Fudgy Sourdough Discard Brownies

Jump to Recipe·Print Recipe

Brownies are one of those treats that remain just as fun to make (and eat!) as they were when I was in elementary school. My recipe, however, has graduated from boxed mix to one that incorporates sourdough starter discard. Still, the method is simple enough for any elementary baker.

Like most brownies, these sourdough discard brownies come together with kitchen staples—and if you’re a reader of The Perfect Loaf, sourdough starter is more than likely on that list. To make the most of the starter discard that results from regular feedings (perhaps you’re looking for ways to make use of your starter discard cache right now) this recipe requires no additional flour or water. Brown the butter for flavor and to reduce excess water content; then whisk in cocoa, sugar, and eggs while it’s warm. Add chopped chocolate and you’re ready to bake.

Fudgy sourdough discard brownies served on a plate — Rich and fudgy brownies ready for some milk. Photo by Rebecca Firkser.

Rich and fudgy, not too sweet but still deeply chocolatey, these brownies are exactly the pick-me-up I crave at 3pm when I’m starting to fade. I recommend a bar alongside a cup of milky black tea (but if you’re more interested in a cold glass of milk, I won’t stop you). Here’s how to make fudgy sourdough discard brownies.

To Remove Excess Water, Brown the Butter

As in my sourdough discard sugar cookie recipe, brown butter does double-duty: Slowly melting the butter allows the most water to evaporate from the fat (to keep the brownies moist but not soupy, we’re adding that hydration via the starter!), and gently browns the butter’s milk solids, creating a rich, nutty flavor.

For Fudgy Brownies, Don’t Add Dry Flour (or Chemical Leaveners)

Brownies need some dry ingredients for structure, but to keep things fudgy as opposed to cakey, limit the gluten. You’ll include just 110 grams, or ½ cup, sourdough starter discard at 100% hydration, meaning there’s just about 55 grams of flour in the mix. 63 grams (¾ cup) cocoa powder offers a bit of additional structure without the gluten. The absence of chemical leaveners like baking powder or soda also keeps the brownies dense and rich. (Think: flourless chocolate cake vs chocolate layer cake.)

Sourdough starter discard brownies sliced — Sliced starter discard brownies. Photo by Rebecca Firkser.

For a Shiny Top, Dissolve the Sugar—and Definitely Add Chocolate

Many bakers have dedicated hours to discovering what exactly creates that lovely shiny surface on a great pan of brownies. Ultimately, it comes down to dissolving sugar and adding chocolate. As the sugar is beaten into the warm butter, it starts to melt, then fully dissolves when vigorously beaten with eggs (Added benefit: The heat from the butter blooms the cocoa powder, much like in this Dark Chocolate-Cherry Sourdough Bread, making for a richer chocolate flavor, as well as removes any lumps in the cocoa—no need to sift!). Adding chopped chocolate or chocolate chips adds another boost of fat and sugar to this mix: The tinier shards melt in the oven, then set up firm and shiny as the brownies cool.

Some recipes go the extra mile of beating sugar and egg into an aerated foam, creating a surface so shiny and crisp it lightens in color and shatters like thin ice as it’s cut, but I prefer simplicity of technique when it comes to brownies.

How Do I Make Parchment Paper Into An Even Square?

To perfectly fit a piece of parchment into an 8×8-inch pan, cut a piece of parchment into a 12×12-inch square. Place the greased pan on top of the parchment as a guide if you’d like, then use scissors to cut out a 2-inch square from each corner of the parchment. Press the parchment into the greased pan: the removed corners will fold in perfectly. For a visual, see the below guideline.

Diagram showing how to cut parchment paper to fit a square — How to cut a piece of parchment paper to fit a square pan.

If this is confusing, use two 8-inch-wide pieces of parchment with an overhang on all sides, greasing both the interior of the pan and the inside of the first piece of parchment so the second one adheres.

Fudgy Sourdough Discard Brownies Recipe

Fudgy Sourdough Discard Brownies

5 Stars 4 Stars 3 Stars 2 Stars 1 Star No reviews

Author: Rebecca Firkser
Prep Time: 15 minutes
Cook Time: 32 minutes
Total Time: 47 minutes
Yield: 16 brownies
Category: Dessert, Snack
Cuisine: American

Print Recipe

Save Recipe

Description

The easiest rich, fudgy, and glossy brownies using your ripe sourdough starter.

Ingredients

Nonstick cooking spray or unsalted butter, for greasing the pan
141 grams (10 tablespoons) unsalted butter, cut into 1-inch pieces
63 grams (¾ cup) Dutch-process or natural cocoa powder
2 teaspoons vanilla extract
267 grams (1 ⅓ cups) granulated sugar
5 grams (1 ½ teaspoons) Diamond Crystal or ¾ teaspoon Morton kosher salt
100 grams (2 large) eggs
110 grams (½ cup) sourdough starter discard (unfed, 100% hydration)
85 grams (3 ounces, ½ cup) chopped bittersweet chocolate or chocolate chunks/chips, divided
Flaky sea salt

Instructions

Heat the oven to 375ºF with a rack in the center. Spray an 8×8-inch metal square cake pan with nonstick cooking spray, then line with parchment (see steps and diagram above), leaving an overhang on all four sides.
Place the butter in a small saucepan or skillet over medium heat. Melt the butter until it starts to foam and sputter, 2-4 minutes. Whisking often, continue to cook the butter until it starts to quiet down, smells nutty, and turns deeply golden brown, another 3-5 minutes. As you whisk, try to lift any browning milk solids that are stuck to the pan. Remove from the heat and immediately pour into a large heatsafe bowl placed over a digital scale, making sure to scrape in as many browned bits stuck to the pan as possible. You should have about 113 grams of butter remaining.
Immediately whisk the cocoa and vanilla into the warm brown butter until smooth. Whisk the sugar and salt into the brown butter mixture until combined. Beat in the eggs one at a time, whisking vigorously to combine, about 1 minute (after the first egg the mixture will look lumpy and separated but after beating in the second it will form into a smooth, glossy mixture). Fold in the starter discard until combined, then fold in 59 grams (2 ounces, about 6 tablespoons) of the chopped chocolate.
Pour the batter into the prepared pan and smooth as needed to make an even layer. Sprinkle over the remaining chopped chocolate. Bake until a tester inserted into the center comes out with some moist (not totally gooey) crumbs, 29 to 32 minutes. Immediately sprinkle the surface with flaky salt, then let cool for at least 35 minutes, but ideally 1 hour—these are fudgy! (If you can, let the pan cool at room temperature for at least 15 minutes so it’s not searing hot, transfer the pan to the refrigerator and chill for at least another 15 minutes, or up to overnight.)
Lift the brownies out of the pan by the parchment and place on a cutting board. Cut into pieces (I like cutting the batch into 9 large, 12 medium, or 16 bite-sized pieces). Brownies will keep in an airtight container at room temperature for up to 5 days, in the fridge for up to 10 days (I love cold brownies, this is my preference), or in the freezer for up to 4 months.

Can I use a sourdough starter discard from the refrigerator?

Yes! The starter discard here is acting purely as flour for structure and water for additional moisture, making an extra-fudgy texture—not as a leavening source. Many fudgy brownie recipes, like this one, do not call for any chemical leavener (as opposed to cakey brownies or blondies, which often include baking soda or powder). Still, the wild yeast in the starter will always provide some kind of lift, and that plus eggs are just right for these bars.

Can I use ripe sourdough starter discard?

You can! Brownies made with a ripe, extremely active starter (instead of a refrigerated starter) may be a smidge airier, but it won’t drastically affect the recipe.

Can I increase or decrease the amount of starter discard in the recipe?

Since the only flour in this brownie recipe comes from the starter, adding or removing the discard will alter the structure and hydration of the recipe. If using less discard, you’ll need to make up the difference with fresh water and flour. If using more, the recipe will be slightly cakier, making this more a tray of moist chocolate cake than fudgy brownie. Not a problem per se, but if you’re trying to make brownies, I say stick to the recipe.

Can I use a vegan butter or oil here?

Some readers have luck browning Miyoko’s Creamery European Style Plant Milk Butter, which is made with a mix of coconut and sunflower oils, cashew milk, and water. Plain coconut butter can also be similarly browned. Both should work much the same as butter, but the timings may be different, and be sure to double-check that the final product weighs about 113 grams after browning.

You could also theoretically use pure oil, with some adjustments. Your best bet is likely to use coconut oil (refined for a neutral flavor, unrefined for a subtle nutty flavor), which is solid at room temperature, like butter. The state will provide fudginess to the set brownies—as opposed to just moisture. Use 113 grams, as there’s no water-removing step. To ensure the cocoa is bloomed and the brownies keep their shiny top as outlined above, heat the oil over medium until it’s very warm, then follow the recipe as written. If using pure vegetable, canola, or olive oil, the brownies will likely be more delicate—for the most fudgy and set texture, keep them chilled.

Can I swap the eggs with a vegan substitute?

It won’t be identical, but for the best results, swap in a 1:1 egg replacement.

What’s Next?

Feel like cookies instead of fudgy sourdough discard brownies? Try our sourdough starter discard sugar cookies or sourdough chocolate chip cookies 🍪

Or, see the collection of sourdough starter discard recipes for easy (and tasty) recipes!

Rebecca Firkser

Rebecca Firkser is a Brooklyn-based writer, editor, recipe developer, and food stylist. Most of her work consists of translating professional cooking into content that’s digestible—figuratively and literally—to home cooks. You can find her work at Epicurious, Bon Appetit, NYT Cooking, Food52, Serious Eats, Kitchn, and TASTE, among others. She's currently working on her first cookbook, a deep-dive into galettes. Once upon a time, she studied theater design and art history at Smith College, so if you want to talk about Wayne Thiebaud's cakes, she's your girl.

Do sourdough posts like this help you in your baking? Join The Baker’s Corner for only $60 a year, and get: