Kefir was discovered in ancient times, when nomadic shepherds in the Caucasus Mountains of Eastern Europe found that the milk they carried in leather sacks occasionally fermented into a creamy, bubbly drink. Its tart and refreshing flavor is often compared to yogurt. The difference is, Kefir is drinkable and it contains many more of the friendly bacteria known as “probiotics.”
So, how does milk become Kefir? The fermentation is triggered by Kefir “grains,” consisting of various species of symbiotic bacteria and yeast. Bacteria (mostly lactobacteria and streptococci) ferment lactose, the sugar found in milk; yeasts perform alcohol fermentation, producing negligible amounts of alcohol. The resulting drink has a pleasantly tangy taste. Easy to digest, Kefir cleanses the intestines while boosting your immune response to illness. And all that is due to the presence of probiotics.