What are Milk Kefir Grains?

Milk kefir grains are a combination of live bacteria and yeasts that exist in a symbiotic matrix on a surface of a complex polysaccharide with a casein core. The make-up of kefir grains can vary depending on the culturing location and culturing conditions.

This means the community of lactic acid bacteria and yeasts can be highly variable in batches of kefir cultured in different places by different people.

The following is a list of bacteria and yeast strains found to comprise kefir grains from different regions through 2 different scientific studies.* The strains listed may include numerous subspecies and variants.