Airag - Fermented Mare's Milk
Surprisingly tasty for being what it was.
Twitter notes from actual time of drinking:
6%. Aroma: whiff of horse; flavour: milk w/ white wine and a bit of lemon. Slight fizz. Dry. Kind of tasty!
Colour me pleasantly surprised. It was store bought though, as none of the people we ran into while out riding had any left :/