You are at the grocery store and a bottle with a brightly colored label catches your attention: You read the word “kefir” on it and wonder what it is. Sensing your curiosity, the bottle answers: “My name is kefir: I am a type of fermented milk. I have a creamy consistency, a slightly sour taste and a mild yeasty aroma. You can buy me, or you can make me at home. You can drink me or use me creatively.”
Kefir is now more widely available in supermarkets and natural food stores than it was a few years ago. It is a unique cultured dairy product created by the combination of lactic acid and alcoholic fermentation of lactose in milk. And it is rich in probiotics, living microorganisms that can exert health benefits beyond basic nutrition. In his book On Food and Cooking, Harold McGee writes: “[Kefir] is most popular in the Caucasus and may well have originated there. Unlike other fermented milks, in which the fermenting microbes are evenly dispersed, kefir is made by large, complex particles known as kefir grains, which house a dozen or more kinds of microbes, including lactobacilli, lactococci, yeasts and vinegar bacteria.”
Laboratory studies have looked at the composition of kefir grains and at various effects of kefir given to mice and rats, and there are studies evaluating specific health effects of kefir consumption in humans. One study published in the Journal of the American Dietetic Association found that kefir improved lactose digestion and tolerance in people with lactose maldigestion. In other health areas, results have been mixed. I hope that more well controlled studies will be conducted to provide clearer evidence regarding other desirable effects of kefir. In the meantime, I will continue making and using kefir at home, because we have come to appreciate it as an ingredient in beverages and other dishes.
I obtained my original kefir grains from a fellow food blogger who shared some of hers with me. Since the grains grow while making kefir, extra grains become available to be passed along. If you don't know anybody who has kefir grains, you can purchase them from one of several sources. An online search using the words: "order milk kefir grains," will yield a number of options, although I don't have first-hand experience with any of the suppliers. If you want to get a sense whether you like kefir, or prefer not to take care of kefir grains, you can make a version of kefir using freeze-dried kefir culture, which comes with its own set of instructions for use (both local Co-op stores sell kefir starter kits).
What follows is my personal application of the procedure to make kefir using grains. Sterilize a glass jar by putting it upright in the oven at 200 degrees for 10 minutes. The lid and other implements should be sterilized in boiling water. Pour milk into the cooled jar without filling it completely, then add the kefir grains. (My experience is only with pasteurized cow milk, but I know people who use goat milk.) Cover the jar, leaving the lid just a bit loose to prevent buildup of the carbon dioxide produced during fermentation, and wrap it in a kitchen towel (to protect it from light). Then set it aside in a draft-free place. The kefir grains take it from there. Gently rock the jar a couple of times during fermentation. It takes about 24 hours to get kefir, depending on the room temperature (the cooler the incubating temperature, the slower the process) and the amount of grains. First the milk thickens. Then it sets -- and the cycle can start again. When a batch of kefir is ready, pour it through the strainer to separate the grains, shaking the strainer gently. A small amount of kefir adheres to the grains and that is fine. Once strained, store your kefir in the refrigerator. Let it rest for a day before using it. You can use the drained grains immediately to make a new batch of kefir, or you can store them in a sterilized jar with enough milk to cover them. Put the jar in the fridge for a few days, then use the grains again to make kefir.
The flavor, consistency and composition of the final product depend on several factors, including the type of milk used, the duration of fermentation and the composition of the grains or culture. Since the grains grow while making kefir, you will end up with extra grains to pass along. Save the drained grains in a sterilized jar with enough milk to cover them; put the jar in the fridge for a few days.
Once you have kefir available, you may come up with new ways of using it. Drinking it, plain or flavored, is the number one use. My husband loves Indian food and always orders a mango lassi when he eats at an Indian restaurant. Lassi is a traditional Indian drink usually made with yogurt. My variation uses homemade kefir (see recipe card on this page). I have also added kefir to soup instead of sour cream You’ll find a recipe on my blog: bricole.typepad.com. I also regularly replace buttermilk with kefir when I make scones.
Another thing you can make is kefir cheese. Pour kefir into a colander lined with a piece of sterilized, tightly woven cotton cloth set over a bowl (to catch the whey), then tie the cloth into a bundle and hang it up to drain for 24 hours, or until the cheese acquires the desired consistency. The draining can occur at room temperature or in the refrigerator. You can consume the cheese plain or flavor it with a mix of fresh herbs, dill, mint, chives or parsley for example. Chop herbs of choice finely, add a bit of salt and freshly milled pepper and stir into the drained kefir. You might mold it using a cheese mold of appropriate size, but that is optional. The flavor of the cheese is pleasantly tangy and the herbs, if you use them, give it a nice nuance. It is particularly nice spread over a slightly sweet bread like challah.
Variation on the theme of mango lassi
Flesh of a ripe mango, chopped
2 cups of plain [homemade] kefir, divided
Agave nectar or honey, to taste
Put half the mango flesh into the blender.
Add 1 cup of kefir and a bit of agave nectar and blend well.
Pour into a tall glass and serve.
Repeat with the other half of the ingredients.
A post on my blog titled “Making kefir at home” includes pointers to a few online resources.
Scientific papers on kefir are available by searching the National Library of Medicine's PubMed site.