Water kefir grains consist of a complex polysaccharide matrix, in which live a combination of live bacteria and yeasts existing in a symbiotic matrix. Kefir grain make-up can vary depending on culturing location and conditions, resulting in a highly variable community of lactic acid bacteria and yeasts.

Following is one scientific study's list of bacteria and yeast strains found to comprise water kefir grains.* The strains listed may include numerous subspecies and variants.

Please Note: This list is for general informational purposes only. We do not test individual batches of water kefir grains for yeast and bacteria content; therefore, we cannot make any guarantees as to the exact probiotic makeup of our water kefir grains.


Species Lactobacillus
L. brevis
L. casei
L. hilgardii
L. hordei
L. nagelii

Species Leuconostoc
L. citreum
L. mesenteroides

Species Acetobacter
A. fabarum
A. orientalis

Species Streptococcus
S. lactis


Hanseniaospora valbyensis
Lachancea fermentati
Saccharomyces cerevisiae
Zygotorulaspora florentina