Soured milk denotes a range of food products produced by the
acidification
Acidification may refer to:
* Ocean acidification, decrease in the pH of the Earth's oceans
* Freshwater acidification, atmospheric depositions and soil leaching of SOx and NOx
* Soil acidification, buildup of hydrogen cations, which reduces the ...
of
milk
Milk is a white liquid food produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals (including breastfed human infants) before they are able to digestion, digest solid food. Immune factors and immune ...
. Acidification, which gives the milk a tart taste, is achieved either through bacterial
fermentation
Fermentation is a metabolic process that produces chemical changes in organic substrates through the action of enzymes. In biochemistry, it is narrowly defined as the extraction of energy from carbohydrates in the absence of oxygen. In food ...
or through the addition of an acid, such as lemon juice or
vinegar
Vinegar is an aqueous solution of acetic acid and trace compounds that may include flavorings. Vinegar typically contains 5–8% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting simple sugars to et ...
. The acid causes milk to coagulate and thicken, inhibiting the growth of harmful bacteria and improving the product's shelf life.
Soured milk that is produced by bacterial fermentation is more specifically called
fermented milk
Fermented milk products or fermented dairy products, also known as cultured dairy foods, cultured dairy products, or cultured milk products, are dairy foods that have been fermented with lactic acid bacteria such as ''Lactobacillus'', ''Lactococc ...
or
cultured milk
Fermented milk products or fermented dairy products, also known as cultured dairy foods, cultured dairy products, or cultured milk products, are dairy foods that have been fermented with lactic acid bacteria such as ''Lactobacillus'', '' Lactococ ...
.
Traditionally, soured milk was simply fresh milk that was left to ferment and sour by keeping it in a warm place for a day, often near a stove. Modern commercial soured milk may differ from milk that has become sour naturally.
Soured milk that is produced by the addition of an acid, with or without the addition of microbial organisms, is more specifically called acidified milk.
In the United States, acids used to manufacture acidified milk include
acetic acid
Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main component ...
(commonly found in vinegar),
adipic acid
Adipic acid or hexanedioic acid is the organic compound with the formula (CH2)4(COOH)2. From an industrial perspective, it is the most important dicarboxylic acid: about 2.5 billion kilograms of this white crystalline powder are produced annuall ...
,
citric acid
Citric acid is an organic compound with the chemical formula HOC(CO2H)(CH2CO2H)2. It is a colorless weak organic acid. It occurs naturally in citrus fruits. In biochemistry, it is an intermediate in the citric acid cycle, which occurs in ...
(commonly found in lemon juice),
fumaric acid
Fumaric acid is an organic compound with the formula HO2CCH=CHCO2H. A white solid, fumaric acid occurs widely in nature. It has a fruit-like taste and has been used as a food additive. Its E number is E297.
The salts and esters are known as fu ...
,
glucono-delta-lactone,
hydrochloric acid
Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid
Acid strength is the tendency of an acid, symbol ...
,
lactic acid
Lactic acid is an organic acid. It has a molecular formula . It is white in the solid state and it is miscible with water. When in the dissolved state, it forms a colorless solution. Production includes both artificial synthesis as well as natu ...
,
malic acid
Malic acid is an organic compound with the molecular formula . It is a dicarboxylic acid that is made by all living organisms, contributes to the sour taste of fruits, and is used as a food additive. Malic acid has two stereoisomeric forms ...
,
phosphoric acid
Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is a colorless, odorless phosphorus-containing solid, and inorganic compound with the chemical formula . It is commonly encountered as an 85% aqueous solution, w ...
,
succinic acid
Succinic acid () is a dicarboxylic acid with the chemical formula (CH2)2(CO2H)2. The name derives from Latin ''succinum'', meaning amber. In living organisms, succinic acid takes the form of an anion, succinate, which has multiple biological ro ...
, and
tartaric acid
Tartaric acid is a white, crystalline organic acid that occurs naturally in many fruits, most notably in grapes, but also in bananas, tamarinds, and citrus. Its salt, potassium bitartrate, commonly known as cream of tartar, develops naturally ...
.
Soured milk is commonly made at home or is sold and consumed in Europe, especially in Eastern Europe (Bulgaria, Belarus, Poland, Russia, Ukraine, Lithuania), all over the countries of the former Yugoslavia (Macedonia, Serbia, Montenegro, Bosnia and Herzegovina, Croatia, Slovenia), Romania, Hungary, Greece, Finland, Germany, Scandinavia and Slovakia.
It is also made at home or sold in supermarkets and consumed in the Great Lakes region of Somalia and
Eastern Africa
East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territories make up Eastern Africa:
Due to the historica ...
(
Kenya
)
, national_anthem = "Ee Mungu Nguvu Yetu"()
, image_map =
, map_caption =
, image_map2 =
, capital = Nairobi
, coordinates =
, largest_city = Nairobi
, ...
,
Uganda
}), is a landlocked country in East Africa
East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territor ...
,
Rwanda
Rwanda (; rw, u Rwanda ), officially the Republic of Rwanda, is a landlocked country in the Great Rift Valley of Central Africa, where the African Great Lakes region and Southeast Africa converge. Located a few degrees south of the Equator ...
,
Burundi
Burundi (, ), officially the Republic of Burundi ( rn, Repuburika y’Uburundi ; Swahili language, Swahili: ''Jamuhuri ya Burundi''; French language, French: ''République du Burundi'' ), is a landlocked country in the Great Rift Valley at the ...
and
Tanzania
Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands and ...
). It is also a
traditional food
Traditional foods are foods and dishes that are passed on through generations or which have been consumed for many generations. Traditional foods and dishes are traditional in nature, and may have a historic precedent in a national dish, regio ...
of the
Bantu people
The Bantu peoples, or Bantu, are an ethnolinguistic grouping of approximately 400 distinct List of ethnic groups of Africa, ethnic groups who speak Bantu languages. They are native to 24 countries spread over a vast area from Central Africa to Sou ...
of
Southern Africa
Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number of ...
.
Since the 1970s, some producers have used chemical acidification in place of biological agents.
[
]
In recipes
Raw milk
Raw milk or unpasteurized milk is milk that has not been pasteurized, a process of heating liquid foods to kill pathogens for safe consumption and extending the shelf life.
Proponents of raw milk have asserted numerous supposed benefits to consu ...
that has not gone sour is sometimes referred to as "sweet milk", because it contains the sugar
lactose. Fermentation converts the lactose to
lactic acid
Lactic acid is an organic acid. It has a molecular formula . It is white in the solid state and it is miscible with water. When in the dissolved state, it forms a colorless solution. Production includes both artificial synthesis as well as natu ...
, which has a sour flavor. Before the invention of
refrigeration
The term refrigeration refers to the process of removing heat from an enclosed space or substance for the purpose of lowering the temperature.International Dictionary of Refrigeration, http://dictionary.iifiir.org/search.phpASHRAE Terminology, ht ...
, raw milk commonly became sour before it could be consumed, and various recipes incorporate such leftover milk as an ingredient. Sour milk produced by fermentation differs in flavor from that produced by acidification, because the acids commonly added in commercial manufacture have different flavors from lactic acid, and also because fermentation can introduce new flavors.
Buttermilk
Buttermilk is a fermented dairy drink. Traditionally, it was the liquid left behind after churning butter out of cultured cream. As most modern butter in western countries is not made with cultured cream but uncultured sweet cream, most mod ...
is a common modern substitute for naturally soured milk.
See also
*
*
*
References
{{Authority control
Fermented dairy products
Russian drinks
Russian dairy products