Milk Beverages

Raw mare's milk is rarely consumed, because it usually leads to diarrhea in humans (on the other hand, that effect can be applied for medical treatment). Therefore almost all of it is turned into ayrag, the national beverage of the mongols.

All other milk beverages are based on milk of cattle, yaks, or camels (sometimes sheep or goats). In most cases, the "white butter" urum is taken away first and only the remaining smimmed milk gets processed further.

 Ayrag                      -Fermented mare's milk 
 Tarag                     -Yoghurt 
 Isgelen Tarag      -Kefir 
 Mongol Arkhi        -Light liquor made from Isgelen Tarag (or Ayrag). 

Ayrag
Fermented Mare's Milk (known as Kumys in other countries)

 
The mongolian beverage every traveller is talking about. The most important animal of the Mongols is the horse. Horses don't only serve as riding animals, the mare's milk also has a special significance. It is not consumed raw, because it usually leads to diarrhea in humans (on the other hand, that effect can be applied for medical treatment). Instead, it almost always gets fermented into Ayrag.

Preparation
The milk is filtered through a cloth, and poured into a large open leather sack (Khukhuur), which is usually suspended next to the entrance of the yurt. Alternatively, a vat from larch wood (Gan), or in modern times also from plastic, can be used. Within this container, it gets stirred with a wooden masher, in order to introduce air, and especially oxygen.

The stirring then needs to be repeated regularly over one or two days. Traditionally, anyone entering or leaving the yurt would do a few strokes. The added oxygen helps the fermentation process by a combination of lactic acid bacteria and yeast, similar to Kefir.

Use
 
Ayrag refreshens and sparkles softly on the tongue. It contains a small amount of carbon dioxide, and up to 2% of alcohol. The taste is slightly sour, but quite agreeable after getting used to it. The exact taste depends both of the characteristics of the pastures and the exact method of production. The beverage is a rich source of vitamins and minerals for the nomads.

Hospitality mandates to present a bowl of ayrag to each visitor. A Mongolian will normally empty it, but it is also ok to just take a sip and return the bowl. To reject the offer right away would be gravely impolite.

Similar to Isgelen Tarag (Kefir), it is possible to distill Ayrag into Mongol Arkhi (milk liquor)