First you have to find someone who has extra kefir grains to get rid of. (you may be able to check at your local health food store, someone there may know how you can get a hold of some) you can also buy them from online retailers like Cultures for Health.

In cooler weather I find the milk cultures better if I warm the milk up to room temperature before adding the grains. In warm weather I just place the grains into the milk while it’s still cold.

Place 1 Tbsp kefir grains into jar and stir around.

Cover lightly with a lid and place in a cupboard overnight. (about 24 hours)

Let sit out, stirring or swishing the grains around until slightly thickened, like runny yogurt. Drain kefir grains out of the milk and place newly made kefir into the fridge

Start again with fresh milk and the same kefir grains.

The grains will start to expand and grow, so you can either make more kefir each time (1 Tbsp to each 1 cup of milk), or pass them along to someone else. I’ve also frozen a couple tablespoons of the grains in a bit of milk to have on hand should anything happen to the ones I’m actively using. If you want to take a break from making it for awhile, place in a jar of milk and refrigerate for up to a couple weeks.