Douzhir (Fermented Mung Bean Drink)

Douzhir is a uniquely old-Beijing fermented drink, made from the by-product of mung-bean starch production; grey-green and sourly pungent, it is the local snack that most tests an outsider's palate.

Douzhir has a long history; by the Qing it was an everyday street food, and the morning douzhir stall was once a fixture of old-Beijing lanes — steeped in everyday city memory.

Hot douzhir is sipped while still steaming, paired without fail with a golden deep-fried jiaoquan dough ring and a dish of finely shredded pickles — salty, spicy and sour together, the quintessential old-Beijing breakfast set.

The flavor is singular and divisive: most balk at the sourness at first, but the accustomed find it mellow and oddly moreish. Whether you can stomach douzhir is a half-joking test of true old-Beijing credentials.