The champagne of milk
Back in 1994, a dairy industry newsletter was already calling kefir “the twenty-first century yogurt.” Kefir has a more interesting taste than yogurt, and different milks produce a variety of flavours. Like beer and sparkling wine, kefir gives off a little carbon dioxide during fermentation, which gives it a gentle effervescence. It also contains a trace of alcohol — about 0.2 to 0.5 percent, a negligible amount. So you could say: yogurt is to milk what wine is to grapes, but kefir is to milk what champagne is to grapes. Kefir truly is the champagne of milk.
Not just thin yogurt
Yogurt is made with a handful of bacterial strains. Kefir is made by a whole living community — lactic acid bacteria and yeasts together — housed in “grains”: cauliflower-like clusters held together by a natural gum called kefiran, which the microbes produce themselves. Drop the grains into milk and the colony wakes up and goes to work. Kefir also forms much smaller curds than yogurt, which is one reason many people find it easier to digest: digestive enzymes have far more surface area to work on.
Kefir vs. yogurt at home
- No pre-heating. Milk for yogurt usually has to be heated and cooled to a precise temperature first; kefir grains go straight into the milk. (One modern note: unpasteurized milk is not sold legally in Canada, so home kefir here is made with pasteurized milk — the grains handle that perfectly well.)
- The culture renews itself. Yogurt starters lose potency quickly and have to be bought again and again. Kefir grains keep growing with every batch — cared for, one set of grains can last indefinitely, which makes home kefir remarkably inexpensive.
- Very forgiving. Kefir tolerates a wide range of temperatures and conditions, unlike fussier yogurt cultures.
Where did kefir come from?
Fermented milk is ancient: India’s Vedic scriptures mention a fermented milk called dadhi, Sumerian clay tablets record fermented milk, and the Bible mentions soured milk. Kefir itself comes from the northern Caucasus Mountains. Legend says the grains were given to the Orthodox Christians of the region by the Prophet Mohammed and guarded jealously for centuries — which is why kefir stayed a local secret long after yogurt had travelled the world.
Right-turning and left-turning lactic acid
Here is one of kefir’s distinctive features. Lactic acid comes in two mirror-image forms, called isomers: right-turning (L+) and left-turning (D−). They have the same chemical formula but different shapes, and the body treats them differently. L+ lactic acid is the body’s own form — heart muscle cells, for example, use it readily as fuel. D− lactic acid is less familiar to our metabolism; much of it is simply flushed out in the urine. Ordinary yogurt cultures such as L. bulgaricus produce mostly the D− form — roughly 65 to 70 percent left-turning. Kefir’s mixed culture produces proportionally more of the right-turning L+ form, one traditional reason kefir has been considered a gentler, more “compatible” fermented food.
You already know L+ lactic acid from exercise: after vigorous effort, lactic acid in the blood rises to five or ten times its normal level — that is the burn, and the next day’s soreness. It is your own lactic acid at work.
The old “lactic acid cures” — read with care
Older books on kefir — including Klaus Kaufmann’s Kefir Rediscovered, from which parts of this article are drawn — go much further, crediting lactic acid fermentation with opposing cancer and a long list of diseases. Those claims grew out of an early theory that cancer begins when normal cell respiration fails, and that lactic acid might act as a natural “repressor” of abnormal cells. It is a fascinating chapter in the history of nutrition — but it remains an unproven theory. Laboratory ideas have never become evidence that kefir treats or cures cancer or any other disease, and no food should ever take the place of medical care. The honest version of kefir’s story is more modest, and still well worth your attention.
What kefir is genuinely valued for
What fermented milk does reliably is deliver living cultures in a partly pre-digested food: much of the lactose is already broken down during fermentation, the proteins are partially digested, and the microbes produce B-vitamins and other useful compounds along the way. For generations, kefir has been a traditional food for supporting comfortable digestion and a healthy intestinal flora — and that remains the use it is most valued for today. Readers working on their own digestive health will find kefir an easy, inexpensive place to start.
What modern research says — a recent update
Science has finally begun testing kefir in people rather than only in laboratories. The first systematic review of human intervention studies, published in the journal MicrobiologyOpen, gathered all eight qualifying trials. Its conclusions were measured: drinking kefir produced modest shifts in gut bacteria — the beneficial genus Bifidobacterium increased in three of the four studies that measured it — and kefir’s own microbes could be detected in stool samples while people were drinking it, suggesting they survive the journey through the gut. Effects varied from study to study, and the reviewers are clear that larger, longer trials are needed. Since so much of the immune system is organized around the gut, researchers are also watching kefir’s possible role in immune health — another reason for trials rather than promises. In short: kefir is a genuinely living food with real, if modest, effects — a good food, not a miracle.
More about the making of kefir in future articles…
Reference and credits: Kefir Rediscovered by Klaus Kaufmann. This information is written by David Chan, CNP, ROHP, and is educational only — it is not intended to replace the medical advice of your doctor. Please consult your doctor for advice about a specific medical condition.