What is kefir and why do we have to feed it?

Now We Know: A weekly column answering the food questions you didn’t even know you had

A glass jar on my kitchen windowsill is home to a couple of spoonfuls of what look like finely chopped cauliflower swimming in milk. This is my kefir. The feeding times of these little lodgers have become part of my week; I give them fresh, raw milk to dine on for a full day before straining off the milk, which has transformed into a tangy, milky yogurt.

The sticky grains get topped up with more milk to gorge on until I need another batch of kefir. These babies are alive, and they multiply when healthy. I’ve even given away portions of my sticky scoby as gifts to friends fascinated by fermentation. My original scoby was a gift from my friend Helen who lives on Inishturk Island off the coast of Mayo.

What are these mysterious little grains? I ask Ireland's foremost fermentation experts, Hans and Gaby Wieland, who run courses from their Sligo farm, Neantóg (www.neantog.com). "Milk kefir is a powerful probiotic beverage made by inoculating milk with kefir grains and letting the milk ferment at room temperature for 12 to 24 hours. A kefir scoby is a symbiotic community of more than 30 different types of microbes."

But where did these little guys from, and who made the first scoby? “It is thought they come from the Caucasus Mountains where they have existed for thousands of years,” says Hans. “The word ‘kefir’ comes from the Turk word ‘keif’, which means ‘good feeling’.”


You are what you eat,' he said in a TedXTalk in Dublin in 2017, 'and you are what your microbes eat'

Prof John Cryan is principal investigator at the APC Microbiome Institute at UCC, with an expert interest in the interaction between our brain, our gut and the community of bacteria that live in our gut known as the microbiome. He and his colleagues discovered a live bacteria probiotic proven to reduce stress, improve mental function and memory in humans. “You are what you eat,” he said in a TedXTalk in Dublin in 2017, “and you are what your microbes eat”.

Microbes love acidic fermented foods. The tangy fizz of a kefir contains living microorganisms that, according to Wieland and other fermentation experts, can survive in the digestive tract, aiding digestion, bolstering the immune system and helping absorb large amounts of nutrients from food. Time to get your hands on a few of these magical little kefir babies.