The Best Sourdough Banana Bread (With Long-Ferment Option)

If you’re looking for a cozy, naturally leavened twist on a classic quick bread, this sourdough banana bread recipe is your new go-to. Perfectly moist, gently tangy, and loaded with banana flavor, it’s a delicious way to use up your sourdough discard while nourishing your family with a gut-friendly treat.

In this post, you’ll get a tried-and-true sourdough banana bread recipe that’s easy to whip up—and we’ll also walk you through a long-fermented option for extra digestibility and depth of flavor. Whether you’re an experienced sourdough baker or brand new to discard recipes, you’ll love how simple and satisfying this banana bread is.

Scroll down for the recipe card, followed by detailed step-by-step instructions (with photos). 

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Sourdough Discard Banana Bread Recipe

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Sourdough Banana Bread

This sourdough banana bread is soft, moist, and naturally fermented, giving it a rich depth of flavor. Made with ripe bananas and an active sourdough starter, it's a great way to use up excess starter while baking a delicious treat.

Prep Time15 minutes mins

Cook Time55 minutes mins

Fermentation Time12 hours hrs

Total Time13 hours hrs 10 minutes mins

Course: Breads

Keyword: Sourdough Banana Bread

Servings: 1 Loaf

Calories: 112kcal

Author: Ashley Nicole

Equipment

• Silicone Spatula Set
• Digital Kitchen Scale
• Dough Whisk
• Measuring Cups & Spoons
• Loaf Pan
• Stainless steel mixing bowl set

Ingredients

• 1 ¾ cups 220g all-purpose flour
• 1 teaspoon baking soda
• ½ teaspoon salt
• 1 teaspoon ground cinnamon optional
• ½ cup 113g butter, melted and slightly cooled
• ¾ cup 150g brown sugar
• 2 large eggs
• 1 ½ cups 3–4 mashed ripe bananas
• ½ cup 120g sourdough discard
• 1 teaspoon vanilla extract

Instructions

1. Mix the Wet Ingredients

• In a large bowl, whisk together the melted butter and brown sugar until smooth. Add eggs, mashed bananas, sourdough starter, and vanilla extract. Stir until combined.

2. Mix the Dry Ingredients

• In a separate bowl, whisk together the flour, baking soda, salt, and cinnamon (if using).

3. Combine & Ferment

• Gradually add the dry ingredients to the wet ingredients, stirring until just combined. Cover and let ferment at room temperature for 4–6 hours (or overnight in the fridge for 8–12 hours).

4. Preheat & Prepare

• When ready to bake, preheat the oven to 350°F (177°C). Grease a 9×5-inch loaf pan or line it with parchment paper.

5. Bake

• Pour the batter into the prepared pan and bake for 55–65 minutes, or until a toothpick inserted in the center comes out clean.

6. Cool & Serve

• Let the banana bread cool in the pan for 10 minutes before transferring it to a wire rack. Slice and enjoy!

Notes

• The fermentation process enhances flavor and digestibility.
• For a quicker version, skip the long fermentation and bake immediately after mixing.
• Add-ins like chocolate chips, nuts, or dried fruit can be mixed in before baking.

Enjoy your homemade sourdough banana bread!

Why Bake Sourdough Banana Bread?

You might be wondering: why add sourdough to banana bread in the first place?

Here are a few reasons to love it:

• Reduces waste: Put that sourdough discard to good use instead of tossing it!
• Adds flavor: Sourdough discard adds a subtle tang that beautifully complements sweet bananas and brown sugar.
• Easier on digestion: With a long ferment, the sourdough bacteria help break down gluten and phytic acid, making the bread gentler on your tummy.
• Perfect texture: This recipe gives you a moist, tender crumb with just the right amount of structure.

Ingredients for Sourdough Banana Bread

You likely have everything on hand already! Here’s what you’ll need:

• 1 ¾ cups (220g) all-purpose flour
• 1 teaspoon baking soda
• ½ teaspoon salt
• 1 teaspoon ground cinnamon (optional, but so good!)
• ½ cup (113g) butter, melted and slightly cooled
• ¾ cup (150g) brown sugar
• 2 large eggs
• 1 ½ cups mashed ripe bananas (about 3–4 medium bananas)
• ½ cup (120g) sourdough discard (unfed starter at room temp)
• 1 teaspoon vanilla extract

Step-by-Step Instructions

Quick Version (No Long Ferment)

This is your go-to when you want to bake same-day.

1. Preheat and prep.
Preheat your oven to 350°F (175°C). Grease a 9×5-inch loaf pan or line it with parchment paper.

2. Mix dry ingredients.
In a medium bowl, whisk together flour, baking soda, salt, and cinnamon.

3. Mix wet ingredients.
In a large bowl, combine melted butter and brown sugar. Whisk in the eggs, one at a time. Add mashed bananas, sourdough discard, and vanilla extract. Stir until smooth.

4. Combine.
Gradually add the dry ingredients to the wet, mixing just until no dry flour remains. Do not overmix.

5. Bake.
Pour the batter into the prepared loaf pan. Bake for 55–65 minutes, or until a toothpick inserted in the center comes out clean.

6. Cool.
Let cool in the pan for 10–15 minutes before transferring to a wire rack.

Long-Fermented Option (Overnight)

If you want all the benefits of sourdough fermentation, this version is for you.

Long Ferment Instructions:

Night Before (Fermenting the Base):

1. In a bowl, mix the following:
   • 1 ¾ cups flour
   • ½ cup sourdough discard
   • 1 ½ cups mashed bananas
   • ½ cup melted butter
2. Cover the bowl and let it sit at room temperature for 8–12 hours. If your kitchen is warm, 8 hours is plenty. You can also ferment in the fridge for up to 24 hours.

Next Day (Final Mixing & Baking):
3. Stir in the remaining ingredients:

• ¾ cup brown sugar
• 2 eggs
• 1 teaspoon vanilla
• 1 teaspoon baking soda
• ½ teaspoon salt
• 1 teaspoon cinnamon

4. Mix gently just until combined. Pour into your loaf pan and bake as directed above.

The long fermentation gives this banana bread a deeper flavor and makes it even more nourishing—especially helpful if you or your family members are sensitive to gluten.

Tips for Success

• Use very ripe bananas. The riper, the better. They should be covered in brown spots for max sweetness.
• Room temp eggs help. Cold eggs can cause the butter to seize—let them sit out for 20 minutes before mixing.
• Don’t overmix. Stir gently to keep the crumb tender.
• Store it well. Wrap in foil or place in an airtight container at room temperature for up to 3 days, or freeze for up to 2 months.

Variations and Add-Ins

Want to switch things up? Try these:

• Chocolate chips – Add ½ to 1 cup for a banana-chocolate combo.
• Walnuts or pecans – Fold in ½ cup chopped nuts for crunch.
• Coconut flakes – Add ¼ cup shredded coconut for a tropical twist.
• Maple syrup – Sub part of the sugar with maple for extra flavor depth.

Frequently Asked Questions