Kefir

Kefir is a fermented milk drink that originated in the North Caucasus region, traditionally made by inoculating cow, goat or sheep milk with kefir grains, a gelatinous cluster of symbiotic bacteria and yeast held together in a polysaccharide matrix. Fermentation gives the drink a tangy, slightly sour taste and a light natural effervescence from carbon dioxide, with a consistency thinner than yogurt and typically drinkable rather than spooned. Kefir has spread from its Caucasus and Central Asian origins to become a widely sold probiotic beverage internationally, valued for its live bacterial and yeast cultures.