How to properly freeze kefir grains
Less complicated than the other method, but similar steps at the beginning. I have used two methods and both worked. I have heard success stories for grains in the freezer for over a year. No milk powder involved.


Wash the grains in both cases.


Methods:


Put in fresh milk (the same you used before to make the kefir) and then freeze in a plastic container or so (I used a plastic bag)
Let the grains dry. Not just with kitchen tissue, but actually leave it dry for an hour or two. Finally put it into kitchen tissue and wrap that in a plastic bag or so for freezing.


For thawing I left the grains in the fridge for half a day and then gave them directly into milk.

I tested both methods, as stated. Both worked just fine. In my case the max. time was more than 2 months. However, when "reactivating" the grains it took both some time and the results of the first two or three batches were not consumable (well, I guess they were, but just not pleasurable as kefir proper).