Sourdough Banana Nut Bread

I discovered this recipe by accident on a Tuesday morning when my sourdough starter was bubbling over and I had three overripe bananas staring at me from the counter. Instead of discarding either one, I thought: why not make something that celebrates both? The result was a loaf so tender and tangy that my partner asked for seconds before I'd even finished cooling it, and suddenly I had a new reason to keep feeding my starter.

My mother came over on a rainy Saturday and sat at the kitchen counter while I mixed this together, and I remember her saying the batter smelled like "something between banana bread and sourdough pizza." When we pulled it from the oven, the brown sugar crust had deepened to an amber color that made the whole kitchen smell like caramel and cinnamon, and she cut into it while it was still warm enough to steam.

Ingredients

• Ripe bananas, mashed: Look for bananas with brown spots; they're sweeter and easier to mash, and they won't make your bread gummy the way underripe ones can.
• Sourdough discard: Use discard that hasn't been fed recently so it's at peak tang; it should smell pleasantly sour, almost yogurt-like, which means it'll add depth without overpowering the banana.
• Unsalted butter, melted and cooled: Cooling it slightly prevents the eggs from scrambling when you fold everything together, and it distributes more evenly through the batter.
• Eggs and milk: Room temperature ingredients mix more smoothly and create a more tender crumb, so pull them out of the fridge 20 minutes before you start.
• All-purpose flour and baking soda: The baking soda reacts with the acidity of the sourdough and bananas, giving you rise without needing too much baking powder.
• Walnuts, toasted: Toasting them first brings out their flavor so they taste nutty rather than bland; raw walnuts can taste bitter and muddy the whole loaf.
• Brown sugar crust: This is what makes people stop mid-conversation when they taste it—the butter and brown sugar create a caramelized shell that's almost like a streusel, but simpler.

Instructions

Prep and preheat:

Get your oven to 350°F and line your loaf pan with parchment paper; this makes pulling the bread out later feel effortless instead of stressful.

Combine wet ingredients:

Whisk together the bananas, sourdough discard, melted butter, eggs, milk, and vanilla until it's smooth and almost creamy. You're looking for a texture where you don't see streaks of banana anymore.

Mix dry ingredients separately:

In another bowl, whisk flour, granulated sugar, baking soda, baking powder, salt, and cinnamon together so everything's evenly distributed before it hits the wet mixture.

Combine wet and dry:

Pour the dry ingredients into the wet mixture and stir gently with a spatula until you just barely see no white flour streaks; stop before you're tempted to keep stirring, because overmixing makes the crumb tough and dense.

Fold in the walnuts:

Add your toasted walnuts and fold them in gently so they're scattered throughout rather than sinking to the bottom.

Pour and top:

Transfer the batter to your prepared pan and smooth the top with the back of a spatula. Mix the brown sugar, melted butter, and cinnamon in a small bowl until it looks like wet sand, then sprinkle it evenly over the batter so every slice gets some crust.

Bake:

Slide it into the oven for 50 to 60 minutes—start checking around 50 minutes by inserting a toothpick into the center, and when it comes out clean or with just a few moist crumbs, you're done. The top should be golden and the crust should smell like caramel.

Cool properly:

Let it sit in the pan for 15 minutes so it sets just enough to handle, then turn it out onto a wire rack to cool completely so the bottom doesn't get soggy from sitting in residual heat.

Save

One morning last month, I made this bread and my neighbor stopped by unexpectedly, and somehow a slice of warm banana nut bread with butter melting into it became the thing that turned a rushed Tuesday into something worth remembering. That's when I realized this recipe isn't just about using up sourdough discard—it's about having something simple and good to share.

Why Sourdough Discard Works Here

Sourdough discard is tangy and slightly acidic, which means it reacts with the baking soda to help the bread rise gently and evenly without needing too much chemical leavening. More importantly, it adds a subtle complexity to banana bread that makes people pause and ask what you did differently; they taste the familiar sweetness but there's something more happening underneath, something slightly funky and fermented that makes the whole thing more interesting. The discard also keeps the crumb moist longer because the natural acids help retain moisture, so a slice tastes just as good on day three as it does the day you bake it.

The Brown Sugar Crust Secret

This isn't a complicated topping, but it's doing important work—while the bread bakes, the brown sugar and butter meld together and caramelize slightly, creating a shell that's crispy on the outside and sweet on the inside. It looks like you spent time getting fancy, but it takes maybe two minutes to mix together. The key is sprinkling it on before you bake, not after, so it has time to toast and set into the top of the loaf rather than sliding off when you slice it.

Storage and Serving Ideas

This bread keeps beautifully wrapped loosely in foil or in an airtight container for up to four days on the counter, and it actually tastes better on day two when the flavors have settled and the crumb has finished absorbing moisture evenly. You can slice it thick and toast it with a pat of butter, or serve it with cream cheese if you want something richer. It pairs perfectly with black tea or a light roast coffee, and it's also lovely sliced thin and tucked into lunchboxes or paired with cheese on a casual board.

• Warm slices taste even more tender and luxurious when you toast them gently in a skillet with a little butter.
• If you find the loaf is drying out after a couple of days, wrap it in foil to trap moisture and keep it soft.
• You can freeze the whole cooled loaf wrapped tightly in plastic wrap and foil for up to three months, then thaw it on the counter before slicing.

Save

This loaf has become my answer to the question "what should I do with my sourdough discard?" because it turns something that feels like an obligation into something worth anticipating. Make it once and you'll find yourself planning to feed your starter just so you have an excuse to bake it again.

Kitchen Guide

→ What does sourdough discard add to the loaf?

It provides a subtle tang and depth, enhancing flavor complexity and texture without overpowering the banana sweetness.

→ Can I substitute the walnuts with other nuts?

Yes, pecans or almonds work well and add their own unique crunch and flavor to the loaf.

→ How do I achieve a crispy brown sugar crust?

Mix brown sugar with melted butter and cinnamon, then sprinkle evenly over the batter before baking for a sweet, crunchy topping.

→ What is the best way to store this bread?

Keep it wrapped tightly at room temperature for up to two days or refrigerate to maintain freshness longer.

→ Can I add chocolate chips to the mixture?

Yes, folding in chocolate chips provides extra sweetness and complements the nutty and tangy flavors beautifully.