It arrives in a wooden bowl, offered with two hands. The liquid is whitish, slightly cloudy, still carrying a faint fizz from the fermentation. The smell hits first — sour, slightly yeasty, unmistakably alive. You take a sip because refusing would be impolite, and also because this is one of those moments you came to Mongolia for: the moment before a taste that will stay with you forever. Airag. Fermented mare's milk. Mongolia's national drink, its summer companion, its oldest hospitality ritual, and possibly the world's most ancient continuously produced fermented beverage. If you are traveling to Mongolia between June and October, you will encounter airag constantly — offered in nomadic gers, sold in plastic bottles at roadside stalls, ladled from communal barrels at Naadam festival. Understanding what it is, how it is made, what it means, and how to drink it politely will transform your experience of Mongolian culture in ways that guidebooks rarely capture.
What Is Airag?
Airag (also spelled ayrag in some romanizations, and known as kumis in Turkic-speaking parts of Central Asia) is a mildly alcoholic fermented beverage made from fresh mare's milk. It has a light, slightly effervescent quality, a sour-tangy taste, and an alcohol content that typically ranges from 1 to 3 percent — roughly equivalent to a light beer, though the production process is entirely different. It is not just a drink. In Mongolian culture, airag occupies a position somewhere between bread and wine in European civilization — fundamental, sacred, deeply tied to the rhythms of the year and the rituals of social life. The UNESCO Representative List of Intangible Cultural Heritage of Humanity recognized the traditional technique of making airag in the khokhuur in 2019 — a recognition that the drink is not merely food, but cultural heritage.
How Airag Is Made: The Ancient Art of the Khokhuur
The production of airag is an intimate, labor-intensive process that has changed relatively little in over a thousand years. The UNESCO documentation describes the basic technique as "milking the mares, cooling the fresh milk, and repeatedly churning it inside the khokhuur — over 500 times — with starter left inside to assist fermentation." In practice, most experienced airag-makers churn 3,000 to 5,000 times, or more — a number that reflects both the physical commitment involved and the importance of the drink in daily life.
Step 1: Milking the Mares
Mares are milked in the morning and evening during the summer months, when they are nursing foals and producing milk at their peak. The foal is briefly separated from its mother, the mare is milked by hand — typically yielding 1 to 3 liters per session — and then the foal is returned to nurse. The milking season runs from roughly June to October, which is why airag is fundamentally a summer drink. In a productive summer, a herder family with 10 to 15 milking mares might collect 15 to 30 liters of fresh milk per day. The surplus beyond what foals need goes into airag production.
Step 2: The Khokhuur
The heart of traditional airag production is the khokhuur — a large leather vessel made from cow hide (or sometimes horse hide), stitched and dried into a bag that can hold 40 to 200 liters of fermenting milk. The khokhuur is not just a container; it is an ecosystem. The hide is cured and seasoned over years of use, and the microorganisms living in its walls — strains of Lactobacillus helveticus and various yeasts — provide the starter culture that drives fermentation. A well-seasoned khokhuur is a family treasure, passed down through generations. Fresh mare's milk is poured into the khokhuur, where it joins a residue of previously fermented airag that provides the starter. This is the same principle as sourdough bread — the culture is never entirely depleted; it is always perpetuated.
Step 3: Churning
The buluur — a long wooden paddle — is used to churn the fermenting milk inside the khokhuur. This churning is the physical heart of airag production. It must be done repeatedly throughout the day, breaking up any curdled proteins, incorporating air, and ensuring even fermentation. Traditional custom holds that anyone passing a family making airag should stop and give the khokhuur a few churns — it is a gesture of community and goodwill, and it ensures the fermentation proceeds evenly. The fermentation process takes one to two days, during which the milk transforms: lactobacilli convert lactose into lactic acid (creating the sour taste and lowering pH), and yeasts produce carbon dioxide and a small amount of ethanol (creating the fizz and gentle alcoholic content). According to research published in the Journal of Animal Science and Technology, the predominant bacterium in airag is Lactobacillus helveticus, which plays the primary role in acidification.
Modern Adaptations
In recent decades, plastic barrels have increasingly replaced traditional khokhuur leather bags for airag production. Research from the National Center for Intangible Cultural Heritage and published microbiome studies show that plastic containers produce airag with a more uniform but less microbially diverse profile than traditional leather vessels — the khokhuur itself is a source of unique bacterial species that enrich the drink's character and probiotic content. Traditional practitioners and cultural preservationists argue strongly for maintaining the khokhuur.
What Does Airag Taste Like?
This is the question every traveler asks before their first sip. Imagine thin, liquid yogurt that has been left to ferment slightly — sour, tangy, with a clean dairy base. Now add a very gentle effervescence, like a barely carbonated drink, and a slight yeasty note in the finish. There is no sweetness to speak of, but there is a refreshing quality that explains why people in the Mongolian summer heat can drink four liters of it in a day. The flavor varies significantly depending on:
- Stage of fermentation: Fresh airag (one day old) is milder and less sour. Older airag is sharper, more acidic, and more strongly alcoholic.
- Season: Early-season airag (June) is typically lighter; late-season (September-October) can be quite strong.
- The mare: Different breeds and individual mares produce milk with slightly different fat and sugar content.
- The container: Airag from a seasoned khokhuur has more complexity and depth than airag from a plastic barrel.
Most first-time drinkers find it surprisingly pleasant once past the initial surprise of the sourness. Many people who visit Mongolia in summer find themselves genuinely craving it after a hot afternoon on horseback.
The Cultural Significance of Airag
To understand airag's role in Mongolian culture, consider this: the word for "offering" and the act of pouring a few drops of airag to the sky (or fire or earth) as a blessing are intertwined practices that date back to before written history.
The Drink of Hospitality
In Mongolian culture, hospitality is not optional — it is a moral obligation. And the first expression of hospitality in summer is a bowl of airag. When you arrive at a nomadic family's ger between June and October, airag will be among the first things offered to you, typically in a piyala (a small bowl). Refusing it is impolite. Accepting it — even if you only take a small sip — is a profound gesture of mutual respect. The custom holds that every person who enters a ger where airag is being made should stir the khokhuur at least once. This is participatory hospitality: you are not just a guest, you are briefly part of the production of the household's most important summer drink.
Ceremonies and Rituals
Airag appears at nearly every important Mongolian ceremony and celebration. At Naadam — the midsummer festival of wrestling, archery, and horse racing — airag flows freely, offered at festival grounds, in family gers, and at the races where children jockeys ride horses back from long courses. At Tsagaan Sar (Lunar New Year), a bowl of airag is placed on the ceremonial table alongside buuz and ul boov. At weddings, births, and the first milk of the season, airag is offered to the sky as a blessing. The tradition of deejii — offering the first portion of any food or drink to heaven, the fire, or ancestors before consuming it yourself — applies particularly to airag. A small sprinkle from the fingertips toward the sky acknowledges that the drink comes from the earth and belongs first to the cosmos before it belongs to you.
The Airag Season
Because airag depends on lactating mares, it is strictly seasonal: production begins when foals are born in late May or June and ends when mares dry up in October. This seasonality makes airag a treasured thing — associated with summer, abundance, warmth, and the best months of nomadic life. The arrival of fresh airag each year is a genuine celebration.
Health Benefits of Airag
Mongolian traditional medicine has long attributed significant health benefits to airag, and modern science has increasingly validated these claims. Probiotic richness: Airag contains a diverse community of beneficial bacteria and yeasts, including multiple strains of Lactobacillus — microorganisms that support gut health, improve digestion, and strengthen immune function. Research published in Bioscience of Microbiota, Food and Health found that airag produced in traditional khokhuur leather vessels has significantly higher microbial diversity than airag from plastic containers, with broader populations of probiotic bacteria. Nutrient profile: Mare's milk is nutritionally distinctive — lower in fat than cow's milk but higher in lactose, vitamin C, and certain B vitamins. Fermentation further transforms these nutrients, making them more bioavailable. Mongols historically attributed airag with stamina-giving properties, and the science suggests this is not merely tradition: a herder in summer who drinks two to four liters of airag per day is receiving a meaningful source of energy, vitamins, and beneficial microorganisms. Gut health: Studies on Mongolian populations have found higher levels of Lactobacillus in the gut microbiome compared to other Asian populations — a difference researchers have linked to the high traditional consumption of fermented dairy products including airag. Traditional uses: Mongolian herbal and traditional medicine prescribed airag for tuberculosis treatment during the 19th and early 20th centuries (a practice with some basis in the nutritional support fermented milk provides to recovering patients), and as a general tonic for fatigue, digestive complaints, and convalescence. Modern practitioners continue to recommend it for gut disorders.
How to Drink Airag Politely: The Etiquette
Getting the etiquette right around airag is simple but important. Here is what you need to know: Accept with the right hand, or with both hands, or with your right hand supported by your left at the elbow — all three are acceptable. Accepting with only the left hand is impolite. Take at least a sip. You do not have to drain the bowl, but you must taste it. A sip and a nod of appreciation is the minimum expected. Refusing entirely is considered rude and creates social awkwardness. Hold the bowl at the base or sides, not by a rim that will touch your host's lips. The bowl is often shared communally, so handle it with care. After drinking, return the bowl to your host or pass it to the next person, depending on the context. In a communal setting, the bowl moves around the group. If offered more, you may decline politely after having tasted — a small bow or gesture of thanks and a wave of the hand. Most hosts will refill once without asking; beyond that, a gentle refusal is accepted gracefully. Do not pour it out or leave it untouched on the table. This wastes a gift.
Where Travelers Can Try Airag
Naadam Festival (July): The best single opportunity to taste airag alongside thousands of celebrating Mongolians. Airag is sold at the festival grounds in Ulaanbaatar and at local Naadam celebrations in every aimag (province). The festival runs in mid-July. Nomadic family homestays (June–October): Staying with a herding family in summer virtually guarantees fresh airag — often made that morning. This is the most authentic and memorable way to encounter it. Ger camps with cultural programs: Most quality ger camps in summer include airag as part of their cultural experience, and some offer demonstrations of the churning process. Ulaanbaatar markets and restaurants: During summer, airag is sold in plastic bottles at Ulaanbaatar's Narantul Market and other central markets. Quality varies significantly — the best is always the freshest, and the plastic container versions are noticeably less complex than khokhuur-fermented airag from the countryside. Uvurkhangai Province: This central Mongolian province is considered the heartland of airag production, and some tour operators specifically arrange visits to airag-producing families here during peak season. Expect to pay around $2–$5 for a generous bowl at a family homestay or market stall.
A Drink That Connects You to the Steppe
There are certain foods and drinks that carry the weight of an entire culture in a single taste. Airag is one of them. Every sip connects you to the millennia of nomadic life on the Mongolian steppe — to the mares milked at dawn, to the leather bags churned thousands of times in the summer sun, to the gesture of offering a bowl to a stranger arriving at your door. When you taste airag in Mongolia, you are not drinking a novelty. You are participating in one of the oldest food traditions on earth — a tradition that UNESCO has recognized as irreplaceable human heritage, and that Mongolian herders are working hard to preserve even as the world around them changes faster than at any point in history. Take the bowl with two hands. Take a sip. Let the sourness settle into warmth. You are on the steppe now.
*Want to taste fresh airag straight from the khokhuur? Unveil Mongolia's summer tours include authentic experiences with nomadic herder families during the airag season — from helping churn the khokhuur to sharing a bowl at Naadam. **Plan your Mongolia journey at *unveilmongolia.com.
