Frequently Asked Questions About Milk Kefir


Why is my milk kefir starting to separate and curdle?

It has cultured faster than expected. This happens for one of two reasons: Your grains have grown, but the amount of milk you’re using hasn’t increased; or your kitchen is quite warm. If the former, either remove some of the grains or add more milk for the next batch, so the grains to milk ratio remains correct. If a too cozy kitchen is the problem, reduce the amount of time that you leave the kefir out to culture.

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cruise ship

I’m going on vacation. How do I keep my grains alive and happy while I’m gone?

If you don’t want to make new kefir and want to store it, place the grains in at least 2-4 cups of milk, remembering the “1 tablespoon of grains to 2 cup of milk” rule. Then add a little more milk. I like to store mine in at least 4 cups of milk to make sure that they have plenty of food to eat. Then you place this in the refrigerator. This will last for one week. If you want to store it longer, drain the milk and add new milk after 1 week. If you are going to be gone longer than a week, double the milk you add. It eats the lactose (milk sugar) out of the milk and you want to be sure it has plenty to eat and won’t die. It is a living colony and needs food, just as you do. Also, the grains will be a little slower making kefir when you first take them out of the fridge. The cold just slows them down a bit, after being in the fridge and then coming back out onto the counter to make kefir. The second time you make kefir they will be back up to speed.

kefir grains and milk

I left my milk kefir grains in the refrigerator for a few months. Are they still good?

Probably not. Kefir grains eat the milk sugars (lactose) out of the milk to live and to make their bacteria. This is why the milk gets more sour. When the grains run out of food, they begin to die. They’re living organisms and need food. Treat them like a pet and make sure you feed them. The only way to tell is to try and make a jar of kefir. If the milk turns sour and tart tasting then the good bacteria is working and your grains should be fine.


I stored my milk kefir grains in the fridge for a week. Is the milk that the grains were stored in okay to drink?

The milk that the grains were stored in is not really kefir. It won’t hurt you to drink it, but it probably won’t taste very good. Milk needs to culture at a warmer temperature to really turn into kefir. Always give the grains new milk when bringing them back on the counter to culture. There won't be enough lactose left in the milk to culture properly if you don't give them fresh milk.

kefir jars

Do I culture milk kefir with a lid or with cheesecloth?

I always culture my kefir with a lid on. I use a one-quart glass canning jar with a plastic lid, but a metal lid is also fine as well. Many people have trouble when they use a cloth and rubber band due to wild yeast or cross contamination from other cultures. They can get a fuzzy pink yeast on their grains, and although this isn't harmful it can can change the taste of your kefir, so I always recommend a lid.

Kefir grains

Why aren’t my milk kefir grains growing?

If you are making kefir every day, your grains should be growing and multiplying. If they aren’t, it is because the temperature in your house is cooler than usual, slowing down the grains, or your kefir grains have died. If your milk is turning into kefir by becoming sour and thick, your grains are still working, just at a slower rate. You can purchase more or get some new grains from a friend.


How do I know if my milk kefir grains are still good?

They will culture your milk and turn it sour and thick within 24 hours. Make sure that you have enough grains for the amount of milk that you are using or it will separate into whey and curds which is still ok to drink but not as thick.