Breads (Sourdough) - Soft Buns/Rolls
Purple Sweet Potato Sourdough Buns – Soft, Fluffy & Naturally Vibrant
November 16, 2020
| Recipe by Bake with Paws
Updated: July 2025
By Bake with Paws
Purple Sweet Potato Sourdough Buns – Soft, Fluffy & Naturally Vibrant
Sweet potatoes are one of my favorite ingredients in bread making. They naturally add moisture, sweetness, and beautiful color to the dough. For these Purple Sweet Potato Soft Sourdough Buns, I wanted to create a bread that’s not only delicious and soft but also visually stunning, using purple sweet potato for its vibrant hue.
These buns are naturally leavened with my Sweet Stiff Sourdough Starter, giving them a soft, fluffy crumb and mild flavor—no sour tang, just a hint of natural sweetness from the sweet potato. Whether enjoyed plain, with butter, or your favorite spread, they make a wholesome, eye-catching addition to your bread basket.
What Makes This Recipe Special:
✔️ Sweet Stiff Starter: Gives the buns a soft, moist crumb without tanginess.
✔️ Naturally Vibrant: The stunning purple color comes entirely from mashed purple sweet potato—no artificial coloring needed.✔️ Fluffy & Soft: Tender, pillow-like texture that stays soft for days.
✔️ Simple, Wholesome Ingredients: No commercial yeast, no additives—just natural fermentation and plant-based color.
✔️ Versatile: Great for breakfast, tea time, or as a sandwich bun.
What is Sweet Stiff Starter?
A Sweet Stiff Starter is a type of sourdough starter that is firm in texture and slightly sweetened during the feeding process. Unlike the typical liquid sourdough starter, which has a pourable consistency, a stiff starter is much firmer and easier to handle, with a dough-like texture.
For sweet breads and enriched doughs like these Purple Sweet Potato Buns, a sweet stiff starter is my preferred choice because:
✔️ Milder Flavor: It produces a bread with little to no sour tang—perfect for sweet and soft breads.
✔️ Better Rise in Sweet Doughs: Sweet stiff starter can handle enriched dough (with fats and sugars) better, giving a good oven spring.✔️ Stronger Yeast Activity: The stiff texture encourages strong yeast development, leading to a fluffy, light crumb.
I maintain my sweet stiff starter by feeding it with flour, water, and a small amount of sugar. If you want to learn how to make one, check out more details about Sweet Stiff Sourdough Starter.
How To Make Purple Sweet Potato Soft Sourdough Buns
Ingredients (Yields: 16 buns)
Sweet Stiff Starter:
60g sourdough starter (100% Hydration), use at its peak
180g bread flour (I used Japan High Gluten Flour)
75g water
30g sugar (I used organic brown sugar)
Main Dough:
140g bread flour (I used Japan High Gluten Flour)
120g mashed purple sweet potato (about 200g raw sweet potato)
120g mashed purple sweet potato (about 200g raw sweet potato)
All the sweet stiff starter
10g brown sugar
10g brown sugar
1 tsp salt
60g - 80g milk (Add 60g first and slowly add in the balance if the dough too dry. I used total 80g. The amount of liquid also depend on the hydration of mashed sweet potatoes and also the bread flour)
50g whisked egg (from 1 large egg)
35g butter
Egg Wash:
1 egg + 1 Tbsp water
Step-By-Step Instruction
- Mashed Purple Sweet Potato:
- Wash, peel, cut and steam the purple sweet potatoes for about 20 minutes. Mash with potato riser.
- Sweet Stiff Starter:
- In a bowl of stand mixer, dilute starter with water, stir in sugar and add in bread flour. Mix with paddle attachment until well mixed and all come together. It can be done by hand mixing too.
- Cover and let it ferment until tripled. I prepared a night before and leave it in aircond room (approximately 24 - 25C room temperature) overnight until tripled. It took about 8 - 9 hours depending on your starter. It should take around 4 - 6 hours to get triple at room temperature at 28C - 30C.
- Main Dough:
- Put all ingredients (except butter) into a bowl of stand mixer. I usually torn the stiff starter dough into pieces first.
- Slightly combine the mixture by hand with the paddle attachment before turning on the machine so that the flour will not splash out. Using the paddle attachment, mix for 2 minutes or until all incorporated. This step is critical to prevent an uneven mixed dough as the stiff starter is rather hard and a dough hook may not be able to mix it well enough.
- Change to hook attachment and knead for another 3 minutes or until the dough comes together. Add in butter and continue knead for 10 - 12 minutes or until reach window pane stage. During the whole kneading process, I stopped few times to scrape down the dough from the hook to be sure it is evenly kneaded and also to prevent the motor from overheating.
- First Proofing/Resting The Dough:
- In the same bowl, let the dough rest for 60 minutes. Keep it covered with clingfilm or use a lid. The dough did not rise a lot in 60 minutes.
- To shape:
- Transfer the dough to a clean floured surface then divide dough into 16 equal portions. About 49.40g each. Please use a kitchen scale if you want to be exact.
- Form each portion to a ball.
- Place place bun onto the baking pans. Arrange 4 buns by 4 buns.
- Final Proofing:
- Let the dough rise until double in size. This bread took me around 2.5 hours at room temperature of around 29C- 30C. The duration of proofing depends on your ambient temperature and starter.
- To Bake:
- Preheat oven at 190C (top & bottom heat) or 170C (fan-forced) for 10 - 15 minutes.
- Brush with egg wash.
- Bake in a preheated oven for 18 - 20 minutes, or until golden brown.
- Remove buns from oven and pan. Let them cool on rack.
Sweet Stiff Starter
Main Dough
Top Tips for Best Results
- Sourdough Starter:
- A healthy starter is essential for successful bread baking. To ensure your bread rises well, it's important to feed your starter regularly and use it (the levain) at its peak. A consistently fed starter will be more active and reliable. If the mother starter isn’t strong, the dough may still struggle to rise properly, even if the levain is used at its peak. For more information, click the links: "How To Make Sourdough Starter" and "Sourdough Maintenance".
- Gluten Development:
- Essential for soft, airy bread, gluten is created when flour hydrates. To develop it, use techniques like autolyse or kneading. The windowpane test checks readiness—dough should stretch thin without tearing. From my experience, high hydration dough with high percentage of fat will be easy to stretch and achieve a paper thin windowpane stage.
- Kneading:
- Please regard the timing provided as an indication only. It is only meant as a guide. Times vary by flour and mixer type. For higher fat dough, knead longer (18–20 minutes).
- Flour & Hydration:
- Use high-gluten flour for optimal texture. Always reserve some liquid to adjust dough consistency for best results. If dough is too dry, add the reserve liquid one tablespoon at a time until the right consistency.
- Dough Temperature:
- Maintaining the right dough temperature during kneading is crucial for a fine crumb. If the dough becomes too warm, the crumb will become too big and uneven. To prevent this, use cold water, milk, or eggs, and chill your mixing bowl or hook attachment in the freezer. Knead at low speeds, and if your kitchen is warm, rest the dough in a cooler spot. Proper dough temperature ensures a soft, fluffy bread with a fine, even crumb.
- Proofing:
- Proofing time depends on your environment. Use the finger poke test to gauge readiness. To check dough readiness, lightly press the side with your finger:
- If it bounces back instantly, it’s under-proofed and needs more time.
- If the indentation stays, it’s over-proofed.
- If the indentation slowly bounces back, it’s ready to bake.
- There’s also a final rise called oven spring when the dough bakes, which adds to the bread’s height.
- Wrinkle Top or Shrinking:
- If your bread collapses or develops wrinkles on top after baking, it might be over-proofed during the second rise. Aim for the dough to rise to 80-90% of its final size or just below the rim of the pan to prevent this. Over-proofing leads to weaker structure, causing the bread to lose shape.
- Baking & Oven Temperarate:
- Do also note that the baking temperature and timing provided are what works for my oven and should also be regarded as a guide only. Every oven behaves a little differently, so please adjust accordingly for your oven.
Troubleshooting (FAQs):
1. Why is my dough sticky?
Purple sweet potato adds moisture, making the dough slightly sticky. Use lightly oiled hands and surfaces when handling the dough.
2. Can I use orange sweet potato instead?
Yes! Orange sweet potato works just as well, though the color will be different.
3. Why doesn’t my bread look as purple as yours?
Natural purple sweet potato color can fade during baking. Some varieties retain color better than others. Steaming the sweet potato instead of boiling also helps preserve the hue.
5. Can I refrigerate the dough overnight?
Yes, place in fridge after bulk fermentation. The next day, bring them to room temperature, shape, proof and bake.
Have a Question or Tried This Recipe?
I’d love to hear from you! If you have any questions, feel free to drop them in the comments below.
Tried this recipe? Tag me on Instagram @bakewithpaws and use the hashtag #bakewithpaws — I’d love to see your creations and share them!
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More Recipes to Try:
Love colorful, soft sourdough buns? Check out these favorites:
-
Halloween Pumpkin Sourdough Buns – Cute, festive, and fun to make.
- Orange Cranberry Soft Sourdough Bread – Naturally sweet with a gorgeous orange hue.
- Orange Cranberry Soft Sourdough Bread – Fruity and festive.
- Soft Sourdough Pumpkin Loaf – Classic pillowy bread for everyday use.
Purple Sweet Potato Soft Sourdough Buns
Yield:
16
Prep time: 35 MinCook time: 20 MinInactive time: 11 H & 30 MTotal time: 12 H & 25 M
Characteristics of this bread: The texture is especially soft and moist on the first day. It lost only a little of its softness on the 2nd day. However, I discovered that higher percentage of potatoes used produced more moist texture bread and tends to stay fresh longer.
Ingredients
SWEET STIFF STARTER:
MAIN DOUGH:
EGG WASH:
UTENSIL:
Instructions
MASHED PURPLE SWEET POTATO
- Wash, peel, cut and steam the purple sweet potatoes for about 20 minutes.
- Mash with potato riser. Set ] aside to cool down.
SWEET STIFF STARTER
- In a bowl of stand mixer, dilute starter with water, stir in sugar and add in bread flour. Mix with paddle attachment until well mixed and all come together. It can be done by hand mixing too.
- Cover and let it ferment until tripled. I prepared a night before and leave it in aircond room (approximately 24 - 25C room temperature) overnight until tripled. It took about 8 - 9 hours depending on your starter. It should take around 4 - 6 hours to get triple at room temperature at 28C - 30C.
MAIN DOUGH
- Put all ingredients (except butter) into a bowl of stand mixer. I usually torn the stiff starter dough into pieces first.
- Slightly combine the mixture by hand with the paddle attachment before turning on the machine so that the flour will not splash out. Using the paddle attachment, mix for 2 minutes or until all incorporated. This step is critical to prevent an uneven mixed dough as the stiff starter is rather hard and a dough hook may not be able to mix it well enough.
- Change to hook attachment and knead for another 3 minutes or until the dough comes together. Add in butter and continue knead for 10 - 12 minutes or until reach window pane stage. During the whole kneading process, I stopped few times to scrape down the dough from the hook to be sure it is evenly kneaded and also to prevent the motor from overheating.
FIRST PROOFING/RESTING THE DOUGH
- In the same bowl, let the dough rest for 60 minutes. Keep it covered with clingfilm or use a lid. The dough did not rise a lot in 60 minutes.
TO SHAPE
- Transfer the dough to a clean floured surface then divide dough into 16 equal portions. About 49.40g each. Please use a kitchen scale if you want to be exact.
- Form each portion to a ball.
- Place place bun onto the baking pans. Arrange 4 buns by 4 buns.
FINAL PROOFING
- Let the dough rise until double in size. This bread took me around 2.5 hours at room temperature of around 29C- 30C. The duration of proofing depends on your ambient temperature and starter.
TO BAKE
- Preheat oven at 190C (top & bottom heat) or 170C (fan-forced) for 10 - 15 minutes.
- Brush with egg wash.
- Bake in a preheated oven for 18 - 20 minutes, or until golden brown.
- Remove buns from oven and pan. Let them cool on rack.
Labels:
Breads (Sourdough) - Soft Buns/Rolls,
Could I use yudane method in this recipe? Thank you so much.
ReplyDeleteHi, yes you can if you use low percentage. But if you use high percentage like 42.8% than yudane dough is not required. It is because Potato starch also absorbs more water than wheat starch and this makes the bread texture more moist and have better shelf live.
DeleteCheers 😊
I have the purple potato powder, how should i substitute it?
ReplyDeleteHi, I never used purple potato powder before.. I am not too sure.
DeleteHowever, You can use the same recipe and omit the mashed sweet potato and add purple sweet potato powder into the dough. I am not sure how much. You also need to adjust the hydration by increasing the milk.
Cheers :)
Great recipe! Many thanks. Instead of sweet potato, I used purple carrot. It turned out light and fluffy. And so yummy - hard to stop at 1 bun!
ReplyDeleteHi, thank you for trying and let me know the outcome. Great to hear that you like it. By the way, I have purple carrot sourdough recipe too. Both recipes are quite similar.
DeleteCheers :)
Stay safe...
Hi, do you think it will be possible to tackle this with hand kneading?
ReplyDeleteHi, thanks for reading this post.
DeleteTo be honest, I have not tried hand kneading before. However, it should work too if you know how to use hand kneading.
Cheers :)