How to Make Homemade Kefir

My house is full of pets. These aren’t your typical pets, but they are alive, they require daily care and feeding, and they bring joy to our household. Yes, Zach and I have quite the menagerie... of bacteria colonies. Tasty, tasty bacteria colonies. (And some yeast, too, I guess.) 

Most people just call our pets “cultured foods.” I still think of them as pets. I mean, sure, we eat them, but the bacteria find new and happy homes in our tummies, a symbiotic habitat of life and good gut health.

You can find our pets tucked here and there throughout the house. We have a bucket of half-fermented mead in one room (I think our chilly winter house killed it), a jar of homemade apple cider vinegar in progress on top of the microwave, a bowl of sourdough starter on top of the fridge, and a new kombucha pet in a jar in the oven. In upcoming weeks I hope to tell you more about our fermenting projects, but I wanted to start with one of the simplest pets we own, a tasty liquid called kefir.

What is kefir?

Kefir is a cultured dairy drink: it’s similar to yogurt, just a bit runnier and with a slightly yeasty aroma. I started making it at home a couple years ago because it’s SO much easier to make than yogurt. Basically, you throw the starter (called “grains”) into a glass of milk, let it sit at room temperature for 24 hours, strain out the grains, and voila! You have a thick, tart dairy drink you can throw in the fridge. And if you don’t feel like making kefir any given day, just put the starter in milk in the refrigerator and you can hibernate it for a week or two.

How to make kefir

What you need:

• kefir “grains” (a colony of yeast and bacteria)— I bought mine from Cultures for Health, and they’re available elsewhere online. 

• milk— cow, goat, or sheep, as long as it isn’t ultra-pasteurized. Apparently you can make coconut kefir as well, although I haven’t tried that.

• a plastic strainer— not metal. The holes don’t have to be very small, but smaller than, say, a pasta strainer. Lately my grains have been floating to the top of the milk, and I just spoon them out.

• glass jars

• a cloth and a rubber band

To make it:

1. Rehydrate the grains according to the instructions that the grains came with. 

2. Plop the grains into the bottom of a glass jar. Fill the jar with milk. Cover the top with a cloth and secure it with a rubber band.

3. Leave it alone in a decently warm place for 24 hours. It will culture just fine at most people’s house temperature. During the winter, I culture mine in the oven with the light on. 

4. Check it by jiggling the jar to see if the milk has coagulated. You should smell a clean, sour smell. 

This is what my grains look like right now.

5. If it’s thickened, pour it into another container through a plastic strainer. You should easily spot the grains left behind in the strainer. Dump these into a clean jar and pour fresh milk over them. 

6. Repeat the process.

Other notes: 

If it’s not thickened after 24 hours, move it to a warmer place and leave it up to 12 more hours. If it’s not thickened by then, strain out the milk and put the grains in fresh milk.

To “hibernate” kefir, let it culture and thicken, then place the whole jar in the refrigerator. I’ve left mine in there for almost a month with no negative consequences, but the internet tells me that you shouldn’t leave it much longer than a week this way. When you’re ready to use it again, just strain out the grains, put them in fresh milk, and put the “old” kefir back in the fridge to eat later.

Tomorrow I’ll talk about my favorite ways to use kefir in recipes. However, it’s pretty tasty just drunk straight, with a bit of sweetener. If you’re interested in getting a bacteria pet of your very own, kefir is a great place to start!

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