Once upon a time, I foolishly considered myself a soup dumpling expert. After all, I had tracked down terrific versions at a select group of Chinatown restaurants, and could devour those explosively juicy snacks without burning my lips or staining my shirt. Then I visited Shanghai, where soup dumplings aren’t just an occasional snack. They’re a city-wide fetish, and I had much to learn.

Like a ship in a bottle, soup dumplings, or shao long bao, miraculously trap scalding-hot broth and a pork or pork-and-crab filling within a fragile dumpling skin. As the dumplings steam, the filling infuses the broth with a double dose of flavor. And for a lover of these remarkable dumplings, a tour of Shanghai can be a pilgrimage to a shrine.

Nan Xiang restaurant is the perfect place to start. Located in Shanghai’s Old City district, Nan Xiang (85 Yuyuan Lu, 86-21-6355-4206) specializes in a range of soup dumplings that puts Joe’s Shanghai or Goody’s to shame. Shanghai is known as a shopper’s paradise, and the reputation certainly fits here: Each of the restaurant’s three floors serves soup dumplings of a different price and service level.

Throughout the restaurant, though, freshness is paramount. At a New York soup dumpling house, you might see dumplings occasionally being made in the window. At Nan Xiang, an army of women pick crabmeat from freshly steamed hairy crabs, men roll out dumpling skin and crimp the dumplings, and a stacks of steamer baskets tower above the heads of the cooks.

All three floors serve the same dumplings, with thin skins and a savory filling packed with freshly picked crab. The difference is the level of service. The first floor is takeout only, with the lowest prices and an impressively long line. The second floor is as crowded as a stock exchange, with bare-bones service and customers jockeying for seats at the packed tables. The third floor is fancier, with a prix-fixe menu that includes other Shanghainese snacks.

But soup dumplings in Shanghai manage to be delicious even in the unlikeliest places. A bare-bones, state-run restaurant on Ruijin Road in the Xuhui district is bright, clean, and bustling. One of its specialties is a soup dumpling made with thick, yeast-raised dough and pan-fried in a giant cast-iron pan.This is the country cousin of regular soup dumplings, with a coarser skin, an all-pork filling, and an addictive crunch. They’ll squirt juice just like the steamed version if you don’t eat them carefully.

But just as Prada trumps Old Navy, the best dumplings I ate in Shanghai were the most expensive. Din Tai Fung (12-20 Shuicheng Lu, 86-21-6208- 4188) is a refined Taiwanese restaurant that is famous for its soup dumplings (it has two other locations, in Taipei and Los Angeles). Located in the ritzy Xintiandi shopping district, it’s a luxurious place to refuel after spending too much money on presents for friends back home. The walls are covered with modern murals, the tables set with pristine tablecloths and porcelain tea cups, and the xiao long bao are perfect. The dumpling skin was tender and paperthin, but with structural integrity. The filling included not only pork and crab, but also luscious crab roe. The black vinegar in the dipping sauce was top-quality, topped with gossamer-thin shredded ginger.

Eating in that elegant room, I was especially grateful for all those years of practice back in New York. I didn’t have to worry about a soup dumpling disaster. Instead, I calmly lifted a dumpling with my chopsticks, dipped it in black vinegar, placed it on a wide spoon, sucked out the juice, and devoured the rest. No embarrassing spills, no disapproving stares. Perhaps that’s all the expertise that really counts.