Wuzhi Oil Tea

Wuzhi oil tea takes its name from its home, Wuzhi county in what was Huaiqing prefecture (怀庆府), today part of Jiaozuo in northern Henan, and from its method: the flour is fried (油) in oil before being made into a gruel that is drunk like tea. Local accounts give it a long pedigree under earlier names — 甘醪膏汤 said to date from the Qin, and 膏汤枳壳茶 from the Han — and attach two ruler stories: that the future Han founder Liu Bang was nursed back to health on it at Wude and later honored it, and that the Qing Yongzheng emperor, inspecting Yellow River flood works at Wuzhi, tasted it and praised it ('怀庆油茶润如酥' — Huaiqing oil tea is smooth as cream). These origin tales are folklore handed down rather than documented in a firm text, and the exact dates are unverifiable; what is solid is that Wuzhi oil tea is a long-established Huaiqing specialty, listed among Henan's provincial intangible cultural heritage. Its identity is a toasted-flour, spice-and-nut savory gruel of the region.

Good Wuzhi oil tea is thick but pourable, smooth and lump-free, the color of milky tea; it tastes deeply of toasted grain and sesame oil, savory and faintly salty, studded with little bits of fried peanut, sesame, and walnut that give crunch against the silky gruel, with a warm background hum of the spices. Drunk hot it coats and warms. A badly made bowl is lumpy because the powder was dumped into the water instead of whisked, or thin and pasty-tasting because the flour was under-toasted and tastes raw, or rancid and bitter if the nuts or oil have gone off.

The dish is built on a dry roux. Toasting the wheat flour, then frying it in sesame oil, does two things: heat breaks down the starch and browns the flour through the Maillard reaction and caramelization, building the deep toasted aroma and killing the raw-flour taste; and coating each particle of flour in oil keeps the grains separate, so that when the powder meets boiling water it disperses and thickens smoothly instead of clumping into paste. A little pearl starch adds extra body and gloss. The thickening itself is starch gelatinization — the toasted, oil-coated starch granules swell in the hot water and set the gruel. Whisking constantly while pouring in the powder is what prevents lumps, because the outer grains gel instantly on contact with the water and would otherwise seal a dry core. The fried peanuts, sesame, and walnuts add fat, protein, and crunch, and the ground spice blend perfumes the whole; frying the nuts first develops their flavor and keeps them crisp in the wet gruel for a while.