Abstract: In this paper, the effect of kefir grains increase with different incubations and nutrimental resource was studied. The result showed that, when inoculated ratio of kefir grains was 5%, incubation temperature of 25℃, multiplication was lowed with rinsing or kefir grains preserved at 4℃, doubled mass grains produced with agitation. The grains increase was little with single carbon resource, even restrained with compound carbon resource in a sense. Factors influencing grains increase — enrichment with L-methionine 0.002%, tryptose 0.5% and yeast extract 0.5%, and with MnSO·4H2O 0.001%, MgSO·47H2O 0.002% and K2HPO·43H2O 0.001%. Fermented characteristic and flora proportion of kefir grains were no changes after increasing.

Key words: kefir grains, increase, agitation, rinse, nutrient addition