I left my kefir grains in the fridge …

It happens to all of us, leaving grains in the fridge for a short or long period of time, then not knowing if the grains can be used for fermentation or not. Most common reason is going on vacation or just taking a little break from fermentation. In this blog, we will talk about different scenarios and how to make sure your grains are still fine to use.

Here are some examples of reviving the grains after a certain amount of time. The storing and steps for activating milk and water kefir grains are similar, so we use the term kefir grains in this article unless there is a certain difference important to highlight.

I left grains in the fridge for a short time

You can always leave the grains stored in the fridge for a short period of time. Whether you’re taking a short break from making kefir or are leaving for vacations. If properly stored, the grains will stay dormant in the fridge without a problem. Short time means a week or two weeks at the most and no changing of the milk/water in the meantime.

Grains were stored for a month or so

Leaving the grains in the fridge for a month or even longer will totally slow down their activity. Grains are a live culture that need food for their existence. If they don’t get food they start to starve and after a while will die. This may be prevented if the temperature is low enough and grains have at least some food at the beginning. It also depends on the grains, were they very active before storage? This may improve their chances.

I forgot about the grains for more than a year

This is a very long period for grains to go without food. Because the bacteria and yeasts in the grains did not get any food they started to slow down and eventually die off. If you plan to not use them for a long time there may be a better option. For example, give the grains to someone who would like to make kefir. This person will multiply the grains and in the future you may get a small amount of them back.

You can also think about freezing the grains. Before doing this make sure to tap the grains on a paper towel to get them dry. Activation of frozen kefir grains is not always successful so you will be taking a bit of a risk here.

Another solution can be drying the grains. Make sure you do not heat the grains above 38 °C because higher temperatures will kill off the beneficial bacteria.