Japanese Purple Sweet Potato Bun

by - July 17, 2017

This recipe yields soft and cottony buns that you can eat plain. If you are looking for soft and fluffy buns, this is the recipe for you.  In order to get this nice vibrant purple colour, please use the Japanese Purple Sweet Potato instead of local Purple Sweet Potato.  


Yields:  16 buns


400g bread flour
250g mashed japanese purple sweet potato (about 300 - 350g potato - peeled, sliced, steamed and mashed)
1 ½ tsp instant active yeast
30g brown sugar
1 tsp salt
40g whisked egg (from 1 large egg.  Balance to be used for egg wash)
60g butter
120g - 150g fresh milk

Egg wash - 10g whisked egg + 1 tsp water
2 tbsp sesame seeds for topping

10 inches square pan

  1. Put all ingredients (first add salt, flour, sugar, yeast, butter, egg, mashed potato and lastly fresh milk) in a bowl of stand mixer and knead till the dough come together, until achieve window pane stage (the dough at this stage should be able to be pulled and stretched into membrane).  It takes around 10 to 15 minutes at medium speed.  If the dough is wet, add 1 tablespoon of flour at a time until you get the consistency you want.
  2. Form the dough into a round ball and let it rise in a warm place for 1 hour or until double in size in a large greased bowl, covered with cling film or kitchen towel.  I normally leave the dough in the stand mixer’s bowl and cover with kitchen towel.
  3. Punch down the bread dough to release the air.
  4. Divide dough into 12 equal portions and shape into balls. Place bun onto the baking pans lined with non-stick baking paper. Let buns rise for another 45-60 mins or until double in size.
  5. Brush the buns with egg white/water mixture and sprinkle with some sesame seeds on top.
  6. Bake at pre-heated oven at 170C - 180C for 25 to 30mins.
  7. Remove buns to cool on rack completely.
  1. Add 120g of fresh milk first, then slowly add in the rest if dough is too dry.
  2. If fresh milk is not available, you may use 120g - 150g water + 2 tablespoons (20g) of full cream milk powder.
  3. Please cut down the mashed potato to about 200g - 220g if you find the texture is too moist for you.

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  1. This is super awesome! Ive baked it and gonna bake more and more. Tq for the great recipe!

    1. Hi there,

      Thank you for trying this recipe and your feedback. I am happy to hear that you like it.

      Cheers :)

  2. Rats! Mine had a bitter taste..do you know why it might have turned out like this for me?

  3. Rats! My buns turned out bitter for some reason. Do you know what I might have done wrong? Or did I just have bad sweet potatoes?

    1. Hi, Thank you for trying this recipe. Sorry to hear that your buns turned out bitter. It must be the sweet potatoes potato. There is no other reasons that can make your bread bitter. I have accidentally eaten bad sweet potatoes before, the taste is bitter.

      Cheers :)