itself by a

microbe A microorganism, or microbe, is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells. The possible existence of unseen microbial life was suspected from antiquity, with an early attestation in ...

, such as ''

Lactobacillus ''Lactobacillus'' is a genus of gram-positive, aerotolerant anaerobes or microaerophilic, rod-shaped, non-spore-forming bacteria. Until 2020, the genus ''Lactobacillus'' comprised over 260 phylogenetically, ecologically, and metabolically div ...

''. Souring is similar to

pickling Pickling is the process of food preservation, preserving or extending the shelf life of food by either Anaerobic organism, anaerobic fermentation (food), fermentation in brine or immersion in vinegar. The pickling procedure typically affects t ...

fermentation Fermentation is a type of anaerobic metabolism which harnesses the redox potential of the reactants to make adenosine triphosphate (ATP) and organic end products. Organic molecules, such as glucose or other sugars, are catabolized and reduce ...

, but souring typically occurs in minutes or hours, while pickling and fermentation can take a much longer amount of time.

Examples

Dairy A dairy is a place where milk is stored and where butter, cheese, and other dairy products are made, or a place where those products are sold. It may be a room, a building, or a larger establishment. In the United States, the word may also des ...

products produced by souring include: Clabber,

Cheese Cheese is a type of dairy product produced in a range of flavors, textures, and forms by coagulation of the milk protein casein. It comprises proteins and fat from milk (usually the milk of cows, buffalo, goats or sheep). During prod ...

, ''

Crème fraîche Crème fraîche (English pronunciation: , , lit. "fresh cream") is a dairy product similar to cream cheese, a soured cream containing 10–45% butterfat, with a pH of approximately 4.5. It is soured with a Microbiological culture, bacterial cult ...

'', Cultured buttermilk,

Curd Curd is obtained by Denaturation (biochemistry), coagulating milk in a sequential process called curdling. It can be a final dairy product or the first stage in cheesemaking. The coagulation can be caused by adding rennet, a Kefir cheese, ...

, ''

Filmjölk (), also known as , is a traditional fermented milk product from Sweden, and a common dairy product within most of the Nordic countries. It is made by fermentation (food), fermenting cow's milk with a variety of bacteria from the species ''Lactoc ...

'', ''

Kefir Kefir ( ; alternative spellings: kephir or kefier; ; ; ) is a Fermented milk products, fermented milk drink similar to a thin yogurt or ayran that is made from kefir grains, a specific type of mesophilic SCOBY, symbiotic culture. It is prep ...

'', '' Paneer'', ''Smetana'',

Soured milk Soured milk denotes a range of food products produced by the acidification of milk. Acidification, which gives the milk a tart taste and unpleasant smell, is achieved either through bacterial fermentation or through the addition of an acid, such ...

Sour cream Sour cream (sometimes known as soured cream in British English) is a dairy product obtained by fermenting regular cream with certain kinds of lactic acid bacteria. The bacterial culture, which is introduced either deliberately or naturall ...

, and

Yogurt Yogurt (; , from , ; also spelled yoghurt, yogourt or yoghourt) is a food produced by bacterial Fermentation (food), fermentation of milk. Fermentation of sugars in the milk by these bacteria produces lactic acid, which acts on milk protein to ...

Grain A grain is a small, hard, dry fruit (caryopsis) – with or without an attached husk, hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and ...

products include: Idli,

Sourdough Sourdough is a type of bread that uses the fermentation by naturally occurring yeast and lactobacillus bacteria to raise the dough. In addition to leavening the bread, the fermentation process produces lactic acid, which gives the bread its dis ...

, and

Sour mash Sour mash (or sourmash) is a process used in the distilling industry that uses material from an older batch of mash to adjust the acidity of a new mash. The term can also be used as the name of the type of mash used in such a process, and a bo ...

. Others foods produced by souring include: '' Ceviche'', ''

Kinilaw ''Kinilaw'' ( or , literally "eaten raw") is a raw seafood dish and preparation method native to the Philippines. It is more accurately a cooking process that relies on vinegar and acidic fruit juices (usually citrus) to denature the ingredi ...

'', and

Key lime pie Key lime pie is an American dessert pie. It is made of Key lime juice, egg yolks, and sweetened condensed milk. It may be served with no topping, with a meringue topping made from egg whites, or with whipped cream. Traditionally, Key lime pie i ...

.Key Lime Pie
/ref>

References

External links

Buttermilk substitution

Free lactic acid in sour milk

A comparison of sourdough microflora

{{Cooking techniques Cooking techniques Fermentation in food processing Culinary terminology

Examples

See also

References

External links