Sourdough, sourdough, sourdough, oh yea, sourdough!

Potato Flax Sourdough


Leftover mashed potatoes are a good thing when it comes to baking. I used potatoes and flax seeds to help keep the bread moist for a longer period of time. It really works.  I also used the double hydration technique to obtain a nice spring and crumb with a lower protein all purpose flour. Here ya go…

Potato Flax Sourdough

Start off with: ( I started at 11:30 am)

  • 100 g water

and bring it to a gentle simmer in a small saucepan. Then add

  • 28 g of ground flaxseed meal

( I like to grind my own so it is fresh and I try to use golden flaxeed, as it has the best flavor by far), mix the flaxseed meal into the water and stir  just until it thickens. Remove the pan from the heat and add:

  • 100 g leftover mashed potatoes (of course it will already have butter, milk and salt mixed in)
  • 22 g sea salt

Stir well.

Set the pan aside and allow it to cool.

In your dough trough or large mixing bowl add together:

  • 250 g Sourdough starter, vigorous and at 100% hydration.
  • 650 g water
  • 1100 g all purpose flour
  • 4 g diastatic malt powder (this is optional and if you want the great crust color).

Mix all above ingredients together, the dough will be very stiff and it will take a bit of effort to get it together. Cover the dough and let it autolyse for four hours.

This technique of using double hydration (making a stiff dough and then later adding more liquid) is used so that the gluten strands bond very strongly. After the bonding, water or other liquid is added slowly to bring the hydration up and allow you to have a really wet dough with strong cohesion. If you added all of the water at the beginning, the dough would be a lot  more slack and not be able to form the strong bonds that a low hydration dough can or that can be accomplished using double hydration.


Double hydration is a good technique to use when making Ciabatta.


After the four hours of autolyse is up, add the flaxseed, potato, salt mixture to the dough ball. It will NOT incorporate immediately. It will take two more hours with folds every half hour, to finally incorporate. So every half hour, gently fold the dough and eventually mix all of the flaxseed mixture into the dough. When the dough finally feels incorporated and silky smooth, put the dough into a covered container (the dough trough) and refrigerate it for two hours before shaping.


Divide the dough into three pieces.


Shape the dough and place it into floured bannetons. Cover with plastic and refrigerate over night.  Next day, take out each loaf one at a time, staggered at half hour increments,  take off the plastic and let it warm up and proof and room temperature.  My loaves took about three hours to proof and I put each loaf into a warmed microwave (see below for explanation)  for the last half hour before baking (or use your Brod and Taylor bread proofer at 80F).  Have your oven and baking stone heated to 450F for at least an hour before your first loaf is ready to bake.


*** Five minutes before baking, place a roasting pan lid (make sure it is deep enough at least 4.5 – 5″) into the oven to preheat.


Take out the hot roasting lid (place on top of your oven), turn your proofed loaf out onto a floured peel, slash the loaf and slide it onto the hot baking stone. Spray with water all over the loaf, then place the hot roasting lid over the dough (make sure the lid contacts the stone on all sides and isn’t hanging off the stone), turn your oven down to 425F and bake for 15 minutes. After 15 minutes, take off the roasting pan lid and leave it on top of the oven for the next loaf. Bake the loaf for 15 – 20 more minutes, turning the loaf at least once half way through.


Remove loaf and place on a cooling rack. Turn your oven back up to 450F (put the roasting pan in to preheat) and wait for it to come back up to temperature (about 5 minutes) then repeat from *** for the remaining two loaves. If your last loaf looks like it is already proofed enough, don’t place it in a warmed microwave to finish proofing.


Microwave proofer:

You can use a microwave or dishwasher for a dough proofer (to keep the dough warm). For a microwave, place a coffee cup of water into the microwave and heat it as you would a hot drink or coffee. Then carefully move the hot cup of water to the corner of the microwave and place your banneton of proofing dough into the microwave and close the door (DO NOT MICROWAVE THE DOUGH!!). The heat from the hot cup of water will keep the small space warm. This is a nice easy way to warm up dough while it is proofing.


Dishwasher proofer:

Or you can pour a cup of water in the bottom of your dishwasher(for humidity) and turn the ” heated dry” on.  It is best to use a thermometer for this and not let it go above 90F, then turn the heat off. If you put some clean coffee cups and china dishes into the dishwasher, it will hold the heat longer. Place your banneton with proofing dough onto the racks and allow it to warm and proof.


This crumb was moist and fresh three days after it was baked and that is as long as the three loaves lasted.


Happy Thanksgiving everyone!



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  1. Francesca Francesca
    March 6, 2014    

    Is it ok to use just plain mashed potato without the milk and butter?

    • northwestsourdough northwestsourdough
      March 15, 2014    

      yes, it is.

  2. Holly Holly
    March 12, 2014    

    Today I baked Potato Flax Sourdough. This recipe is awesome! I didn’t have Gold Medal flour on hand so I substituted Wheat Montana Natural White Premium All-Purpose flour. I also didn’t have the diatastic malt powder on hand. But the bread browned well enough. My next market day I’ll pick some up.

    When I made this bread I wasn’t feeling well (fighting the flu). Mixed up the ingredients to make dough and too let ferment, folded the dough twice and placed in the fridge overnight. In the morning instead of baking the loaves one by one on a stone. I divided the dough into 3 portions, let dough rest 20, then shaped the loaves, placed in three 8×4 bread tins, sprayed the top of the loaves with nonstick spray, let prove 2:30 minutes, slashed the loaves, and eliminated using the baking stone. Didn’t even spray the loaves with water. The oven spring was fantastic. And I baked these loaves in a cold start oven on (conventional bake) for 20 minutes, then 30 minutes (Convection bake). When I pulled them out of the oven to let them cool the crust began cracking and singing. The crust was covered with scads of small and large blisters and the crumb was soft and moist. Two of the loaves had an oven spring of 6-inches and the third loaf 61/2-inches. When I picked up one loaf, it felt very light so I new I would have a light airy bread for sandwiches.

    I was just getting ready to bake up another sourdough potato recipe when I came across your recipe. And I do agree with you the potatoes and flaxseed surley make the dough moist. Plus I could see the double hydration would give my loaves better oven spring and crumb. I just had to try baking up this recipe.

    And using mashed potatoes which contain butter and milk would surly help in producing a soft moist bread.

    NOTE: Teresa If I hadn’t been sick I would have used the roaster to bake your (Potato Flax Sourdough)recipe. But if you’re simply not feeling well as I was (fighting the flu). I was looking for any shortcut so I could go back to bed. I was amazed how well the sourdough baked up in my three 8×4 bread tins.

    Did you use the Gold Medal flour to see how strong the double hydration would be using a weaker flour?

    This recipe is a keeper.

    March 17, 2014    



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