If you keep a sourdough starter, chances are you’ve got discard waiting in the fridge. Instead of tossing it, turn it into the fudgiest brownies you’ll make this year. These brownies are deeply chocolatey, soft in the middle, and slightly chewy at the edges.
The sourdough discard adds subtle tang and extra moisture that makes the texture amazing. No special equipment, no tricky steps—just a bowl, a whisk, and a craving for chocolate.
What Makes This Recipe So Good
- Incredible texture: The discard brings moisture and a gentle tang that makes these brownies fudgy and rich.
- Uses up sourdough discard: A smart, tasty way to reduce kitchen waste.
- One-bowl friendly: Minimal mess and easy cleanup.
- Balanced chocolate flavor: Cocoa powder plus melted chocolate gives depth and that classic brownie chew.
- Flexible: Works with active or inactive discard and can be made gluten-free with a simple swap.
Shopping List
- Unsalted butter – for richness and that shiny, crackly top.
- Granulated sugar – sweetness and structure.
- Brown sugar – adds moisture and a hint of caramel.
- Eggs – room temperature if possible.
- Vanilla extract – rounds out the flavor.
- Sourdough discard – 100% hydration works best, but close is fine.
- All-purpose flour – a small amount keeps it fudgy.
- Unsweetened cocoa powder – Dutch-process or natural.
- Semisweet or dark chocolate – chips or chopped.
- Salt – enhances flavor.
- Optional add-ins – espresso powder, chocolate chunks, walnuts, or flaky sea salt.
How to Make It
- Prep the pan and oven: Heat the oven to 350°F (175°C). Line an 8×8-inch pan with parchment, leaving overhang for easy lifting.
Lightly grease the sides.
- Melt the butter and chocolate: In a heatproof bowl, melt butter and half the chocolate together. Use a microwave in short bursts or a double boiler. Stir until smooth and glossy.
- Whisk in the sugars: Add granulated and brown sugar to the warm mixture.
Whisk for 30–60 seconds until thick and slightly shiny. This helps the top get crackly.
- Add eggs and vanilla: Whisk in eggs one at a time, then add vanilla. Mix until the batter looks ribbony and cohesive.
- Stir in the discard: Add sourdough discard and whisk until fully incorporated.
It should look smooth and slightly looser than typical brownie batter.
- Combine dry ingredients: In a small bowl, whisk flour, cocoa powder, and salt. If using espresso powder, add it here.
- Fold dry into wet: Use a spatula to fold the dry mixture into the batter just until no dry streaks remain. Avoid overmixing.
- Add remaining chocolate: Fold in the rest of the chocolate pieces and any nuts or extra chunks.
Save a few for the top if you like.
- Bake: Spread the batter in the pan and smooth the top. Bake 25–32 minutes, until the edges are set and the center has a slight wobble. A toothpick should come out with moist crumbs, not wet batter.
- Cool completely: Let the brownies cool in the pan.
For the cleanest slices and fudgiest texture, cool at room temp, then chill for 30–60 minutes before cutting.
- Finish: Sprinkle with flaky sea salt if you like. Lift out with the parchment and slice into squares.
Storage Instructions
- Room temperature: Store in an airtight container for up to 3 days. They stay soft and fudgy.
- Refrigerator: Keeps for up to 1 week.
Let come to room temp before serving, or enjoy chilled for a denser bite.
- Freezer: Wrap individual squares tightly and freeze up to 2 months. Thaw at room temp or warm briefly in the microwave.
Why This is Good for You
Reduced waste: Using discard means you’re making the most of your sourdough routine. It’s a small win for your kitchen and your budget.
Better texture without additives: The natural acidity and moisture in discard help create that fudgy center and crinkly top, no corn syrup or extra oils needed.
Customizable sweetness: You control the sugar, chocolate intensity, and add-ins, which beats most store-bought mixes.
What Not to Do
- Don’t overbake: Pull them when the center is just set.
Overbaking turns fudgy into cakey fast.
- Don’t skip the cool-down: Cutting too soon leads to messy slices and a gummy texture.
- Don’t overmix after adding flour: Too much mixing develops gluten and makes the brownies tough.
- Don’t use very sour or off-smelling discard: A sharp tang is fine, but discard that smells unpleasant or boozy can affect flavor.
- Don’t swap all the cocoa for chocolate or vice versa without adjustments: The balance of fat and solids matters for structure.
Alternatives
- Gluten-free: Use a 1:1 gluten-free baking flour blend. Let the batter rest 10 minutes before baking for better hydration.
- Dairy-free: Swap butter for a neutral, dairy-free butter or coconut oil, and use dairy-free chocolate. Expect a slightly different crumb but still delicious.
- Less sugar: Reduce granulated sugar by up to 1/4 cup; keep the brown sugar for moisture.
The texture will be slightly less shiny but still fudgy.
- Extra dark: Use dark cocoa and 70% chocolate. Add 1–2 tablespoons more sugar if it tastes too intense.
- Add-ins: Stir in toasted walnuts or pecans, swirl in a few spoons of peanut butter or tahini, or top with a handful of chocolate chips for a bakery-style finish.
FAQ
Can I use active starter instead of discard?
Yes. Active starter works the same here.
The rise comes from eggs and structure, not yeast activity, so there’s no need to wait or proof the batter.
What hydration starter is best?
Use 100% hydration discard for the most predictable results. If your discard is thicker or thinner, adjust with a teaspoon of water or a teaspoon of flour to match a pourable but thick consistency.
Do I need baking powder or baking soda?
No. These are classic fudgy brownies.
The lift comes from the eggs and sugar whipped into the warm batter, which helps create that shiny top.
How tangy will the brownies taste?
Only slightly. The chocolate and sugar mellow the tang, leaving a pleasant depth rather than a sour flavor.
Can I double the recipe?
Yes. Bake in a 9×13-inch pan for about 30–38 minutes.
Start checking early, as ovens vary. The edges will set before the center.
My brownies didn’t get a crackly top. Why?
Make sure the sugar dissolves into the warm butter-chocolate mixture and whisk the eggs well.
Also, don’t skimp on sugar; it’s key to the shiny crust.
What if my discard has been in the fridge for weeks?
If it smells cleanly tangy and not unpleasant, it’s fine. Stir it to recombine any liquid. If the smell is off or harsh, feed your starter and wait for fresher discard.
Can I make these without melted chocolate?
Yes, but they’ll be less rich.
Increase butter by 2 tablespoons and cocoa by 2 tablespoons, and add an extra tablespoon of sugar. Texture will be slightly more cakey.
How do I get neat slices?
Chill the cooled slab for 30–60 minutes, then slice with a hot, clean knife, wiping between cuts. The edges will be sharp and clean.
Is Dutch-process or natural cocoa better?
Either works.
Dutch-process gives a smoother, darker chocolate flavor; natural cocoa tastes a bit brighter. Pick what you prefer or what you have on hand.
Final Thoughts
Sourdough discard brownies are a practical, delicious way to bake with what you’ve got. They’re rich, chewy, and easy enough for a weeknight treat.
Keep a stash of discard in the fridge, and you’re always one bowl away from warm, chocolatey squares. Once you try this, you might never toss discard again—and your brownie game will only get better from here.
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