What the heck are these anyway? Commonly called 'soup dumplings' in English (because there is soup inside the dumpling, not because they are served in soup), these scalding hot water-balloons of meat and soup are the ne plus ultra of the dumpling maker's art. These steamed Shanghai dumplings are made from a thin unleavened hot water dough wrapper surrounding a tasty meatball and lots of hot soup.
Wait a second, unleavened dough? Bao? Aren't bao supposed to bready and yeasty? That confused me too, so I did a little digging. Bao, in the food sense of the word, means bun. It also means wrap, package, or bundle. This makes sense, as the xiao long bao, lit. 'small basket bun,' looks like a bindle. Furthermore, xiao long bao share their crimping method with many of the stuffed baozi. A related dish ,also from the Shanghai region, sheng jian bao, shares the soupy filling of a xiao long bao, but uses a leavened dough, like the other baozi. Also deserving of mention is the Shanghai tang bao, a gigantic mutant xiao long bao that is served with a straw to suck the soup out. Making matters worse, the dishes are also known by xiao long mantou and shen jiang mantou. Mantou is a word used in the rest of China to refer to unfilled, leavened, steamed bread. I chalk it up to Shanghainese idiosyncrasy.
Now, onto the big mystery, how do they get all that soup in there? Aspic, my friends, aspic. Traditionally, a gelatin rich stock is made from such goodness as split pig's feet and skin. It's cooled until it gels, and is then chopped up and mixed with the filling. Now, most cooks just add agar or gelatin to their liquid, rather then making aspic ab initio.
Standards of quality:
- Thin wrapper. Should be almost translucent, and the dough topknot should be small and perfectly cooked.
- Wrapper integrity. No soup leakage is allowed. The wrapper should be strong enough to survive the steaming process, and the short transfer from the steamer basket to the spoon via chopsticks.
- It should be hot.
- Soup to meat balance. As several people have put it, you should be worried about your clothes while eating xiao long bao. I'm going to go with 50-50 meat filling to aspic by weight after an initial canvas of recipes. Keep in mind the meat portion tends to have a lot of liquid as well.
- Flavorful soup.
I didn't include any standards of taste/flavor profile because I regard xiao long bao as a method, rather then a dish in its own right. The classic pork filling is gently flavored and has a slight sweetness from sugar. Seafood (usually crab or shrimp) and pork versions should feature the seafood flavor prominently.