Sourdough Discard Rhubarb Cake

If you’re looking for a delicious way to use up extra sourdough discard, this rhubarb cake is the perfect treat. It combines the tangy flavor of sourdough with the bright, slightly tart taste of fresh rhubarb. The result is a soft, moist cake that’s just the right balance of sweet and tangy.

This cake is especially great for spring and early summer, when rhubarb is at its peak. The sourdough discard gives it a tender crumb and an extra depth of flavor, making it stand out from traditional rhubarb cakes.

Whether served with a dollop of whipped cream, a scoop of vanilla ice cream, or simply enjoyed on its own with a cup of tea, this sourdough discard rhubarb cake is sure to become a seasonal favorite in your kitchen.

⏱ Cooking Time and Serving

• Prep time: 15 minutes
• Cook time: 40–45 minutes
• Total time: ~1 hour
• Servings: 8–10 slices

📋 Ingredients

• 1 cup sourdough discard (unfed, room temperature)
• 1 cup granulated sugar
• ½ cup unsalted butter, softened
• 2 large eggs
• 1 tsp vanilla extract
• 1 ½ cups all-purpose flour
• 1 tsp baking powder
• ½ tsp baking soda
• ½ tsp salt
• ½ cup sour cream or plain yogurt
• 2 cups fresh rhubarb, chopped into ½-inch pieces
• 2 tbsp brown sugar (for topping)
• ½ tsp ground cinnamon (for topping, optional)

👩‍🍳 How to Make

1. Prepare the oven & pan
   • Preheat your oven to 350°F (175°C).
   • Grease and flour a 9×9-inch baking pan or line with parchment paper.
3. Cream butter and sugar
   • In a large mixing bowl, beat together the softened butter and granulated sugar until light and fluffy.
5. Add wet ingredients
   • Mix in the eggs one at a time.
   • Stir in vanilla extract and sourdough discard until well combined.
7. Combine dry ingredients
   • In a separate bowl, whisk together the flour, baking powder, baking soda, and salt.
9. Mix the batter
   • Add the dry ingredients to the wet mixture in two batches, alternating with the sour cream (or yogurt).
   • Stir until just combined—don’t overmix.
11. Add rhubarb
    • Gently fold in the chopped rhubarb.
13. Top and bake
    • Spread the batter evenly into the prepared pan.
    • Sprinkle the brown sugar and cinnamon mixture over the top.
    • Bake for 40–45 minutes, or until a toothpick inserted into the center comes out clean.
15. Cool & serve
    • Let the cake cool in the pan for at least 15 minutes before slicing.
    • Serve warm or at room temperature.

📝 Notes

• You can substitute part of the rhubarb with strawberries for a sweeter flavor balance.
• If you don’t have sour cream, Greek yogurt works well.
• This cake stays moist for up to 3 days if stored in an airtight container at room temperature.
• Freezes well for up to 2 months—wrap tightly before freezing.

❓ FAQs

Q: Can I use frozen rhubarb?

Yes, but thaw it first and drain excess liquid to avoid a soggy cake.

Q: What if I don’t have sourdough discard?

You can substitute with ½ cup flour + ½ cup buttermilk, though the flavor will be slightly different.

Q: Can this be made gluten-free?

Yes, substitute with a 1:1 gluten-free flour blend. Texture may vary slightly.

Q: How do I make it less sweet?

Reduce sugar to ¾ cup for a more tart-forward cake.

🔎 Nutrition (Per Serving – based on 10 servings)