Kumis

Kumis is a fermented dairy drink traditionally made from mares milk, historically central to the diet of nomadic and semi-nomadic peoples of the Central Asian steppe, including the Mongols, Kazakhs and Kyrgyz. Because mares milk contains more lactose than cows milk, its fermentation by lactic acid bacteria and yeast produces a drink that is both sour and mildly alcoholic, typically around one to three percent alcohol by volume. Kumis held major cultural and even medicinal significance historically, described by medieval travelers such as William of Rubruck as a staple of Mongol life, and it remains an important traditional drink in several Central Asian countries today.