Need to Take a Break?
So this whole process of fermenting takes about 24 hours, so unless you take a break you will get a quart of kefir every 24 hours! That is about right to keep our family going, but for you that may be too much. That is where you may want to put the grains in a small jar with a couple cups of milk and store in the refrigerator until you are ready to start a new batch.
Once you are ready to start a new batch, take the jar out of the refrigerator, strain out the grains (I throw out this milk), put grains in a clean quart jar, add milk, stir, cover, and set on the counter for 24 hours.
Need to take a longer break? If you take a break for longer than a week or so, you will need to strain the grains and put them in fresh milk before storing longer. The grains will run out of "food" if stored too long in the same milk, and may eventually die.
If you're going on vacation and are going to be gone for more than a week, then you can freeze the grains in milk. Store them in a jar in the amount of milk you regularly use, leaving a little room at the top for expansion when it freezes. Store in a glass or food-grade plastic jar with a lid and place in the freezer. You can store this for several months and they should be fine. They will take a little while to wake up when you remove them from the freezer, but once they thaw, strain them and give them fresh milk After a few days of making kefir, they should be fine. You will need to discard the milk they were stored in. Freezing kefir grains should only be done once in a while. Freezing and thawing them continuously can diminish or kill them, but once or twice a year should be fine.