The technical comparison of steamed (zheng) and baked (ying) char siu bao: same filling, completely different dough systems and cooking methods. Steamed bao: yeast-leavened, milk-enriched dough, white exterior, soft and fluffy. Baked bao: chemical leavening (baking powder + baking soda), egg-enriched, golden exterior, slightly denser crumb. The baked version's petal-split top is created by scoring, while the steamed version's split is structural from under-proving.
‹Swipe for the next dish›
ServesAbout 12 bao (6 steamed, 6 baked)
Within reach1of 6 in Salt Spring Island
One shipped · one elsewhere in British Columbia · four not yet within reach.
Origin · King Arthur Baking, United StatesNot yet within reach of Salt Spring Island · each reach is counted
1½ tsp
baking powder
Your own market
¼ tsp
baking soda
Your own market
2
eggs
1 for the dough; 1 beaten, reserved for egg wash
Your own market
30 g
caster sugar
Your own market
80 ml
whole milk
Your own market
30 g
unsalted butter
softened
Your own market
Within reach counts in town, delivered, shipped and the nearest city. A staple counts once it has a local seller. Charted from each shop's own pages; not yet vouched by a cook who shops here.
Each tap is counted, so the stockist sees the demand Provenance sends them.
II
The Method
1
Prepare the filling for both versions. Combine the finely diced char siu with oyster sauce, soy sauce, and sugar — using the slightly higher sugar measure if the filling is destined for baked bao, so the sweetness of the centre can hold its own against the caramelised crust rather than disappearing behind it. Mix until uniform, and set aside; the filling is ready when it holds together in a cohesive mass rather than sitting loose.
From the canon — Oyster sauce was invented by accident in the 1880s in Guangdong province when a cook named Lee Kum Sheung left oyster soup simmering too long and discovered … Oyster Sauce (Cantonese — Original Method vs Commercial) →
2
Make the steamed bao dough. Dissolve the yeast and sugar in the lukewarm milk and allow it to activate, so the yeast is visibly foamy and alive before it meets the flour — dead yeast at this stage means no lift at all. Combine with the flour and oil, knead to a smooth, slightly tacky dough, then prove in a covered bowl until doubled in size; the dough is ready when a finger pressed into its surface leaves an indent that springs back slowly, neither snapping back immediately nor collapsing.
3
Make the baked bao dough. Sift the flour with the baking powder and baking soda together so both leaveners are evenly distributed and will give a uniform, even oven spring rather than pockets of dense and airy crumb side by side. Work in the sugar, one egg, milk, and softened butter until a smooth, pliable dough forms that pulls cleanly from the work surface. Because this dough is chemically leavened, no proofing wait is required; proceed directly to shaping.
4
Divide and fill. Portion each dough into six equal pieces of approximately 60–65 g each, then flatten each piece into a round, place a spoonful of filling at the centre, gather the edges, and pleat closed. For the baked bao, score the sealed top with three or four shallow cuts so the dough has defined weak points to open along in the oven, producing the characteristic petal-split rather than a ragged, random burst. For the steamed bao, leave the sealed top unmarked — its split will be structural, not decorative.
5
Steam the steamed bao. This is where the dish lives or dies: do not preheat the steamer. Place the proved bao on squares of parchment into a cold steamer, seal the lid, and bring immediately to maximum heat, so the sudden, violent surge of steam strikes the dough all at once and forces the characteristic xiao kou — the laughing split — at the crown; a preheated steamer delivers heat too gradually and the bao rise without splitting. Steam on maximum heat for 12–15 minutes, until the bao have expanded visibly, the surface is dry and matt to the eye, and the dough yields but springs back firmly when pressed.
6
Bake the baked bao. Place the shaped and scored bao on a lined tray and apply the first coat of beaten egg wash before loading the oven, so the wash has a moment to begin setting and gives the second coat something to grip. Bake until the surface begins to colour, then apply a second coat of egg wash midway through, because a single wash produces insufficient colour depth and the finished bao will look pale rather than deep golden. The bao are done when the exterior is deep golden and the scored petals have opened and set.
7
Rest the baked bao for five minutes after removing from the oven so the steam trapped inside redistributes and softens the crust from within, giving it that yielding quality rather than a shell that shatters on first bite. The bao is ready to serve when the crust gives slightly under gentle pressure rather than crackling hard.
III
Quality Hierarchy
01
Reserve — Char siu made in-house from pork neck or shoulder, roasted over charcoal; milk from a single high-fat herd for both doughs.
02
Estate — Quality purchased char siu from a Cantonese roast-meat house; full-fat fresh milk; cultured butter for the baked dough.
03
Market — Supermarket char siu; semi-skimmed milk acceptable in the steamed dough; standard unsalted butter.
04
House — Tinned or vacuum-packed char siu; any neutral liquid fat in the steamed dough; a single egg wash application on the baked version — expect shallower colour.
IV
Sensory Tests
◇Touch. Steamed bao dough: a finger-press leaves an indent that retreats slowly — neither snapping back nor collapsing.
◇Touch. Baked bao dough: pulls cleanly from the work surface and feels smooth and pliable with no stickiness.
◇Sight. Steamed bao: surface is matt and dry, crown has split open into a visible xiao kou (laughing) aperture.
◇Sight. Baked bao: scored petals have opened and set to a deep, even gold after the second egg wash.
◇Touch. Rested baked bao: crust yields slightly under gentle pressure — no hard crackling — indicating steam has redistributed inside.
◇Where it lives or dies. The steamed bao must go into a cold steamer brought to maximum heat at once — a preheated steamer denies it the thermal shock that forces the xiao kou split and produces a smooth, unsplit dome.
V · Cross-Cuisine Parallels
Japanese nikuman vs yaki nikuman — the same steamed-versus-baked duality applied to a meat-filled bun within Japanese culinary tradition. Filipino siopao — a direct descendant of the Cantonese steamed bao, transplanted and localised in the Philippine culinary canon. Korean Wang manduguk — large steamed dumplings employing a dough of similar character to the yeast-leavened steamed bao.
Pillar V
Cross-cuisine parallels are part of membership.
The dishes this one teaches you, across the cuisines — on every recipe.
Both versions originate in Guangdong Province and co-exist within Cantonese culinary tradition. The steamed bao (zheng) represents the older yeast-leavened lineage of the dim sum canon. The baked bao (ying) diverges from it through the incorporation of Western bakery techniques — chemical leavening and enriched, egg-based doughs — introduced during the colonial period. The same filling unites two technically distinct dough systems, making char siu bao an unusual case study in how a single Cantonese preparation absorbed external baking science without surrendering its identity. Source: Land of Fish and Rice, Fuchsia Dunlop.
Pillar VII
Origin and lineage are part of membership.
Where the dish comes from and how it came to be — on every recipe.