Just got back from a trip to Beijing, where I discovered a fermented soy drink called "dou zhi" (literally "bean juice") that's popular there. I'd never seen that in a restaurant stateside. Its flavor is sharp and sour and it has a milky texture, quite different from anything I'd had before. It's usually served in a bowl alongside a crunchy donut for dipping and some pickled vegetables. Not something I'd want to drink every day, but I enjoyed it enough that I wouldn't mind knowing where to get it here. Is there some restaurant in the Bay Area that serves it?