Moist Sourdough Discard Zucchini Bread

Last Updated on June 19, 2026 by Jamie Saechao

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Soft and tender, moist and fluffy, this is the best sourdough discard zucchini bread recipe! Take advantage of your summer bounty by combining grated zucchini with sourdough discard, spicy cinnamon and a bit of nutmeg.  

Zucchini is bountiful in the summer months, growing so quickly we can barely keep up with it. One of my favorite things to do is bake with excess zucchini- it’s flavorless but adds both nutrition and moisture!

This specific bread is based off of classic zucchini bread recipe and given a sourdough twist. There is a long-ferment option available too, but I typically use leftover sourdough discard (about a day old). 

Add nuts like pecans and walnuts, if you like- or leave them out!

This sourdough quick bread is also very simple and easy to make, meaning you don’t have to stand around in a hot kitchen on a beautiful summer day!  

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For more sourdough discard recipes, try my sourdough chocolate zucchini muffins, sourdough peanut butter cookies, and sourdough banana bread. 

Ingredients

See the recipe card for full details on ingredients:

• Grated zucchini- I like to use small zucchini for the best moisture content and flavor.  Grate with the large side of a cheese grater. 
• All purpose flour
• White + brown sugar- Add sweet flavor and moisture to the dough
• Baking soda
• Cinnamon- The bold flavor of cinnamon warms up this bread
• Nutmeg- Totally optional, but I love the warm flavor a hint of nutmeg adds to this sweet bread!
• Salt- I like to use sea salt when possible
• Large eggs-room temperature eggs work best
• Oil- Any kind of oil will do but I prefer to use avocado oil or melted coconut oil 
• Vanilla
• Chopped pecans and walnuts- optional, for our nut lovers
• Sourdough discard- I like to use fresh sourdough discard for this recipe, though you can also use refrigerated discard- just set it on the counter to warm up before adding it to the dough

*The older your sourdough discard is, the tangier the bread will be. For mild flavor, use discard that is less than 48 hours old. 

Sourdough discard is the un-used, runny portion of sourdough starter that is discarded before you feed it fresh water and flour. I like to feed my sourdough starter 100 grams of flour and 100 grams of water so I have plenty of discard to use.

Looking for more moist sourdough baked goods? Try my sourdough pumpkin bread, sourdough lemon blueberry muffins, sourdough banana muffins.

Tools

This recipe makes two loaves- you will need two 8x 4 loaf pans.  These are the ones I use. 

How To Grate Zucchini

Use a box grater with large holes to grate your zucchini.  No need to blot the excess water from the shredded zucchini.

How To Make The Best Sourdough Zucchini Bread

You need just a few minutes to whip up this batter! First, preheat the oven to 350 degrees F. Grease and flour your two pans, or line them with parchment paper to prevent the dough from sticking. 

In a large bowl whisk together the flour, salt, baking soda, white sugar, cinnamon, nutmeg, and salt. 

In the bowl of a stand mixer whisk the three eggs.  Add in the brown sugar, grated zucchini, oil, vanilla, brown sugar, and sourdough discard and beat well. 

Pour the dry ingredients in the wet ingredients and beat until just combined, taking care not to over mix the batter.  Stir in the nuts if using. 

Transfer the dough equally into the prepared pan, about 450 grams per loaf. Bake for 50-55 minutes or until a toothpick comes out clean. 

Let the bread cool for five minutes, then transfer from the bread pans onto a cooling rack. 

Baking Tips

• Once the wet and dry ingredients are combined, take care not to overmix.  Over mixing your batter can lead to tough bread. 
• For moist and tender bread, remove it from the oven as soon as a toothpick comes out dry. Don’t overbake. 
• I like to use sourdough discard that is 48 hours old or less.  You can use older discard, it will just add more tang to the dough. 

Storage

Store at room temperature in an air-tight container for 3-4 days. 

To freeze: Make sure the bread is cooled completely, then wrap it in plastic wrap, then aluminum foil.  Set in the refrigerator overnight to thaw.