Kefir is a fermented milk drink similar to a thin yogurt or ayran that is made from kefir grains, a specific type of mesophilic symbiotic culture. The drink originated in the North Caucasus, in particular the Elbrus region along the upper mountainous sections of Circassia, Karachay and Balkaria, from where it came to Russia, and from there it spread to Europe and the United States, where it is prepared by inoculating the milk of cows, goats, or sheep with kefir grains.
Kefir is a breakfast, lunch, and dinner drink popular across Belarus, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, Russia, and Ukraine - where it is known as an affordable health drink. It is also known in Norway, Sweden, and Finland, where buttermilk-type fermented dairy drinks are common. Kefir is common particularly among Russian and Estonian minorities.(citation needed) In South Slavic countries, kefir is consumed at any time of the day, especially with zelnik/zeljanica, burek and banitsa/gibanica, as well as in cold soups served in the summer.