What in the World, a free weekly newsletter from our foreign correspondents, is sent every Thursday. Below is an excerpt. Sign up to get the whole newsletter delivered to your inbox. Beijing: In the backstreets of the city’s ancient hutong alleyways , an enterprising Beijinger will sell you perhaps the most unpleasant drink you’ve ever tasted. Pan Xianhua with his self-proclaimed “worst-tasting” douzhi in all of Beijing. It’s called douzhi, a traditional drink in Beijing made from fermented mung beans. It tastes a bit like it smells, which is to say pungently rancid. And Pan Xianhua’s concoction is the most diabolical of them all. At least that is his marketing pitch. For years, Pan, 60, has sold douzhi outside his home in the hutongs, the old inner-city neighbourhoods where you’ll find the Beijingers whose palates were trained on the fermented beverage as children. A woman tries Pan’s douzhi. Earlier this year, Pan put up a sign advertising his drink as “the worst-tasting Old Beijing douzhi”.…