Purple Sweet Potato Open Crumb Sourdough Bread

by - November 11, 2020

Purple Sweet Potato Open Crumb Sourdough Bread

Purple Sweet Potato Open Crumb Sourdough Bread

Purple Sweet Potato Open Crumb Sourdough Bread

Purple Sweet Potato Open Crumb Sourdough Bread

I have been baking a lot of Purple Sweet Potato Bread but this is my first attempt for an Open Crumb Sourdough Bread.  I was so lucky to get sweet potatoes with a deep purple colour this time.  The bread turned out so vibrant.  

Baking open crumb sourdough bread needs a little more technique. It can be a temperamental and is not as straightforward as baking soft sourdough bread.  We cannot just add mashed potatoes together with the flour at the beginning.  That may affect the gluten development and your bread will not turn out with a nice crumb and good oven spring even if the starter is strong and healthy.  I learned this technique from "Full Proof Baking" that incorporates the mashed sweet potato only after adding salt. It makes all the difference! I have made a few slight changes for my personal preference.

Please read the below notes before baking for beginner.

Room temperature in your kitchen plays a very important part in sourdough baking.  It will affect the dough temperature and eventually affect your fermentation time. Warm ambient temperature will contribute to a shorter fermentation time while a cooler room will extend fermentation time.  A longer fermentation duration allows you to have more time to develop the gluten structure . Therefore, high fermentation (warm ambient) doesn’t allow you to work the dough as well.   I learned this from Janet The Soprano

29C – 30C was my kitchen ambient temperature (without air-conditioner)
24C - 26C was my kitchen ambient temperature with the air-conditioner turned on.

I turned on my air-conditioner when I added in levain. My ambient temperature was 24C - 26C during bulk fermentation.  Bulk fermentation is when you let your dough rest after adding in the levain and before you shape your dough.

Usually the best bulk fermentation time that worked for me is 4 - 5 hours at 24C - 26C ambient temperature, provided my starter is healthy and active.  At the end of bulk fermentation, my dough would have increased 40% - 50% in volume. 
A healthy starter is very crucial as advised by Baking with Gina.  It is advisable to feed your starter daily if you want nice big crumb bread that rises nicely and to use the starter (levain) at its peak.

If the mother starter is not strong, the bread dough will not rise much even though the starter is used at its peak.

You may wonder why most of the recipes asked to add salt after autolyze and adding levain.  Salt will tighten the gluten and make it harder to stretch. 

If you have any questions regarding this recipe or any other post, please leave me a comment in the “LEAVE A COMMENT” link and I will reply you as soon as possible.

Recipe - Purple Sweet Potato Open Crumb Sourdough Bread 

Yields:  1 loaf
Total flour:  300g + 30g (from levain) = 330g


270g bread flour (I used Japanese high gluten flour) - 90%
30g whole wheat flour - 10%
224g water (reserve 10g for salt) - 77% final hydration
6g sea salt - 2%
70g mashed purple sweet potatoes (21%)
60g levain (sourdough starter - 100% hydration) – 20%

Banneton (proofing basket)'s size - 6.5" oval shape

Note:  Please double up the ingredients to make 2 loaves.  Divide the dough right before lamination.

  1. Feed starter - Feed ratio of 1:1:1, keep at room temperature (28C – 30C) and wait until tripled, around 2 – 3 hours.
  2. Mashed Purple Sweet Potato - Wash, peel, cut and steam the purple sweet potatoes for about 20 minutes.  Mash with potato riser or folk.
  3. Autolyse - Mix flour and water, stir until there is no more dry flour with a spatula then by hand.  Or use a stand mixer with paddle attachment for 2-3 minutes at low speed. I used machine for these two loaves.  Cover and leave for 1 to 3 hours.
  4. Levain - Wet your hand, add 60g sourdough to the dough and hand mixing until incorporated, about 3 - 4 minutes. Or use a stand mixer with hook attachment and knead for 6 to 8 minutes.  I used hand mixing for these two loaves.  Cover and rest for 30 minutes.
  5. Sea Salt - Dilute sea salt with the balance of 10g water.  Pour on top of the dough, use hand to mix in the sea salt water.  It takes about 5 minutes until it is fully incorporated.  Cover and rest for 15 minutes.
  6. Fold In Mashed Purple Potato  - Slowly fold in the mashed potato.  Do not need to mix mashed potato until it's incorporated with the dough.  Please refer to the diagram below.  Cover and rest for about 30+- minutes or until the dough spread.  Please watch your dough and not the clock.  Time given is just a guideline.
  7. Lamination -  Please watch the video here. Lightly mist the counter top with water and wet your hand.  Pull from centre out to form a rectangle shape.  Pick up one edge and fold into the center.  Pick up other edge and fold into the center over first section.  Fold the top down half way.  Fold the bottom up.  Put dough in a clean dish.  Cover and rest for about 30+- minutes or until the dough spread.  Please watch your dough and not the clock.
  8. Coil Fold 1 - Fold dough in the dish. Cover and rest for about 30+- minutes or until the dough spread.  Please watch the Coil Fold Video here.
  9. Coil Fold 2 - Repeat the same.  Cover and rest for about 30+- minutes or until the dough spread.
  10. Coil Fold 3 - Repeat the same.  Cover and rest for 60 - 90 minutes or until the dough rise about 40 - 50%. 
  11. Shape - Please watch the video here. Flour the counter top.  Shape and transfer to a heavily flour banneton.  
  12. Proof -  I straight away put in the fridge as I could see the dough had risen quite a lot.  I knew it when I placed the dough in the benneton it was already almost filled the basket.  Usually, I will proof at room temperature for 15 minutes.
  13. Retard - Then retard overnight in the fridge for 12 - 16 hours.
  14. Baking 
    1. Preheat oven, with the dutch oven at 250C for 30 minutes before baking.  
    2. Take bread dough out from the fridge, invert onto a parchment paper and scoring (please watch video).  Immediately transfer the dough with the parchment paper to your preheated dutch oven.
    3. Lower the temperature to 230C (fan-forced) and bake with cover on for 20 minutes.  Remove the cover and lower the temperature to 220C (fan-forced), continue bake for another 10 - 15 minutes.
    4. Remove bread from oven and dutch oven. Let it cool on rack completely before slicing.
Usually 3 coil folds should be enough.  But, sometimes you may need extra coil fold if the dough is spread a lot and not enough gluten develop.

Fold In Mashed Sweet Potato

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  1. Hi, may I know the high gluten flour means 12.8%-13.8% protein content correct?
    Also,if I don't have whole wheat flour, is it okay to use 100% Bread Flour?
    Thanks for your tips, the temperature in my kitchen is really giving me alot of issues while handling the dough ��

  2. Hi, thanks for reading this recipe. The Japan High Gluten Flour I used is about 12.2 - 13 %. Yes, you can use 100% bread flour. If your kitchen is warm, try to turn on aircond or use cooler (place cooler in microwave or oven) then place your dough there.

    Please get a thermometer if you can. So, you will know your ambient temperature.

    Cheers :)

    1. Thank you very much!! Hehe my kitchen has no aircon, so I will try again with your cooler method ... hope that one day I will be able to success for making the SD with ear or big belly hahhaa... I used Dutch oven (cast iron) super heavy, but I don't see any steam from inside, but the pot is super duper hot :( either the steam is not enough or my starter still young or not strong enough, it's now 2 months old.
      I followed your Instagram too :)

    2. Hi, thanks for reading this recipe and your comment. I used Dutch Oven from Ikea and it works well. I don't think we can really see the steam.lol :) You will get this crumb and ear if you keep on trying.

      BTW, thanks for following me at IG.

      Cheers :)

  3. Thank you for your encouragement, I hope so :P

  4. Hi BWP �� May I know the 30g levain that you added with the 300g flour was added when it peaks too? I don't have aircond in my kitchen too, probably I should take my dough to my room after I added in the levain ��

    1. Hi, thanks for reading this recipe.

      This one below is just an information for you to know how much total flour used. It is not the ingredients to be used.
      Total flour: 300g + 30g (from levain) = 330g

      Cheers :)

    2. LOL,silly me. It's 270g flour with 60g levain. Thanks!

    3. Sorry, it's total 300g flour + 30g levain with 100% hydration.

  5. Lol, silly me. It's 270g flour with 60g levain, #facepalm. Thanks!

    1. No worry.. Sorry for confusion. I just moved this line before Ingredients so it is more clear.
      Cheers :)