Buy Kefir grains from us and make your own Kefir milk at home. Kefir milk is a natural source of probiotics that keeps your gut healthy. A healthy gut is a healthy you. Kefir milk 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.