Sourdough Discard Zucchini Bread with Cinnamon Brown Sugar Streusel
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If you have sourdough discard and a zucchini on your counter, you are 20 minutes of prep away from two loaves of sourdough discard zucchini bread that will make you forget the store-bought version ever existed. This is the same batter I use for my Easy Sourdough Discard Zucchini Muffins with a Cinnamon Sugar Crust, baked in loaf pans and topped with the same brown sugar cinnamon streusel from my Sourdough Discard Peach Muffins. Chopped pecans fold into the crumb, the sourdough gives you a subtle tang that no standard zucchini bread has, and both loaves freeze beautifully so you can enjoy them long after zucchini season is over.
Ginger’s Thoughts
Growing up, my mom never made zucchini bread. She loves vegetables, but anything in the squash family was a hard no. My dad is from West Virginia and he and I were actually born in the same hospital in Welch, WV. Fun fact: Steve Harvey was born there too. Depending on when you were born, your birth certificate might say “Miners Hospital No. 1” or “Welch Emergency Hospital.” My mom was born in Bristol and is, as my dad and I have always called her, much more of a city girl.
It was my husband, raised in Georgia, who opened my eyes to the squash family. That is when I found zucchini and fell in love. I love it in stews, grilled, boiled, baked, fried and yes, baked into bread. If you have ever grown zucchini, you know exactly what happens. You wait weeks for the first one and then suddenly you are pulling them off the plant every single day and they keep coming back bigger. Finding something to do with all of them is half the battle. This bread is one of my go-to solutions, and I like to bake two loaves at a time so I can freeze one for later. If you want to see how I tackle an overwhelming garden harvest, check out my post on canning cucumbers and all the ways I preserved 72 cucumbers — the zucchini struggle is very real in the same way.
For this bake I used my 8.5×5.5 aluminum loaf pans. Nothing sticks to them as long as they are oiled, I get an even bake every time, and this size fits perfectly in the freezer. Once a loaf is frozen solid, I stand it on its side in our stand-up freezer and can see how many I have at a glance. If you prefer a higher rise, use a narrower and taller pan and add at least 10 minutes to your bake time.
Table of Contents
What Makes This Sourdough Discard Zucchini Bread Different
Most zucchini bread recipes skip the one step that actually matters. Fresh zucchini is full of water and if you fold it straight into your batter, that water releases during baking and turns your loaf dense and gummy in the center. This recipe fixes that with a simple draining step before the zucchini ever touches the batter. You grate it, weigh it, squeeze it dry in a paper towel, and then fold it in. That one step is the difference between a loaf that bakes up tall and tender and one that collapses.
The brown sugar streusel on top sets this loaf apart from any basic zucchini bread you have seen. It bakes into a crumbly caramelized crust on every single slice. The sourdough discard adds a mild tang that balances the sweetness perfectly and the pecans add crunch throughout the crumb.
What You Need to Make Sourdough Discard Zucchini Bread
Ingredients
For the bread:
- 300g zucchini, grated and squeezed dry (weigh before squeezing)
- 203g (1 and 1/3 cups) all-purpose King Arthur flour
- 99g (1/2 cup) granulated sugar
- 170g (3/4 cup) sourdough discard, active or unfed
- 85g (1/4 cup) maple syrup
- 75g (6 tbsp) olive oil
- 2 large eggs
- 2 tsp Watkins pure vanilla extract
- 1 tsp cinnamon
- 1 tsp baking powder
- 1/2 tsp baking soda
- 1 tsp salt
- 1/2 cup chopped pecans
For the brown sugar streusel:
- 40g brown sugar (3 tbsp)
- 10g granulated sugar (2 tsp)
- 3g ground cinnamon (1 tsp)
- 30g unsalted butter, room temperature (2 tbsp)
- 50g all-purpose flour (1/3 cup)
- Pinch of salt
Equipment You Will Need
- SUSTEAS Rotary Cheese Grater – makes shredding zucchini fast and consistent
- OXO Good Grips Kitchen Scale – weighing the zucchini is the most important step in this recipe
- Aluminum Loaf Pans 8.5×5.5 – nothing sticks, even bake, and they fit perfectly in the freezer
- TEEVEA Danish Dough Whisk – makes folding the batter together effortless
- Weck Tulip Jar – what I store my sourdough starter in
- TempPro Digital Instant Read Thermometer – the most reliable way to know when your loaf is done
- Wire Cooling Rack – lets the loaf cool evenly so the crumb sets properly
How to Make Sourdough Discard Zucchini Bread Step by Step
Step 1: Grate and Drain Your Zucchini
Grate your zucchini using a rotary cheese grater or box grater. Weigh out 300g on your kitchen scale before you squeeze out any water. That weight is your starting point. Transfer the grated zucchini to a clean paper towel, wrap it up and squeeze firmly over the sink until no more water comes out. You will be surprised how much liquid releases. Set the drained zucchini aside.
Step 2: Mix Your Dry Ingredients
In a large bowl, whisk together the flour, cinnamon, baking powder, baking soda and salt until combined. Set aside.
Step 3: Mix Your Wet Ingredients
In a separate large bowl, combine the sugar, maple syrup, olive oil, eggs and vanilla extract. Whisk until smooth and fully combined.
Step 4: Add the Sourdough Discard
Add 170g of sourdough discard to your wet ingredients and stir to combine. Cold discard straight from the fridge works perfectly here. You do not need to bring it to room temperature first.
Step 5: Combine Wet and Dry
Pour the wet ingredients into the dry. Using your Danish dough whisk, gently fold until just combined. Stop as soon as you no longer see dry flour. A few streaks are fine at this stage.
Step 6: Fold In the Zucchini and Pecans
Add the drained zucchini and chopped pecans to the batter and fold until evenly distributed. The batter will be thick and you will see the zucchini strands and pecan pieces throughout. This is exactly what you want.
Step 7: Pour Into Your Pans
Preheat your oven to 350 degrees F. Grease two 8.5×5.5 loaf pans well with oil or butter. Divide the batter evenly between the two pans.
Step 8: Make the Brown Sugar Streusel
In a small bowl, combine the brown sugar, granulated sugar, cinnamon, flour and pinch of salt. You have two options for the butter: you can use room temperature butter, or you can do what I prefer and grate cold butter straight from the refrigerator directly into the dry ingredients. Either way, use your hands to work it in until the mixture is crumbly and holds together when you squeeze a pinch. Sprinkle generously and evenly over both loaves.
Step 9: Bake
Slide the pans into your preheated 350 degree F oven and bake for 40 minutes. Do not open the oven door during the first 20 minutes.
Step 10: Check Doneness and Cool
The loaves are done when the tops are deep golden brown and the streusel is set. For accuracy, use your instant read thermometer — you are looking for an internal temperature of at least 200 to 202 degrees F. Let the loaves cool in the pans for 10 minutes, then transfer to a wire cooling rack to finish cooling. The bread slices best once it has cooled for at least 20 minutes.
Pro Tip: Don’t Waste Your Extra Grated Zucchini
Here is something I always do and I want you to do it too. It is nearly impossible to grate zucchini and land on exactly 300g. So what I do is grate 3 or 4 zucchini at a time, then drain and dry all of it as well as I can. Then I weigh out the 300g for this recipe. Whatever is left, I put into a freezer bag, weigh it, and press it flat. I label the bag with what it is, the weight and the date, then put it straight into the freezer.
This makes it so much easier later in the year when your zucchini is not so plentiful. Pull out a bag and you have pre-measured, ready-to-use grated zucchini for soups, stews and yes, more sourdough zucchini bread. You already did the hard work once, so you might as well make it count.
The Zucchini Step You Cannot Skip
This section gets its own heading because it is the most important technique in this recipe. Fresh zucchini holds a lot of water inside its cell walls. When heat hits it in the oven that water releases into your batter. In a loaf that needs to hold its structure and bake through evenly, that extra moisture works against you.
The fix is simple. Grate your zucchini, weigh it, then squeeze it out before it touches the batter. Use a clean paper towel or a thin kitchen towel, bundle the zucchini up and squeeze firmly over the sink. You want to see water dripping out. Keep squeezing until it stops. What goes into your batter should feel almost dry to the touch. Once you do this step once, you will never skip it again.
Tips for Perfect Sourdough Discard Zucchini Bread Every Time
Weigh your zucchini before squeezing, not after. The 300g measurement is your pre-squeezed starting point.
Use a kitchen scale. This recipe was built in grams. Cup measurements for zucchini vary widely depending on how loosely it is packed. The scale removes all guesswork.
Do not overmix once the flour goes in. Fold until just combined and stop. Every extra stir develops gluten and gives you a tough loaf instead of a tender one.
Grease your pans well. These loaves are moist from the zucchini and maple syrup. Oil every corner of the pan.
Both active starter and discard work. Cold discard straight from the fridge is perfectly fine. Active starter at peak gives a slightly milder tang but the result is the same.
For the streusel, use room temperature butter or grate it cold. Room temperature butter mixes in easily. My preference is to grate cold butter straight from the refrigerator into the dry ingredients and use my hands to work it in. Both give you a great crumble.
How to Store
At Room Temperature
Store in an airtight container at room temperature for up to 3 days. Place a paper towel in the bottom of the container to absorb extra moisture from the zucchini.
In the Refrigerator
Store in an airtight container in the refrigerator for up to 5 days. Let slices come to room temperature before eating or warm briefly in the microwave for 15 to 20 seconds.
In the Freezer
These loaves freeze beautifully. Let them cool completely, then wrap tightly in plastic wrap and place in a freezer bag. They keep for up to 3 months. I freeze them whole, and once solid I stand them upright in the freezer so I can see how many I have. Thaw overnight in the refrigerator or on the counter for a couple of hours.
FAQ
Do I need to peel the zucchini before grating it?
No. Leave the skin on. It softens completely during baking and you will not notice it in the finished loaf. It also adds a small amount of color to the crumb.
Can I use active starter instead of sourdough discard?
Yes. This recipe works with both active starter and sourdough discard. Active starter at peak gives a slightly milder tang. Discard that has been in the fridge for up to a week works perfectly and adds more sour flavor.
Why did my bread come out dense?
Dense zucchini bread almost always comes down to one of two things: the zucchini was not squeezed dry before going into the batter, or the batter was overmixed after the flour was added. Go back to the draining step and make sure you are folding gently once the dry ingredients are in.
Can I use a different oil?
Yes. Melted coconut oil or a neutral vegetable oil both work as a substitute. Olive oil gives a very slight depth that pairs well with the cinnamon but it is not a strong flavor in the finished loaf.
Can I make these without maple syrup?
Yes. You can substitute honey in a 1:1 ratio by weight. The flavor will be slightly different but the texture will be the same. You can also use additional granulated sugar if needed.
How do I know when the bread is done?
The tops should be deep golden brown and the streusel should look set and caramelized. An internal temperature of 200 to 202 degrees F on your instant read thermometer is the most reliable confirmation. Check at 35 minutes if your oven runs hot.
Can I skip the pecans?
Yes. The pecans add crunch and texture but the loaf is delicious without them. You can also swap them for walnuts or chocolate chips.
Can I bake this in a different size pan?
Yes. If you use a narrower and taller pan you will get a higher rise. Add at least 10 minutes to your bake time and check the internal temperature rather than relying on the clock.
Sourdough Discard Zucchini Bread with Cinnamon Brown Sugar Streusel
Ingredients
Method
- Grate zucchini and weigh out 300g before squeezing. Wrap in a clean paper towel and squeeze firmly over the sink until no more water releases. Set aside.
- Preheat oven to 350 degrees F. Grease two 8.5×5.5 loaf pans well with oil or butter.
- In a large bowl, whisk together flour, cinnamon, baking powder, baking soda and salt.
- In a separate bowl, combine sugar, maple syrup, olive oil, eggs and vanilla extract. Whisk until smooth.
- Add sourdough discard to the wet ingredients and stir to combine.
- Pour dry ingredients into wet and fold gently until just combined. Do not overmix.
- Fold in the drained zucchini and chopped pecans until evenly distributed.
- Divide batter evenly between the two prepared loaf pans.
- In a small bowl, combine streusel ingredients. Use room temperature butter or grate cold butter straight from the refrigerator. Work it in with your hands until crumbly. Sprinkle generously and evenly over both loaves.
- Bake at 350 degrees F for 40 minutes until tops are deep golden brown and the internal temperature reaches 200 to 202 degrees F.
- Cool in the pans for 10 minutes, then transfer to a wire rack. Bread slices best after cooling at least 20 minutes.
