What is kefir?

What is kefir?

Kefir is a fermented drink, usually made from milk. It is made by adding kefir grains, which are small gelatinous clumps of bacteria and yeasts living together, to milk and letting it ferment. The grains are strained out and reused. The result is tangy, creamy and a little fizzy, thinner than yogurt but richer than buttermilk.

How it is made

1. Add kefir grains to milk (cow, goat or sheep milk are common).
2. Leave it covered at room temperature for about a day, until it thickens and smells tangy.
3. Strain out the grains and chill the kefir.
4. Use the grains again for the next batch.

Fermentation times and temperatures vary, so follow your grain supplier’s instructions.

Types

• Milk kefir: the classic type, from dairy or sometimes plant milks.
• Water kefir: grains fermented in sweetened water or juice; dairy-free and lighter.
• Store-bought kefir: plain, flavored or sweetened. It often uses starter cultures rather than grains.

Taste and uses

It is sour and a little effervescent. Drink it plain, blend into smoothies, use in pancakes or salad dressing, or use it as a starter for ryazhenka (fermented baked milk).

What about health?

A 2017 review in Nutrition Research Reviews describes kefir as a probiotic drink with potential, but notes that many supporting studies were done in the lab or in animals and calls for more clinical trials. The NIH says probiotic benefits are strain-specific and that researchers often cannot tell which strains or doses help. Treat kefir as a food, not a medicine.

Lactose and allergy

• Fermented dairy such as yogurt is lower in lactose than milk, and kefir is often tolerated in a similar way, so some people with lactose intolerance tolerate it, but amounts vary.
• It is still a dairy product with milk protein, so it is not safe for a milk allergy.

Buying tips

• Look for “live and active cultures” if you want live bacteria.
• Check added sugar in flavored versions.
• Check the use-by date, since kefir keeps fermenting in the fridge.