Fudgy Sourdough Brownies Sea Salt

There's something almost magical about sourdough discard brownies—they emerged from that guilty moment when I realized my starter was overflowing and I couldn't bring myself to dump it down the sink. Mixing that tangy, bubbly discard into chocolate batter felt like kitchen redemption, a way to transform something I almost wasted into something genuinely better. The slight sourness plays against the fudgy chocolate in the most unexpected way, and when I added that final sprinkle of sea salt, everything clicked. It's become the brownies I make when I want to impress without pretending I'm doing anything complicated.

I made these for my book club once, right before someone asked if they had a secret ingredient, and I watched their faces when I casually mentioned sourdough starter. The skepticism melted about two bites in—now half the group maintains a starter just to make these. There's something wonderful about a recipe that becomes a talking point, where people genuinely want to know what you did differently.

Ingredients

• Dark chocolate (170 g, 60–70% cocoa): The quality matters here more than anywhere else—this is where chocolate flavor lives, so choose something you'd actually eat by itself.
• Unsalted butter (115 g): Keeping it unsalted lets you control the salt story with that sea salt topping.
• Neutral oil (60 ml): This adds moisture without adding flavor, keeping the focus entirely on chocolate and that subtle sourdough tang.
• Granulated and brown sugar (300 g combined): The combination gives you structure from the granulated side and moisture from the brown sugar's molasses.
• Eggs and egg yolk (2 large eggs plus 1 yolk): That extra yolk is the secret to fudginess—it adds richness without making them cakey.
• Sourdough discard (120 g): Use unfed discard straight from the fridge; the tang is what makes these brownies taste like something more than the sum of their parts.
• Vanilla extract (1 tsp): A quiet amplifier that lets other flavors sing without announcing itself.
• All-purpose flour (60 g): Kept minimal on purpose—too much flour turns these from fudgy to cakey.
• Dutch-process cocoa powder (35 g): The alkali treatment gives you that darker, more sophisticated flavor compared to natural cocoa.
• Fine sea salt (½ tsp): Mixed into the batter to enhance without being obvious.
• Flaky sea salt: This is the finale, the garnish that changes everything with just a few grains.

Instructions

Set your stage:

Preheat that oven to 175°C (350°F) and line your 20x20 cm pan with parchment, leaving some overhang on two sides so you can lift the whole slab out later without wrestling.

Melt your chocolate base:

Get a heatproof bowl sitting over simmering water—not touching the water itself—and melt the chocolate and butter together, stirring constantly until it's silky. This low-and-slow approach prevents the chocolate from seizing and keeps everything smooth.

Build the foundation:

Whisk in that oil after the chocolate cools slightly, then add both sugars and stir until you see that glossy, almost satiny finish.

Add eggs with intention:

Add each whole egg one at a time, whisking well between each, then your egg yolk last. After the final addition, whisk vigorously for a minute or two—you want the mixture thick and pale, almost mousse-like.

Fold in sourdough character:

Stir in your sourdough discard and vanilla until you can't see any streaks anymore; this is where the subtle tang enters the story.

Combine dry ingredients gently:

Sift together the flour, cocoa powder, and salt—sifting matters because cocoa powder loves to clump—then fold into your wet mixture with a spatula just until combined. Overmixing develops gluten and toughens the crumb, so stop folding the moment you don't see dry flour anymore.

Bake to fudginess:

Pour batter into your pan, smooth the top, sprinkle generously with flaky sea salt, then bake for 28–32 minutes. The edges should look set and feel firm, but the center should jiggle just slightly when you shake the pan—that's your signal for fudgy center.

Cool with patience:

Let them cool completely in the pan on a wire rack; cutting warm brownies is a disaster waiting to happen, but cold ones cut clean with almost no crumbling.

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These brownies have a way of becoming the thing people ask you to bring to potlucks, even though you never offered. There's a quiet confidence in serving something that tastes sophisticated and tastes like you actually care, which is maybe the whole point of baking in the first place.

Why Sourdough Discard Changes Everything

The lactic acid and subtle fermented notes in sourdough discard don't make these taste like bread—they make the chocolate taste deeper, somehow more complex. It's similar to how a tiny pinch of coffee powder enhances chocolate without making the brownie taste like coffee. The discard also adds moisture and tenderness, which is why these brownies stay fudgy longer than their regular cousins. I learned this by accident when I was trying to use up starter, and now I can't imagine making them without it.

The Sea Salt Secret

That sprinkle of flaky sea salt isn't just decoration—it's the moment these brownies become something people remember. The salt crystals dissolve on your tongue and create this perfect sweet-salty-bitter balance that somehow makes you want another bite even when you're already satisfied. I tried making them without it once to prove the salt was optional, and it felt like eating a very good chocolate cake instead of something special. Now I'm genuinely apologetic if someone asks for brownies without the salt topping.

Storage and Serving Wisdom

These brownies actually improve slightly after a day or two, as the flavors meld and the texture becomes even more fudgy. Store them in an airtight container at room temperature, and they'll stay phenomenal for three days—though they rarely last that long in my house. They freeze beautifully wrapped individually, which is why I often make a double batch and stash half away.

• Pair these with espresso, cold milk, or even a glass of red wine for an unexpectedly sophisticated moment.
• If you want extra decadence, fold in 100 g of chopped dark chocolate or chips right before pouring into the pan.
• Consider swapping brown sugar for coconut sugar if you want a deeper caramel note underneath the chocolate.

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These brownies became the thing I reach for when I want to prove to myself that baking doesn't require stress or complexity, just intention and decent ingredients. They taste like you spent hours in the kitchen, when really you've got warm chocolate in thirty minutes.

Recipe FAQs

→ What does sourdough discard add to these brownies?

Sourdough discard introduces a gentle tang that enhances the rich chocolate flavor and contributes to a moist, tender crumb.

→ How is the fudgy texture achieved?

Melting dark chocolate with butter and oil, combined with sugars and eggs, creates a dense, shiny batter that bakes into a fudgy consistency.

→ Why sprinkle flaky sea salt on top?

Flaky sea salt provides a crisp contrast and balances the sweetness with a subtle salty bite, elevating overall flavor depth.

→ Can I substitute brown sugar with something else?

Yes, using coconut sugar instead of brown sugar adds a deeper caramel note while preserving moistness.

→ How to know when brownies are perfectly baked?

Edges should be set and center slightly soft; a toothpick inserted will come out with moist crumbs, ensuring fudgy texture.