Kefir is a type of fermented, acidic, slightly alcoholic drink with a creamy consistency, resulting from the fermentation of microorganisms that live in symbiosis in traditional grains or lumps of kefir. Kefir: Nutrition, Consumption and Health Benefits reviews the current literature and presents a "study of art" relating to kefir and its technological advances in product development. The level of microorganisms found in kefir grain are reviewed, along with the ratio of microorganism species to each other, the incubation temperature applied in production, its duration and the storage time of kefir grain.