I did a lot of research on water kefir grains. My mother in law used them for grape juice and also a kind of lemonade. I then used her extras to start ginger beer.
The kefir will mutate slightly to fit whatever you are brewing trading off one kind of yeast for something else, only thing is you need to keep feeding them constantly or they die. They can be refrigerated to go almost dormant, but you still need to change out the liquid every week or two and give them fresh sugar and acids.
My ginger beer recipe was real close to this, but may need adjusted.
Water kefir grains (1/4 - 1 /2 cup)
ginger juice, ground in food processor then pressed; let settle in refrigerator overnight for starch to form on bottom (only use juice) (4 cups){use less if you don't want a hard ginger bite}
Organic cane sugar (3 cups),
lemon juice (1/2 cup),
raisins (12 or so),
black strap molasses (1/2 cup),
crushed egg shell (1/2tsp) [the structure of the grains need calcium]
cream of tartar (1/4tsp)
Water (to make 1 gallon with head space for foam)
Sanitize every thing,
boil water, dissolve sugar and molasses, add lemon juice, egg shell, and cream of tartar put it all in a clean sanitized 1 gallon jug.
Heat ginger juice to 160*, no more.. add raisins. Add to jug.
Allow mix to come down to just above room temp. Then add kefir grains.
affix air lock and allow to ferment for 2 weeks.
Siphon liquid off grains to fresh carboy (use funnel with fine srceen), affix clean air lock. Rinse grains with clean water (they will have multiplied) divide, and start new batch(s).
Or to each cup grains, add 1cup water, 2Tbs lemon juice, and 1/2cup sugar, put in fridge for up to two weeks then change liquid. (drink old stuff, tastes fairly good)
Allow to go dry, sweeten back to taste, and bottle using flip tops (no bottle bombs) I never tried crimp top bottles, as there is no pressure relief. let bottle condition for a month or two, then cold crash.
You may hear some bottles burping every once in a while. Use care when opening bottles as it is highly carbonated at this point. For light carbonation crash after testing a bottle that is where you want it.
I MAY BE DOING IT WRONG, BUT THIS HAS WORKED FOR ME.
When drinking anything fermented with kefir grains, it may take a day or two for some peoples digestive system to adjust to the beneficial bacteria present in the symbiotic structure of the kefir itself.
I started with 1/4 cup and ended up with 12 cups of grains in like 3 or 4 months.
I gave some away and then ended up pickleing the rest of my grains by allowing the alcohol content to get too high in a couple batches and killed them all.
But every one who tasted the ginger beer loved it.
I would post my exact recipe but my son got a hold of my book and now can't find it any where, so this recipe is from memory.
