I’ve been making this Lemon Sourdough Discard Cake on and off for months—partly to use up a surplus starter and partly because the bright lemon cuts through the starter’s tang so well. It’s a small, tender cake that’s forgiving to bake, perfect for a Sunday brunch, an afternoon coffee break, or when you want to turn discard into something impressive without a long, fussy recipe.
Why you’ll love this dish
This cake turns a typically wasted ingredient—sourdough discard—into a moist, subtly tangy lemon cake. It’s quick to pull together, doesn’t need advanced sourdough skills, and balances sweet and tart in a way store-bought cakes rarely do. Because it uses baking powder rather than relying on starter fermentation for lift, it’s fast: mix, bake, and serve the same day.
“Bright lemon, gentle tang from the starter, and a crumb that stays moist for days—this became a weekend staple in my kitchen.”
What makes this recipe special is that it uses discard as flavor rather than as a leavening agent, so you get sourdough depth without the wait.
How this recipe comes together
This is a straightforward creaming-method cake with a sourdough twist. First you cream butter and sugar, then add eggs and vanilla. The starter is mixed in next for flavor and moisture. Dry ingredients are folded in with lemon juice and zest to keep the batter bright. Pour into a 9-inch round pan and bake about 25–30 minutes. Expect a tender crumb with a light, lemony tang.
Gather these items
- 1 cup sourdough starter (discard or active; ~227 g)
- 1/2 cup granulated sugar (~100 g)
- 1/2 cup unsalted butter, softened (~113 g)
- 2 large eggs
- 1 teaspoon vanilla extract
- 1 cup all-purpose flour (~125 g)
- 1 teaspoon baking powder (~4 g)
- 1/4 teaspoon salt
- 1/4 cup lemon juice (fresh is best)
- Zest of 1 lemon
Notes/substitutions:
- For a slightly lighter cake, swap 2–3 tablespoons of butter for plain yogurt or sour cream.
- To make gluten-free, use a 1:1 gluten-free flour blend and add a teaspoon of xanthan gum if your blend doesn’t contain it.
- If your starter is very sour, taste the batter before baking and add an extra tablespoon of sugar if you prefer sweeter cakes.
Directions to follow
- Preheat the oven to 350°F (175°C). Grease a 9-inch round cake pan and line the bottom with parchment for easy removal.
- In a mixing bowl, cream the softened butter and sugar until light and fluffy, about 2–3 minutes with a hand mixer.
- Beat in the eggs one at a time, scraping the bowl between additions. Stir in the vanilla extract.
- Mix in the sourdough starter until evenly incorporated. The batter will be slightly loose and glossy.
- In a separate bowl, whisk together the flour, baking powder, and salt.
- Add the dry ingredients to the wet in two additions, folding gently. Alternate with the lemon juice and fold in the lemon zest. Stop mixing as soon as the flour is incorporated—overmixing will make the cake dense.
- Pour the batter into the prepared pan and smooth the top with a spatula.
- Bake 25–30 minutes, until the top is golden and a toothpick inserted into the center comes out clean or with a few moist crumbs. If the top browns too quickly, tent loosely with foil.
- Let the cake cool in the pan for 10 minutes, then turn out onto a rack to cool completely before slicing.
Best ways to enjoy it
- Serve slices plain with a dusting of powdered sugar or a simple lemon glaze (1 cup powdered sugar + 2–3 tbsp lemon juice).
- Pair with a dollop of whipped cream, Greek yogurt, or a scoop of vanilla ice cream for dessert.
- Brighten brunch: plate with fresh berries and a pot of strong tea or coffee.
- For an afternoon treat, warm a slice briefly in the oven (325°F/160°C for 8–10 minutes) and finish with butter or honey.
Keeping leftovers fresh
- Room temperature: wrapped tightly in plastic wrap or stored in an airtight container for up to 2 days.
- Refrigerator: store in an airtight container for up to 5 days—bring to room temp or warm briefly before serving.
- Freezer: wrap tightly and freeze up to 3 months. Thaw in the fridge overnight and warm slices in a 325°F oven for 8–12 minutes.
Food safety tip: because the cake contains eggs, don’t leave it out more than 2 hours in warm conditions. Refrigerate leftovers promptly.
Pro chef tips
- Measure by weight if you can—1 cup starter ≈ 227 g; 1 cup flour ≈ 125 g—small changes affect texture.
- Don’t overmix once the flour is added. A few streaks of flour left are better than a tough cake from overworked gluten.
- If your starter is refrigerated and dense, stir it or let it sit at room temperature for 15–30 minutes to loosen before measuring. No need to feed it first—this recipe is forgiving.
- For extra lemon perfume, briefly warm the lemon juice before adding; it releases more aroma when mixed into batter.
- Use fresh baking powder (replace every 6–12 months) to ensure proper rise.
Creative twists
- Lemon-blueberry: fold 3/4 cup fresh or frozen blueberries into the batter. Toss frozen berries in 1 tbsp flour first to prevent sinking.
- Poppy seed: add 1–2 tablespoons poppy seeds for texture and look.
- Olive oil version: swap half the butter for high-quality olive oil for a more Mediterranean flavor and a super-moist crumb.
- Citrus swap: replace lemon with lime or orange zest/juice for a different bright note.
- Glaze and topping variations: cream cheese glaze, honey-lemon drizzle, or a sprinkle of toasted almond flakes.
Your questions answered
Q: Can I use a refrigerated sourdough discard?
A: Yes—refrigerated discard is fine. Stir it to loosen and measure. No need to feed it first for this recipe.
Q: What if I want this as a loaf instead of a round cake?
A: Use a greased 9×5-inch loaf pan and bake 35–45 minutes. Check with a toothpick; bake until inserted center comes out clean.
Q: Can I make this dairy-free or vegan?
A: Dairy-free: use vegan butter or neutral oil (olive or vegetable). Vegan (egg-free) swaps are trickier—try two flax eggs (2 tbsp ground flax + 6 tbsp water, set 5 min), but texture will be denser. You may need to add 1–2 tbsp extra liquid (plant milk) and accept a slightly different crumb.
Q: Why is there baking powder if I’m using sourdough?
A: This recipe uses the starter for flavor and moisture, not as the primary leavener. Baking powder ensures reliable rise without long fermentation.
Q: How do I know when it’s done?
A: A toothpick in the center should come out clean or with a few moist crumbs. The top should spring back slightly when touched.
Conclusion
If you like the idea of turning discard into something bright and delicious, this Lemon Sourdough Discard Cake is an easy, reliable option that rewards you with bright citrus and gentle sourdough depth. For more inspiration and different sourdough lemon styles, check out this loaf-style variation at Sourdough Discard Lemon Loaf – Amy Bakes Bread and another approachable take at Easy Sourdough Lemon Cake – Farmhouse on Boone.
Lemon Sourdough Discard Cake
Ingredients
Main Ingredients
- 1 cup sourdough starter (discard or active; ~227 g) Stir to loosen if refrigerated.
- 1/2 cup granulated sugar (~100 g)
- 1/2 cup unsalted butter, softened (~113 g) Can substitute 2-3 tablespoons with yogurt for a lighter cake.
- 2 large eggs
- 1 teaspoon vanilla extract
- 1 cup all-purpose flour (~125 g) Can be made gluten-free with a suitable flour blend.
- 1 teaspoon baking powder (~4 g) Ensure it is fresh for proper rise.
- 1/4 teaspoon salt
- 1/4 cup lemon juice (fresh is best) Warm briefly before adding for extra aroma.
- Zest of 1 lemon
Instructions
Preparation
- Preheat the oven to 350°F (175°C). Grease a 9-inch round cake pan and line the bottom with parchment for easy removal.
- In a mixing bowl, cream the softened butter and sugar until light and fluffy, about 2–3 minutes with a hand mixer.
- Beat in the eggs one at a time, scraping the bowl between additions. Stir in the vanilla extract.
- Mix in the sourdough starter until evenly incorporated; the batter will be slightly loose.
Mixing Dry Ingredients
- In a separate bowl, whisk together the flour, baking powder, and salt.
- Add the dry ingredients to the wet in two additions, folding gently. Alternate with the lemon juice, and fold in the lemon zest.
- Stop mixing as soon as the flour is incorporated to avoid a dense cake.
Baking
- Pour the batter into the prepared pan and smooth the top with a spatula.
- Bake for 25–30 minutes, until the top is golden and a toothpick inserted into the center comes out clean or with a few moist crumbs.
- If the top browns too quickly, tent loosely with foil.
- Let the cake cool in the pan for 10 minutes, then turn out onto a rack to cool completely before slicing.
