Kefir (rhymes with deer) is a traditional yogurt culture from Central Asia. Often described as a fermented milk, kefir is a flavorful, drinkable and slightly effervescent yogurt.
Kefir, though, is made somewhat differently than the yogurt most of us are familiar with. Like yogurt, kefir is made by adding culture to milk and encouraging a fermentation that sours the milk and thickens it into kefir. But unlike yogurt, when kefir is ready, the kefir culture is taken out!
Kefir is not one single bacterial culture, but a community of diverse species of bacteria and fungi that live together in kefir grains. A Symbiotic Community Of Bacteria and Yeasts (SCOBY), kefir grains are known to contain dozens of bacterial and fungal cultures, each species playing a different role in the community, and all of the cultures together transform milk into kefir.
Many of kefir’s cultures are closely related to those found in both raw milk and our digestive tracts, making kefir an excellent probiotic, as well as a superb source of culture for cheesemaking.
Where to Find Kefir Grains
Kefir grains are easy to find, and, if well taken care of, they will provide beneficial cultures for life. Numerous vendors sell them online including Cultures for Health, Yeemoos and GEM cultures.
Alternatively, you can often find them in your community or on Craigslist, Etsy and E-bay.
Kefir Grains: A History
Kefir culture has been passed down from generation to generation for thousands of years. All kefir grains that exist today are descendants of the original grains discovered in Central Asia countless generations ago. (Kefir’s millennia-old cultural lineage puts 100-year-old sourdough starters to shame!)
Kefir’s culture is intertwined with the nomadic culture of Central Asia’s high steppes. Stories from European travelers passing through the area described the traditional practice of keeping kefir as a continual fermentation of sheep or mare’s milk inside a dried sheep’s stomach, hung from the rafters of a yurt, from which kefir would be occasionally drunk.
Kefir likely helped these nomadic people drink the milk of their recently domesticated sheep, goats, and horses. Many residents of Central Asia are lactose-intolerant as adults, and kefir, with significantly less lactose than fresh milk as a result of its fermentation, would have been much more easily digested. The kefir fermentation would have also helped preserve the milk by limiting the growth of unwanted microorganisms.
It is not known how kefir grains came to be — more is known about the origin of the universe than the origin of the kefir! Given, however, that their microbiological profile is very similar to that of raw milk, and considering that the traditional practice of keeping kefir involved a continuous fermentation of raw milk, it is most probable that this multicultural organism evolved from the diverse cultures of raw milk.
Kefir and Cheesemaking
Kefir may be the perfect cheesemaking culture. It’s a biodiverse culture that is very easy to care for, simple to use, and nearly impossible to contaminate. The process of keeping kefir and using it for making cheese is similar to that for keeping sourdough starter for baking bread.
Every cheese can be made with kefir as a starter culture. It is a universal starter, containing both mesophilic and thermophilic bacteria that are adaptable to cheesemaking in any conditions.
Kefir also serves as a source of bacteria for aging cheeses: Kefir contains bacterial species that feed on the products left behind by lactic-acid bacteria. Kefir culture can therefore provide successions of ripening bacteria to any aged cheese.
Cheeses made with kefir as a starter do not taste of kefir — their flavor is akin to traditionally made raw milk cheeses, as the community of microorganisms in kefir is very similar to the community of microorganisms in raw milk.
Homemade Kefir as Part of a Daily Routine
To make kefir, simply place kefir grains in milk. Left at room temperature, the grains will ferment the milk and thicken it into kefir in about 1 day. The grains can then be strained out and placed once again in fresh milk, and the process repeated.
The making of kefir can take on a rhythmic nature: Because it takes kefir one full day to ferment, kefir-making can fit into a daily routine. If you feed kefir grains milk in the morning, by the next morning the kefir will be ready. Every day you can drink the previous day’s kefir while you make preparations for the next day’s.
Recipe for Homemade Kefir
I give my kefir grains as much milk as I wish to drink as kefir the next day. If I want to have a cup of kefir, I’ll give my kefir grains a cup of milk. And I will keep only the appropriate amount of kefir grains to ferment that cup of milk — between 1 teaspoon and 1 tablespoon. Any more, and the kefir will ferment too quickly; any less, and the kefir will ferment too slowly (wild microorganisms may dominate, and the kefir may taste odd).
If you’re making more kefir, add at least 1 tablespoon and no more than ¼ cup of grains per quart of milk. Kefir grains grow as you feed them, so be sure to share excess grains with your friends.
I prefer to give my kefir grains a daily feeding to keep them active. But kefir can also be made in a larger quantity just once a week, and the kefir grains refrigerated in between feedings. However, kefir grains prefer to be fed regularly; keeping them in the fridge slows them down, and makes their first fermentation a bit unpredictable.
Kefir is excellent on its own, with a dash of salt added, or with a bit of honey, maple syrup or fruit preserves mixed in before or after fermentation. One of my favorite additions is fresh cherries, which, if added to the milk before it ferments, become effervescent when the kefir is ready.
Yields 1 cup (240 mL) of kefir.
- 1 teaspoon active kefir grains
- 1 cup (240 mL) milk
- Glass jar, with lid
Around 24 hours
1. Feed the kefir grains: place 1 teaspoon of kefir grains in a jar, and pour the milk over them. Seal the jar tightly. Let the kefir grains ferment the milk for about 1 day until thick: leave the jar to ferment on the counter in the kitchen. There is no need to keep the fermenting milk either warm or cool — kefir grains like room temperature best. After a day, the kefir grains should thicken up the milk into kefir.
2. Strain out the kefir grains, and drink the kefir. You can use a steel or plastic strainer to strain the thickened kefir into a bowl below.
3. Rinse the kefir grains in cool water (if you so choose), and feed them again! The kefir can be eaten right away, or saved in the refrigerator for up to 1 week.
David Asher is an organic farmer and cheesemaker, cheese educator, and cheese writer. He runs the Black Sheep School of Cheesemaking and is the author of The Art of Natural Cheesemaking.