These naturally purple bao buns are soft, fluffy, and steamed — and their color comes entirely from real vegetables, not food dye.
In this recipe, you’ll learn how to make purple bao buns using red cabbage, and more importantly, why the technique works. By extracting color into a strained liquid and using it in a yeast dough, you get an even, vibrant purple without affecting gluten structure. Steaming the buns instead of baking keeps them moist, pillowy, and prevents browning, which helps preserve both texture and color.
Whether you’re looking for a bao bun recipe, experimenting with naturally colored dough, or want to understand how steaming affects yeast dough, this step-by-step guide breaks down the chef techniques in a way that’s easy to apply at home.
This recipe has 12 servings.
Ingredients
For the purple liquid
½ medium red cabbage, roughly chopped
Water, enough to just cover the cabbage
For the bao dough
4¼ cups (510 g) all-purpose / plain flour
2 tbsp caster sugar
Pinch of sea salt
1 tsp baking powder
1½ tsp active dried yeast
1 cup (250 ml) lukewarm water
½ cup (125 ml) strained red cabbage liquid (lukewarm)
Neutral oil, for greasing
Method
1. Prepare the red cabbage liquid
Place the chopped red cabbage in a saucepan and add just enough water to cover it. Bring to a simmer and cook for 10–15 minutes, until the water turns deep purple.
Blend the cabbage and liquid until smooth, then strain through a fine sieve or cloth. Discard the solids and let the liquid cool to lukewarm before using.
Chef note: Using only the strained liquid keeps the dough smooth and elastic. Fibers or small bits can tear the dough structure during mixing and affect the final texture.
2. Make the dough
In a large bowl, mix together the flour, sugar, salt, baking powder, and yeast.
Make a well in the center and add:
the lukewarm water
the lukewarm red cabbage liquid
Mix with a fork or spoon until a rough dough forms.
If the dough feels dry, add a little more liquid. If it feels too wet, dust in a bit more flour — hydration can vary depending on flour type.
Turn the dough out onto a lightly floured surface and knead for 6–8 minutes, until smooth, elastic, and soft.
3. First proof
Lightly oil a clean bowl and place the dough inside. Cover with cling film or a damp cloth and let rise in a warm place for 1½–2 hours, or until doubled in size.
4. Shape the bao
Punch down the dough and knead briefly to release excess air.
Divide into 12 equal portions (about 70–80 g each for large bao). Roll each piece into a smooth ball.
Using a small rolling pin, roll each ball into an oval about 10 cm / 4 inches long, leaving the ends slightly thicker.
Fold each oval in half to form the classic bao shape.
Place each bun on a small square of baking paper.
5. Second proof
Arrange the buns in bamboo steaming baskets (or on trays), leaving space between them. Cover and let rise for about 1 hour, until puffy and airy.
6. Steam
Bring a wok or large pot filled one-quarter full with water to a gentle simmer.
Place the steaming baskets on top, cover, and steam over medium heat for 8–10 minutes, until the buns are light, fluffy, and fully cooked.
Avoid lifting the lid while steaming.
Chef note: Steaming sets the dough without drying it out or forming a crust. This preserves both the soft texture and the vibrant purple color.
Serving
Serve warm and fill with your favorite bao fillings — savory or sweet.
Storage & reheating
Fresh is best, but buns can be stored covered in the fridge for up to 2 days or in the freezer for a few weeks. Reheat by steaming for 2–3 minutes until soft again.
Understanding how these techniques work opens up far more possibilities than just bao buns.
The same method for making naturally colored dough can be used for burger buns, dumpling wrappers, and other yeast doughs, while steaming is a versatile cooking method that works for vegetables, batters, and even steamed cakes when you want softness without browning.
If you enjoyed learning how to make purple bao buns from scratch, explore more recipes and chef techniques on the website to build confidence in the kitchen and cook with intention — not just by following recipes, but by understanding them.