Lau Sa Bao (Chinese Custard Bao)

I experimented with so many different methods of making bao and the custard and settled on slightly firmer custard as opposed to a lava-like one to please the hubby. I also found that using milk and cake flour in the bao dough as opposed to water and AP flour gave me the right texture but you can experiment and see what you like!

Also, if you just want to make unfilled bao to fill later pork belly, seared tofu, etc:

In step 8: roll into an oval instead of a circle; brush the surface with a little more canola or vegetable oil; fold the oval over a lightly oiled chopstick; remove the chopstick and place on the parchment squares. Proceed as directed but only steam for about 8-10 minutes. The second video below shows how to form unfilled bao.


Lau Sa Bao (Salted Egg Yolk Custard Bao)

Bao dough

  • 525 g cake flour
  • 3 g instant yeast
  • 265 g whole milk (room temp)
  • 1 Tbsp canola oil
  • 22 g sugar
  • 1 tsp baking powder
  • ½ tsp salt

Custard Filling

  • 3 duck salted egg yolks (steamed*)
  • 1 chicken egg yolk (hard boiled)
  • 35 g unsalted butter (room temp)
  • 3 g custard powder**
  • 20 g nonfat milk powder

Custard filling

  1. Mash steamed/boiled egg yolks together with a fork or bench scraper.

  2. In the bowl of a stand mixer fitted with the flat beater beat the butter and sugar together until fluffy.

  3. Add the milk powder and custard powder and mix well.

  4. Add the mashed yolks to the butter mixture and beat for a few minutes or until smooth and fluffy.

  5. Refrigerate for one hour or until firm then use a cookie scooper to scoop 18 balls (approx 18g each). Put back in fridge until ready to fill bao.

Bao Dough

  1. Combine the flour, sugar, salt and yeast in a large mixing bowl. Add the yeast and salt to separate sides of the bowl.

  2. Add milk and oil to the flour and mix until a shaggy dough is formed.

  3. Tip out onto lightly floured work surface and knead for 10 minutes or until smooth.

  4. Place dough in a lightly oiled or sprayed bowl, cover with plastic wrap and let rise for about 45 minutes or until about 1½ times its size.

  5. Tip the dough onto a clean work surface , sprinkle the baking soda on top and knead again for about 5 minutes or until smooth again.

  6. Roll the dough onto a long sausage shape and divide into 18 pieces each about 45 g.

  7. Roll each piece into a smooth ball and place seam side down on your work surface. Cover with a tea cloth while you finish rolling them all into balls. Cut eighteen 3-inch squares out of parchment paper.

  8. Use a rolling pin to roll each one out into a 3" round piece (not too thin).

  9. Put one ball of chilled custard into the middle of the dough and gather up the dough around it like pulling up purse strings. Pinch the top several times to make sure it is sealed then roll it on the counter for a few seconds to make sure the seam is sealed and reshape the ball. Set each piece onto an individual parchment paper square and then arrange on two baking sheets. Cover with lightly sprayed plastic wrap and proof for 30 minutes.

  10. Set your steamer basket in a deep pan with one inch of water and bring to a boil. A typical two tiered bamboo steamer basket can hold 4-5 bao per tier so you will have to steam them in batches. Load the steamer basket with the bao, put the lid on, turn the heat to medium and steam for 12 minutes. Remove the bao from the steamer and remove the parchment paper.

  11. Allow to cool for only a couple of minutes before digging in !

    • Even if you buy salted egg yolks that are labeled as “cooked” they need to be steamed for 5-7 minutes or until they look opaque and pale yellow.  You could also use all chicken egg yolks that are hard boiled. 
    • I use Bird’s custard powder that I found in my local supermarket’s “British food” section.