Sourdough Discard Brownies

Gathering Ingredients

Dry and wet ingredients with exact amounts:

• 200 g unsalted butter
• 150 g bittersweet chocolate (60–70% cacao), chopped
• 300 g granulated sugar
• 2 large eggs + 1 large egg yolk (room temperature)
• 200 g active sourdough discard (100% hydration), stirred
• 1 teaspoon vanilla extract
• 90 g all-purpose flour
• 30 g unsweetened cocoa powder, sifted
• 1/2 teaspoon fine sea salt
• 1/2 teaspoon baking soda
• Optional: 100 g chocolate chips or chopped nuts
• Optional: 1 teaspoon espresso powder to deepen chocolate

Ingredient notes and substitutions:

• Use sourdough discard at room temperature for even mixing; cold discard can seize melted chocolate when combined.
• For fudgier brownies keep flour at the lower end (90 g) and avoid overbaking; for cakier texture increase flour to 105–115 g.
• If using salted butter, reduce added salt to 1/4 teaspoon.
• Cocoa should be unsweetened and sifted to prevent lumps; Dutch-process cocoa gives deeper color but may change leavening reaction with baking soda — add 1/2 teaspoon baking powder if full Dutch-process is used.
• If discard is thicker than 100% hydration, weigh and thin with 10–20 g water to match texture and maintain batter balance.

Quality and timing tips:
Use high-quality chocolate for flavor; buy chopped bars rather than chips for smoother melt. Measure flour by weight for consistency; spoon into the scale bowl rather than scooping. Bring eggs and discard to room temperature for 30–60 minutes before mixing; this helps the melted chocolate integrate smoothly and supports a glossy top during baking.

Equipment and Pan Prep

Required equipment:

• 20 x 20 cm (8 x 8 in) square baking pan or 23 x 23 cm (9 x 9 in) for thinner brownies
• Parchment paper long enough to overhang two sides for easy removal
• Medium saucepan or double boiler for melting
• Heatproof bowl for chocolate
• Digital kitchen scale for accurate measurements
• Whisk and rubber spatula
• Cooling rack and sharp serrated knife for cutting

Pan preparation steps:
Line the pan with parchment paper leaving at least 2–3 cm overhang on two opposite sides; this makes lifting the brownies out cleanly easier. Lightly butter or spray the pan before placing parchment to prevent shifting; press parchment into corners so the batter spreads evenly without pooling in creases. For a crisper edge, grease the exposed sides of the pan lightly before placing parchment.

Oven and temperature tools:
Preheat the oven to 175°C (350°F) for a standard bake; for a slightly fudgier center reduce to 170°C (338°F) and extend baking time by 2–4 minutes, checking doneness. Use an oven thermometer to confirm actual oven temperature; many ovens run 10–20°C off and that affects set time. A probe thermometer target of 88–95°C (190–203°F) in the center corresponds with fudgy but set brownies; higher readings indicate a drier crumb. Place the oven rack in the center for even heat distribution and avoid the top rack to prevent the top from browning too fast.

Preparing the Sourdough Discard

Assessing and adjusting discard consistency:
Sourdough discard at 100% hydration behaves like thick yogurt; it should be spoonable but not runny. If discard is overly loose (more than a 1:1 flour-to-water ratio by weight), measure and reduce the water slightly: mix 10–20 g flour into the discard, let it rest 5–10 minutes to hydrate, and re-assess. Cold discard can cause the melted chocolate to seize; if the discard has been refrigerated, let it sit at room temperature for 30–60 minutes.

Acidity and leavening balance:
Sourdough discard adds acidity that reacts with baking soda to create light lift and a tender crumb. For the formula listed, 1/2 teaspoon baking soda is sufficient with 200 g discard at 100% hydration. If using discard with unusual strength (very sour), reduce baking soda to 1/4 teaspoon and add 1/4 teaspoon baking powder to avoid metallic flavor while preserving lift.

Flavor and safety notes:
Fresh discard gives a mild tang that complements chocolate without tasting sour. If discard smells strongly of acetone or has visible discoloration, discard it and use fresh starter feed instead. To maintain clean texture, stir the discard gently to remove large bubbles or pockets of excess liquid; avoid vigorous whipping, which incorporates air and can alter final texture. If you prefer no tang, replace 50 g of discard with additional melted chocolate and reduce sugar by 10 g to keep balance.

Melting Chocolate and Preparing the Wet Mixture

Melt butter and chocolate correctly:
Chop chocolate into even pieces to ensure uniform melting. Use a heavy-bottomed saucepan over the lowest heat or a double boiler: simmer water gently, place a heatproof bowl over the pan with the chocolate and butter, and stir slowly until smooth. Remove from heat just before fully melted and stir until silk-smooth; residual heat finishes the melt. Avoid overheating above 55–60°C (131–140°F) to prevent chocolate from seizing or grainy texture.

Combine sugar and eggs for structure:
Add granulated sugar to the slightly cooled chocolate mixture while still warm (not hot) and whisk to dissolve some sugar crystals; this step helps develop the glossy crackly top. Whisk in eggs and yolk one at a time with a steady motion; do not whip vigorously — aim to combine until homogeneous and slightly thickened. Incorporate vanilla and optional espresso powder now to magnify chocolate notes.

Integrating the discard:
Temper the room-temperature discard by stirring a small spoonful of the warm chocolate into the discard, then add the warmed discard back to the main bowl in two additions. This prevents sudden temperature shock that can cause chocolate to seize. The final wet mixture should be glossy, pourable, and heavy; if the mix looks curdled, continue gentle whisking off heat until smooth.

Mixing Dry Ingredients and Final Batter

Sift and combine dry ingredients:
Sift cocoa powder and flour together with salt and baking soda to remove lumps and ensure even distribution. Reserve a small spoonful of flour-cocoa mix to dust over added chocolate chips so they don't sink. Stir the rest gently to a homogeneous blend.

Folding technique to avoid overdevelopment:
Add the dry mix to the wet mixture in two additions using a rubber spatula. Use broad folding strokes: cut through the center, scrape the bottom, fold over, and rotate the bowl. Stop mixing when no streaks of flour remain; a few small flour ribbons are acceptable. Overmixing develops gluten and yields tougher, cakier brownies. Aim for a dense, shiny batter that drops slowly from the spatula.

Add-ins and adjustments:
Fold in chocolate chips or chopped nuts gently to maintain batter viscosity. If batter appears too thick to spread — stiff, not flowing — add 10–20 g warm milk or extra beaten egg yolk to loosen without thinning; add in 5 g increments. If batter is too thin (runs like cake batter), sprinkle 1 tablespoon sifted flour and fold once. Scrape batter into the prepared pan, tapping the pan twice on the counter to level the surface and remove large air pockets.

Baking, Checking Doneness, and Cooling

Baking temperature and time guide:
Preheat oven to 175°C (350°F). Bake in the center rack for 20–26 minutes for an 8 x 8 inch pan; start checking at 18 minutes if you prefer very fudgy brownies. For a slightly thicker pan or higher-altitude adjustments, increase bake time by 2–6 minutes. Rotating the pan halfway through is not necessary unless your oven has known hot spots.

Visual and tactile doneness cues:
Look for a shiny, crackly top and slightly pulling away from the pan edges. Insert a toothpick into the center: for fudgy brownies remove with a few moist crumbs attached; for more cake-like remove with minimal wet batter. A probe thermometer reading of 88–95°C (190–203°F) in the center indicates set but fudgy. Avoid waiting until the center is completely dry — residual heat in the pan will continue to set the crumb.

Cooling protocol for texture:
Allow brownies to cool in the pan on a wire rack for 30–45 minutes; this initial rest finishes the interior and prevents collapsing when removed. Lift brownies using parchment overhang and transfer to the rack for additional cooling to near room temperature before slicing. For the fudgiest slices, refrigerate the fully cooled brownies for 1–2 hours; chilling firms them for clean cuts and concentrates flavor. Warm slightly before serving to restore chewiness: 10–15 seconds in a microwave per serving or 5 minutes at 150°C (302°F) in oven.

Cutting, Serving, and Storage

Best method to cut clean squares:
For neat edges, chill brownies until firm (30–60 minutes in the fridge) then use a sharp knife warmed under hot water and dried between cuts. Score the top gently before cutting for perfectly even portions. For softer, room-temperature brownies, a serrated knife works better; use a sawing motion and clean the blade between slices.

Serving suggestions and portioning:
Cut into 9 large or 16 small squares depending on richness and serving size. Serve warm with a scoop of ice cream, a dusting of cocoa or powdered sugar, or a spoonful of whipped cream; chilled brownies pair well with espresso or milk. For a more decadent bar, warm a slice and drizzle with melted chocolate or salted caramel just before serving.

Storage and freezing instructions:
Store cooled brownies in an airtight container at room temperature for up to 3 days; add a slice of bread to the container to maintain moisture if the environment is dry. Refrigerate for up to 7 days to preserve freshness and improve slicing. To freeze, wrap individual squares tightly in plastic wrap and place in a freezer-safe container for up to 3 months; thaw in the refrigerator overnight and bring to room temperature or warm briefly to serve. Reheat single portions in the microwave for 10–20 seconds or in a 150°C oven for 5–8 minutes for a fresh-baked texture.

Frequently Asked Questions

Can I use active starter instead of discard?
Yes: replace the discard weight-for-weight with active starter if you plan to feed and use immediately, but active starter is more acidic and vigorous; reduce baking soda to 1/4 teaspoon and consider increasing sugar by 10 g if the starter tastes particularly sour. If using active starter that is bubbly and fed, reduce the discard by 20 g to compensate for added fermentation strength and to preserve texture.

What if I only have whole wheat or gluten-free flour?
Whole wheat: substitute up to 30% of the all-purpose flour with whole wheat and increase liquid by 5–10 g if batter seems dry. Expect a denser crumb and nuttier flavor. Gluten-free: use a 1:1 gluten-free flour blend with xanthan gum included; batter may be slightly more fragile — avoid overmixing and bake a little longer while testing for set.
Why are my brownies cakey instead of fudgy?
Common causes: too much flour, overbaking, or overmixing. Use precise weighing, remove from oven when a few moist crumbs cling to a toothpick, and stop stirring once dry streaks disappear. Reduce flour by 10 g next batch or lower oven temperature by 5–10°C and add a minute or two to bake time to increase fudginess without dried edges.
Can I omit eggs or use an egg substitute?
Eggs provide structure and shine to the top; replacing eggs reduces gloss and can change crumb. For egg-free: use a commercial egg replacer or 60 g silken tofu blended until smooth plus 1 tablespoon neutral oil per egg; expect a chewier texture and slightly different rise. Adding an extra tablespoon of melted chocolate can help with richness when omitting eggs.
How does discard affect flavor and shelf life?
Discard adds a subtle tang that balances the sweetness of chocolate and intensifies perceived depth. It does not significantly reduce shelf life if properly baked and cooled; acidic components can even help preserve moistness. Store as directed: room temperature up to 3 days, refrigerated up to 7 days, or frozen for longer storage.
Can I make this recipe ahead for events?
Yes: bake and cool fully, then refrigerate for 1–2 days to make clean cuts and maintain fresh texture. For the best flavor, bring chilled brownies to room temperature 30 minutes before serving or warm briefly. For make-ahead gifting, freeze individual wrapped squares and thaw on the day of serving; finish with a quick warm to restore chewiness.