Bao, short for baozi, comes from China, where stuffed steamed buns have been a staple food for close to two thousand years. The earliest written descriptions of filled wheat buns date to the Western Jin Dynasty (266–316 CE), though their actual origins likely stretch back to the Han Dynasty several centuries earlier. From those beginnings in northern and central China, bao evolved into dozens of regional styles and eventually spread across East Asia, Southeast Asia, and the rest of the world.
The Legend of Zhuge Liang
The most popular origin story credits Zhuge Liang, a military strategist during the Three Kingdoms period (220–280 CE). As the legend goes, Zhuge Liang and his troops were on an expedition through southern China when a plague swept through the army. He fashioned buns from flour, pork, and beef, shaping them like human heads to offer as a sacrifice to the gods. The buns were then given to the sick soldiers. Whether or not the story is historically accurate, it has cemented Zhuge Liang’s name in Chinese food lore as the symbolic inventor of the steamed bun.
How Baozi Got Its Name
For most of their early history, stuffed buns were simply called mantou. During the Western Jin Dynasty, a scholar named Shu Xi described mantou as large meat-filled dumplings eaten at spring banquets, grouping them with other wheat-based foods collectively known as bing. Those filled buns remained under the mantou label for centuries.
The split happened during the Song Dynasty (960–1279). By then, mantou came with all sorts of fillings: meat, poultry, fish, vegetables. They were a common snack for students and a fixture at markets. During this period, the word baozi emerged as an alternative name for filled buns, and mantou gradually shifted to mean the unfilled version. By the Qing Dynasty (1644–1911), the vocabulary had settled into its modern form: baozi refers to buns with fillings, mantou to plain steamed buns, and jiao to thin-skinned dumplings.
Regional Styles Across China
China’s size and culinary diversity mean bao looks and tastes completely different depending on where you are. Two styles in particular have become internationally famous.
Char Siu Bao (Cantonese BBQ Pork Bun)
Char siu bao originated in Guangdong province, rooted in the region’s long tradition of roasted meats. The earliest versions wrapped Cantonese-style barbecue pork in a slightly sweet, fluffy bun. The traditional Guangdong version has a soft, pillowy texture, while the Hong Kong variation is lighter and airier, engineered to crack open at the top during steaming. That distinctive “bursting top” appearance has become one of the most recognizable sights in dim sum restaurants worldwide.
Xiao Long Bao (Shanghai Soup Dumplings)
Xiao long bao, the famous soup-filled dumplings, trace back to the 1870s in Nanxiang, a district of Shanghai. A restaurant owner named Huang Mingxian is credited with the innovation: he added aspic (a savory gelatin made from pork stock) to his ground pork filling. When the dumplings were steamed, the aspic melted into liquid, creating a burst of hot soup inside a thin, delicate wrapper. Technically a type of bao, xiao long bao sit at the border between bun and dumpling, with a wrapper far thinner than a typical baozi.
What Makes Bao Dough Different
Traditional baozi dough is a yeasted wheat dough that gets its characteristic soft, white, slightly springy texture from a combination of techniques. The process starts with a starter dough: flour and water are heated together until they thicken, then cooled before yeast is added. This cooked-flour starter, sometimes called a tangzhong-style method, helps the dough retain moisture and creates a softer crumb after steaming.
The starter ferments for four to six hours at room temperature before being incorporated into the main dough, which typically includes sugar, dry milk, and a small amount of lard or vegetable shortening for richness. Some traditional bakers save a portion of fermented dough from each batch to mix into the next one, similar to maintaining a sourdough starter. This carryover dough adds depth of flavor that fresh yeast alone can’t replicate. If the fermented dough turns slightly sour, a pinch of baking soda corrects the acidity, though it can tint the bun skin faintly yellow. Many restaurants also use bleached flour specifically to keep the buns bright white.
How Bao Spread Across Asia
Chinese immigrants carried bao traditions throughout the region, and each country adapted the concept to local tastes.
In Japan, steamed buns arrived as “chukaman,” meaning Chinese-style steamed buns, and were initially sold only in Chinatown specialty shops. By 1927, vendors began selling them to Japanese consumers more broadly. The meat-filled version, called nikuman, proved especially popular and gradually spread nationwide. The real explosion came in the 1990s, when Japanese convenience stores began stocking nikuman in heated cases near the register, turning them into one of the country’s go-to winter snacks.
In Vietnam, Chinese immigrants introduced a version based on the Cantonese da bao (large bun), which became bánh bao. The Vietnamese adaptation kept the ball-shaped steamed exterior but developed its own signature filling: seasoned ground pork with a quail egg tucked inside, often alongside mushrooms, onions, and Chinese sausage. Vegetarian versions are also common.
Bao’s Rise in Western Food Culture
Bao existed in Western Chinatowns for decades, but the moment it crossed into mainstream food culture is often linked to David Chang’s Momofuku Noodle Bar in New York. His pork buns, featuring thick slices of braised pork belly with pickled cucumbers and hoisin sauce tucked into a folded steamed bun, became an unexpected sensation. Chang himself described the appeal as a mix of salty pork fat, cool crunchy pickles, sweet sauce, and soft pillowy bread. He didn’t anticipate the dish’s success, but customers routinely ate six or eight at a sitting, and long lines became a fixture outside the restaurant.
That style of open-faced bao, closely related to the Taiwanese gua bao, became a template for chefs across the U.S., U.K., and Australia throughout the 2010s. Restaurants began treating the steamed bun as a vessel for almost anything: fried chicken, pulled pork, tofu, even ice cream. What started as a 1,800-year-old Chinese staple had become one of the most versatile formats in global street food.