Perfect Sourdough Discard Banana Bread

If you’re anything like me, you probably have a jar of sourdough discard sitting in your fridge right now, and a bunch of overripe bananas turning brown on your counter. It’s such a waste to toss either one, but finding ways to use them up can feel like a puzzle you don’t have time to solve.

That’s where this sourdough discard banana bread comes in. It combines two ingredients you’d otherwise throw away into one seriously good loaf that’s moist, flavorful, and perfect for breakfast or an afternoon snack. Plus, it’s straightforward enough to whip up on a lazy Sunday morning, and it makes your kitchen smell amazing.

SAVE NOW

What Kind of Bananas Should I Use?

The best bananas for this recipe are the ones sitting on your counter that are already overripe – you know, the ones with lots of brown spots or even completely brown peels. Those super ripe bananas are naturally sweeter and mash up much easier, which means they’ll blend perfectly into your batter. If your bananas are still yellow and firm, you can speed up the ripening process by placing them in a paper bag for a day or two, or even pop them in a 300°F oven for about 15 minutes until the peels turn black. Just make sure to let them cool before mashing, and don’t worry if they look a little ugly – that’s exactly what you want for the best banana bread.

SAVE NOW

Options for Substitutions

This banana bread is pretty forgiving when it comes to swaps, so here are some options if you need them:

• Sourdough starter: If you don’t have sourdough discard, you can replace it with an equal amount of Greek yogurt or sour cream (100 g). The bread won’t have that slight tang, but it’ll still be moist and tasty.
• Butter: You can swap butter for vegetable oil or melted coconut oil (use about 70 g since oil is more concentrated). The texture will be slightly different but still good.
• Brown sugar and white sugar: Feel free to use all brown sugar for a deeper molasses flavor, or all white sugar if that’s what you have. You can also try coconut sugar or maple sugar for a different twist.
• Golden syrup: Honey, maple syrup, or corn syrup work as substitutes. You can even skip it entirely and add an extra 20 g of sugar, though you’ll lose a bit of moisture.
• Flour: All-purpose flour is best here and shouldn’t be substituted with whole wheat or alternative flours, as they’ll make the bread dense and dry. Stick with regular flour for the right texture.
• Bananas: Make sure your bananas are really ripe – the darker and spottier, the better. You can’t really substitute these as they’re the star of the show.

Watch Out for These Mistakes While Baking

The biggest mistake when making banana bread is overmixing the batter once you add the dry ingredients to the wet – stir just until the flour disappears, even if you see a few lumps, because overmixing develops the gluten and creates a tough, dense loaf instead of a tender one.

Another common error is not using bananas that are ripe enough – look for bananas with lots of brown spots or even completely black peels, as underripe bananas won’t give you that sweet, intense banana flavor and moisture you’re after.

Since every oven runs differently, start checking your bread at the 50-minute mark by inserting a toothpick into the center – it should come out with just a few moist crumbs, not wet batter, and if the top is browning too quickly, tent it loosely with foil for the remaining bake time.

Finally, resist the urge to slice into the bread right away, as cutting it while still warm can cause it to fall apart and lose that perfect texture.

SAVE NOW

What to Serve With Banana Bread?

Banana bread is perfect for breakfast or an afternoon snack, and I love serving it warm with a generous smear of salted butter that melts right into each slice. A hot cup of coffee or tea is really all you need to make it feel like a complete treat, though a glass of cold milk works great too, especially for kids. If you want to dress it up a bit for brunch, try toasting a slice and topping it with cream cheese or a drizzle of honey. You can also serve it alongside fresh fruit like strawberries or blueberries to balance out the sweetness.

Storage Instructions

Store: This banana bread stays moist and delicious for several days at room temperature. Just wrap it tightly in plastic wrap or keep it in an airtight container for up to 4 days. If your kitchen is really warm, you can pop it in the fridge where it’ll last up to a week.

Freeze: Banana bread freezes really well, which makes it perfect for meal prep. Wrap individual slices in plastic wrap, then store them all together in a freezer bag for up to 3 months. You can grab a slice whenever you need a quick breakfast or snack.

Enjoy: For the best texture, let frozen slices thaw at room temperature for about 30 minutes. If you’re in a hurry, microwave a slice for 20-30 seconds until it’s warmed through. I love mine slightly warm with a bit of butter spread on top!

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 1750-1900
• Protein: 27-32 g
• Fat: 70-80 g
• Carbohydrates: 255-275 g

Ingredients

For the wet mixture:

• 10 oz bananas (very overripe with black spots for best sweetness)
• 2 eggs (room temperature, about 70°F)
• 1.5 tsp vanilla extract
• 3.5 oz unsalted butter (I like Kerrygold unsalted butter for this)
• 3.5 oz sourdough starter

For the dry mix:

• 1.5 cups all-purpose flour (I always use King Arthur all-purpose flour)
• 2.5 tsp baking powder (sifted to remove lumps)
• 1/2 cup brown sugar
• 3 tbsp granulated sugar
• 1/4 tsp salt
• 1/2 tsp ground cinnamon
• 1/4 tsp ground nutmeg

For the glaze:

• 1.5 tbsp golden syrup (I use Lyle’s for a rich caramel flavor)

Step 1: Prepare Your Mise en Place and Preheat

• 2 eggs
• 2.5 tsp baking powder

Preheat your oven to 180°C (350°F).

While it heats, gather all ingredients and allow eggs to reach room temperature if needed—this helps them incorporate smoothly into the batter.

Grease a standard loaf tin (about 9×5 inches) with butter or cooking spray, then line the bottom with parchment paper for easy removal.

Sift the baking powder into a small bowl to remove any lumps, which ensures even leavening throughout the bread.

Step 2: Combine Wet Ingredients

• 10 oz bananas
• 2 eggs
• 1.5 tsp vanilla extract
• 3.5 oz unsalted butter
• 3.5 oz sourdough starter

Mash the very overripe bananas in a large mixing bowl until mostly smooth with just a few small lumps remaining—this creates the best texture.

Add the room-temperature eggs and vanilla extract, whisking vigorously until well combined.

Melt the butter over gentle heat or in the microwave, then stir it into the banana mixture along with the sourdough starter.

Mix until everything is fully incorporated and smooth.

I find that sourdough starter incorporates best when gently folded in rather than whisked aggressively, which helps preserve some of the tangy flavor.

Step 3: Combine Dry Ingredients

• 1.5 cups all-purpose flour
• 2.5 tsp baking powder
• 1/2 cup brown sugar
• 3 tbsp granulated sugar
• 1/4 tsp salt
• 1/2 tsp ground cinnamon
• 1/4 tsp ground nutmeg

In a separate bowl, whisk together the all-purpose flour, sifted baking powder, brown sugar, granulated sugar, salt, cinnamon, and nutmeg.

Make sure everything is evenly distributed, especially the spices, so each bite has consistent flavor throughout the bread.

Step 4: Combine Wet and Dry Mixtures

• wet ingredient mixture from Step 2
• dry ingredient mixture from Step 3

Pour the dry ingredient mixture from Step 3 into the wet ingredients from Step 2, folding gently with a spatula until just combined.

Don’t overmix—a few small flour streaks are fine, and overmixing develops gluten which can make the bread tough and dense.

The batter should be thick but pourable.

Step 5: Bake the Bread

• batter from Step 4

Pour the batter into your prepared loaf tin and smooth the top with a spatula.

Bake at 180°C (350°F) for approximately 1 hour, or until a toothpick inserted into the center comes out clean with just a few moist crumbs—not wet batter.

The bread is done when the top is golden brown and the edges pull slightly away from the sides of the tin.

Step 6: Finish and Cool

• 1.5 tbsp golden syrup

Remove the bread from the oven and immediately brush the top with the golden syrup while still warm—the heat helps the syrup soak in slightly for extra moisture and richness.

Let the bread cool in the tin for 30 minutes, which allows it to set enough to handle without falling apart.

I always brush with syrup right out of the oven rather than waiting, as it gives a better finish and helps lock in moisture.

Step 7: Remove and Cool Completely

Turn the banana bread out onto a wire rack and peel away the parchment paper if using.

Allow it to cool completely before slicing—this rests the crumb structure and makes for cleaner, neater slices.

Once cooled, wrap tightly and store at room temperature for up to 3 days, or freeze for longer storage.

Perfect Sourdough Discard Banana Bread

Delicious Perfect Sourdough Discard Banana Bread recipe with step-by-step instructions.

Print Recipe Pin Recipe

Prep Time 30 minutes mins

Cook Time 1 hour hr 5 minutes mins

Total Time 1 hour hr 35 minutes mins

Servings 10 slices

Calories 1825 kcal

Ingredients

  

For the wet mixture::

• 10 oz bananas (very overripe with black spots for best sweetness)
• 2 eggs (room temperature, about 70°F)
• 1.5 tsp vanilla extract
• 3.5 oz unsalted butter (I like Kerrygold unsalted butter for this)
• 3.5 oz sourdough starter

For the dry mix::

• 1.5 cups all-purpose flour (I always use King Arthur all-purpose flour)
• 2.5 tsp baking powder (sifted to remove lumps)
• 1/2 cup brown sugar
• 3 tbsp granulated sugar
• 1/4 tsp salt
• 1/2 tsp ground cinnamon
• 1/4 tsp ground nutmeg

For the glaze::

• 1.5 tbsp golden syrup (I use Lyle's for a rich caramel flavor)

Instructions

 

• Preheat your oven to 180°C (350°F). While it heats, gather all ingredients and allow eggs to reach room temperature if needed—this helps them incorporate smoothly into the batter. Grease a standard loaf tin (about 9x5 inches) with butter or cooking spray, then line the bottom with parchment paper for easy removal. Sift the baking powder into a small bowl to remove any lumps, which ensures even leavening throughout the bread.
• Mash the very overripe bananas in a large mixing bowl until mostly smooth with just a few small lumps remaining—this creates the best texture. Add the room-temperature eggs and vanilla extract, whisking vigorously until well combined. Melt the butter over gentle heat or in the microwave, then stir it into the banana mixture along with the sourdough starter. Mix until everything is fully incorporated and smooth. I find that sourdough starter incorporates best when gently folded in rather than whisked aggressively, which helps preserve some of the tangy flavor.
• In a separate bowl, whisk together the all-purpose flour, sifted baking powder, brown sugar, granulated sugar, salt, cinnamon, and nutmeg. Make sure everything is evenly distributed, especially the spices, so each bite has consistent flavor throughout the bread.
• Pour the dry ingredient mixture from Step 3 into the wet ingredients from Step 2, folding gently with a spatula until just combined. Don't overmix—a few small flour streaks are fine, and overmixing develops gluten which can make the bread tough and dense. The batter should be thick but pourable.
• Pour the batter into your prepared loaf tin and smooth the top with a spatula. Bake at 180°C (350°F) for approximately 1 hour, or until a toothpick inserted into the center comes out clean with just a few moist crumbs—not wet batter. The bread is done when the top is golden brown and the edges pull slightly away from the sides of the tin.
• Remove the bread from the oven and immediately brush the top with the golden syrup while still warm—the heat helps the syrup soak in slightly for extra moisture and richness. Let the bread cool in the tin for 30 minutes, which allows it to set enough to handle without falling apart. I always brush with syrup right out of the oven rather than waiting, as it gives a better finish and helps lock in moisture.
• Turn the banana bread out onto a wire rack and peel away the parchment paper if using. Allow it to cool completely before slicing—this rests the crumb structure and makes for cleaner, neater slices. Once cooled, wrap tightly and store at room temperature for up to 3 days, or freeze for longer storage.