Pickles & ferment bases
Airag
Айраг · Airag is the traditional Mongolian fermented beverage made from fresh raw mare's milk, soured and lightly alcoholic through lactic acid bacteria and wild yeast in a leather or wooden vessel. It functions as a living base preparation: each batch yields a portion reserved as the starter culture for the next, sustaining an unbroken fermentation lineage that is the cultural and biochemical heart of Mongolian nomadic life.
The formula
~1 part mature starter : 10 parts fresh mare's milk; ferment 2–5 days at 20–30°C with repeated churning
Ratios are flexible; the starter is a slop of finished airag carried over from the prior batch, not a measured inoculation.
Identity
- National beverage of Mongolia and a formal symbol of hospitality
- Wild lactic-acid + yeast fermentation of mare's milk (no distillation, no added sugar)
- Typically ~2–5% ABV with a sour, lightly effervescent, mildly cheesy profile
- Made continuously by repeated churning in a khukhuur (cowhide sack), wooden barrel, or modern plastic container
- Endemic to the Mongol horse-culture steppe; tied to Naadam and Tsagaan Sar ceremonies
- A reusable, living culture: a portion of every batch is held back to inoculate the next
Ingredients
| Base | Raw fresh mare's milk | Cow's or goat's milk does not behave identically (mare's milk has unusually high lactose and low casein). |
| Culture | Reserved starter from previous airag batch | Carries the resident lactic acid bacteria and yeast; first batches can be started with a commercial kefir culture or trusted neighbor's airag. |
| Enrichment | Optional dried starter tablets or dried previous-batch sediment | Used when no fresh starter is available, to reseed a new sack. |
Method
- 1Milk the mare into a clean vessel and strain through cloth.Removes hair and gross debris; raw unheated milk keeps the native lactose intact for the culture to feed on.
- 2Pour the fresh mare's milk into a khukhuur (cowhide sack), wooden barrel, or food-grade plastic container, leaving ~10% headspace.The porous cowhide breathes oxygen, which the yeasts need; the vessel keeps the milk warm against the cool steppe night.
- 3Add roughly 10–20% by volume of mature starter from the previous batch (or kefir grains as a substitute first time).Provides the lactobacilli and yeast that drive both the souring and the trace ethanol production; without them, raw mare's milk simply spoils rather than ferments cleanly.
- 4Churn vigorously with a wooden paddle (the traditional 'toono' stick) for several minutes, then rest, then churn again — repeated many times over the day.Agitation incorporates oxygen for the yeasts, distributes the culture, breaks the curd into the fine suspension that gives airag its characteristic fizzy, milky body rather than a hard yogurt.
- 5Ferment at roughly 20–30°C for 2–5 days, with at least 3–5 churning sessions per day, tasting daily.Warmth and motion accelerate the parallel lactic-acid and yeast tracks; stopping too early leaves it sweet and milky, stopping too late pushes it sharply sour and high in ethanol.
- 6Reserve ~10–20% of the finished airag in a sealed jar as the next-batch starter; pour or ladle the rest for drinking.Airag is defined by being a continuously propagated culture — the recipe literally is the previous batch.
Techniques that matter
Khukhuur churning
Repeated mechanical agitation in a porous leather sack keeps the milk mixed, oxygenated for yeasts, and prevents a single hard curd from setting.
Back-slopping / starter carry-over
Airag relies on a live mixed culture passed from one batch to the next rather than a defined starter; this is the same principle as sourdough, kefir, or sourdough motherdough.
Wild fermentation under a leather lid
The cowhide allows gas exchange but keeps contamination out, letting the resident lactic flora dominate.
Variations & derivatives
ArkhiMongolia
Airag is repeatedly distilled (often in a felt-lined still) to produce a clear ~12%+ Mongolian spirit; the still-charging pot holds seasoned airag.
Khoyor dog (paired double fermentation)Mongolian steppe
A second, longer-fermented airag is held back and used as a stronger starter; prized for ceremonial Tsagaan Sar pours.
Koumiss / KumysKazakh, Kyrgyz, Bashkir, Tatar regions
Closely related fermented mare's milk traditions, also sour and mildly alcoholic; subtly different vessel and churning customs.
Used in these dishes
Substitutions
- Fresh mare's milk → Cow, goat, or yak milk — Produces a related but texturally and chemically different drink — much thicker curdling, lower final alcohol because mare's milk is unusually lactose-rich.changes result
- Reserved airag starter → Live kefir grains or heirloom yogurt culture — Acceptable for an initial batch; yeast contribution (and therefore alcohol) is typically weaker than a true airag mother.
- Khukhuur (cowhide sack) → Wooden barrel or food-grade plastic vessel — Used by settled Mongolians and urban makers; flavor is slightly less 'wild', but fermentation still works.
Troubleshooting
Batch smells or tastes harshly cheesy or rotten rather than clean-sour
Contamination from unclean vessel, or the culture was allowed to sit still too long without churning → Discard, scrub and sun-dry the khukhuur/barrel, and restart with a fresh splash of trusted starter from a neighbor.
Almost no sourness and no fizz after several days
Too cold for the culture, or the starter was dead / old → Move vessel into a warmed corner of the ger, increase churning frequency, and seed with a teaspoon of active kefir or fresh, lively airag.
Separates into hard clumps of curds and clear whey instead of uniform milky liquid
Too much resting, too little churning; or milk from a species other than mare (lower lactose, higher casein) → Whisk or churn aggressively to re-emulsify; commit to several churning sessions per day on the next batch.
Bitter or yeasty off-flavor dominating the sourness
Fermentation pushed too long or too warm — yeast track outran the lactic track → Drink this batch as a strong starter, and shorten the next batch by 12–24 hours while keeping it cooler.