Kefir is a tangy, probiotic-rich drink made by fermenting cow’s or goat’s milk or water with a culture starter called kefir grains — small clusters of bacteria and yeast that resemble tiny cauliflower ...

Kefir is a tangy, fermented dairy drink that may offer more gut benefits than other fermented foods, including sauerkraut. It’s made by adding kefir grains (a mix of bacteria and yeast) to milk, ...