Mexico Bun - Water Roux (汤种) Starter Bun Dough

Don't ask me why is this call Mexico Bun. I believe all the Mexican people here have no idea what is this. I have not seen this bun been sold in the bakery shops here, where the place closer to Mexico. Weird huh?? LOL!!

In order to get the best result of my bun making (softest and longer lasting freshness), I keep trying out different kind of dough recipes, I believe that by trial and error, I will improve the technique and knowledge of the dough handling.

I have learned about this water roux (汤种) long time ago. Today, I finally got the chance to try it out, I think I have found the best sweet bun dough so far, you may use the same dough for savory filling or topping, the texture and softness of the buns are exactly the same you could get from the bakery shop.



Besides Mexico Bun, I also made some BBQ pork bun with the left over filling from the char siu bao I made the other day. Of course, can't miss hot dog onion buns too, it's our favorite now. lol!! Please refer to my older posts for the filling/topping recipe of BBQ pork, Parmesan Oregano sticks and Hot Dog Onion. I will only post the dough making and Mexico bun topping recipe in this post.


Assorted bun again...

The making of the water roux is not as complicated as I thought. Following are the recipe and steps I would like to share, please try it out and see if this is the one you have been long looking for.


A) Water Roux Starter (make 125g starter)
i) 25g bread flour
ii) 1/2 cup water (approx. 150ml or 125g)
** The ratio (based on weight) of the flour and water should be 1 : 5 **
Steps of making water roux starter :

1. Mix the flour and water in a non-stick sauce pan until well blended (lump free).
2. Cook it over medium low heat (stir continuously) until the mixture reaches 65C (approx. 149F).
3. Remove the pan from heat immediately, cover with plastic film and let it cool to room temperature.

** If you don't have the thermometer to measure the mixture while cooking, the estimated cooking time is about 2~3 minutes, the mixture should be thicken by then (the texture is like the egg and flour mixture of sponge cake batter). **
Temperature and texture of the water roux.

B) The Bun Dough Ingredients :

i) 350g bread flour
ii) 100g all purpose flour
iii) 35g milk powder
iv) 55g sugar
v) 1/2 tsp salt
vi) 10g instant yeast.
vii) 2 egg（100g) - lightly beaten.
viii) 135g water
ix) 45g unsalted butter


Steps (I tried my best to describe the process with the bread machine method and hand kneading method) :

1. Sieve together all the dry ingredients except yeast.
2. For bread machine user, pour in ingredients in sequence - water, egg then flour mixture.
3. Form a small well (not too deep to the liquid ingredients), add in yeast.
4. Select the dough function and press start.
5. After 5~6 minutes of mixing (the mixture should be crumbly now), add in water roux starter.
6. About 15 minutes later, add in butter and let the machine continue to run.
7. The whole mixing and kneading process is 30 minutes.
8.This time, I let the dough rise in the machine for 1 hour after it stopped kneading. Due to the dry weather here, I placed a damp tower on top of the bread pan, and cover with lid.
9. Alternatively, you may remove the dough from the machine, and rise in a lightly greased mixing bowl, cover the bowl with plastic film, rise at temperature 78F/28C for 1 hour.
10. After one hour, test the dough by poke it down with your finger, if it does not bounce back, means that you are ready to go, otherwise, rise until it reaches the condition.
11. Punch down the dough with your fist to deflate the gas.
12. Divide it to your desired portions, roll each of them to a round ball.
13. Let them rest for another 10 minutes, then you can go ahead to shape what ever buns you like to make.
14. After shaping, let the buns rise for another hour at temperature 100F/38C. For most consistent results, I let them rise in an un-heated oven, put a bowl of boil water in the oven, close the door and let it rise until last 15 minutes, remove the buns and water when you preheat the oven.
15. Bake according to your recipe's instruction.
16. After its done baking, once you remove the baking sheet from the oven, transfer your buns to the cooling rack immediately, This is one of the IMPORTANT steps, as the heat of the baking sheet will make the bottom dry and hard.

For hand kneading baker :1. Sieve together all the dry ingredients on your working surface.
2. Make a small well in the middle of the flour mixture, slowly add in water, egg and water roux starter.
3. Knead for about 15~20 minutes, add in butter and continue to knead for at least 30 minutes. (To test if the dough has been kneaded enough, stretch a little of it, it should not tear off easily and looks translucent).
4. Place the dough in a lightly greased mixing bowl, cover it with plastic film, rise at 78F/26C for 1 hour.
The rest of the steps are the same as machine method - steps # 10~13.


C) Mexico Bun

1. Filing - 10g butter cube for each bun.

2. Topping :
i) 70~75g all purpose flour 70g first, add extra if necessary - I like it thicker, as it will create crispier topping after baking)
ii) 60g salted butter - soften in room temperature.
iii) 65g sugar
iv) 1 tsp coffee paste
v) 1 tbsp (add extra if you wish to have stronger taste) instant coffee dissolved in 1 tbsp water


Steps :
1. Whisk the butter and sugar until well blended.
2. Stir in coffee paste and liquid, mix well.
3. Sieve the flour into the mixture (sieve 70g first, add extra if the mixture is too runny, I like it thicker as it will result crispier topping after baked).
4. Stir to well combined (lump free). Refrigerate until needed.
5. Scoop the mixture into a icing piping bag.

Steps to make the buns :
1. Flatten the ball (the small dough portions that have been rested for 10 minutes), place a cube of butter in the middle, pinch and seal the edge.
2. Let the the buns rest for 1 hour.
3. Pipe (squirt on with cake decorating tube) the coffee mixture on top of the bun in a swirl pattern.
4. Bake at 375F for 12 minutes. (Different oven will give different result, I adjust it by trial and error, this is the best temperature and timing for me).
5. Remove the buns from the oven and transfer them to the cooking rack.

Mexico Bun before baking.