Rustic Zucchini & Walnut Sourdough Bread Recipe

Last Updated on June 21, 2020

Yes, another garden zucchini recipe. Sorry, not sorry. I don’t know about you, but by midsummer we’re drowning in the stuff! Even if you’re not in the same (zucchini) boat as us, this zucchini sourdough recipe is most certainly worth making!

This moist, fluffy, chewy zucchini sourdough bread is a healthy and savory twist on traditional zucchini bread. It is the perfect way to use up some of your excess homegrown zucchini, or simply inject more veggies into your life – which is always a good thing! It’s also much more versatile than sweet zucchini bread, and can easily be enjoyed on its own, as sandwich bread, or as a side with other meals. 

Before we get mixing and baking, I should note that this article will be most easy to follow for those who are familiar with making sourdough bread. Meaning, I am not going to go into extreme detail when explaining each step – such as “stretch and fold”. It follows the same process we use for our basic sourdough bread, but with a few tweaks along the way. Therefore, if you’re new to sourdough baking, you may find it helpful to check out this simple sourdough loaf recipe to get your feet wet first.

If you are in need of a sourdough starter culture, learn how to easily make your own from scratch here! Or, if you aren’t up for making a starter from scratch, feel free to pick up a dry (but alive!) organic sourdough starter the Homestead and Chill shop. All it needs a little water, flour, and few days to get active again.

INGREDIENTS

• 295 grams of white bread flour, or all-purpose flour. We use King Arthur organic bread flour.
• 140 grams of whole wheat flour. Bob’s Red Mill organic whole wheat is our go-to choice
• 20 grams of rye flour. If you don’t have rye, simply increase the whole wheat amount by 20 grams.
• 1 ¼ cup of warm filtered water
• 120 grams of active sourdough starter
• 1 to 1 ½ cups grated zucchini (see sliding scale info in directions below)
• 9 grams of salt
• ½ cup of walnuts – We use raw, unsalted, halves & pieces (substitute with unsalted sunflower seeds or pumpkin seeds for those with walnut allergies)
• Optional, but delicious: 1/2 tsp of garlic powder and 2 tsp onion of powder

Timing: We generally make our dough over the course of one afternoon. This includes about 5 to 6 hours total, from initial mixing of the autolyse to forming into loaf that evening – with plenty of resting down time mixed in of course! We then let the dough cold proof in the fridge overnight, and finally bake it the following morning. 

DIRECTIONS

1) Feed Your Sourdough Starter 

Wake up your sourdough starter and get it ready for baking! Feed your starter as you typically would, at least several hours before you wish to begin making dough. If you starter has been refrigerated, I recommend taking it out the night before and feeding it at least twice to reach peak activity. 

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2) Create an Autolyse

About an hour before you think your sourdough starter will be at peak activity and ready to use, weigh and combine the called-for flour and water in a large mixing bowl. Avoid adding cold water to the flour. Mix well – I use my hands! Let this mixture sit for an hour, covered with a tea towel. If possible, keep it in a location with an ambient temperature between 70-80 degrees Fahrenheit. The same temperature range is ideal for the bulk fermentation described below.

Note that this autolyse uses less water than our classic loaf recipe, and will likely seem more dry than usual. That is intentional! We need to scale back on the water here a tad, to compensate for the additional moisture that will be added to the loaf through the zucchini. 

3) Prepare the Zucchini

Once the autolyse has been mixed and resting for about 40 minutes, begin prepping the zucchini. It needs about 15 minutes of its own “rest time” before being added to the dough too!  Grate the zucchini into medium-fine shreds – we use a basic box cheese grater. Here is the note about the sliding scale: If you’re after a “taller”, open-crumb sourdough loaf, use closer to 1 cup of grated zucchini. We chose to use a heavier hand and go with 1.5 cups. It is zucchini sourdough bread after all! However, the additional moisture and weight from the zucchini makes the loaf slightly more flattened than our average loaves. We don’t mind. You can see from the photos that it is still plenty airy!

Add the grated zucchini to a strainer. Next, sprinkle the zucchini with a few light shakes of salt, and toss to mix. Rest the strainer in a very clean sink, or set it over a larger bowl. Over the next 15 minutes, the salt is going to help draw excess water out of the zucchini, which will drain away. To help remove even more moisture, I suggest tossing, pressing and lightly wringing out the zucchini every 5 minutes – a total of three times. Do not add the collected zucchini water to the recipe!

4) Combine to Create Dough

Now that the autolyse has sat for an hour, and the zucchini has weeped, let’s mix up our dough! In the bowl with the autolyse, add the grated zucchini, 9 grams salt, 120 grams of active sourdough starter, and if you have some, ½  tsp of garlic powder and 2 tsp of onion powder. The seasonings are from our garden as well. If you’re interested, check out these tutorials about how to make your own garlic powder and onion powder!

Thoroughly mix to combine all of the ingredients. Again, using your hands to pinch, toss, and knead will help accomplish this. Finally, give it a “slap and fold” to help further combine and tighten the dough. Place the formed dough ball in your bulk ferment container of choice. We place it back in the mixing bowl. Cover the container with a tea towel and let it rest for 30 minutes. 

5) Stretch & Fold + Add Walnuts

Next, it is time to add the walnuts. We do this during the first set of “stretch and fold”, which gives the walnuts time to become evenly distributed throughout the zucchini sourdough during the following sets. Add ½ cup of walnuts and fold it into your dough. See the video below for a demonstration!

6) Bulk Ferment

Continue bulk fermentation at room temperature for about 4 to 5 hours. During the first couple of hours, repeat at least 3 more sets of stretch and fold, about 30 minutes apart. Then let the dough rest and rise undisturbed for the remainder of bulk ferment.

7) Form & Proof

Now that your sourdough has finished fermenting at room temperature, it is time to get the loaf formed, tucked into its banneton (proofing basket), and put away to sleep in the fridge. On a lightly floured surface, form your loaf into the desired shape with a few folds and tucks. Afterward, we generally let it sit to bench rest for about ten minutes, give it one final fold and form, and then slip it into a floured banneton. Cover the banneton with a tea towel once again, and allow the dough to cold proof overnight in the refrigerator. 

8) Bake 

Time to wake and bake! Preheat your oven to 475°F for one hour, with your empty cast iron combo cooker or dutch oven inside. After everything has preheated for an hour, carefully slip your cold dough straight from the fridge into the piping hot dutch oven or cast iron. For a smooth transition, we place a piece of parchment paper on top of the banneton, a cutting board on top of that, then flip the whole thing upside down. Out comes the dough ball. Give it a very light dusting of flour, and a fancy or simple score with your bread lame across the top if you wish, before easing it into your hot pan. Cover the pan with its lid, and get it into the oven.

Bake covered for 40 minutes, remove the lid and bake for an additional 5 minutes. 

Baking tip: Some people struggle with the bottom of their loaves burning. If you place a baking sheet on the empty oven rack below the one your bread is baking on, it helps absorb and deflect some of the heat. No more burnt bottoms!

9) Enjoy Your Zucchini Sourdough!

Once the loaf is finished baking, immediately (and carefully!) transfer your finished zucchini sourdough bread from the hot pan to a cooling rack. As difficult as it is to resist, allow the bread to cool for several hours before slicing into it. This prevents all that delicious moisture from escaping! Once it is cool, dig in!

Fresh sourdough bread is always best the day of or after baking. To store your bread, I suggest wrapping it in a lint-free tea towel before putting it inside a paper bag. That way, you can enjoy it over four to five days. However, if it becomes stale, you could also toast or broil it first!

We like to eat our zucchini sourdough bread much like we do any other sourdough bread recipe – any and every way! It is superb on its own, especially with those walnut bits and extra little spunk of garlic and onion goodness. We also like to pile on veggie sandwich toppings, like hummus or homemade “besto pesto“, tomato, cucumber, avocado, sliced radishes – whatever is available from the garden! Of course, zucchini sourdough would make an excellent side to any dinner meal, such as with soup, lentils, eggs, sautéed veggies, and more!

Ok guys. Finally, it is time for you to go make your own sourdough zucchini bread! But be sure to report back on how much you love it! Feel free to ask any questions, and spread the sourdough love by sharing this post. Pin it below!

You may also be interested in:

• How to Use Discarded Sourdough Starter: Sourdough Herb Crackers Recipe
• Cast Iron Whole Wheat & Herb Sourdough Pizza Crust Recipe
• Baked Sourdough Tortilla Corn Chips
• Simple Sourdough Focaccia Bread Recipe
• Sourdough Corn Bread Recipe (with Vegan Options)

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5 from 4 votes

Rustic Zucchini and Walnut Sourdough Bread Recipe

This moist, fluffy, chewy zucchini sourdough bread is a healthy and savory twist on traditional zucchini bread. It is the perfect way to use up some of your excess homegrown zucchini, or simply inject more veggies into your life – which is always a good thing! It’s also much more versatile than sweet zucchini bread, and can easily be enjoyed on its own, as sandwich bread, or as a side with other meals.

Prep Time30 minutes mins

Cook Time45 minutes mins

Ferment & Proofing Time16 hours hrs

Servings: 1 loaf of bread

Equipment

• Large mixing bowl
• Lined banneton bread basket, for shaping and proofing dough
• Kitchen scale
• Cast iron combo cooker or dutch oven
• Grater, to shred zucchini
• Colander or strainer
• Bread lame for scoring (optional)

Ingredients

• 120 grams active sourdough starter
• 455 grams total flour – we use 295 grams of white bread flour, 140 grams of whole wheat, and 20 grams of rye flour
• 1.25 cups filtered water in very humid climates, start with 1 cup of water and add more as needed
• 9 grams salt – sea salt, kosher salt, or Himalayan salt is preferred over iodized table salt (plus a sprinkle on the zucchini)
• 1 medium zucchini, grated (approximately 1 to 1.5 cups, see sliding scale notes below)
• 1/2 cup walnuts – we use raw, unsalted, halves & pieces substitute with unsalted sunflower seeds or pumpkin seeds for those with walnut allergies
• optional: ½ tsp of garlic powder and 2 tsp of onion powder

Instructions

• Before making the dough, be sure to feed your sourdough starter at least twice, allowing it to reach peak activity level.
• Make an autolyse by combining the flour and water in a bowl until thoroughly mixed. Let it sit covered at room temperature (70-75 degrees is optimal) for about an hour. (The dough may seem more dry than usual sourdough, because the zucchini will add more moisture soon)
• While the autolyse is resting, prepare the zucchini – which also needs to sit and rest after grating. Use a box grater to shred one medium zucchini into a colander or strainer. Next, sprinkle the zucchini with a few light shakes of salt, and toss to mix. Rest the strainer in a very clean sink, or set it over a larger bowl. Over the next 15 to 30 minutes, the salt will draw excess water out of the zucchini. Toss and lightly press (wring out) the zucchini a few times while you wait – about 5 to 10 minutes apart. Do not add the collected zucchini water to the recipe!
• After the autolyse has rested for nearly an hour, mix in the called-for active sourdough starter, salt, and grated drained zucchini until thoroughly combined. Mixing with your hands is normal and acceptable. (Also add optional ½ tsp of garlic powder and 2 tsp of onion powder).
• Optional: Lift the dough ball (which may be quite loose) out of bowl and on a clean counter use the “slap and fold” technique to tighten the dough.
• Once finished, put the dough back in the bowl and allow to rest at room temperature for 30 minutes. Cover the bowl with a damp tea towel or similar. This begins the "bulk fermentation" time.
• After 30 minutes, add the walnuts and then start the first round of “stretch and fold” – gently lifting up on one side of the dough and folding it back over itself. Give the bowl a quarter turn and continue to stretch and fold the dough until it is taught and resists pulling. Avoid tearing the dough. Use wet hands to prevent sticking. Cover the bowl again, and let sit.
• Repeat the stretch and fold process every 30 minutes for a total of 3 or 4 rounds.
• After about 4 hours of bulk fermentation at room temperature, stretch and fold the dough one final time to help it tighten up.
• Next, set the dough on a lightly floured surface and shape the loaf into a similar shape as your banneton (proofing basket – e.g. a round loaf, or long oval loaf). Let the dough “bench rest” for a final 10 minutes.
• After the final bench rest, place the dough in a flour-dusted (and potentially cloth-lined) banneton proofing basket of choice. Cover with a breathable towel, and place in the refrigerator to proof for 8 to 16 hours. We usually do this overnight.
• After cold-proofing in the refrigerator, preheat the oven to 475 to 500 degrees F. (Experiment to see what temperature works best for your oven). If you’re using a dutch oven or combo cooker, place it in the oven to preheat for one hour.
• After an hour of preheating, quickly and carefully transfer the cold dough (straight from the fridge) out of the banneton and into the hot combo cooker or dutch oven. Line the combo cooker or dutch oven with parchment paper first. Score the top of the loaf with a bread lame if desired. (See Note 1 below)
• Bake the loaf covered for approximately 40 minutes, and then remove the lid and bake for an additional 5 minutes uncovered. (See Note 2 and Note 3 below)
• Once done, immediately remove the finished sourdough loaf from the oven and combo cooker and place the loaf on a wire rack to cool.
• Let the sourdough bread loaf sit at room temperature for several hours before cutting. The steam trapped inside is important moisture to retain!
• Enjoy!
• To store your bread, I suggest wrapping it in a lint-free tea towel before putting it inside a paper bag. That way, you can enjoy it over four to five days. However, if it becomes stale, you could also toast or broil it first!

Notes

1. To transfer the dough from the banneton to the hot combo cooker or dutch oven, try this trick: Place a piece of parchment paper (cut to just larger than the banneton and loaf) on top of the banneton and exposed dough. Then place a cutting board on top. Holding both the cutting board and banneton, flip the whole thing over. Lift the banneton away, leaving the dough ball sitting on the parchment paper and cutting board. Carefully slide the parchment paper into the combo cooker or dutch oven. 
2. Baking times may vary slightly depending on your oven. Lately we’ve been doing 37 minutes covered and 5 minutes uncovered.
3. If the bottom of your loaf seems to brown more than you’d like, try adding an empty baking or cookie sheet to the empty oven rack directly below your combo cooker or dutch oven. It deflects some of the heat away from the bottom of the loaf, reducing burning or browning. 
4. To double this recipe, double all ingredients and follow the same steps until it is time to form the loaf and bench rest. At that time, split the larger dough into two equal balls. Form each loaf and allow each to bench rest, and then proceed with the instructions using two proofing baskets. Keep the spare loaf refrigerated while the other is baking, unless you have the ability to bake them at the same time.