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.
Did this recipe rise to the occasion?
★★★★★
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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.
Annie says
I baked them twice now. I used spelt flour and less sugar, also Xylit.
While baking I read that a glass baking form isn’t the best, I used the glass and will switch it next time. I also switched chocolate chips with a organic bar of 60% dark chocolate. The taste is fantastic but it came out a little oily.
I think the spelt flour might be not ideal?
Hannah Dela Cruz says
Hi Annie! As you can see in the blog post, this recipe was extremely well researched to get the ideal result. I'm afraid changing any combination of ingredients will have negative effects on the taste and texture of the brownies. Since you changed multiple important ingredients, like the the sugar content and types of flour, chocolate and sweetener used, I really can't pinpoint why your brownies turned out oily. It could be a combination of factors like your substitutions or the way your batter was mixed. Since I haven't tested the particular combination you ended up using - I really can't say.
Laurie says
These were absolutely amazing. The brownie recipe I’ve been searching for, for years. I subbed avocado oil for the vegetable oil. I’ve already made them twice this week. Once to take to a potluck and tonight for here at home haha. The second time I didn’t have Dutch cocoa so I subbed with cacao and it still came out equally delicious! Thank you
Hannah Dela Cruz says
I'm so happy you loved these!
Amanda says
Delicious. Followed the recipe to the gram and turned out a very nice product. I did not have Dutch cocoa, only cacao and the addition resulted in taller brownies. Oh my! The chocolate chips in these enhance to 10/10.
Hannah Dela Cruz says
Yay! I'm so glad you loved this brownie recipe. It's one of my favorite recipes on the blog.
Sarah says
These look amazing, but I don’t use vegetable oil. Could I substitute additional butter? Have you tried this?
Hannah Dela Cruz says
This recipe was formulated especially with these ingredients to achieve the shiny top and light but fudgy texture. I would recommend using another type of oil like grape seed or even olive oil.
Janet says
My daughter says these are the best brownies she has ever had, and I bake a lot. They are very close to perfect!
Hannah Dela Cruz says
High praise indeed. Thank you for trying them out, Janet!
Grace says
Hi there! Haven't made it yet but am dying to try! My daughter has an egg allergy- what would you recommend for an egg substitute/alternative for this recipe? Thanks!
Hannah Dela Cruz says
Hi! The egg whites play a huge role in this recipe as it helps create a light texture and the shiny crust on the brownies. Although I've never tried it before, you can perhaps try adding 60 grams of aquafaba to the batter and getting rid of the eggs. Again, I've never tried this so try it at your own risk. Let me know how it goes.
Emily says
Hannah, you are incredibly talented! Your sourghdough discard brownie recipe is simply the best! So easy to follow and tastes delicious. Thank you so much for sharing it…it has helped get me through my pregnancy!
Hannah Dela Cruz says
Thanks so much for the kind words! I'm so so glad you found a brownie recipe that you love and that it helped you through your pregnancy. This is so touching!
Kellie says
I love the flavor of these brownies. I’ve made them twice now, and both times, the outer edge, all the way around, rises higher than the center. I’d like them to be flat… so I can serve to company. Any suggestions?
Hannah Dela Cruz says
Ooh I'm not quite sure why it may be sinking. You could try whisking it more and building more air into the batter. Also try to bake the brownies for a minute or 2 longer.
Kelly says
How would you do this recipe if I wanted to allow for a full 24 hour fermentation?
Hannah Dela Cruz says
Simply refrigerate the batter after mixing.
Al says
I'm at 6,000ft elevation had this problem myself. what I've done to help is 2-3 T more flour and raise my oven temp 10 -15○ and a baking sheet underneath. makes more even rise for my circumstance.
Hannah Dela Cruz says
Thanks for sharing your tips!
Katie says
This recipe is INCREDIBLE. It has quickly become a staple for me when company is over, when I need to use up discard, or when I want something sweet. Everyone loves it.
I’ve made it so often that I’ve started experimenting with the recipe! I started using 50g white chocolate chips and 50g semi-sweet chocolate chips. Fantastic!
Any recommendations or thoughts on other ways to experiment with the brownies? I was thinking about substituting some of the oil for flavored oil (like blood orange) but don’t want to do so if it will mess with perfection.
Hannah Dela Cruz says
Hi Katie! I'm so thrilled to hear that you love the recipe and white chocolate is such a great addition. Blood orange flavored oil would be a great addition. I also think crushed peanuts, crushed oreos or swirling peanut butter on top would be delicious too. I also love folding walnuts or substitute butterscotch chips for half of the chocolate chips! Let me know if you try any of these ideas. I'd love to hear.
Katie says
I made the brownies again with 1/2 blood orange oil and 1/2 vegetable oil (because I ran out of my blood orange!). They are SO good.
I’ll try the butterscotch chips next 😍
Thanks, Hannah!
Hannah Dela Cruz says
You're so welcome! I am so excited to hear about these additions and I'm glad that they are working well. I think you'll love the butterscotch!
Taylor says
Okay, after letting them cool and eating a few, I still have some issues with texture and weirdness about the timing and temperature, but man, do these taste AMAZING despite some flaws! Super rich and delicious. Much yummier than I expected.
Shannon says
I made these by weight and they came out super greasy.
Hannah Dela Cruz says
This has definitely happened to me with both brownies and blondies before. The main issue for this usually is not getting enough air in the brownie batter. Make sure you really whisk your brownie batter if you want to try again.
Taylor says
I truly had high hopes...they taste good, but the texture didn't work out for me, despite measuring all with a kitchen scale. I think the issue is they didn't hold together, and the recommendation to lift out of the pan on the parchment sling to cool made them fall apart even more. I raised the temp to 335 and them 350 after 30 min, put them in longer than 30 min (maybe close to 40??) and they still came out looking unfinished. I didn't want to leave them in longer and ruin them completely. The top crust came out a bit crackly, but not excessively. Full disclosure, I did substitute some Guillards's semi-sweet chocolate bar cut into bits instead of all chocolate chips, so I guess it could be that? possibly, I think it was the oven temp. They also seem dense and oily...will probably be a hit with my daughter either way!
Hannah Dela Cruz says
Hi Taylor - Glad you ended up liking the brownies after all. Just from your description, the issue here could be that your batter was not aerated enough which is why they seemed oily and "unfinished." Try whipping your batter quite a bit more before baking. Adding chopped chocolate could have also affected the texture - chocolate chips contain soy lecithin which helps with the papery brownie crust.
Cathy says
I made them! So yummy! My question is how to adjust the recipe if I don’t have any sourdough starter at the time.
Hannah Dela Cruz says
Hi Cathy! Glad you loved the brownies. You can always use freshly fed sourdough starter or just add 28 grams of flour and 28 grams of water to your batter!
Peter says
These are our favorite brownies! They are perfect. I was wondering, do you think they’d freeze well?
Hannah Dela Cruz says
Hi Peter! So thrilled you love the brownies. I think they would freeze wonderfully. I would either wrap the slices individually or pre-slice and wrap it up with plastic wrap with the parchment paper. Try it out and let me know!
Stephanie says
I don’t have a microwave. Should I melt the sugar and butter on a double boiler? I tried directly on the stove and it turned into caramel.
Hannah Dela Cruz says
I would pour melted butter over sugar in a heat-proof bowl. Whisk until the sugar has dissolved.
Heather says
Hi! These look amazing! I’m wanting to try baking these in individual cups. Possibly 4 oz or 8 oz aluminum cups. Any suggestions on baking time?
Hannah Dela Cruz says
I'm not sure since I've never done this! My best guess would be keeping the temp and baking for 15 mins. To be sure, you can probably look up a recipe that uses those aluminum cups and use those timings and temperature as a guide.
Sarah says
Hi! Do you think I can use butter instead of vegetable oil? Or avocado oil?
Hannah Dela Cruz says
Avocado oil will work great! The oil is there to keep the brownies moist and prevent them from drying out. All-butter brownies have a tendency to be overly dry, so I wouldn't get rid of the oil in the recipe.