For those of you that are unaware, kefir is a fermented milk product, similar to drinkable yogurt. It's chock full of probiotics and all that good stuff, but it tastes like sour yogurt unless you mix in some honey or fruit juice or whatever. I like to make cheese/dip/etc with it, but I'm not big on drinking it. The kefir grains are a polysaccharide sort of 'ship' for the bacteria/yeasts to live on and get funky. After a few successive batches, these grains start to grow. You can split it into multiple batches of traditional kefir, or you can switch the grains over to other fermentables.

There are water kefir grains that are already adapted to non lactose sugars, but milk grains work just fine. They won't grow once they're off milk, as the water kefir grains would, but they don't really need to. I've found that for the milk-juice kefir grains work the best with grape juice. You can use other juices, or lemonade, whatever, but grape juice tastes the best.

Just rinse the milk off and plop them in some juice. No fuss, no muss. I like to use a mason jar with a lid on it so I can drink it with just a little fizz. Bottling is probably a bad idea, as these bugs will ferment out all sugars, all the way. I usually only ferment for about 24 hrs, as if you wait longer than that, all the sugars will be gone and the drink gets a little vinegary.