Sourdough Zucchini Bread (With Discard) – Easy Recipe

Every summer, we end up with more zucchini than we know what to do with, and this sourdough zucchini bread has become one of the easiest ways to use it up. It started as a way to use extra sourdough discard, but quickly turned into something we make on repeat. The zucchini keeps it soft and moist, the apple adds a bit of natural sweetness, and the whole wheat flour brings just enough depth without making it heavy. It’s lightly spiced, not too sweet, and works just as well for breakfast as it does for a quick snack.

Why You Will Love This Recipe

• A great use for discard – Turns extra starter into something you’ll actually want to bake again.
• Stays soft and moist – The zucchini and apple keep the crumb tender for days without making it heavy.
• Not overly sweet – Lightly spiced with just enough sweetness for breakfast or a quick snack.
• A simple way to add whole grains – Whole wheat flour brings flavour and a bit more nutrition without weighing it down.
• Easy to adapt – Swap the nuts, change the fruit, or bake it as muffins, depending on what you have on hand.

Whether you are baking in peak zucchini season or looking for a new way to use your discard, this sourdough zucchini bread with apple and walnuts easily fits into your weekly rotation!

Key Ingredients for Sourdough Zucchini Bread

• Sourdough discard – Adds a light tang and a bit more depth. No need to bring it to room temp, straight from the fridge works fine.
• Zucchini – The main source of moisture. No need to peel it, just grate it. If it’s really wet, give it a light squeeze.
• Apple – Adds natural sweetness and keeps the crumb soft. Pear works well here too.
• Whole wheat flour – Brings a bit of nuttiness and structure without making the loaf heavy.
• Brown sugar – Adds moisture and a deeper flavour than white sugar alone.
• Greek yogurt – Helps keep the crumb tender and adds a bit of richness.
• Warm spices – Cinnamon, nutmeg, and allspice give it that classic zucchini bread flavour.
• Toasted walnuts – Add texture and richness. You can swap or leave them out if needed.

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Tools You’ll Need

• 8 x 4-inch loaf pan – Gives your sourdough zucchini bread the right height and an even bake.
• Mixing bowls – One for dry ingredients and one for wet ingredients.
• Whisk – Used to evenly combine dry ingredients and mix wet ingredients until smooth.
• Spatula – For folding the batter and incorporating zucchini, apple, and walnuts without overmixing.
• Box grater or food processor – If you’d like to shred the apple instead of dicing it.
• Offset spatula (optional) – Useful for smoothing the top before baking.
• Cake tester or skewer – Used to check doneness at the centre of the loaf.

How to Make Sourdough Zucchini Bread

1. Preheat the oven
   Preheat to 350°F (175°C) and grease an 8 × 4-inch loaf pan.
2. Mix the dry ingredients
   In a medium bowl, whisk together the all-purpose flour, whole wheat flour, baking soda, baking powder, cinnamon, nutmeg, allspice, and salt.
3. Mix the wet ingredients
   In a separate bowl, combine the sourdough discard, brown sugar, white sugar, oil, eggs, and Greek yogurt. Whisk until smooth and fully combined.
4. Combine wet and dry
   Add the dry ingredients to the wet and fold gently until no dry flour remains. Don’t overmix here—this is where the texture can go wrong.
5. Add the zucchini and apple
   Fold in the shredded zucchini and apple (and walnuts if using) until evenly distributed.
6. Transfer to the pan
   Pour the batter into your prepared loaf pan and smooth the top.
7. Bake
   Bake at 350°F for 50–60 minutes, until a cake tester inserted in the centre comes out clean.
8. Cool before slicing
   Let the loaf cool in the pan for at least 15–20 minutes, then transfer to a rack. Try to wait before slicing—this sets the crumb properly.

Tips for the Best Sourdough Zucchini Bread

• Don’t overmix the batter – Overmixing will give you a dense, slightly gummy loaf.
• Watch the moisture in your zucchini – If it’s really watery, give it a light squeeze before adding it in. Too much moisture can throw off the texture.
• Grate, don’t chop – You want the zucchini and apple to disappear into the batter. Big chunks will make the loaf uneven.
• Use the right pan size – An 8 × 4-inch pan gives you the proper height and bake. A larger pan will spread it out and bake faster (and drier).
• Don’t rush the bake – If the top is done but the centre isn’t, give it more time. A slightly underbaked loaf will sink and feel gummy when sliced.
• Let it cool before slicing – This is the hardest part, but it matters. Cutting too early will make it feel underbaked even if it isn’t.

Variations & Substitutions

This is a pretty forgiving batter, so you’ve got some flexibility depending on what you have on hand. You can swap the apple for a pear, change up the nuts, or skip them entirely. It also works well as muffins if you’re after something easier to portion and freeze. As long as you keep the overall balance of wet and dry ingredients close, this sourdough zucchini bread will still turn out.

• No apple – You can leave it out or replace it with a pear. The loaf will be slightly less sweet but still works well.
• Different nuts (or no nuts) – Walnuts can be swapped for pecans, hazelnuts, or left out completely if needed.
• Bake as muffins – Divide into a muffin tin and bake at 350°F for 18–22 minutes. Great for freezing and quick snacks.
• Oil swaps – A neutral oil works best, but melted butter or even olive oil will work if that’s what you have.
• Flour adjustments – You can use all-purpose flour instead of whole wheat, but you’ll lose a bit of flavour and structure.
• Add-ins – Chocolate chips, raisins, or seeds can be folded in at the end if you want to change it up.

Storage & Freezing

We usually just leave this sourdough zucchini bread on the counter, and it disappears pretty quickly, but if you want to plan ahead (or make two), it freezes really well.

• Room temperature – Once cooled, store the sourdough zucchini bread in an airtight container or wrapped well. It will stay soft for 2–3 days.
• Fridge (if needed) – You can refrigerate it for up to a week, but it may dry out slightly. Warm slices before serving to bring it back.
• Freezing – Slice the loaf and freeze in a sealed container or freezer bag for up to 4–6 weeks. This makes it easy to grab a piece when you need it.
• To reheat – Warm slices in the toaster, oven, or microwave until soft and heated through.

FAQ

• Can I omit the sourdough discard? Yes, the recipe will still work, though it will lose some depth of flavour; replace with an equal amount of flour and liquid such as milk or yogurt to maintain balance.
• Does this taste sour? No, the flavour is balanced with only a mild tang from the discard.
• Why is my zucchini bread dense? Overmixing or excess moisture from zucchini can lead to a dense texture.
• Do I need to drain the zucchini? If the zucchini is very wet, remove a small amount of moisture to keep the batter balanced.
• Can I replace the apple? Yes, apple can be replaced with other fruit such as pear or omitted if needed.
• Can I omit the walnuts? Yes, walnuts can be replaced with other nuts or left out entirely.
• Can I use only all purpose flour? Yes, but the whole wheat flour adds flavour, fibre and slight structure.
• How do I know when it is done? A cake tester inserted into the centre should come out clean.
• Can I freeze zucchini bread? Yes, slice and freeze in a container or freezer bag for 4-6 weeks, thaw in microwave, toaster or oven on a low temperature.
• Can I make sourdough zucchini bread into muffins? Yes, divide the batter into a lined or greased muffin tin and bake at 350°F for 18–22 minutes, or until a tester comes out clean.

More Sourdough Discard Recipes

We use sourdough discard in baking all the time—it’s one of the easiest ways to add a bit more flavour without any extra work. Once you get into the habit, you’ll start finding spots for it everywhere.

If you’ve got some extra on hand, here are a few recipes from the blog that we make regularly:

• Sourdough Discard Apple Muffins
• Sourdough Carrot Cake
• Sourdough Discard Scones
• Sourdough Granola Bars

You can also check out my YouTube channel for full step-by-step videos if you want to see the process in action.

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