I have been talking a lot about Soy Kefir lately... and it's only fair to post how I make this awesome ingredient. This most likely can be made 100% vegan, but I have only cultured it in a dairy base. but given how it continues to reproduce, I'm fairly certain that you can culture soymilk with no ill effects.
The original instructions which is what we followed.... and I have been using the original kefir as a starter for my soymilk keifr! In a sterilized Mason Jar add 3 cups soymmilk and 1/4 cup kefir. Cover with a towel and let the mixture ferment for 12-24 hours. Make sure to reserve 1/4 cup kefir each time for the next batch and then continue on... !!
I love to use my soy kefir in smoothies!