Kumis & Arkhi — the Steppe's Milk Drinks
Fermented mare's milk (0.7-2.5% ABV) · the distilled derivative arkhi (10-20% ABV) · freeze distillation "jacking" · the 13th-century Mongol distillation link to Korean soju · why dairy spirits carry no methanol risk
Verified: documented steppe-culture kumis/airag production history · documented arkhi history and distillation-transmission literature
Kumis, also called airag in Mongolia, is a naturally fermented mare milk beverage traditional to the nomadic Turkic and Mongolic peoples of the Central and East Asian steppe, including Kazakhs, Kyrgyz, Mongols, Bashkirs and Kalmyks. Mare milk contains unusually high lactose content compared to cow milk, and wild yeasts together with lactic acid bacteria ferment this lactose into a mildly alcoholic, tangy, slightly carbonated drink typically containing between 0.7% and 2.5% ABV. From this fermented base, several steppe cultures developed a distilled derivative called arkhi (or shimiin arkhi in Mongolia), made by heating airag or a similar fermented dairy product in a simple pot still and condensing the resulting vapour, producing a clear spirit typically containing 10% to 20% ABV, occasionally higher with repeated distillation. The Mongols adopted this distillation technique from Arab and Islamic producers of arak around the 13th century during the height of the Mongol Empire, substituting their own fermented dairy base for arak's grape base — and the resulting spread of distillation knowledge across the Mongol Empire's vast trade and administrative networks is credited with helping introduce distillation methods that reached Korea, contributing to the eventual development of soju there. Nomads on the steppe also traditionally used freeze distillation, exploiting the different freezing points of water and ethanol to concentrate alcohol content without a still. A notable feature of dairy-based distillation is that it carries no risk of methanol formation, unlike distillation of fruit or grain mash, because methanol arises from pectin present in plant cell walls, entirely absent from animal milk.
Kumis / Airag — the Ferment
Before any distillation happens at all, the steppe's core alcoholic tradition is a naturally fermented dairy drink built entirely around the specific properties of mare's milk.
Why Mare's Milk Specifically
Mare's milk contains significantly more lactose (milk sugar) than cow's, goat's, or most other commonly milked animals' milk. This higher sugar content is precisely what makes kumis meaningfully more alcoholic than most other fermented dairy products worldwide — the wild yeasts and lactic acid bacteria naturally present have considerably more fermentable sugar to work with. Fresh, unfermented mare's milk is also a strong natural laxative, which is part of why fermentation isn't merely a flavour or preservation choice but a practical necessity for making the milk reliably drinkable.
Traditional Production
Historically, kumis was fermented in horsehide containers, sometimes left atop a yurt or strapped to a saddle so that the natural motion of riding or daily activity provided the continuous agitation the fermentation benefits from — a genuinely elegant piece of nomadic practicality, turning ordinary movement into part of the production process. Modern production more commonly uses wooden vats or plastic containers, though the fundamental fermentation biology remains unchanged.
Arkhi — the Distilled Spirit
Kumis alone rarely exceeds beer-adjacent strength — for a genuinely stronger drink, several steppe cultures developed a distilled version.
From Airag to Arkhi
Arkhi (Mongolian: архи, literally "alcohol," sometimes translated loosely as "vodka") is produced by distilling airag or a similar fermented dairy base — sometimes made from cow, yak, camel, or reindeer milk depending on local availability rather than exclusively mare's milk. The traditional apparatus is simple: fermented milk is heated in a vessel such as a wok, and a hollow cylinder (called a bürkheer) placed on top acts as a rough chimney, with a bowl of cold water on top serving as a condenser — vapour rises, cools against the vessel above, and drips down into a collection point.
| Name | Milk source |
|---|---|
| Airag (distilled) | Mare's milk |
| Khoormog | Camel milk |
| Shimiin arkhi | Cow's milk (or generic term for milk-distilled spirit) |
The 13th-Century Link to Korean Soju
Arkhi's most historically significant role may not be the drink itself, but the technology transfer it represents — one of the more consequential distillation-history threads documented on the Codex.
How Distillation Reached the Mongols
The Mongols adopted pot-still distillation technology from Arab and Islamic arak producers around the 13th century, during the height of the Mongol Empire's vast territorial reach and trade/administrative networks stretching from East Asia to the Middle East and Europe. Rather than adopting arak's grape base, Mongol distillers substituted their own locally abundant fermented dairy products — airag and related milk ferments — producing arkhi as a genuinely local adaptation of a borrowed technique.
Onward Transmission to Korea
The Mongol Empire's administrative and military presence in Korea during the 13th–14th centuries is credited with transmitting distillation technology onward to the Korean peninsula, contributing to the eventual development of soju (documented in depth elsewhere on the Codex) — meaning the same underlying pot-still distillation knowledge that gave the Levant arak, gave the steppe arkhi, and gave Korea the technological foundation for what would eventually become one of the world's best-selling spirits.
Freeze Distillation — "Jacking" Without a Still
Central Asian nomads also had a genuinely clever alternative method for strengthening kumis that required no distillation apparatus whatsoever.
Exploiting Different Freezing Points
Water freezes at a higher temperature than ethanol. By leaving fermented mare's milk exposed to the extreme cold of the steppe winter, nomads could allow much of the water content to freeze into ice while the remaining, more alcohol-concentrated liquid stayed unfrozen — separating out and discarding the ice left a stronger, more concentrated drink behind. This technique, sometimes called "jacking" in English-language literature on distillation history (after the similar Applejack tradition in colonial America, which used the same freeze-concentration principle on fermented apple cider), required nothing more than genuinely cold weather and patience.
No Methanol Risk — a Genuine Dairy-Distillation Advantage
One of the more reassuring facts about milk-based distilled spirits concerns a hazard that looms large in the wider world of home and informal spirit production.
Where Methanol Actually Comes From
Dangerous methanol contamination in poorly made spirits — a serious, sometimes fatal risk associated with informally or improperly distilled fruit brandies and grain spirits worldwide — arises specifically from pectin, a structural compound found in plant cell walls (particularly concentrated in fruit skins and stems). During fermentation and distillation of plant-based mash, pectin can break down into methanol. Because animal milk contains no pectin and no plant cell wall material whatsoever, dairy-based fermentation and distillation — kumis into arkhi — carries essentially no risk of methanol formation, regardless of how crude or uncontrolled the traditional home-distillation equipment used might be.