This is the best sourdough zucchini bread, made with sourdough starter discard. It is lightly sweetened, subtly spiced with cinnamon, and includes chopped walnuts for a satisfying crunch!

If you happen to have excess zucchini and leftover sourdough starter discard, don't miss out on making this easy sourdough zucchini bread recipe. In fact, why not bake a few loaves and store them in the freezer for later?
Similar to our recipes for sourdough lemon cake, sourdough pumpkin bread, and sourdough banana bread, this recipe is incredibly simple to make, and you'll be amazed by its tender and moist texture.
We love creating recipes that make good use of sourdough discard, as it helps minimize food waste while adding an extra layer of flavor to this quick bread.
This recipe offers a delicious way to encourage your family to consume more veggies too!
Enjoy this lightly sweetened quick bread at any time of the day, whether it's morning, noon, or night.

Ingredients needed
An added convenience of this recipe is that you don't need an electric mixer. The ingredients effortlessly come together with just a spatula, making the mixing process a breeze.

- freshly grated zucchini
- light brown sugar
- eggs
- sourdough starter
- vanilla extract
- avocado oil
- flour
- baking soda
- baking powder
- salt, cinnamon
- chopped walnuts
- chocolate chips or raisins (optional)

How to make it
Step 1: Preheat the oven
Preheat your oven to 350°F (176°C) and lightly grease a 9" x 5" baking pan.
Step 2: Prepare zucchini
Grate the zucchini using a box grater or a food processor. Use your hands to squeeze the zucchini to release any extra moisture and excess water. Leave the zucchini in a colander while you mix the remaining ingredients.

NOTE: To ensure consistent results with every bake, use grated zucchini that has been thoroughly drained to remove excess moisture. The variation in moisture content of each zucchini can greatly affect the outcome, and our method helps maintain consistency.
Step 3: Mix dry ingredients
Mix the dry ingredients together in a small bowl and set aside.

Step 4: Mix wet ingredients
In a large mixing bowl, combine the wet ingredients and stir until the mixture is smooth.
Add the dry ingredients to the wet ingredients and stir until combined. Give the zucchini one last squeeze and fold it into the batter.

Step 5: Bake
Pour the batter into a greased 9” x 5” baking dish and bake at 350°F (176°C) for 55-60 minutes or until a toothpick inserted into the center comes out clean.
NOTE: The batter can be cold fermented in the fridge overnight after it has been mixed and poured into the baking dish. Keep it covered until you are ready to bake.

Step 6: Cool
Let the zucchini bread cool for 15 minutes. Run a butter knife around the edges to release them from the dish and transfer the bread to a cooling rack.
Enjoy warm or at room temperature.

How to store and freeze
For storage, once the sourdough zucchini bread has cooled entirely, cover it and keep any leftovers at room temperature for 1-2 days. Alternatively, you can store it in the refrigerator for up to 7 days.
If you wish to freeze the bread, wrap the cooled loaf first in plastic wrap and then in aluminum foil. It can be frozen for up to 3 months.
To thaw the frozen bread, allow it to thaw overnight in the refrigerator. Once thawed, bring it to room temperature before slicing and serving.

Recommended kitchen tools
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- 9" x 5" baking dish (affiliate link)
- mixing bowls (affiliate link)
More sourdough discard recipes:
We love sharing recipes that utilize sourdough discard. Browse through our sourdough discard recipes for a little baking inspiration. Here are just a few!
- sourdough brownies
- sourdough chocolate chip cookies
- sourdough banana nut muffins
- sourdough pop tarts

Sourdough Zucchini Bread
EQUIPMENT
- 9 x 5 inch loaf pan
INGREDIENTS
Dry Ingredients
- 2 cups (240 g) all-purpose flour
- 2 teaspoons baking powder
- ½ teaspoon baking soda
- 1 teaspoon (5 g) fine sea salt
- 2 teaspoons ground cinnamon
- ½ cup (60 g) chopped walnuts
Wet Ingredients
- 1 cup (220 g) light brown sugar
- 2 large eggs
- ½ cup (125 g) sourdough starter discard
- 2 teaspoons (10 g) vanilla extract
- ½ cup (109 g) avocado oil
- 1 ¾ cups (220 g) grated zucchini (squeeze out excess liquid)
INSTRUCTIONS
- Preheat oven to 350°F (176°C) and lightly grease a 9" x 5" loaf pan.
- Grate the zucchini using the large holes of a cheese grater. Place it in a colander and squeeze out excess moisture. Leave the zucchini in the colander while you mix the remaining ingredients.
- In a large bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon and chopped walnuts. Set aside.
- In a separate bowl, mix the light brown sugar, eggs, sourdough starter discard, vanilla extract and oil with a spatula until smooth. Pour the dry ingredients into the wet ingredients and mix until just combined. Stir in the grated zucchini.
- Pour the batter into the greased baking pan and bake for 55-60 minutes, or until a toothpick inserted in the center comes out clean. (See notes)
- Let the bread cool for 10-15 minutes before transferring it to a cooling rack. Slice and serve.
NOTES
- The batter can be cold fermented in the fridge overnight after it has been mixed and poured into the baking dish. Keep it covered until you are ready to bake.
- To store: Allow the bread to cool completely. Cover and store leftover bread at room temperature for up to 1-2 days or in the refrigerator for up to 7 days.
- To freeze: Wrap the cooled loaf in a layer of plastic wrap and then a layer of aluminum foil. Freeze up to 3 months.
- To thaw: Allow to thaw overnight in the refrigerator and bring to room temperature before slicing and serving.
Diane says
Love this zucchini bread! It isn't oily like a lot of recipes and it can be long fermented. During the long ferment, does the sourdough starter ever go after the brown sugar instead of the flour making it not as easily digestible?
Amy says
I'm not sure but I would think that it would just help to multiply the yeast as it ferments.
Ken Dueck says
I made this zucchini bread for my first time and wow it was delicious, I made a loaf for our neighbour and she is always asking for more lol
Thank you for all of your recipes
Carli says
SO YUMMY!! For those like me who can't help but make everything "healthy" and are wondering how it would go-- I used all whole wheat pastry flour, replaced eggs with flax eggs, subbed 1/2 the oil with applesauce, and reduced the sugar by almost 1/2 (and used coconut sugar), and they turned out perfect. Admittedly, many people would enjoy them sweeter, but all of my kids loved them!
Amy-- your instructions are so clear and easy to follow, and the weighted measurements are so so helpful! I'm slowly working my way through your sourdough recipes and we are loving everything!