Tough on the outside, chewy on the inside is how I'd describe the Steamed Chinese Barbecue Pork Buns I've made thus far. Also known as Char Siu Bao, these fluffy, white buns are commonly served at Chinese restaurants during dim sum. At their best, Char Siu Bao are soft as a pillow and filled with a savory mixture of minced Chinese barbecue pork (char siu), soy sauce, oyster sauce, scallions and sugar.
My recent attempts at this wonderful snack have left me disappointed. As you can see from the picture above, my Char Siu Bao are slightly yellow with a dry, tough exterior and a dense, chewy texture. Only the filling has been acceptable, which is why my trash can is now filled with buns that have been hollowed out.
I'm not exactly sure what I've been doing wrong, so I'm hoping someone out there would be able to lead me in the right direction. So far, I've made two different Char Siu Bao recipes. One from Corinne Trang's Essentials of Asian Cuisine, available here; and the other from Martin Yan's Chinatowns, available here. They're both similar in ingredients and technique. Basically: combine yeast with warm water, rest until bubbly, stir into flour mixture, hand knead five to ten minutes or until smooth and elastic, proof for two hours, knead five minutes, wrap with barbeque pork mixture, and steam in a bamboo steamer over high heat for 12 to 15 minutes.
I've come up with a few possible theories to explain my poor results, but please feel free to debunk my hypotheses or add your own:
1. Excessive kneading is overdeveloping the gluten and making the dough too firm and chewy.
2. Insufficient proofing is causing poor volume and dense texture.
3. Insufficient baking powder is causing poor volume and dense texture.
4. The higher protein levels in Canadian flour (cake: 10%, all-purpose: 12%) are overdeveloping the gluten. I'll assume the recipes were tested using American flours which have lower protein levels.
5. Using an improper steaming temperature is causing poor volume, or collapsing the buns.
6. The dough is too dry and contains insufficient fat. I noticed that after leaving the raw dough uncovered for a few minutes, it developed a thin crust.
7. Oversteaming is causing the buns to shrivel up and turn yellow. Though this may be compounding the problem, I'm almost certain that there’s something wrong with my dough. During one of my trials, I peered into the bamboo steamer after three minutes, and the buns had already developed a firm exterior.
Of course it could be possible that there's something wrong with the recipes. However, I've looked at least a dozen recipes for Char Siu Bao, and they appear to be similar in both ingredients and technique. I've also had good results with recipes from Corinne Trang and Martin Yan in the past, so being an inexperienced baker, it's likely the problem is on my side.