you strain the grains and add them to fresh milk every day. you can get them to make less by dividing the grains and tossing or eating some. It will get pretty thick if your bacteria are chugging out acid. My kefir would always end up not sour after a week or so. I could revive it for a bit by adding some lifeway kefir, but the ambient temp favored the yeast. A less cold fridge might let the grains run and favor the bacteria to keep it sour. Also lifeway kefir makes a good yogurt starter.
