Spent Grain Sourdough

I love being able to turn what would normally be composted or trashed into something delicious. Spent grain is what’s left over after removing all the sugars from malted barley and other grains during the mashing process of making beer. I dry the grain and grind it into a flour. At about 10% of the total flour bill, this gives a great nuttiness and whole grain flavor to the bread.

spent grain sourdough in dutch oven
Sourdough bread made with spent grain from brewing beer

Schedule: I based this loaf off of my sourdough schedule.

Since this is a 100% naturally leavened bread, I created a levain with my sourdough starter that was last fed 24 hours prior. This levain provides enough for 3 loaves of bread, plus a little extra to keep your starter going.

I made this loaf at the same time as my cranberry + walnut bread so a lot of the timing is very similar.

30 minutes before mixing the levain, salt and other ingredients into the dough, I performed an autolyse by mixing the water and flour together.



Started at 8am with the following ingredients. Mix everything together and loosely cover and let it ferment for about 8 hours.

  • 50g unfed sourdough starter (last feeding was 24 hours prior)
  • 250g filtered water @ 85-90’F
  • 200g Bob’s Red Mill bread flour
  • 50g King Arthur whole wheat flour


  • 400g Bob’s Red Mill bread flour
  • 45g spent grain flour (see my ‘How to Make Spent Grain Flour‘ tutorial)
  • 350g filtered water @ 90-95’F
  • 108g levain
  • 11g sea salt
Spent grain bread proofing in banneton
Spent grain sourdough proofing in a banneton


After mixing the dough, I performed 4 stretch and folds within the first 2-4 hours.

Before proofing, I added some oats and sesame seeds to the banneton and then put the loaf on top to proof. Doing this helps the topping adhere to the loaf so it doesn’t just fall off.

I baked the loaf in a preheated dutch oven at 450’F for 38 minutes covered, then removed the lid of the dutch oven and baked for an additional 14 minutes.


I probably proofed this for a half hour or so too long so I didn’t get quite the rise as I was hoping for. The more you proof the dough past its peak, the gluten starts to lose its strength and it doesn’t hold its shape very well.

Even with some slight over proofing, the bread still turned out tasting great. I’ve played with adding more spent grain flour but at more than about 10%, it ends up causing the dough to be very stiff and dry. I might try upping the spent grain as well as the hydration in a future experiment.

The long bulk fermentation helps give this loaf a nice sourness that compliments the earthiness and nuttiness from the spent grain flour very well.

Spent grain sourdough crumb shot
Spent grain sourdough crumb shot
Spent grain sourdough crumb shot

My Baking Notes

  • Ambient Temperature: 74’F
  • Started autolyse @ 3:00pm
  • Water temp: 92’F
  • Dough was 88’F at autolyse
  • Mixed @ 3:40pm
  • Dough was 80’F after mixing
  • 4 stretch and folds in first 4 hours
  • Started proof @ 7:00am
  • Preheated oven @ 9:45am
  • Into oven @ 10:32am
Spent grain sourdough top view
Spent grain sourdough top view

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