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

Method 1 (Fold in mashed potato) ⇧


Purple Sweet Potato Open Crumb Sourdough Bread

Purple Sweet Potato Open Crumb Sourdough Bread

Method 2 (Spread mashed potato during lamination) ⇧


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.

I tried again with method 2 by spreading the mashed potatoes during lamination to create the marble look.  

Please read the below notes before baking for beginner.

SOURDOUGH STARTER

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.

My daily feeding schedule:
9.00 am - Ratio 1:5:5 @ room temperature of 26 - 28C
9.00 pm - Ratio 1:5:5 @ room temperature of 26 - 28C

I learnt making sourdough starter from "How To Make Starter From Scratch" by Full Proof Baking.  Thank you to Full Proof Baking for the detailed video which proved invaluable.

BULK FERMENTATION

Bulk fermentation starts when you add in levain to the dough and ends when the dough is ready for shaping.  

TEMPERATURE DURING BULK FERMENTATION

Ambient temperature plays a very important part in sourdough baking.  It will affect the dough temperature and eventually affect your fermentation time. Warm ambient temperature will shorten the fermentation time while cooler ambient will extend fermentation time.  For this bread, we prefer a longer fermentation as this allows you to have more time to develop the gluten structure . Therefore, short fermentation in  warm ambient doesn’t allow you to work the dough as well.  Credit to Janet The Soprano

The ambient temperature that worked for me is between 24C - 25C and bulk fermentation time is between 4.5 hours to 5.5 hours.  At the end of bulk fermentation, my dough would have increased 40% - 50% in volume. 

But, my kitchen ambient temperature (without air-conditioner) was 29C - 30C.  So, I have to bring down the temperature. 

How to bring down ambient temperature?
  1. Air-conditioner room - Rest the dough in air-conditioner room during bulk fermentation.  I used this option sometimes.  I turned on my air-conditioner when I added in levain and try to maintain temperature between 24C - 25C.
  2. Home oven (that's turned off) -  Place ice cooler packs inside along with an ambient temperature thermometer.  Then place your dough during bulk fermentation in the oven. Keep an eye on that thermometer and try to keep between 24 - 25 C.
  3. Cooler bag - Place ice cooler packs inside a cooler bag.  Then rest the dough inside the cooler bag during bulk fermentation.  Try to maintain temperature 24C - 25C.
DOUGH STRENGTH AND EXTENSIBILITY

The number of coil folds is not fixed and very much depends on the strength and extensibility of the dough.   Over-working the dough may affect the crumb structure and oven spring.  

As demonstrated in an experiment by Kristen (Full Proof Baking) the over-worked dough rose super tall but was smaller in overall size and had a more dense crumb while the control dough rose tall during the oven spring and had a better overall result.

How do we know when it is enough and no more coil folds are needed? 
We usually do 3 coil folds for this method.  However, if by the second coil fold the dough is strong with less extensibility as you lift up a part of the dough then it should be the last coil fold, or just do a half coil folds instead of full. The resistance of the dough to being folded should be an indication to refrain from folding further.

How do we know when to do the next coil fold or stretch & pull?
When the dough spreads. Please do not rely on the time given in the recipe as it is just a guideline.  Please watch your dough and not the clock.  


SALT

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

INGREDIENTS:

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 (active 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.

Please watch my Basic Open Crumb Sourdough Bread video for reference.

METHOD 1 (Fold in mashed mashed potato):
  1. Feed starter - Feed ratio of 1:1:1, keep at room temperature (28C – 30C) and wait until tripled, around 2 – 3 hours.  Please feed your starter at the ratio that fit your schedule as long as the starter is at its peak when use.
  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 -  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 - 45 minutes or until the dough spread.  Please watch your dough and not the clock.
  8. Coil Fold 1 -  At this stage, the dough is weak and extensible.  Fold the dough in the dish. Cover and rest for about 30 - 45 minutes or until dough spreads.
  9. Coil Fold 2 -  At this stage the dough still extensible but stronger compare with the dough  before the 1st coil fold.  Fold the dough in the dish.  Cover and rest for about 30 - 45 minutes or until dough spreads.
  10. Coil Fold 3 -  At this stage, the dough is quite strong and not so extensible and will be the last coil fold.  However, if the dough is still quite extensible and spread a lot, then you will need one or two more coil folds.   Fold the dough in the dish.  Cover and rest for 60 - 90 minutes or until dough rise 40 - 50% in size since you added the levain.  
  11. Shape - 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.


Fold In Mashed Sweet Potato



METHOD 2 (Spread mashed mashed potato during 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. Bench Fold -  Do a light fold on counter.  Return to the same bowl.  Cover and rest for about 30 minutes or until dough spreads.
  7. Lamination and Spread Mashed Potato -
    1. Lightly mist the counter top with water and wet your hand.  Pull the dough into a rectangle shape and pull from centre out to form a bigger rectangle shape.  
    2. Spread the mashed pumpkin on the dough.
    3. 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 new dish (square pyrex dish).  The reason to use a square dish is because it is easier to judge how much  the dough has spread.  
    4. Cover and rest for about 30 - 45 minutes or until dough spreads.  
  8. Coil Fold 1 -  At this stage, the dough is weak and extensible.  Fold the dough in the dish. Cover and rest for about 30 - 45 minutes or until dough spreads.
  9. Coil Fold 2 -  At this stage the dough still extensible but stronger compare with the dough  before the 1st coil fold.  Fold the dough in the dish.  Cover and rest for about 30 - 45 minutes or until dough spreads.
  10. Coil Fold 3 -  At this stage, the dough is quite strong and not so extensible and will be the last coil fold.  However, if the dough is still quite extensible and spread a lot, then you will need one or two more coil folds.   Fold the dough in the dish.  I did half fold instead of full fold. My dough was quite strong and less extensibility after doing the half fold,  so I decided to stop. Cover and rest for 60 - 90 minutes or until dough rise 40 - 50% in size since you added the levain.  
  11. Shape - The total fermentation time is 5 hours and 30 minutes. 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.

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12 comments

  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 ��

    ReplyDelete
  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 :)

    ReplyDelete
    Replies
    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 :)

      Delete
    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 :)

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

    ReplyDelete
  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 ��

    ReplyDelete
    Replies
    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 :)

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

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

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

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

      Delete

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