Sourdough Discard Rhubarb Cake
This tender sourdough discard rhubarb cake is the perfect way to use up your extra starter while celebrating spring's tangiest fruit. Moist, lightly sweet, and beautifully golden, it doubles as a stunning Easter breakfast pastry or an everyday bakery-worthy treat.
The Best Thing You Can Do With Your Sourdough Discard This Spring
If you keep a sourdough starter, you already know the quiet guilt of scraping out that cup of discard before the next feeding. You hate to waste it, but scrambled eggs and crackers can only take you so far. Enter this sourdough discard rhubarb cake: a tender, golden, bakery-worthy beauty that transforms your leftover starter into something genuinely special.
This is one of those different sourdough recipes that feels elevated without being fussy. It sits somewhere between a classic English baked good and a relaxed weekend breakfast pastry, which makes it equally at home on an Easter brunch table or a Tuesday afternoon with a cup of tea.
Why This Recipe Works So Well
Rhubarb and sourdough are a natural pairing that most bakers overlook. The bright acidity of rhubarb echoes the tang in the discard, while the sour cream in the batter keeps every crumb incredibly moist. The result is a cake that tastes like it came from a very good bakery, not from a jar of starter you almost threw away.
A few things that make this cake stand out among sourdough discard pastry recipes:
- No need to feed or activate your starter. Unfed discard works perfectly here.
- The turbinado sugar topping bakes into a crackly, caramelised crust that is irresistible.
- It is sturdy enough to slice cleanly, but tender enough to pull apart with your hands over the sink at midnight.
Chef's Tip: Room temperature ingredients are not just a suggestion here. Cold butter will not cream properly, and cold eggs can cause the batter to seize. Pull everything out of the fridge at least 30 minutes before you start.
Choosing Your Rhubarb
Fresh rhubarb is ideal when it is in season from late spring through early summer. Look for firm, deeply coloured stalks with no soft spots. The redder the stalk, the more visually striking the cake will be, though greener stalks taste just as good.
If you are making this outside of rhubarb season, frozen rhubarb is a perfectly fine substitute. Just thaw it completely and pat it very dry with paper towels before folding it into the batter. Extra moisture from frozen fruit is the enemy of a good crumb.
The quality of your baking tools matters more than most people realise. A heavy-bottomed cake pan distributes heat evenly and prevents overbrowning on the base, and a reliable hand mixer makes the creaming step effortless.
How to Get the Perfect Texture Every Time
This is a quick discard dessert recipe in spirit, but a few small techniques take it from good to extraordinary.
Do not overmix. Once the flour goes in, fold gently. Overworking the batter develops gluten and turns your cake tough. A few streaks of flour that disappear on the last fold are perfectly fine.
Sink and top the rhubarb. Folding most of the rhubarb into the batter ensures tart pockets throughout the cake, while pressing a handful on top creates that gorgeous rustic, bakery food recipe look that makes everyone reach for a second slice.
Check early. Ovens vary. Start checking for doneness at the 38-minute mark. The top should be deeply golden and a toothpick should come out with just a few moist crumbs attached.
Chef's Tip: If the top is browning faster than the centre is baking, loosely tent the pan with foil. This is especially common in fan-forced ovens.
Ready to bake? Here is the full step-by-step recipe card:
Sourdough Discard Rhubarb Cake
This tender sourdough discard rhubarb cake is the perfect way to use up your extra starter while celebrating spring's tangiest fruit. Moist, lightly sweet, and beautifully golden, it doubles as a stunning Easter breakfast pastry or an everyday bakery-worthy treat.
Ingredients
- 2 cups all-purpose flour, spooned and leveled
- 1 1/2 tsp baking powder
- 1/2 tsp baking soda
- 1/2 tsp fine sea salt
- 1/2 tsp ground cinnamon
- 1/2 cup unsalted butter, softened to room temperature
- 3/4 cup granulated sugar
- 2 large eggs, room temperature
- 1/2 cup sourdough discard, unfed, at room temperature
- 1/2 cup full-fat sour cream, or plain whole-milk yogurt
- 1 tsp vanilla extract, pure
- 2 cups fresh rhubarb, trimmed and cut into 0.5-inch pieces
- 2 tbsp turbinado sugar, for topping, coarse raw sugar works well
Instruction
Preheat your oven to 350 degrees F (175 degrees C). Grease a 9-inch round cake pan and line the base with parchment paper.
In a medium bowl, whisk together the flour, baking powder, baking soda, salt, and cinnamon. Set aside.
In a large bowl, beat the softened butter and granulated sugar together with a hand mixer or stand mixer on medium-high speed for 3 to 4 minutes until pale and fluffy.
Add the eggs one at a time, beating well after each addition. Mix in the vanilla extract.
Add the sourdough discard and sour cream to the butter mixture and stir gently to combine. The batter may look slightly curdled at this point, which is completely normal.
Fold the dry ingredients into the wet ingredients using a rubber spatula until just combined. Do not overmix.
Gently fold in three-quarters of the chopped rhubarb, reserving the rest for the top.
Pour the batter into the prepared cake pan and smooth the top. Scatter the reserved rhubarb evenly over the surface and press it in very lightly.
Sprinkle the turbinado sugar over the top of the cake.
Bake for 40 to 45 minutes, or until a toothpick inserted in the centre comes out clean and the top is golden. If the top begins to brown too quickly after 30 minutes, tent loosely with foil.
Cool in the pan for 15 minutes, then turn out onto a wire rack. Serve warm or at room temperature.
Equipment
- 9-inch round cake pan
- Parchment paper
- Large mixing bowl
- Medium mixing bowl
- Hand mixer or stand mixer
- Rubber spatula
- Whisk
- Wire cooling rack
- Toothpick
Notes
Serving, Storing, and Variations
This cake is wonderful slightly warm with a dusting of powdered sugar and a spoonful of clotted cream or creme fraiche on the side. It also makes a stunning Easter breakfast pastry served alongside fresh fruit and good coffee.
For a sweet sourdough loaf version, simply pour the batter into a loaf pan and extend the bake time to around 60 minutes. It slices beautifully and makes a thoughtful homemade gift.
Leftovers keep well at room temperature for two days or in the fridge for up to five. Individual slices also freeze brilliantly, making this one of the most practical desserts made with sourdough discard in your repertoire. Bake once, enjoy all week.
