Runny Yolk Buns

Heya! Thank you for watching the recipe video on runny yolk buns.

As promised, here's more info on various aspects of the recipe:

Rice flour:

Fig. 1: Rice flour

I recommend getting the cheap Asian brands instead of the ones marketed for gluten-free baking. Rice flour is gonna be gluten-free. If it costs more than $1.30 for a package like this, it's over-priced! In fact, $0.79 (CAD) is about the regular price for this. Rice flour usually comes in the red-print package (Figure 1). For other western baking recipes (eg. shortbread) that call for rice flour, this is usually the variety to go for.

If you go to an Asian grocery store, you'll see a wide variety of starches and flours in addition to rice flour: Tapioca starch, sweet potato starch, water chestnut flour, glutinous rice flour. Tapioca starch is kinda like cornstarch, but gelatinizes more water than cornstarch. It is usually opaque when gelatinized. Sweet potato starch clear when gelatinized. It creates a bit of a chewy texture and is good for binding ingredients together in vegetable pancakes, oyster pancakes, etc. when you add a little to the batter. Water chestnut flour is clear when gelatinized and can look and feel similar to jello. This is the most expensive of of the lot and is about 4 times as costly as an equal-sized package of cornstarch. Glutinous rice flour turns mixture chewy and sticky, like mochi. (Will add pictures once I get a chance!)

Steamers:

Traditional bamboo steamers work a lot better for this recipe than the metal ones. I tried using the metal one that came with my pots set, but the buns turned out too wet. Bamboo steamers (Figures 2 & 3) are more permeable to steam, which work well for steamed buns. In terms of caring for bamboo steamers, they're pretty durable. I generally don't wash these with soap and water after use unless something oily drips onto them. So for steaming meat and vegetables, I would place the plate or bowl inside the steamer. Usually just a rinse under hot water will do. They should air dry thoroughly before being placed away. While not using, they should be placed away from heat and sun.

To use a steamer, you need a pot with an opening roughly the same size and set the steamer on an open pot with ~2 cm (~1") water inside (add more depending on how long you're steaming things for). I use some damp towels along the edge of the pot so the steamer sits snugly on the pot (Figure 4). The idea is to create some sort of seal between the pot of water and the steamer so the steam funnels up into the steamer instead of out the sides. If you have a wok with sloping sides, the widest part just has to be bigger than the steamer, so you can place the steamer inside with some water on the bottom.

Fig. 2: Steamer lid

Fig. 3: Steamer basket

Fig. 4: Steamer snugly fit on pot

Salted duck eggs:

Fig. 6: Salted eggs (bottom 2) comparison

Fig. 5: Salted eggs and chicken egg

In general salted eggs are duck eggs. There are two types of preserved duck eggs: salted (鹹蛋) and thousand-year eggs (皮蛋). Salted eggs have a rich golden yolk that can be used for making all sorts of sweet and savoury dishes. They're also used in mooncakes. They are often wrapped in salted dirt (Figures 5 & 6), or in a styrofoam packaging in liquid. At max, they should be $1 per egg. These are the ones you want for this recipe. Thousand-year eggs are disgusting. They are jelly-like and look like an ancient sea monster's eyeballs. I don't know why anyone would want to eat them. (haha, just personal opinion, but my family loves them. They have a deep, savoury flavour and are often mixed with congee. They're also used in a pastry called 皮蛋蘇 where a thousand-year egg is wrapped with a piece of pickled ginger in a flaky pastry dough.)

Easier filling technique:

As mentioned in the video, you can mash the yolks with a fork instead of the spatula (Figure 7). Instead of chilling and rolling the filling by hand, which can get messy, use a piping bag with a large, round tip (at least 1 cm, Figure 8) to squeeze out small mountains (Figure 9). Then place the entire plate into the freezer to freeze until hard. As long as they're roughly round lumps, they will be fine!

Fig. 7: Using a fork to mash egg yolks

Fig. 8: Large round piping tip

Fig. 9: Piped filling mountains

Hope this recipe works well for you. I'll put the video and ingredient list below for reference.

Ingredients:

Bread dough:

180 g all-purpose flour
40 g rice flour
2 g salt
10 g granulated sugar
4 g baking powder
4 g instant yeast
115–135g water (can sub with milk)
9 g oil (any cooking oil)

Filling:

3 salted duck eggs (yolks only)
1 large chicken egg (yolk only)
3 g cornstarch
25 g coconut milk (canned stuff with the fat, not the low fat milk substitute one. Can sub with 10% or 35% cream, cream substitute is ok too! I suppose creamer is fine too when in a pinch. Just stick with vanilla flavour)
35 g unsalted butter
40 g icing sugar
1/2 tsp vanilla extract

Happy steaming! :-)