Chocolate Sourdough Zucchini Muffins

Use up summer zucchini in these rich chocolate sourdough zucchini muffins, with shredded zucchini (no draining or drying!), nuts, and sourdough discard.

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How This Recipe Works

These sourdough zucchini muffins are the latest addition in our ongoing efforts to add as many sourdough discard recipes to the Baked Collective as we can. We're avid sourdough bakers - and you probably are too! - so that means we often have old starter or sourdough discard kicking around that we want to use up.

Depending on your goal for these sourdough muffins, you can use one of two methods. If you don't necessarily use a discard method (if you make levain instead) but would like a long-fermented muffin recipe, you can let the batter rest for up to 12 hours before baking it. If you just need a way to use up discard or excess starter then feel free to bake immediately.

If you prefer a zucchini muffin without the chocolate, you can try baking our sourdough zucchini bread in a muffin tin. I developed and tested this recipe.

Ingredients You'll Need and Why

If measuring in cups, grate the zucchini and place it in the measuring cup, packing lightly. If you have a baking scale all the better. These are our notes from recipe testing and you can find the full recipe card below with complete measurements and instructions.

• Flour: this should be plain all-purpose flour. Replace some of the white flour with whole wheat if you prefer. We haven't tested these with a gluten-free blend but it would probably be fine.
• Zucchini: any zucchini you have, big or small. We haven't tested with frozen zucchini and it might be a little too watery.
• Milk: use whole milk for the richest muffins. For a dairy-free alternative, we recommend soy milk but any unsweetened option will work (not canned coconut milk).
• Sourdough starter: this can be active starter or discard. If using discard note that if it's very old, grey, and smells strongly of alcohol that it will impact the flavour of the muffins.
• Oil: use your preferred baking oil. We like olive oil for a little sharpness against the zucchini and cocoa but neutral oil is generally better for kids or people who prefer a sweeter muffin.
• Sugar: plain white granulated sugar. You can substitute cane sugar or muscovado sugar. Brown sugar does change the texture of the muffins slightly.
• Cocoa: this should be unsweetened cocoa powder. Dutch process is best for a deep, smooth chocolate taste but natural cocoa is great too if that's what you have. The muffins are leavened only with baking powder so either will work.
• Eggs: large eggs at room temperature if possible. To quickly bring cold eggs to room temperature, submerge them in a bowl of warm water for 10 minutes.
• Nuts: try walnuts, pecans, or hazelnuts. Sunflower seeds are good too. Substitute chocolate chips for a more chocolate-forward muffin.

Use the JUMP TO RECIPE button at the top, or scroll to the bottom of the post to see the printable recipe card with full ingredient measurements and complete instructions.

How to Make Sourdough Muffins

Sifting the dry ingredients into the bowl removes any lumps, especially from the cocoa powder and baking powder, which are both tricky to whisk in properly and can really ruin a bite.

Step 1: place the dry ingredients into a fine sieve. If you don't have a large fine mesh sieve as pictured, the cocoa and baking powder can be sifted in something like a tea strainer (I've done it!).

Step 2: sift into a large mixing bowl, then whisk to fully combine. You'll notice just how lumpy the cocoa powder was before sifting. Most store-bought flour is also very compressed when you buy it, which is also why we recommend baking with kitchen scales for accuracy.

Step 3: in another bowl, whisk together the wet ingredients. Beat the eggs first so that they're easier to incorporate.

Step 4: add the wet ingredients to the flour mixture, then mix about halfway before adding the nuts or chocolate chips. This helps to prevent over-mixing.

Step 5: gently fold the nuts into the muffin batter, being careful not to over-mix, which makes muffins tough and chewy.

Step 6: divide the batter equally between the 12 muffin cups. You can line or grease the muffin cups for this recipe, and greasing with butter makes for a nice exterior texture and a little flavour boost.

Step 7: bake at 425°F for the first 5 minutes, then reduce the temperature and bake for another 15 minutes or so. This gives the muffins a higher dome and fluffier texture.

Step 8: cool fully on a wire rack, especially if you've done a longer ferment, before serving. The muffins are even better after being stored in a sealed container for a day.

Expert Tips for the Best Muffins

• Fully cool before serving: this is especially the case if you've long-fermented the muffins, which gives them a more bread-like texture. They'll be too chewy when still warm but excellent once cooled fully, much like sourdough bread.
• Start the oven hot: baking the muffins for a few minutes at a hot temperature makes them rise more quickly at the beginning, for taller, fluffier muffins.
• Use any summer squash: classic green zucchini is the most common, but you can use any type of zucchini or summer squash for this recipe (pattypan, round, yellow, striped, and so on).
• Save big zucchinis for baking: small, delicate summer squash tastes the best and you should always choose small, firm zucchinis when buying or harvesting them. If they've gotten away from you or they're on offer at the market or shop and too big to cook with, use them for baking instead, where the texture matters much less.
• Finely grate for picky eaters: if you want to be sneaky about the zucchini, grate in on the smaller side of the box grater and optionally peel it. The green skin is the most visible element once baked and peeling helps it really blend in.

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