Method
- Pour the fresh mare's milk into a clean fermentation vessel. The traditional Mongolian khokhuur (leather bag) imparts a particular flavour; modern home fermentation can use a clean glass or ceramic vessel.
- Add the starter culture (previous airag batch). Stir vigorously to combine. Cover with muslin cloth to keep insects out while allowing airflow.
- Stir the mixture vigorously every 30 minutes for the first 12 hours — the agitation is essential to develop the characteristic effervescence and tang. Mongolian herders traditionally stir 1000+ times a day during peak fermentation.
- Continue stirring less frequently (every 2?3 hours) for days 2?3 (the cook time listed reflects only active prep; the fermentation is passive). The mixture will sour, lightly carbonate, and develop a faint alcoholic kick (1?3% ABV).
- After 3 days the airag is ready: tart, slightly fizzy, with a sour-yogurt aroma and very faint alcohol.
- Strain through muslin cloth into bowls. Serve cold. Reserve 100ml as starter for the next batch — airag is a continuous fermentation tradition. Drink during summer; airag has cooling, hydrating properties valued by Mongolian herders during hot work days.
Common questions
Can Airag be made ahead?
Airag is best made and eaten the same day, but the components can be prepped earlier — chop and measure the ingredients up to a day ahead, refrigerated separately. Final cooking takes about 30 minutes.
Is Airag spicy?
Airag as written is mild to mildly warming — the heat comes from aromatics rather than chili. Add fresh sliced chili or chili oil at the end if you'd like to push it spicier.
Is Airag vegetarian or gluten-free?
This recipe is suitable for most diets. If you have specific restrictions, the substitutions section in each ingredient note covers the most common swaps.
How hard is Airag to make at home?
Airag is more demanding — total time around 90 minutes plus marinating/resting where noted. Specific technique (knife work, wok hei, fermentation) makes the difference between a passable result and the real thing.
Can Airag be scaled up or down?
This recipe is written for 8 servings. To scale, multiply each ingredient proportionally; the cooking times stay the same up to about double the volume. Beyond that, expect to cook in batches because of pan size and heat distribution.
Cultural Note
Airag is the Mongolian fermented mare's milk — the most culturally significant drink of the country, central to pastoral identity. Mongolian herders consume airag in vast quantities during summer — some herders' diets are 70% airag during peak season. The drink is served at hospitality rituals: every Mongolian guest is offered airag from a wooden bowl. Naadam Festival has airag as the official summer drink, with thousands of liters served. The Mongolian saying goes: 'a household without airag is a household without dignity'.
