Traditionally, kefir grains have been replicated in cows’ milk. However, Abraham
and de Antoni11 have shown that the same grains that grow in cows’ milk can grow
and replicate in soybean milk. When soybean milk was used, the resulting grains
are more compact and smaller in size, and have a yellowish color—most likely due
to the protein. When the grains are added to the soybean milk, the pH is lower after
30 h than it is in cows’ milk. After 20 subcultures, the soybean-grown grains had a
higher protein content and lower polysaccharide content than the milk-grown grains,
although the microbial profiles of the two grains were similar.