Well, for the milk kefir you don't need a yogurt maker which provides the perfect temperature, though at one point I used to make yogurt without all that. I had the yogurt frozen into ice-cubes, and I simply dropped one into a carton of milk, left it sitting for a day at regular room temperature, and it bam! It always worked... well, until winter came, and room temperature stopped being what it used to be. With kefir, however, I never had that issue. It would turn even if I left it in an apartment that remained mostly unheated until I came back in the evening.