Sourdough brownies have a rich chocolate flavor, fudgy texture, and a signature sourdough kick. Whip them up in an afternoon or long ferment them overnight.

This sourdough brownie recipe is one of my favorite ways to utilize sourdough starter discard. (See some of my other sourdough discard recipes in this post.)
When chocolate cravings hit, it is usually sourdough chocolate cake, fresh milled chocolate chip cookies, sourdough chocolate rolls, or these brownies that find their way to my oven.
If you are used to grabbing a box mix for brownies, you have to give this a try. These easy sourdough brownies are so simple and do not require an extra trip to the grocery store. Everything in the recipe is likely in your fridge or pantry already.
Serve with a cold glass of milk, a dollop of whipped cream, or a scoop of homemade vanilla ice cream for the perfect treat.
Why You’ll Love This Recipe
Delicious – Gooey centers with a crackly top, these are classic brownies with a burst of sourdough flavor.
Long Fermented (optional) – Long ferment this recipe it to help break down the phytic acid, reduce the gluten content, and make the nutrients more bioavailable.
Great way to use discard – If you have a brand new starter, this is a great recipe to use up the discard.
Ingredients

Butter – Use unsalted butter to control the amount of salt in the recipe. You can also use a neutral oil, like avocado oil.
Semi-sweet chocolate chips – This gives it a nice balance without making the brownies too sweet.
Vanilla – I use homemade vanilla extract.
Flour – Whole wheat flour, spelt, or all purpose flour will work. You can also check out my brownie recipe using freshly milled flour.
A full ingredient list with exact amounts can be found in the recipe card below.
How To Make Sourdough Brownies

Step 1: Preheat the oven to 350 degrees Fahrenheit and prepare a 9″ × 9″ pan by lining it with parchment paper. In a medium saucepan over low/medium heat, melt butter. Take off heat and add chocolate chips and vanilla.

Step 2: Stir until all melted together.

Step 3: In a medium or large bowl, combine flour, sugar, cocoa powder, and salt. Stir to combine.

Step 4: Pour melted chocolate mixture into the dry ingredients. Add in eggs and sourdough discard. Stir well until there are no clumps.

Step 5: Pour the sourdough brownie batter into prepared pan.

Step 6: Bake for 40 minutes in the prepared 9″ x 9″ pan or until a toothpick comes out clean and the middle is set. Allow to cool completely before slicing and serving. This will help it set up and also develop the flavors.
Tips
- My sourdough starter is at 100% hydration, meaning I feed it with equal parts flour and water.
- Make sure your eggs are room temperature. If you forgot to take your eggs out of the fridge ahead of time, you can bring them up to room temperature by placing them in a bowl of hot water for 5 to10 minutes.
- Allow the brownies to cool totally before cutting. Once they are completely cooled, the flavor will have developed, and the brownies will hold together.
- Long ferment the dough overnight to add more delicious tang from the fermentation of the grains. Combine the flour, sourdough starter, sugar, and half a cup of melted butter the night before. Cover and leave overnight or up to 24 hours. The next day, add the rest of the ingredients.
Recipe FAQ’s
Basically sourdough adds flavor. If you have excess sourdough starter, this is an easy recipe to try! If you long ferment the recipe overnight, you will gain the benefit of easier digestion thanks to the breakdown of phytic acid.
If these are made without long fermenting, then they are basically the same as regular brownies. If long fermented, sourdough helps to make the gluten in the brownies easier to digest.
Fudgy brownies have more fat in them than flour, while cake like brownies have more flour than fat.
Store in an airtight container for up to 2 or 3 days at room temperature or in the fridge for 3 to 5 days. These also freeze well! Freeze for up to three months once completely cooled.
More Sourdough Dessert Recipes
- Sourdough Chocolate Chip Cookies
- Sourdough Monster Cookies
- Sourdough Monkey Bread
- Sourdough Discard Double Chocolate Bread
- Sourdough Discard Blondies
If you try this recipe and love it, I would love it if you could come back and give it 5 stars! Tag me on Instagram @farmhouseonboone.















Thanks for a new family favourite. The fudgy texture is perfectly the way we like our brownies. I use rye flour, which plays up the chocolate and sourdough perfectly. Sometimes I sprinkle in a handful of walnuts or pecans as I pour the batter into the baking pan.
If I am using active starter instead, should I still use 1/2 cup? Or is there a different measurement for active vs. discard? Thanks!
I made these with a long ferment – 24 hours on the counter – and they were phenomenal! I baked them in an 8×8 pan for 35 min at 350. They were over 205 by then so I pulled them out and it left a really gooey brownie. Next time I’ll use my stand mixer to combine the ingredients after the ferment.
Best brownie recipe , my family loved them
If you put the batter in the fridge overnight, does it need to come back to room temperature before you bake?
No, you can bake it cold.
Made with “flax eggs” in place of regular eggs, fermented in a very warm spot for about an hour (better to have even a little extra fermentation rather than just using discard), then baked. These turned out so chocolate-y and delicious! Thanks for a terrific recipe.
Do I have to add the chocolate chips in or no
No.
My family said these were the best brownies I’ve ever made so thank you for this recipe. It’s the second great recipe I’ve made on your website and I can’t wait to try more. Thank you 💜
These are absolutely delicious. We’ve been making them often and they always turn out percent!
Can I use 3 day old discard from a brand new starter?
Yes.