These are super soft, light rolls filled with a silky sweet black bean paste. The secret to their longlasting softness is the tangzhong method – which involves the addition of a water roux. This is effectively just a small amount of the flour cooked with boiling water, kind of like a milk roux. It gives the bread a texture similar to brioche, except without all that butter! Seriously, this is like the fifth time I’ve made something using the tangzhong method, and everytime I’m surprised by its magic and I wonder why it’s not a bigger thing over here in the West; where low fat versions of things (e.g. frozen yoghurt) are so popular.
But of course, it can’t be magic! What’s the science behind it? Truth is, I’m not entirely sure. It seems to be that when the flour is mixed with the hot water, the starch granules swell and eventually leads to gelatinisation. This gelatinisation somehow locks the water content into the flour, and a higher hydration = softer bread. It was first developed by a Chinese lady called Yvonne Chen in her book “65 degrees Tangzhong Bread”. I wonder what she could tell us about the science behind it. Does anyone else know? There’s a lot of different information on the net.
The water roux has to be made the night before so that it can chill in the fridge – so this needs a little planning ahead. But then it’s pretty smooth sailing. I adapted this recipe from this blog, and it was very helpful in showing the steps. Though, I used sweet black bean paste instead of red bean because I had loads left over.
Ingredients for the water roux:
- 50g white bread flour
- 35g boiling water
Ingredients for the rest of the dough:
- 150g bread flour
- 50g plain flour
- 40g sugar
- 3g salt
- 4g instant yeast
- 10g milk powder
- 30g of egg (about half an egg. Leave the other half for brushing on top of the rolls)
- 30g unsalted butter
plus about 250g sweetened black bean paste (I got mine from a tin) for filling the dough, and sesame seeds to sprinkle on top.
1) First make the water roux by stirring the boiling water with the flour. Stir until it forms a rough dough, then cover and then leave in the fridge overnight.
2) The next day, mix together the water roux with all the ingredients for the dough, apart from the butter. Mix til it forms a rough ball, then turn out on to a kitchen surface and knead til smooth and passes the windowpane test. The dough shouldn’t stick to the surface.
3) Knead in the butter. This is added later as the butter makes the dough a little stickier and more difficult to knead. Once the butter is evenly incorporated and the dough is no longer sticky, it’s ready for the first rise. Let the dough rise in a bowl covered with cling film for about an hour, or doubled in size.
4) Once risen, divide into 6 pieces (about 80g each). Roll each one into a thin rectangle, like this:
5) Cover half of the rectangles with an even layer of black bean paste:
6) Then place a rectangle over this, pinch together the edges to seal, and cut several slits into it (I used a pizza cutter):
7) Roll up (starting from the short edge) like a swiss roll. Repeat these steps to make three rolls. Place these seam side down on a baking sheet. Sorry for my ugly baking tin!
This is what they looked like before rising. They rise A LOT so make sure they are spaced out well! They need to rise until doubled in size again, so about 45 mins to an hour (whilst covered with cling film), depending on the temperature.
8) Next, brush the tops with the leftover egg from earlier, and sprinkle with sesame seeds. Bake in an oven preheated to 190C for about 15 mins, til lovely and golden.
By the way, don’t judge me but yes I am wearing pyjamas in the garden these pictures. Only because I was just hanging about at home in the kitchen all day, and had to pop outside to take these pictures because the lighting in my kitchen is not so great. I’ve been having a couple of lazy days in between finishing my masters and waiting to start my new job. I’m excited because I’m going to be working in the NHS. Dream 🙂
Also here’s a little bean joke. Where did the green bean go to have a few drinks on friday night?
…The salad bar 🙂