Jiang Mian Tiao (Fermented Sour Noodles)

Jiang mian tiao, known locally as 'jiang fan', is built on a base of fermented, mildly sour mung-bean liquid: brought to a boil, the noodles are simmered in it to a porridge-like body, then dressed with salt, chili, scallion, celery and green beans — a pale, tart and appetizing bowl that is everyday food in Luoyang.

It grows from a thrifty use of mung-bean liquid: the jiang left over from making starch is fermented into a sour broth and then used to cook noodles — frugal, appetizing folk wisdom long popular around Luoyang and Ruzhou.

Usually a home-style main eaten hot, dressed with chili oil, chive flower or pickles — tart, cutting through richness, warming and filling, especially welcome in summer, and one of the most familiar tastes from a Luoyang family's kitchen.

The flavor turns on a gentle fermented sourness — light, lingering and more moreish with each bite — an everyday noodle dish distilled into a tangy taste of local memory.