Sourdough Chocolate Cake (Moist, From Discard)
This sourdough chocolate cake turns leftover starter into a deeply chocolatey, tender cake that stays moist for days. The batter comes together quickly, and the tang from the sourdough balances the sweetness beautifully.
What Makes This Sourdough Cake So Good
The crumb is exceptionally soft, thanks to the starter and a splash of hot coffee. It stays moist for days, unlike many chocolate cakes that dry out.
The flavor has a subtle tang that cuts through the richness, making it taste more complex. It is my go-to when I have extra starter and want something easy but impressive.
Ingredients
- 1 1/2 cups all-purpose flour: spooned and leveled
- 1/2 cup unsweetened cocoa powder: Dutch-processed gives deeper color, but natural works
- 1 teaspoon baking soda
- 1/2 teaspoon salt
- 1/2 cup unsalted butter, softened: or use neutral oil for a dairy-free option
- 1 cup granulated sugar
- 2 large eggs: at room temperature
- 1 teaspoon vanilla extract
- 1 cup sourdough starter discard: 100% hydration, unfed
- 1/2 cup hot brewed coffee: or hot water
- Powdered sugar: for dusting, optional
Variations and Substitutions
- Brown sugar: Swap half the granulated sugar for packed brown sugar to add a caramel note.
- Oil for butter: Use 1/2 cup vegetable oil and skip the creaming step. The cake will be slightly denser but extra moist.
- Gluten-free: Use a 1:1 gluten-free flour blend that contains xanthan gum.
For another way to use up starter, try our Sourdough Banana Bread.
How to Make Sourdough Chocolate Cake
Step 1: Whisk the Dry Ingredients
Preheat the oven to 350°F (175°C). Grease an 8-inch round cake pan and line the bottom with parchment paper. In a medium bowl, whisk together the 1 1/2 cups flour, 1/2 cup cocoa powder, 1 teaspoon baking soda, and 1/2 teaspoon salt until no lumps remain.
This step makes sure the leavening and salt are evenly distributed, so you avoid a bitter bite of soda.
Step 2: Cream the Butter and Sugar
In a large bowl, beat the 1/2 cup softened butter and 1 cup granulated sugar with an electric mixer on medium speed for about 3 minutes, until pale and fluffy. Then beat in the 2 eggs one at a time, followed by the 1 teaspoon vanilla. Add the 1 cup sourdough starter discard and mix on low just until incorporated.
The mixture may look slightly curdled after you add the starter, which is perfectly fine. Scrape the bowl to make sure everything is combined.
Step 3: Combine the Dry and Wet Mixtures
Add half of the dry ingredients to the butter mixture and mix on low until just combined. Pour in the 1/2 cup hot coffee and stir until the batter loosens, then add the remaining dry ingredients and mix until no streaks of flour remain.
The batter will be very thin, almost like a thick crepe batter. This is normal and leads to a moist cake.
Step 4: Bake the Cake
Pour the batter into the prepared pan and smooth the top. Bake for 30 to 35 minutes, until a toothpick inserted in the center comes out clean or with a few moist crumbs.
The top will spring back when pressed lightly, and the edges will start pulling away from the pan. Set the pan on a wire rack to cool.
Step 5: Dust with Powdered Sugar and Slice
Let the cake cool in the pan for 10 minutes, then turn it out onto the rack to cool completely. Once cool, dust generously with powdered sugar using a fine mesh strainer. Slice and serve.
The cake slices cleanly and the powdered sugar gives it a simple, elegant finish.
Tips for a Perfect Sourdough Chocolate Cake
- Use room temperature ingredients: Cold eggs or butter will not cream smoothly, so let them sit out for 30 minutes before you start.
- Measure flour carefully: Too much flour makes the cake dry. Spoon it into the measuring cup and level it off, or use a kitchen scale (190g).
- Do not skip the hot liquid: Hot coffee or water blooms the cocoa, intensifying the chocolate flavor without making the batter taste like coffee.
- Check for doneness early: Start testing at 30 minutes because every oven is different.
- Let it cool completely: The cake structure sets as it cools, so slicing while warm can make it crumbly.
Bake times by pan:
| Pan Size | Material | Approx. Time |
|---|---|---|
| 8-inch round | metal | 30-35 mins |
| 9-inch round | metal | 25-30 mins |
| 8×8-inch square | metal | 28-32 mins |
| 9×5-inch loaf | metal | 45-50 mins |
Storing Leftover Cake
- Refrigerate: Wrap the cake tightly in plastic or store in an airtight container for up to 5 days.
- Reheating: Warm individual slices in the microwave for 10 to 15 seconds if you like.
- Serve cold: The cake is delicious straight from the fridge, too.
Frequently Asked Questions
Can I use active sourdough starter instead of discard?
Yes, active starter works just as well. The cake may have a slightly more pronounced tang, but the texture will be similar.
My cake sank in the middle. What went wrong?
Most likely the cake was underbaked, or you opened the oven door too early and caused a temperature drop. Make sure the toothpick comes out clean before removing it.
Can I make this cake dairy-free?
Yes. Use a neutral oil like vegetable or canola in place of butter and make sure your starter is fed with only flour and water. The texture will be a bit more tender.
Why is my cake dense and heavy?
Overmixing the batter once the flour is added can develop gluten and lead to a dense crumb. Stir just until the flour disappears.
Sourdough Chocolate Cake Recipe
Ingredients
Method
- Preheat oven to 350°F (175°C). Grease an 8-inch round cake pan and line with parchment. Whisk flour, cocoa powder, baking soda, and salt.
- Beat butter and sugar until fluffy, then beat in eggs, vanilla, and sourdough starter.
- Mix in half the dry ingredients, then add hot coffee. Stir in remaining dry ingredients until just combined.
- Pour batter into pan and bake 30 to 35 minutes, until a toothpick comes out clean.
- Cool in pan 10 minutes, then turn out to cool completely. Dust with powdered sugar before slicing.
