Kefir (alternately kephir, kewra, talai, mudu kekiya, matsoun, matsoni, waterkefir, milkkefir) is a fermented milk drink originating in the Caucasus.

Kefir grains are a combination of probiotic bacteria and yeasts in a matrix of proteins, lipids and sugars. The exact combination of bacteria and yeasts vary between cultures. The resulting beverage is a faintly fizzy and slightly alcoholic drink.

To ensure consistency, commercial producers now generally use a powdered starter culture rather than grains. However, such cultures do not form grains or continue to culture indefinitely, making kefir grains the preferred choice for individuals.

Kefir is grown in milk (most commonly cow or goat milk) for a day or more at room temperature. The result is similar to yoghurt.

Waterkefir (or kefir d'acqua) is grown in water with sugar, dry fruit such as figs and lemon juice for a day or more at room temperature.

Variations that thrive in various other liquids exist. They may vary markedly from waterkefir or kefir in both appearance and microbial composition.

In Chile this beverage is called "Yoghurt de Pajaritos".

Due to the slight amount of alcohol in kefir, Russians often use it as a hangover cure.

See also: other dairy products and Kombucha

Further Reading

For more information, see Dominic N. Anfiteatro's kefir in-site (http://users.chariot.net.au/~dna/kefirpage.html).

For more information in Portuguese, see Carlos F. Dias Jr in-site (http://geocities.yahoo.com.br/kefirbrasil/) and (http://kefir.vilabol.uol.com.br) Variations that thrive in various other liquids (typically fruit or sugar based solutions) exist. They may vary markedly from milk kefir in both appearance and microbial composition. The beverage made from them is called kefir d'acqua or waterkefir.

For International Kefir grains database see Adnan's kefir site: http://66.46.11.99/clarkson/Show/Clarkson/kefir/search.asp