Ingredients
This recipe makes 16 brownies using an 8-inch (20 cm) square baking pan.
- ½ cup (113 g) unsalted butter
- 4 oz (113 g) semi-sweet or dark chocolate, finely chopped
- ¾ cup (150 g) granulated sugar
- ¼ cup (50 g) light brown sugar, packed
- 2 large eggs, at room temperature
- 1 teaspoon vanilla extract
- ½ cup (120 g) sourdough discard, stirred before measuring
- ½ cup (50 g) unsweetened cocoa powder
- ½ cup (65 g) all-purpose flour
- ¼ teaspoon salt
- ½ cup (85 g) chocolate chips or chunks, optional
Ingredient notes: Use 100% hydration sourdough discard for the intended consistency. If your discard is unusually thick or thin, the texture may vary slightly. Dutch-process cocoa creates a smooth, mellow chocolate flavor, while natural cocoa gives a slightly sharper chocolate taste. Choose chocolate with around 50–70% cocoa for a balanced, rich result.
Step-by-Step Instructions
Step 1: Prepare the pan and oven
Preheat your oven to 350°F (175°C). Line an 8-inch square baking pan with parchment paper, leaving a little overhang on two sides to make removing the brownies easier. Lightly grease the parchment if needed.
Step 2: Melt the butter and chocolate
Place the butter and chopped chocolate in a heatproof bowl. Melt them in the microwave in 20-second intervals, stirring between each interval, or use a heatproof bowl over gently simmering water. Stir until smooth, then allow the mixture to cool for a few minutes.
Step 3: Whisk the eggs and sugar
In a separate large bowl, whisk the granulated sugar, brown sugar, and eggs for about 2–3 minutes until the mixture looks slightly thickened and glossy. Whisk in the vanilla extract. This step helps incorporate air and encourages a delicate crackly crust.
Step 4: Add the chocolate and sourdough discard
Slowly whisk the cooled melted chocolate mixture into the egg mixture until combined. Add the sourdough discard and stir until smooth. Make sure the chocolate mixture is not piping hot before adding it, as excessive heat can scramble the eggs.
Step 5: Fold in the dry ingredients
Sift in the cocoa powder, flour, and salt. Gently fold with a spatula until no dry streaks remain. If using chocolate chips or chunks, fold them in now. Avoid overmixing, as too much mixing can make the finished brownies tougher.
Step 6: Bake the brownies
Spread the batter evenly in the prepared pan and smooth the top. Bake for 30–35 minutes. Begin checking around 28 minutes because ovens and pans vary. A toothpick inserted into the center should come out with moist crumbs, but not a stream of raw batter.
Step 7: Cool and slice
Let the brownies cool completely in the pan, ideally for at least 1–2 hours. Use the parchment overhang to lift them out, then slice into 16 squares with a sharp knife. For especially neat slices, wipe the knife clean between cuts.
Tips for the Fudgiest Brownies
- Don’t overbake. Brownies continue setting as they cool, so remove them while the center still looks slightly soft.
- Measure flour accurately. Weighing it in grams is the most reliable way to avoid dry brownies.
- Use room-temperature eggs. They combine more evenly with the chocolate mixture.
- Choose the right pan. A metal baking pan usually gives more even edges and a better crust than a thick glass dish.
- Wait before slicing. Warm brownies are delicious but fragile. Cooling allows the chocolate and butter to set into a fudgy texture.
- Don’t add extra flour to compensate for the discard. The recipe is designed to account for the moisture in standard 100%-hydration starter.
Delicious Variations
Walnut brownies
Fold ½ cup of chopped toasted walnuts into the batter for a nutty crunch that complements the rich chocolate.
Sea salt brownies
Sprinkle a small pinch of flaky sea salt over the batter just before baking to enhance the chocolate flavor.
Peanut butter swirl
Swirl 2–3 tablespoons of slightly warmed peanut butter across the top of the batter before baking.
Brownie sundae
Serve a slightly warmed brownie with vanilla ice cream and a drizzle of chocolate sauce for an easy dessert.
Storage and Make-Ahead Instructions
Store completely cooled brownies in an airtight container at room temperature for up to 3 days, or refrigerate them for up to a week. Refrigeration makes them firmer and more truffle-like; let them sit at room temperature before serving if you prefer a softer texture.
For longer storage, wrap individual squares tightly and freeze in an airtight container for up to 3 months for best quality. Thaw at room temperature or warm a brownie briefly in the microwave for a freshly baked feel.
You can also prepare these brownies a day ahead. Their chocolate flavor often becomes even more pronounced after resting overnight.
Frequently Asked Questions
Can I use sourdough discard straight from the fridge?
Yes. Stir it well before measuring and allow it to sit briefly at room temperature if convenient. Cold discard works, although it may cool the batter slightly.
Do these brownies taste sour?
No, not strongly. The chocolate and sugar largely mask the acidity, leaving a subtle tang that balances the sweetness. Older discard may have a more noticeable tang.
Can I use active sourdough starter instead?
Yes, provided it is a standard 100%-hydration starter. The brownies do not need the starter’s leavening activity, so unfed discard is ideal.
Why aren’t my brownies fudgy?
They may have been overbaked, or too much flour may have been added. Next time, check earlier, weigh your flour, and allow the brownies to cool before judging the final texture.
How do I know when they’re done?
Look for set edges, a crackly surface, and a center that is no longer liquid. A toothpick should have moist crumbs attached rather than wet batter.
Final Thoughts
Sourdough discard fudgy brownies are proof that leftover starter can become something truly special. With a crackly top, a rich chocolate center, and just the right balance of sweetness, these brownies are easy enough for everyday baking and delicious enough to serve to guests.
Enjoy them plain, sprinkle them with sea salt, or pair them with a scoop of vanilla ice cream. Once you try this recipe, you may find yourself saving sourdough discard specifically to make another batch.
