I used to make kefir from organic raw milk. I've told the story here. It made an enormous difference in my life.

I made kefir several times a week and fed the whey to the chickens in their daily mash. But in 2019 I started having trouble with raw milk again and eventually stopped making the kefir. I tried a very good quality yogurt for a short while, but again I had problems.

So now I have sauerkraut for the probiotics.