Fudgy Sourdough Brownies

The perfect fudgy brownie with a crackly top is made even better with a dash of sourdough discard. Can a brownie be both fudgy and airy at the same time? Yep!

a stack of sourdough brownies on a white plate

A brownie can be both fudgy and airy if you add a cup of sourdough discard to the batter. These brownies are nice and rich, but with a surprisingly light crumb thanks to a little lift from the natural yeast in the sourdough starter.

But wait, there’s more…

The discard also enhances the flavor of the brownie. There’s a slight background tang that somehow makes the chocolate flavor even more chocolatey. It’s so, so good.

If you don’t have one, check out my post to learn How to Make a Sourdough Starter. Then check out my system to Feed and Maintain Sourdough Starter.

If you’re still craving chocolate but want something a little lighter than a brownie, you can make Sourdough Chocolate Cake too.

Scroll through the step by step photos to see how to make fudgy Sourdough Brownies:

showing how to mix sourdough brownie batter
Add the eggs and stir vigorously to incorporate air into the batter. This helps form the crackly crust. Fold in the sourdough discard.
showing how to add flour to sourdough brownie batter
Fold in the discard until almost combined, then fold in the flour.
sourdough brownies before and after baking.
Line the pan with parchment to make it easy to lift the brownies out of the pan

Tips for making and storing Sourdough Brownies:

  • The recipe can be halved and baked in an 8″ or 9″ square pan.
  • Unfed sourdough starter will add a tangy flavor to the batter. I got great results with a starter that had been in the refrigerator, unfed, for about a week.
  • Butter the pan and line with parchment paper. This not only prevents sticking, it makes it much easier to lift the brownies out of the pan.
  • Stirring the batter vigorously after adding the eggs will incorporate air into the batter. This will help form a crust on the top of the brownies. If you prefer a soft top on your brownies, you can skip that step.
  • Cool the brownies in the pan then use the parchment to transfer them to a cutting board.
  • To appreciate the subtle tangy flavor, I prefer to serve these spectacular brownies without any frosting
  • The Brownies will keep at room temperature for several days.
  • Leftover brownies can be frozen. Layer them with parchment paper or plastic wrap to prevent them from sticking together. They’re delicious straight from the freezer or defrosted.

You might like these other fabulous brownie recipes: Classic Fudgy Brownies, Habanero Brownies, Chocolate Cherry Brownies, Malted Milk Brownies, Roasted Beet Brownies, and White Chocolate Raspberry Brownies.

You might also like these recipes for the brownies’ cousin, Butterscotch Ripple Blondies and Malted Milk Blondies

I know you hate to throw away that sourdough discard. Check out these recipes that use sourdough discard.

a stack of sourdough brownies on a white plate
a hand holding a bite of a sourdough brownie

You might also want to try Sourdough Shortbread or Sourdough Chocolate Chip Cookies made with sourdough powder.

If you love this recipe as much as I do, I’d really appreciate a 5-star review.

a stack of sourdough brownies
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4.56 from 122 reviews

Fudgy Sourdough Brownies

The perfect fudgy brownie with a crusty top is made even better with a cup of sourdough discard.
Prep Time30 minutes
Bake Time20 minutes
Total Time50 minutes
24 brownies
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  • 9 oz semi-sweet chocolate (chopped)
  • 8 oz unsalted butter (cut into 1″ chunks)
  • 8 oz granulated sugar (1 cup)
  • 4 oz brown sugar (½ cup)
  • ½ teaspoon salt
  • 1 tablespoon vanilla extract
  • 3 large eggs
  • 8 oz sourdough discard (1 cup)
  • 2 ½ oz all purpose flour (½ cup, see note)


  • Preheat the oven to 350 °F. Butter a 13"x9" inch baking pan. Line the pan in one direction with parchment paper.
  • Combine 9 oz semi-sweet chocolate and 8 oz unsalted butter in a large microwave safe bowl. Microwave for 1 minute, stir to combine. Microwave in 30 second increments (stirring between) until all the chocolate is melted.
  • Add 8 oz granulated sugar, 4 oz brown sugar, ½ teaspoon salt and 1 tablespoon vanilla extract, stir to combine. Add 3 large eggs, stir until combined then stir vigorously for 30 seconds.
  • Fold in8 oz sourdough discard. Add 2 ½ oz all purpose flour and stir just until combined. Spread the batter evenly into the prepared pan.
  • Bake until the brownies puff up a bit and a toothpick inserted in the center comes out with a few moist crumbs (30 minutes).
  • Cool in the pan to room temperature then refrigerate until the brownies are firm. Use the parchment paper to lift the brownies out of the pan onto a cutting board.
  • Cut into 24 portions.

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If measuring the flour by volume use the “dip & sweep” method. That is, dip the measuring cup into the flour bin, overfill it, then sweep away the excess.
This recipe can be halved and baked in a 9×9 square pan.


Serving: 1slice | Calories: 212kcal | Carbohydrates: 24g | Protein: 2g | Fat: 12g | Saturated Fat: 7g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 3g | Trans Fat: 0.3g | Cholesterol: 41mg | Sodium: 60mg | Potassium: 81mg | Fiber: 1g | Sugar: 18g | Vitamin A: 271IU | Calcium: 16mg | Iron: 1mg
Have you tried this recipe?Mention @eileen.bakingsense or tag #bakingsense!

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Recipe Rating


  1. 5 stars
    I made a batch of these brownies yesterday for the fourth of July. I broke a few of them into small pieces and put them atop vanilla ice cream with hot fudge sauce, whipped cream and cherries. Perfect brownie sundaes for a summer treat. My son rated the brownies “awesome”.

    1. You’d have to rework the recipe to use cocoa instead of chocolate. I couldn’t say off the top of my head how to adapt the recipe to cocoa. You’d have to account for the extra sugar and fat in the chocolate vs. cocoa.

  2. Eileen i am am big fan of yours. I have jade a love at least 1/2 of your ice cream recipes and plan to try the cheesecake today. I also love your sour dough bread recipe as well as your sour dough rye. I have a lot or discard to use since I do so much of your baking. I have the sour dough soda bread in the oven now, my 3rd batch, and would like to try your brownie reccipe. I only have dark brown sugar at the present. Do you think I could use it in place of light brown sugar. Thanks for your recipes. LOVE then.Jenny B

    1. Yes, certainly. The only difference between light brown and dark brown sugar is the amount of molasses.

  3. I made this recipe with a Stevia product (mine said 0.5g of Stevia = 3g sugar) so I could share the brownies with a diabetic. I only made half the quantity in case it didn’t work and was worried about it being too sweet. I used 26g Stevia to substitute the total sugar of 168g and one large duck egg and one small chicken egg. All others ingredients quantities were halved. The result was very edible although not as good as the original recipe. It was also a bit flat but not too sweet as I feared. Next time I may try whisking the egg white before adding it as suggested elsewhere. Thanks for sharing this recipe.

  4. I would like to make these but realized I only have unsweetened chocolate. Have you ever tried it with that? Could I just add more sugar? Thank you

  5. Hi Eileen. I just made these decadent brownies and I have a question. Why do you put the pan in the refrigerator? I was curious, so I took a little taste before going in the fridge. They were light and almost cakey (if that’s a word). It was delicious. However, my policy with recipes is that I make it according to the directions the first time and then I make changes after that. They came out of the fridge very dense and fudgy. Have you ever made them and not put the pan into the fridge? The men in my family will love the dense chocolate but I would rather have the lighter density. I’m just curious if they would stay light without the cold.

    1. I refrigerate them mostly to get them firm enough to lift out of the pan. Otherwise, they might crack apart as they are lifted out of the pan.

  6. Hi

    I halved the recipe but when i cut during cooled down the bottom is still wet.. what went wrong?
    My toothpick came out clean and top was crispy…

    1. What type of pan did you use? Do you have an oven thermometer to check for accuracy. Also, if you don’t mix the batter evenly you might get the dense stuff at the bottom where the eggs aren’t completely mixed in.

    1. I think that would work. I can’t say if the texture of the brownie will change much since I haven’t tried it. Because butter is firm at room temp and oil is liquid at room temp, the brownies may be a bit mushy if you use a full cup of oil to replace the butter. I would try using 3/4 cup of oil and see how that works.

      1. I was wondering that as well I keep kosher and after meals were we eat meat we can not eat milk for a few hours so I am always on the hunt for good dairy free resipes maybe I will do that next time

        1. Another option might be butter flavored vegetable shortening. Since it is solid at room temp the texture might be better than using liquid oil.

  7. Love your recipes! Can I make the sour dough brownies using a box mix? Love Ghiradelli brownie box mix but want to see if I can add sour dough .

    1. I honestly have no idea since I don’t use box mixes. But I can’t imagine it wouldn’t work. Brownies are pretty forgiving since they naturally have a soft structure. All I can say is to give it a try and see what happens.

  8. I normally make bite-sized Nutella brownies for all of the football gatherings we host or attend. But since I received a gift starter a few weeks ago, I really wanted to try out some of your discard recipes because I hated throwing it out when I fed the starter, and I just don’t let myself bake as often as I’d l. My husband was quite upset with me until he tasted these. These.Are. Amazing! Flavor was so nice without being too overly sweet like some brownies can be. Definitely in the rotation! Thank you so much for this recipe.

  9. Thank you for the recipe! I think my discard was a little too active because the brownies rose quite a bit. They are like a light but very chocolatey spongy cake. I prefer a dense fudgy brownie but these were a wonderful change of pace and a great way to use discard.

    1. Yes, I’ve made these several times and the texture will depend on your starter. I love these made with really ripe starter. Next time you can leave the discard at room temp for a day or two before making the brownies to get a real tang without any rise.

  10. Could I leave the batter to ferment overnight? My stomach isn’t good with grains unless they’re fermented… But these look delicious!

    1. I wouldn’t leave a batter with eggs overnight at room temperature. You could leave the batter in the refrigerator.

  11. Just made the sourdough brownies. I’m not sure they are done in the center. My toothpick keeps coming out looking wet. In even cooked them 10 minutes longer. I am going to let them cool and see what they are like in the morning.

    1. The times listed in a recipe are always just an estimate since there are many factors that contribute to the exact number of minutes. But I would start checking the brownies at 15 minutes and take them out of the oven when a toothpick inserted in the center comes away with a few wet crumbs.

    1. I couldn’t say without some testing. The butter is a significant portion of the recipe and switching to oil would make a big difference. If anything, I would try using vegetable shortening or margarine since it would add less water to the mix. Again, I haven’t tried it so I can’t say what kind of results you will get.

  12. I absolutely loved these brownies! The taste was amazing! However the texture was crumbly and fragile. We had difficulty cutting them and eating them. The only things I did differently was adding 2T espresso and 1/2 tsp baking soda cause my discard was pretty old. Would that change the texture that drastically?

    1. The baking soda would make the brownies rise and could definitely affect the texture. 1/2 teaspoon of baking soda is enough to rise a recipe with 2 cups of flour. There is only a 1/2 cup of flour in this recipe (1 cup if you count the flour in the starter). The starter is not in the brownies to give them a rise, it’s more about flavor and texture.

  13. Could I supplement the brown sugar and granulated sugar with honey? If so, how? I want to make these tomorrow, and I only have raw honey on hand…Thanks!

    1. By “supplement” how much do you mean? The honey will add moisture to the batter so you might have to compensate for that if you use a lot of honey. Up to about 1/2 a cup should be ok, but much more than that and you might have to make some other changes.

  14. Just tried a brownie, or two.. They are so good, all gooey and chocolatey. I have them sliced and back in the refrigerator until after dinner. Then I’m putting them into the freezer. It’s farther to go for a treat. Thank you for replying so quickly. I look forward to making more recipes of yours. I love how you have set them up to only need 8 oz. of starter!
    Sue H

  15. Eileen,
    Thank you for creating and maintaining this site. I am a baker, but this is my first foray into sourdough. I have my first loaf of White Sandwich Sourdough Bread rising now. I also am having the problem of using the discard, so I want to try this Brownie recipe today as a treat to my husband. Can I substitute dark chocolate chips for the bittersweet chocolate? I have the dark and semi-sweet chips, but don’t have any bittersweet chocolate bars.
    Thanks for working to lead us all.

    1. Yes, the chips should work. The texture might be slightly different since chips have some added ingredients, but I’m sure they’ll still be good.

    1. You can either use 1 egg plus 1 yolk or you can whisk the second egg and pour half into the batter. Save the rest for egg wash or add to an omlet, give it to the dog, etc….

  16. I have to be honest, your blog is basically always pulled up on my computer these days. I found you thanks to your sourdough sandwich bread, which now I make 2-3 times a week in our house. But now I have also made your sourdough scones and these brownies which are amazing! I have 3 different starters going at the moment so I am sure I will continue to work through your recipes 🙂

      1. Thanks so much for sharing your crusty sourdough brownie recipe! It is delicious, and I even reduced the amount of white sugar!

    1. Hi Celia, I haven’t tried making them with cocoa. But generally to replace semi sweet chocolate with cocoa for each oz of chocolate you would use 3 tablespoons of cocoa+1.5 teaspoon sugar+1 tablespoon of butter (or oil). So for this recipe that comes out to about 1 2/3 cups of cocoa+2 oz (1/4 cup) sugar+4.5 oz (9 tablespoons) butter. The butter and sugar amounts are in addition to what is already in the recipe. The texture of the brownies won’t be exactly the same, but it’s the best adjustment without having chocolate available.