Kefir is consumed at any time of the day, such as alongside European pastries like zelnik (zeljanica), burek and banitsa/gibanica, as well as being an ingredient in cold soups.

[7] More likely is another Caucasian origin; compare Georgian კეფირი (k’epiri), Mingrelian ქიფური (kipuri), Ossetian къӕпы (k’æpy), and Karachay-Balkar гыпы (gıpı).

[9][10] Kefir spread from the former Soviet Union to the rest of Europe, Canada, Japan, and the United States by the early 21st century.

Fermentation of the lactose yields a sour, carbonated, slightly alcoholic beverage, with a consistency and taste similar to drinkable yogurt.

A complex and highly variable symbiotic community can be found in these grains, which can include acetic acid bacteria (such as Acetobacter aceti and A. rasens), yeasts (such as Candida kefyr, Saccharomyces cerevisiae, M. turicensis) and a number of Lactobacillus species, such as L. parakefiri, L. kefiranofaciens (and subsp.

[6] In recent years, the use of freeze-dried starter culture has become common due to stability of the fermentation result, because the species of microbes are selected in laboratory conditions, as well as easy transportation.

[33] Kefir products contain nutrients in varying amounts from negligible to significant, including dietary minerals, vitamins, essential amino acids, and conjugated linoleic acid,[34][35] At a pH of 4.2 – 4.6,[36] kefir is composed mainly of water and by-products of the fermentation process, including carbon dioxide and ethanol.

[37] Several dietary minerals are found in kefir, such as calcium, iron, phosphorus, magnesium, potassium, sodium, copper, molybdenum, manganese, and zinc in amounts that have not been standardized to a reputable nutrient database.

[21][34][38] Lactobacilli in kefir may exist in concentrations varying from approximately 1 million to 1 billion colony-forming units per milliliter, and are the bacteria responsible for the synthesis of the polysaccharide kefiran.

The mixture is then placed in a corrosion-resistant container, such as a glass jar, and stored preferably in the dark to prevent degradation of light-sensitive vitamins.

After a period between 12 and 24 hours of fermentation at mild temperature, ideally 20–25 °C (68–77 °F),[26] the grains are strained from the milk using a corrosion-resistant (stainless steel or plastic) utensil and kept to produce another batch.

Typical animal milks used include cow, goat, and sheep, each with varying organoleptic (flavor, aroma, and texture) and nutritional qualities.

Milk sugar is not essential for the synthesis of the polysaccharide that makes up the grains (kefiran), and rice hydrolysate is a suitable alternative medium.

[42] Additionally, kefir grains will reproduce when fermenting soy milk, although they will change in appearance and size due to the differing proteins available to them.

Kefir may be used in place of milk on cereal, granola, milkshakes, salad dressing, ice cream, smoothies and soup.