🍶 Kumis

Kumis is a fermented drink made from fresh mare’s milk: milky white, sour, with a slightly alcoholic taste and a little carbon dioxide. Fresh milk is filtered, cooled to about 20 °C and poured into a vessel containing some kumis left from the previous batch, which serves as the starter ¹.

The mixture is stirred vigorously with a wooden stick and left to ferment at ambient temperature for one to three days. Lactic acid bacteria and yeasts take part in the fermentation, turning lactose into lactic acid, alcohol and carbon dioxide ¹.

The Codex standard defines kumys by its starter, Lactobacillus delbrueckii subsp. bulgaricus and the yeast Kluyveromyces marxianus. It requires at least 0.7% acidity as lactic acid, at least 0.5% ethanol and under 10% milk fat, with at least 10⁷ cfu/g of starter and 10⁴ cfu/g of yeasts ⁴.

Kumis is the traditional drink of nomadic herders of the steppes. Kazakh horse breeders open the season of making and sharing it with the spring rite kymyz muryndyk, and in Mongolia, where it is called airag, it is part of herders’ everyday diet. It was made in leather bags (saba, torsuk) and wooden tubs. Mare’s milk contains more lactose than the milk of other domestic animals. ¹²³

Mare's milk suits this drink because it forms no firm curd with rennet, so it cannot be used for cheese, but it does form a weak coagulum under acidic conditions ⁵. In Mongolia kumys is called airag and is the national drink, and a distilled version, arkhi, is also made ⁵.

In Mongolia, the traditional technique uses a cowhide vessel, the khokhuur. Fresh milk is cooled and churned in it more than 500 times, with starter left inside. UNESCO inscribed this technique on its Representative List in 2019 ².

Kumis or kefir? Compare them by process rather than taste: kumis is made from fresh mare’s milk, which has more lactose than cow’s milk and forms no firm curd with rennet, and it is fermented for one to three days by lactic acid bacteria and yeasts. Kumis or airag? The same drink under a Mongolian name, with its own technique in the khokhuur. Kumis or yoghurt? The Codex defines kumys by its starter and requires at least 0.7% acidity and 0.5% ethanol, so it is sour and slightly alcoholic.

Check the ingredient list: the milk should be named, since FAO says kumys is generally made from mare’s or goat’s milk. The name appears as “kumis”, “kumys” or “koumiss”, and it can also be sold as “airag”. Because the Codex requires at least 0.5% ethanol, it is not a soft drink. It is a speciality item, found mainly at delicatessens and food shops serving Central Asian and Eastern European communities.

Why it matters to you. Check the ingredients, because FAO says kumys is generally made from equine or goat milk ⁵. It contains alcohol, at least 0.5% under the Codex ⁴. Its health effects have so far been confirmed only in limited animal studies, despite its long reputation as a remedy ¹.