Steamed buns are a family favorite, and these are filled with purple yam that my mother grew in her garden! The spiral design on the dough is made from rolling two different doughs together – one that has a little bit of purple yam kneaded into it. The recipe for the dough is the same used for my mantou.
Recipe
First, make the paste:
- Steam or boil yams until soft.
- Peel the skin off.
- Mash the yams. If you want to make the paste smoother, you may blend it in food processor.
- Add generous amount of oil to pan, then cook the yams in the oil until you get a paste the consistency of peanut butter. Expect to cook for about 40 minutes or so. Add sugar to taste.
- Put in fridge. It’s easier to roll the yam paste into balls when it is cold.
Second, activate the yeast:
- Activate yeast (about 1 tsp yeast for every 4 cups of flour) of by mixing active dry yeast with warm water (and a sprinkle of sugar may help feed the yeast), and wait 10 minute or so or until you see a lot of foam on top of the water. Then pour in with the dough.
Third, make the dough:
- Mix 4 parts all-purpose flour: 2 parts water (with the activated yeast): ½ part sugar (or less if you prefer). While buns are generally fat-free, they do get quite dry the next day when cold, unless you steam them again. Thus, you may add 1/8 part oil as an option into the dough, but add this after kneading everything together (kneading helps gluten formation, which causes bread to be chewy) because oil hinders gluten formation and if you add oil too early, the dough gets messy.
- Knead for a few minutes, shape into a ball. If it’s too wet and sticky, add more flour. If it’s too dry and flaky, add more water. Keep kneading until you get a really smooth and elastic dough. If you poke your finger in the dough, the dough should indent then bounce right back.
Fourth, let it rise:
- Let the dough with the yeast rise for 1 hr (or more, depending on the temperature of the environment), or until double the size. This step is called “first proofing” or “bulk fermentation.” Don’t let it over-rise or else later when you steam, you will have wrinkly buns.
Fifth, shape:
- Punch down the risen dough and knead it again to get rid of the big bubbles created by the yeast.
- To create a spiral design, split the dough in two, and add color to one of the doughs. For purple, knead purple yam paste into the dough.
- For each dough, fold in thirds, roll out again, then fold in thirds again, then do over and over until you get plenty of “layers” of dough on each other. This will create a smooth surface when you steam the buns.
- Roll each dough into a flat sheet, then layer one on top of the other.
- Roll the layered dough into a log, then cut cross-sections to reveal the round spirals.
- Flatten each round spiral, then wrap it around ball of purple yam paste then pinch shut.
Sixth, let it rise again:
- Place each bun on parchment paper and place in a bamboo steamer under warm water to let rise for another 20 min or until texture is springy. Do not let it rise beyond 20 min as it will over-rise, which can lead to the bun surface over-stretching during steaming, then collapsing after steaming, causing a wrinkled surface appearance.
Seventh, steam:
- Pour out the warm water, and replace with cold water in pan and steam slowly for at least 20 minutes.
- Keep lid on for 5 minutes before opening. If you open too soon, you risk the bun surface collapsing, causing wrinkles on the surface.
- Enjoy while it’s warm. If you fridge it, be sure to steam for a few minutes again before eating. Or, wrap it with a wet paper towel, then microwaving it for 10-15 seconds.
