Fermented Granola

How to make sourdough granola

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Fermenting granola before cooking is a great way to make crunchy, toasted granola without using any additional sweetener. It is a healthy and nutritious way to start your day. Use your favorite culture, sourdough starter, kombucha, or yogurt!


Units Scale


  • 8 cups of rolled oats
  • 2 cups mixed nuts and seeds
  • 1 cup culture (see notes)
  • 2 cups of filtered water

Remaining Ingredients

  • 1 tsp salt
  • 1 Tbsp ground cinnamon
  • 1 Tbsp vanilla extract
  • 1/2 cup oil (vegetable or melted coconut)
  • 1/2 cup of liquid sweetener (optional)


  1. Mix the oats, seeds, culture, and water in a large bowl. Allow the mixture to soak for at least 30 min and up to 12 hours. Stir the soaking granola at least twice during the first 2 hours of the fermentation to keep it from forming large clumps at the bottom of the bowl.
  2. When you are ready to bake, mix in the remaining ingredients and stir thoroughly to combine. Feel free to skip the sweetener in this recipe (see notes). 
  3. Spread the granola mixture out in an even layer on 2 large cookie sheets and toast at 300 F (150C) for 1-2 hours, stirring every half an hour until it’s crispy.
  4. Allow to cool before mixing in any dried fruit, cereal flakes, etc. See the section above for more delicious flavor options.
  5. Store in an air-tight container and enjoy within 1 month.


  • Pre-fermenting this granola recipe is optional. If you’re short on time, mix in the liquid and allow it to sit for at least 30 minutes so that you can enjoy crunchy granola without added sweetener.
  • Any fermented liquid will work for culturing granola. Dairy productsvegan yogurt, or sourdough starter are all delicious options.
  • Liquid sweeteners for this recipe include honey, maple syrup, agave, etc.  Personally, we don’t use any sweeteners, however, we always serve fresh fruit or dried fruit with our breakfast for some natural sweetness. Granola without any sweetener is a bit strange at first, but we’ve learned to love it!