Chocolate lovers rejoice! This rich sourdough chocolate cake is the perfect way to use your sourdough discard starter and makes a delicious cake for a special occasion.
This chocolate sourdough cake is filled with creamy chocolate frosting and topped with a rich chocolate ganache.
Are you looking for a great use for extra sourdough starter? This sourdough discard chocolate cake is the perfect recipe to use your starter in! It's a rich chocolate cake and makes a wonderful birthday cake or cake for any occasion.

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Sourdough discard
The great thing about sourdough discard recipes is that you can simply save up all the starter discard in a jar in the fridge and use it when you want. Other sourdough starter discard recipes include puff pastry and overnight sourdough pancakes.
Don't have a starter yet? Learn to make your own starter with this sourdough starter recipe.
Chocolate cake with sourdough starter
This sourdough cake recipe doesn't rely on the yeast in the starter the way that sourdough bread does. It uses the acid that has been produced by the Lactobacillus bacteria in the starter.
This is a starter that hasn't been fed in a while, or it has passed its peak and has become runny or split. This means the yeast in the starter has run out of food and the starter is now very acidic.
That's not good for sourdough bread, but it's great for this sourdough chocolate cake (or sourdough red velvet cake!)
Ingredients
The actual amounts of the ingredients for this easy sourdough chocolate cake recipe are written in the recipe card at the bottom of this post but here is a rundown. This sourdough cake recipe is made with:
- Brown sugar
- White sugar
- Large eggs
- Vanilla paste or good quality vanilla extract
- Discard sourdough starter
- Vegetable oil (liquid coconut oil, light olive oil or other neutral-tasting vegetable oil)
- Salt
- All-purpose flour
- Cocoa powder (this can be natural cocoa powder or dutch processed cocoa powder)
- Baking powder
- Baking soda
- Hot coffee (I use instant espresso powder dissolved in boiling water)
If you're not a fan of coffee, don't worry you won't taste it. The coffee just helps to strengthen the chocolate flavor. If you really want to leave it out, it can be substituted for hot water instead.
Why make a cake with a sourdough starter?
The acidity in the sourdough starter makes a really tender chocolate cake and helps it rise. It reacts with baking soda to give it a fluffy yet still moist texture.
Fermented chocolate cake
The batter can be made the night before and left to ferment in the fridge. This helps with breaking down the starches in the flour and helps with digestion. Cover the bowl of cake batter tightly with a lid, beeswax wrap or compostable plastic wrap.
Sourdough cake pan sizes
This sourdough chocolate cake is best baked in two 8-inch cake pans. It can however be baked in one larger pan and sliced in half, but it will bake more evenly when baked in two.
The method
Grease and line the cake pans with parchment paper.
In a large mixing bowl, whisk together the flour, cocoa, salt, baking powder, and baking soda and set it aside.
In a separate bowl, whisk together the sourdough starter, eggs, vanilla, oil, milk, and sugars.
Pour the wet ingredients into the flour mixture and fold gently for a minute before pouring over the hot coffee.
Mix the wet and dry ingredients briskly together but don't over mix the batter.
Pour the chocolate cake batter into the greased cake pans and bake until a skewer inserted into the center of the cakes comes out clean and the top of the cakes springs back when touched.
Let the cakes cool in the pan for 5 minutes before removing and placing them on a wire cooling rack to cool completely before frosting.
Frosting
The sourdough chocolate cake is topped with creamy chocolate buttercream frosting.
In a bowl of a stand mixer fitted with a paddle attachment, beat the room temperature butter until light and creamy. Add in the cocoa powder and half the powdered sugar and beat on low to medium speed until combined. Add in the remaining powdered sugar and a little milk. Once the powdered sugar is combined, beat on high speed until light and creamy.
Spread ¼ of the buttercream on one cake round, so it reaches the edges. Add the second cake round on top. Top this round with another ¼ of the buttercream and spread it out with an offset spatula. Use the remaining buttercream to cover the edges of the cake and use a dough scraper to smooth it out.
The chocolate ganache
Afterwards, the sourdough cake is topped with a glossy and rich chocolate ganache. This part is optional, but it adds a real decadent touch to the chocolate cake.
The ganache is made by heating the cream first in a small saucepan until just simmering, taking it off the heat and adding in the chocolate. Let them melt, then stir them together until glossy.
Leave the ganache to cool and thicken a bit first before pouring it on the cake so it can be spread in a thick layer.
If you're wanting to use a coloured ganache on this cake, check out this helpful post on how to colour white chocolate ganache.
Keen to make some other delicious recipes? Try this sourdough red velvet cake or other sourdough recipes that are not bread like sourdough croissants or homemade sourdough waffles.
For something a little different, try your hand at this lemon yogurt cake or a zesty rhubarb custard tart!
Full Recipe
Sourdough Chocolate Cake
This rich sourdough chocolate cake is the perfect way to use your sourdough discard starter.
Ingredients
Cake
- 225g (1 ½ cups) all-purpose flour
- 70g (¾ cup) cocoa powder
- ½ teaspoon salt
- 1 teaspoon baking powder
- 1 teaspoon baking soda
- 2 large eggs
- 1 teaspoon vanilla extract
- 187ml (¾ cup) vegetable oil
- 100g (½ cup) sourdough discard starter
- 130g (⅔ cup) granulated sugar
- 130g (⅔ cup) soft brown sugar
- 250ml (1 cup) milk
- 125ml (½ cup) hot strong coffee
Chocolate Buttercream
- 200g unsalted butter, softened to room temperature
- 320-375g (2 ½-3 cups) powdered sugar
- 30g (⅓ cup) cocoa powder
- 2-3 tablespoon milk or cream, at room temperature
- ¼ teaspoon salt
Chocolate Ganache
- 125ml (½ cup) pouring cream
- 150g dark chocolate, chopped
Instructions
- Preheat the oven to 180°C (356°F) and grease and line two 8-inch round cake pans.
- In a large bowl, mix together the flour, cocoa powder, salt, baking powder, and baking soda. Set it aside.
- In a separate bowl, whisk together the sourdough starter, eggs, vanilla, oil, milk, and sugars.
- Pour the wet mixture into the flour mixture and fold gently for a minute before pouring over the hot coffee.
- Mix briskly together but don't over mix.
- Pour into the prepared cake pans and bake for 25-30 minutes until a skewer inserted into the cakes comes out clean.
Chocolate Buttercream
- In a bowl of a stand mixer fitted with a whisk, beat the butter until light and creamy.
- Carefully add in half the powdered sugar and cocoa powder and beat on low speed until combined. The cocoa powder will puff up so take care! Add in the remaining powdered sugar.
- Once incorporated, beat on high for 5 minutes and add in 2-3 tablespoons of milk or cream as needed until it is light, creamy, and spreadable.
Chocolate Ganache
- In a small saucepan, heat the cream until just simmering. Take it off the heat and add the chopped chocolate.
- Leave it to sit for 5 minutes, then stir until it is glossy and all the chocolate has melted. Let it cool down until it has thickened a bit before pouring on the cake.
Notes
The calorie count for this recipe is for one serving of sourdough chocolate cake. It does not include the frosting or ganache topping.
The batter can be made the night before and left to ferment in the fridge. This helps with breaking down the starches in the flour.
Nutrition Information:
Yield: 12 Serving Size: 1 sliceAmount Per Serving: Calories: 300Total Fat: 16gSaturated Fat: 12gUnsaturated Fat: 0gCholesterol: 29mgSodium: 301mgCarbohydrates: 39gFiber: 2gSugar: 24gProtein: 4g
Erin says
Can this be made with a 9inch bundt pan as well?
Home Grown Happiness says
I haven’t tried that but I would imagine it would! 🙂
Xan says
Hi! This sounds delicious! Have you tried baking ahead and freezing the cakes?
Home Grown Happiness says
yes! the baked cakes freeze very well 🙂
Amy says
I want to try making cupcakes with the batter ingredients instead of a layered cake. How long would you recommend baking the cupcakes for?
Home Grown Happiness says
Hey Amy I’m not exactly sure how long they would take to bake but perhaps around 18-20 minutes. Test that they’re ready by gently pressing their tops and they should spring back 🙂
Rhi says
Hey there, just wondering what you can use in place of the hot coffee - hot water or milk? Hubby doesn’t like coffee but the rest of this cake sounds like a dream!
Home Grown Happiness says
Yup you can just sub with hot water! 🙂
Kristina says
The brief statement at the top of the recipe says cook time of 45 minutes, but then at the bottom of the instructions it says 25-30 minutes. This is rather confusing and should be amended if wrong.
Home Grown Happiness says
You’re so right! I’ve updated that now. Thank you 🙂