What is Kefir?

Kefir alternatively milk kefir, or búlgaros, is a fermented milk drink that originated in the north Caucasus Mountains made with kefir "grains", a yeast/bacterial fermentation starter. It is prepared by inoculating cow, goat, or sheep milk with kefir grains. Traditional kefir was made in goatskin bags that were hung near a doorway; the bag would be knocked by anyone passing through to help keep the milk and kefir grains well mixed.

Kefir is a refreshing cultured-milk beverage which originated in the northern slopes of the Caucasus Mountains, believed to date back at least 1,000 years. The tribes-folk of this particular region who possibly developed kefir by shear accident consumed the nutritious beverage in large quantities. These people were renowned for longevity, living long, healthy lives with little to no known disease. An active life span of over one hundred years was common for folks living in the region where kefir was cultured and liberally consumed as part of a staple diet.

Kefir has a uniform, slightly creamy consistency, a sour refreshing flavour, with a slight subtle aroma of fresh yeast [or a very subtle beer-like aroma]. Kefir also has a slightest hint of a natural effervescent zesty tang. There is an assortment of some 40 aromatic compounds contributing to the unique flavour and distinctive pleasant aroma of kefir. Rounding this off, kefir contains between 0.08% to 2% alcohol. However, about .08 to .1% alcohol is a realistic figure for 1-day cultured kefir. Whereas kefir stored for a number of days after separating the natural mother-culture, kefir grains [see following], contains up to 2 and possibly 3% alcohol, depending on milk-type and ripening conditions.

Traditional kefir is fermented at ambient temperatures, generally overnight. Fermentation of the lactose yields a sour, carbonated, slightly alcoholic beverage, with a consistency and taste similar to thin yogurt.

Source :

https://en.wikipedia.org/wiki/Kefir

http://users.sa.chariot.net.au/~dna/kefirpage.html#what-is-kefir