We make our own milk Kefir and a few years back we experimented with making it in coconut milk. It was a bit hard on the kefir grains, but we kept them alive by switching them back and forth between cows milk and coconut milk. We did that for a few months and it worked out OK. Especially since I'm the only one that tries to avoid dairy. My wife would have the milk based and I would have the coconut based. I still mostly avoid dairy but decided to draw my boundaries to include milk based kefir/yogurt for the probiotic benefits.