It's really late and I don't have the time or energy to post much beyond this, but hey! I have real, live, kefir grains!
I have a fresh batch of raw milk with fermenting on my stove as I type this. It's a complete experiment with me, as I've never even TASTED kefir, let alone made it. But I know how good it is for us, so I'll try it. I'm thinking I'll make a smoothie with a bit of milk and some frozen blueberries tomorrow. Update will follow.