After "losing" mine a couple of times (if that makes you scratch your head, just wait until you have goats and are filtering quarts of milk twice a day AND straining your kefir, and you can't figure out WHICH jar you put the grains in!) I dried some in a basket lined with paper towels, then put them in a small jar and put the jar into a ziploc and put it in the door of the freezer. I used these to send to people here on the forum, and they are supposed to be viable for two years. And I remembered to put a date on the bag this time....
Free's solution is a good one. I de-hydrate (using lowest heat possible) some of my extra, and store them in a small jar with some powdered milk, as a moisture absorber, in the 'fridge (yes, I know about dry milk, but I dried the first lot last year,before I knew, and the latest lot just got the sifted milk from the last lot - does that make any sense at all? ). This is as backup in case I somehow kill the active ones on the counter. To "put some on hold" for a shorter time, I just put them in a jar with some fresh milk,screw the top on tight, and store in the 'fridge. This slows things down nicely. I do this when we go away from home for awhile. "They" say that this is good for a week or so; I have done it, inadvertantly, for several months, and all was fine. If I have way more grains than I can use, or give away, I just put them in the morning treats for the chickens; they love them!
I need to get some to Gina and I have another friend who would like some, but they would have to be shipped.....and these little buggers are really growing lately!
My kefir has FINALLY doubled in a month, but now I think I'm going to freeze the slimy sucker. I've tried the kefir on several occasions now. It still tastes like bile, vile, vomit, and retch. I think that maybe it does not go with goat milk very well. I'll revive it once the the rest of the girls are lactating again. I think maybe the sweeter Nubian milk will taste better.