Breads (Sourdough) - Soft Loaves

Marbled Purple Sweet Potato Sourdough Bread Recipe – Soft, Naturally Leavened & Vibrantly Colored

July 06, 2021 | Recipe by Bake with Paws
Updated: May 2025
By Bake with Paws


Pattern No. 1 ⬆


Pattern No. 2 ⬆

Marbled Purple Sweet Potato Sourdough Bread (Naturally Leavened & Beautifully Soft)


This Marbled Purple Sweet Potato Sourdough Bread is naturally leavened with a sweet stiff sourdough starter and swirled with two vibrant shades of purple sweet potato. Soft, fluffy, and mildly sweet, this loaf is as nourishing as it is stunning. If you love naturally colored bakes and the subtle flavor of sweet potato, this bread is for you.





Why You’ll Love This Recipe


  • Naturally Leavened – No commercial yeast. This bread is leavened with a sweet stiff sourdough starter, giving it a mild flavor and soft crumb with no sour tang.
  • All-Natural Color – The beautiful marbled swirl is achieved using two varieties of steamed purple sweet potato—no artificial coloring needed.
  • Soft & Fluffy Texture – Thanks to the yudane method and enriched dough, this loaf is pillowy soft with a fine, tender crumb.
  • Visually Stunning – The marbled interior makes every slice a work of art—perfect for gifting or a beautiful brunch table centerpiece.

Behind the Recipe


This bread was inspired by my love for natural ingredients, sourdough fermentation, and visually creative baking. I used a sweet stiff sourdough starter, which yields a soft, mildly flavored loaf—perfect for enriched doughs. To further enhance the texture, I incorporated the Yudane method, where a portion of flour is scalded with boiling water. This pre-gelatinizes the starches, helping the bread retain moisture and stay soft for longer. The marbled pattern is created by combining a portion of plain dough with dough tinted using purple sweet potato powder. This method allows me to prepare one main batch of dough, then simply mix the powder into a portion to achieve a striking two-tone effect with minimal fuss.

I’ve been experimenting with sweet stiff starters in many of my enriched sourdough breads, and they consistently deliver better oven spring, a shorter proofing time, and a gentle, non-sour flavor—just right for soft, naturally leavened loaves like this one.

What is a Sweet Stiff Sourdough Starter?


A sweet stiff starter is a type of low-hydration (usually 50%–60%) sourdough starter that’s regularly fed and kept sweet by short, frequent feedings. It produces a mild, non-sour flavor, ideal for enriched doughs like milk bread, brioche, and naturally leavened soft loaves like this.

I build my sweet stiff starter fresh for each bake to ensure peak activity and consistent results. You can find more details sweet stiff stater "Here"

How To Make Marbled Purple Sweet Potato Bread


Yields: 2 square loaves

INGREDIENTS:

Yudane Dough:
65g bread flour (I used Japan High Gluten Flour)
65g boiling water

Sweet Stiff Starter:
50g sourdough starter (100% Hydration), preferably use at its peak 
175g bread flour (I used Japan High Gluten Flour)
72g water or 88g milk
25g sugar (I used organic brown sugar)

Main Dough:
65g bread flour (I used Japan High Gluten Flour)
All stiff starter (above)
All the yudane dough (above0
10g brown sugar (I used organic brown sugar)
1 tsp salt
20 milk powder (omit if SST is fed with milk)
40g egg, whisked (from 1 medium egg)
20g water (reserve 10g and add in later if needed) I used total 15g of water
20g butter, room temperature

2 1/2 tsp sweet potato powder
5 tsp pandan powder (optional)

Utensil:
Square Loaf Pan (11.5 X 11.4 X 10.6 cm  / 4.5" X 4.5" X 4.2")  X 2

METHOD:
  1. Yudane:
    1. Add bread flour in a bowl, pour the boiling water and mix well with spatula or spoon until no dry flour.
    2. Cling film and leave on the counter for at least 4 hours or overnight in the fridge.  I prepared the night before.
    3. Use directly from the fridge.
  2. Sweet Stiff Starter 
    1. 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.
    2. 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. 
    3. However, if you feed your starter with milk, the starter will take longer time to proof and very much depend on your stater.  Mine took about 9 - 10 hours to proof overnight.  And the starter did not rise until triple in size compared feeding with water.  It rose almost 2.5 to 3 in size.   It is because natural yeast takes longer time to digest the milk than it does in water.
  3. Main Dough:
    1. Put all ingredients (except butter) into a bowl of stand mixer.  I usually slightly torn the stiff starter and yudane dough first.
    2. 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.
    3. Change to hook attachment and knead for another 3 minutes or until the dough comes together. Add in butter and continue knead for about 5 minutes or until the dough come together.
    4. Divide the dough into two equal portions. 
    5. Add in sweet potato powders into one of the dough and continue kneading for another 5 - 6 minutes or until the dough become smooth, silky and reach window pane stage.  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.
    6. Repeat the same on another dough with pandan powder.
  4. 1st Proofing/Resting:  
    1. Let the dough rest for 45 - 60 minutes. Keep it covered with clingfilm or use a lid.  This dough I rested for 45 minutes and the dough didn't rise much. 
  5. Shaping:
    1. Transfer the dough to a clean floured surface then divide dough into 8 equal portions (Shaping No.1) or 18 equal portions (Shaping No. 2) for both sweet potato and pandan dough.  Please use a kitchen scale if you want to be exact.  
    2. Form each portion to a ball.  
    3. Place the dough balls 2 X 2 (Shaping No. 1) or 3 X 3 (Shaping No. 2) in a checkered pattern and alternate the pattern for the next layer.
  6. Final Proofing:
    1. Let it proof in a warm place until the dough rise until it reaches slightly below the rim of the pan.   This one took approximately 2 hours and 45 minutes at at room temperature of 29C - 30C.  The duration of proofing depends on your ambient temperature and the starter.
    2. Cover the pans with lids.
  7. Baking:
    1. Preheat oven at 190C - 200C (top & bottom heat) or 170C - 180C (fan-forced) for 10 - 15 minutes.
    2. Bake in a preheated oven for about 30 minutes, or until golden brown.
    3. Remove bread from oven and pan.   Let them cool on rack.

Yudane Dough

Sweet Stiff Starter

Main Dough

Shaping No. 1 (2 X 2) 

Shaping No. 2 (3 X 3) 


Tips for Baking Soft Sourdough Bread


  1. 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".
  2. 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.
  3. 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).
  4. 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.
  5. 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.
  6. 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.
  7. 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.
  8. 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.

Storage Tips


Once cooled, store in an airtight container at room temperature for up to 3 days. For longer storage, slice and freeze. The bread reheats well in a toaster or warm oven.

Serving Ideas


➤    Toasted with butter and jam
➤    Savory toast with cheese or eggs
➤    Eye-catching French toast

FAQ'S about this bread

Q:  Why use a sweet stiff starter instead of liquid levain?
Sweet stiff starters work especially well in enriched sourdough breads. They provide a milder flavor, stronger fermentation, and more structure, which improves oven spring and crumb softness.

Q:  Can I make this without yudane?
The yudane method adds softness and shelf life. If needed, you can replace it with a tangzhong or omit it by slightly increasing the hydration.

Q:  Why my dough is sticky and can't achieve windowpane stage?
If your dough is sticky or you're struggling to reach the windowpane stage, it may be due to excessive hydration, under-kneading, weak flour, inactive starter, environmental factors, or insufficient resting time.

Final Thoughts


This Marbled Purple Sweet Potato Sourdough Bread is a creative and nourishing way to showcase natural ingredients through sourdough baking. With its soft texture, gorgeous swirl, and subtle sweetness, it’s a loaf that delights in both flavor and appearance.

If you try it, I’d love to see your version! Tag me on Instagram @Bakewithpaws or leave a comment below if you have any questions about this recipe.

Happy Baking,
YL πŸ’œ

Other Soft and Fluffy Sourdough Breads You’ll Love


BAKING TEMPERATURE AND TIME

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.
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  1. box of cake11 July 2021 at 22:03

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