I made kefir for a while but not very successfully. Got grains from a friend who makes it. Went back to making yogurt which is easier. I kind of do the best I can, which is not always the best...
temperature has a lot to do with it. I have the same grains going strong and have split many to give away.
I used to make yogurt in a slow cooker. Mixed results.
Broke down and spent $60 on a yogurt maker. Money well spent. Perfect yogurt over night every time:)
I need to look into kefir.