📷 Closely related photo — Photo: Изд. маг. В.И. Асмолов и Ко. в Самаре / Wikimedia Commons · Public domain
Traces of mare's milk found in pottery at Botai in northern Kazakhstan suggest people there were milking horses around 5,500 years ago.
Kumis is made by fermenting raw mare's milk with lactic bacteria and yeast, producing a tangy, effervescent drink with a light alcohol content. It's traditionally made and sold at roadside stalls and yurts during the summer grazing season, when mares' milk is most plentiful.
Why it's made this way: As Kazakhstan's national drink, kumis carries deep nomadic roots — refusing a host's offered cup was historically considered a serious breach of hospitality.