If you're looking for brownies with crispy edges, fudgy centers, a shiny crackly top, and rich chocolate flavor, this one's for you. Sourdough discard adds a subtle tang that enhances the rich cocoa flavor, while a few simple techniques keep the texture chewy instead of cakey or underbaked. Made with just a bowl, a whisk, and a few pantry staples, the batter comes together quickly for brownies that taste better than a box mix without much extra effort.
This recipe was originally published on July 2022. I have since updated it with new photos and additional tips for success.
5-Star Review ★
My daughter says these are the best brownies she has ever had, and I bake a lot. They are very close to perfect!
Janet
If you're like me, you know sourdough discard is too precious to throw away. It's why I love sharing recipes like my sourdough discard chocolate cake and sourdough discard chocolate chip cookies but adding discard to brownies can be tricky. Sourdough discard adds extra moisture, which can turn brownies cakey instead of fudgy, and its tang can taste a little off if the brownies are underbaked.
Pro-Tips for the Fudgiest Sourdough Brownies
You guys know I love explaining the "why" behind a bake. After plenty of testing, I finally found the secret to getting that perfect crackly top and chewy center while still using your sourdough discard.
How to Get a Shiny, Crackly Crust
Grab your whisk and dissolve the sugar completely. I microwave the sugar with the butter. Since sugar dissolves in water (not fat), the moisture in the butter (combined with the water naturally found in sourdough discard) helps the sugar migrate to the surface as it bakes, forming that signature delicate crust.
Pro Tip: This technique is a game-changer for sourdough blondies, too.
Getting the Perfect Texture
Too much liquid is the enemy of a fudgy brownie. To balance the extra moisture from sourdough discard, I add a small amount of cornstarch. It helps bind excess water so the brownies stay dense and chewy instead of dry and cakey.
The "Secret" Ingredient
I've had the chance to work with the King Arthur Baking Company test kitchen on numerous occasions, so I tend to trust their recommendations. My fellow contributor, PJ Hamel, suggests adding chocolate chips to help create the glossy top.
It's thought that the soy lecithin acts as an emulsifier that helps reduce the separation of cocoa butter, cocoa solids, and sugar, allowing the mixture to form that thin, shiny, crackly, delicate meringue layer on top.
Ingredients
Granulated sugar: White sugar is the best choice for brownies since it doesn't contain as much moisture as other sugars. Organic cane sugar will work for this recipe, but do not try to use brown sugar or another type of sweetener (like maple syrup, honey or artificial sweeteners) since they have different chemical properties and moisture content.
Sourdough discard: You can use your sourdough discard or excess sourdough starter directly from the fridge. Add 28 grams of flour and 28 grams of water into your batter if you don't have any sourdough discard.
Cocoa powder: I used Dutch-processed cocoa powder, natural cocoa powder will work just as well for this recipe, but your brownies may turn out lighter in color.
All-purpose flour: Do not substitute whole wheat flour or cake flour, or it will ruin the texture of these brownies.
Chocolate chips: USE CHOCOLATE CHIPS not chocolate bars. This is extremely important since chocolate chips contain soy lecithin which contributes to getting a shiny crust. Milk chocolate or semi-sweet also work best since they have more sugar.
See recipe card for full ingredient amounts.
Step-by-step Instructions (with photos)
STEP 1: Melt the butter and sugar
Microwave sugar and butter together and whisk. Whisk in egg and egg yolks until the sugar looks completely dissolved. This step is pivotal for these brownies since hot butter and moisture from the egg whites and sourdough discard helps properly dissolve sugar, leading to a papery thin crackly crust.
STEP 2: Make the batter
Stir in the vegetable oil, cocoa powder. Whisk in sourdough discard until no traces remain or you may end up with gummy patches of sourdough in your brownies. Using a rubber spatula stir in the dry ingredients. Fold in the chocolate chips until evenly distributed.
STEP 3: Bake
Transfer the batter to a parchment-lined metal baking pan (8 by 8 inches). Bake the brownies at 325 F for 30 minutes. Do not over bake these brownies or they will taste chalky.
Notes from Hannah's Test Kitchen
- Both active sourdough starter and sourdough discard will work for this recipe. No starter? Just add 28 grams of flour and 28 grams of water to your batter.
- Use a metal pan. Baking brownies in a metal pan result in taller, thicker and chewier brownies compared to a glass or ceramic pan.
- Don't over bake your brownies. Over baking chocolate tends to dull its flavor, so if your brownies stay in the oven too long they will taste chalky and bland.
Make Ahead Instructions
- To Store: Slice and wrap individual pieces in plastic wrap, or wrap the entire tray tightly.
To Serve: Defrost at room temperature for a quick snack, or pop a slice in the microwave for a few seconds.
The Upgrade: Warm brownies and top with a dollop of vanilla ice cream = fudgy perfection.
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Sourdough Brownie Recipe
Equipment
- 8 by 8 inch baking pan
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Ingredients
- 70 grams unsalted butter
- 250 grams granulated sugar
- 1 egg large
- 2 egg yolks
- 72 grams vegetable oil
- 75 grams cocoa powder Dutch-processed
- 56 grams sourdough discard
- 40 grams all-purpose flour
- ⅛ teaspoon baking soda
- 7 grams cornstarch
- 4 grams salt Morton's Kosher Salt
- 100 grams chocolate chips
- Pinch flaky sea salt optional
Click US Customary to view volume measurements
Instructions
- Prep: Preheat the oven to 325 F with the rack in the middle. Line an 8-by-8 baking pan with two pieces of parchment stacked perpendicular to each other, cut longer pieces for an overhang.
- Mix sugar and butter: Combine butter and sugar in a large mixing bowl (you'll be using this bowl for the entire recipe so choose an appropriate size). Microwave for 2 minutes, whisk until completely combined.70 grams unsalted butter, 250 grams granulated sugar
- Whisk in eggs: Let the mixture cool slightly to prevent your eggs from heating up too much and getting scrambled. Whisk in the egg and egg yolks until the sugar appears completely dissolved.1 egg, 2 egg yolks
- Add in cocoa powder and wet ingredients: Whisk in the cocoa powder and vegetable oil. Stir in the sourdough discard thoroughly until no traces remain.72 grams vegetable oil, 75 grams cocoa powder, 56 grams sourdough discard
- Fold in dry ingredients: Add the all-purpose flour, baking soda, cornstarch and salt. Use a rubber spatula to fold the ingredients in until no dry bits remain.40 grams all-purpose flour, ⅛ teaspoon baking soda, 7 grams cornstarch, 4 grams salt
- Add chocolate chips: Stir the chocolate chips into the batter until evenly distributed.100 grams chocolate chips
- Bake: Pour the batter into your prepared pan. Bake for 30 minutes or until the brownies are set and a toothpick inserted in the center comes out with moist crumbs attached. Transfer the pan to a wire rack to cool completely before slicing.
- Enjoy and store: Sprinkle flaky sea salt on top, if using. Slice the brownies into 9 to 16 squares. Store brownies in an airtight container at room temperature for up to 3 days.Pinch flaky sea salt
Tips
These recipes were developed and tested using grams for precise measurements. To increase your chances of success, I recommend investing in a kitchen scale. I've included rough volume estimates (in tablespoons and cups), but they might not be totally accurate.
Remember all ovens are unique, these recipes were tested in my oven which runs cooler than others. You might need to lower the temperature if your bake appears to be browning too quickly. Monitor your bake closely and make adjustments if needed.
Notes
Nutrition
I am not a nutritionist or dietitian, any nutrition information provided is an estimate.
Louise Dunworth says
Mmmmm, delicious! And an easy recipe, all in one bowl. I appreciate all of the tips, too, it really helps!
Hannah Dela Cruz says
You're so welcome, Louise! Thank you for the lovely comment.