Sourdough Chocolate Brownies Recipe (Starter or Discard)

Name: Sourdough Chocolate Brownies Recipe (Starter or Discard)
Prep time: 10 min
Cook time: 40 min
Ingredients: 6 tablespoons unsalted butter; 1/2 cup granulated white sugar; 1/2 cup light brown sugar (lightly packed); 1/2 tablespoon pure vanilla extract; 1/4 teaspoon instant espresso powder (dissolved in 1/2 teaspoon hot water (optional)); 1 large egg yolk; 1/4 cup sourdough starter (you can use active starter or unfed discard); 7 tablespoons unsweetened cocoa powder; 1/4 cup all-purpose flour; 1/2 teaspoon salt; 6 tablespoons walnuts (chopped; or chocolate chips (optional))

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This recipe for fudgy sourdough discard brownies features crackled tops, gooey middles, and rich chocolate flavor. If you’re looking for a quick and easy dessert with sourdough discard or starter, brownies are it!

top view of sourdough brownies with crackly crinkly tops

I’m a chocolate girl, through and through. Yes, fruit is healthy. Pie is lovely, cozy, and homey. Cookies are great. But chocolate takes the cake! Dip fruit in chocolate fondue, make a silken chocolate pie, or integrate chocolate into your cookies and now you’re speaking my love language.

Since I started my starter, I’ve wanted to make brownies with it. I began by tinkering with my all-time favorite brownies recipe from my other website. It took me more tries and tweaks and experimentation than I can remember, but eventually I got these brownies to the place where they are exactly where I want them. They have deep chocolate flavor thanks to cocoa powder, and rich chewy, gooey texture.

If you’re a chocolate girl or guy too (or know someone who is), you’ll want these in your regular rotation.

What Makes These Brownies Special

Texture and flavor. Crinkly on top and fudgy in the middle with rich, nuanced notes of chocolate bliss.
Pantry staples. You can add chocolate chips or not because we treat them like an add-in (like walnuts) instead of melting them into the batter and using them to create the chocolate brownie flavor. Being able to make sourdough discard brownies without chocolate chips is a bonus for me because I always have cocoa powder on hand, but I may or may not have chocolate chips stashed in my pantry.
No waiting and no planning ahead. This recipe is great if a sudden chocolate craving strikes! You can use sourdough starter or discard, and it works well right from the fridge. And once you mix up the batter, it’s ready to bake right away, no waiting time or fermenting required!
Small batch. This recipe makes a loaf pan of brownies because even though I love chocolate, I don’t necessarily need a huge pan of brownies on hand at any given time. I cut it into 8 small brownies because they’re very rich. However, this recipe is easy to double if you need dessert for a crowd.

stack of fudgy chewy sourdough brownies made with cocoa powder without chocolate chips

Ingredients

INGREDIENTS EXPLAINED

Here the ingredients are explained and applicable substitutions are given. For the full recipe (with ingredient amounts), please see the recipe card below.

Unsalted butter – For rich flavor and fudgy texture.
White sugar and light brown sugar – We use a blend of granulated white sugar and light brown sugar. The molasses in the brown sugar helps with the chewy texture and adds rich caramel-like notes.
Vanilla extract – Intensifies the chocolate flavor.
Instant espresso powder – This is optional but recommended, and you can use decaf instant espresso powder if you like. You won’t taste coffee here; the espresso just coaxes the natural flavor nuances out of the chocolate.
Egg yolk – Using egg yolk (instead of the whole egg) in brownies results in a denser, fudge texture and richer flavor.
Sourdough – You can use active starter or unfed discard. My preference is discard because I like how its super tanginess balances the sweet richness.
Unsweetened cocoa powder – Look for natural cocoa powder here (not Dutch-processed). Using cocoa powder instead of melting down chocolate (or chocolate chips) is what gives these brownies deeper, richer chocolate flavor.
Flour – We use a little bit of all-purpose flour.
Salt – To enhance the flavor of the chocolate.
Chocolate chips or chopped nuts – It’s completely optional, but feel free to add chocolate chips or chopped nuts (walnuts are my go-to) if you like them in your brownies!

Step-by-Step Instructions

Prep. Preheat the oven to 350F. Line an 8.5 by 4.5-inch loaf pan with parchment paper.
Make the batter. Melt the butter, white sugar, and brown sugar together in a large bowl in the microwave or in a double boiler. Whisk until the sugar is fully dissolved (this is the key step for crackly tops!), and then let it cool for a couple minutes. Whisk in the vanilla, dissolved espresso powder, and egg yolk, and then the sourdough discard until smooth. Add the cocoa powder, flour, and salt, and whisk to combine, being careful not to over-mix. If you’re adding the walnuts chocolate chips, stir them in now.
Bake. Transfer the batter to the prepared pan and bake until the brownies are set along the outside and shiny in the center, about 40 minutes.
Cool. Cool completely before cutting and serving.

Storage

Once they’re cool, individually wrap each brownie and pop them into an airtight container. Store them at room temperature for up to 4 days, in the fridge for up to 1 week, or in the freezer for up to 3 months.

How To Easily Make a Double Batch

This recipe is easy to double! It’s perfect if you want a unique bake sale item or need a crowd-pleasing dessert to bring to a potluck.

To make a double batch, use 2 egg yolks (don’t be tempted to use 1 whole egg instead). Bake it in an 8 by 8-inch pan, and note that it’ll likely need 10 to 15 minutes longer in the oven.

chocolate brownies made with sourdough starter or discard

Pro Tips For the Best Sourdough Brownies

1. Melt the butter and sugar together, and then stir it like your life depends on it. You’re done when the mixture looks like thick caramel and the sugar is dissolved. (This is the trick to brownies with crepey crinkly tops!)
2. Cocoa powder all the way. It results in the richest brownies with the deepest chocolate flavor.
3. Watch the bake time carefully. These need to bake for a bit longer than regular (i.e., non-sourdough) brownies. At 40 minutes, a loaf pan of these brownies is perfectly done.
4. Don’t cut them while they’re hot. These brownies will be chocolate lava until they’re fully cooled. However, they set as they cool, and for your patience you’ll be rewarded with deliciously fudgy, chewy brownies.

Frequently Asked Questions

Why put sourdough in brownies?

Just like savory recipes, sweet recipes should be balanced. Think about it; many (if not most) desserts call for a little bit of salt to help balance out the sweetness. Similarly, incorporating sourdough into chocolate brownies adds complexity and contributes to a more balanced, nuanced flavor profile. Namely, the tangy flavor of sourdough cuts through the rich sweet flavor.

Don’t these brownies need baking powder or baking soda?

Nope! Please don’t add it here or you run the risk of ruining their gorgeous texture. Even most brownie recipes without sourdough don’t contain a leavening agent (i.e., baking powder, baking soda, or commercial yeast). This is because of the nature of brownies; they’re meant to be dense, fudgy, and even gooey. The more you lighten up the batter, the more cake-like they become. This isn’t bad, it’s just not a brownie!

How do you make brownies with crackly tops?

There are a bunch of methods floating around that all claim to provide crinkly topped brownies; it’s almost become some kind of urban legend!

But I have a simple no-fail method: the sugar has to be completely dissolved in the fat. Meaning, you have to melt the butter, white sugar, and brown sugar together, and then stir like the dickens. At first it’ll look like an oily mess, but with some elbow grease the mixture will come together to form something that looks like thick caramel, which is exactly what we want.