These Sourdough Zucchini Chocolate Chip Muffins strike a lovely balance between comforting and indulgent. They’re moist, slightly tangy from the discard, and studded with little pockets of melted chocolate. They come together quickly and are a great way to use sourdough discard and abundant summer zucchini.

If you bake sourdough regularly, keeping a few discard-friendly recipes on hand is wise — it’s a shame to waste that flavor. These muffins are simple, forgiving, and reliable: no mixer required, no unusual ingredients, and adaptable to what you have on hand.

Why you’ll love these sourdough muffins

• Hidden vegetable boost. Grated zucchini adds moisture and a bit of nutrition without making the muffins taste overly vegetal.
• Chocolate in every bite. Mini chocolate chips disperse throughout the batter for consistent pockets of chocolate.
• Subtle tang. Sourdough discard contributes tender crumb and a gentle depth of flavor.
• Fast and easy. Simple mixing, optional brief rest, and a short bake time make these approachable any day of the week.
• Seasonal favorite. A great way to use zucchini when it’s plentiful in spring and summer.

How to make sourdough zucchini muffins

Here is an overview of the process. Full ingredient amounts and step-by-step instructions follow in the recipe card below.

1. Mix wet and dry separately. Combine eggs, melted butter, sourdough discard, sour cream, sugar, vanilla, and the drained grated zucchini in one bowl. Whisk flour, baking powder, baking soda, salt, and any spices in another.
2. Fold together gently. Add dry ingredients to wet and fold until just combined. Fold in the chocolate chips last.
3. Optional rest. Let the batter rest for up to an hour at room temperature to allow the flour to hydrate and the discard flavor to soften.
4. Bake. Fill lined muffin cups nearly to the top and bake at 350°F until tops spring back, about 15–20 minutes.

Top tips for success

Remove excess moisture. Zucchini holds a lot of water. After grating, place it in a colander or a clean dish towel and press or squeeze gently to remove excess liquid. You don’t need to dry it completely — just eliminate the free-dripping moisture so batter consistency stays right.

Mix lightly. Overworking the batter will create dense muffins. Fold the dry ingredients in until no large streaks of flour remain.

Use a fresh discard for a milder tang. If you prefer a subtle sourdough note, use discard that hasn’t gone too long without feeding. Older discard will produce a more pronounced tang, which some people enjoy.

Resting the batter helps. Letting the batter sit for up to an hour allows the flour to hydrate and the flavors to develop, producing a thicker batter and better rise.

Fill muffin cups high. For bakery-style domes, fill each liner nearly to the top. These muffins bake up with tall, attractive tops when the cups are well filled.

Variations & substitutions

Orange zest. Add a teaspoon of orange zest to brighten the chocolate.

Different chocolate. Use regular or dark chocolate chips, chopped chocolate, or cacao nibs for texture and flavor contrast.

Nuts. Fold in ½ cup chopped walnuts or pecans for crunch.

Sour cream swap. Plain whole-milk yogurt works well in place of sour cream.

How to store muffins

Room temperature: Store in an airtight container for up to 4 days.

Freeze for later: Wrap muffins individually in plastic or freezer wrap, place in a freezer bag, and freeze. Thaw to room temperature or warm briefly before serving.

To refresh: Warm a split muffin in a 350°F oven for a few minutes or heat gently in a covered skillet for a revived just-baked taste. A quick microwave zap can work in a pinch, but the oven gives the best texture.

Sourdough Zucchini Chocolate Chip Muffins

Yield: 12 muffins • Prep: 10 mins • Cook: 15 mins • Total: 25 mins • Author: Karie Kirkpatrick

Ingredients

• 2 medium zucchinis, grated (about 3 cups)
• ¾ cup sugar
• 2 ounces (½ stick) unsalted butter, melted
• 2 eggs
• ¼ cup sour cream (or plain whole-milk yogurt)
• ½ cup sourdough discard
• 1 teaspoon vanilla extract
• 2 cups all-purpose flour
• ½ teaspoon baking soda
• 2 teaspoons baking powder
• ½ teaspoon salt
• ½ teaspoon ground cinnamon (optional)
• 1 cup mini chocolate chips

Instructions

1. Grate the zucchini and place it in a colander lined with several layers of cheesecloth, paper towels, or a clean dish towel. Press or squeeze to remove excess water so the grated zucchini is moist but not dripping.
2. In a large bowl, whisk together the grated zucchini, sugar, melted butter, eggs, sour cream, sourdough discard, and vanilla until combined.
3. In a separate bowl, whisk the flour, baking soda, baking powder, salt, and cinnamon (if using).
4. Add the dry ingredients to the wet ingredients and fold gently until only a few streaks of flour remain. Avoid overmixing. Fold in the mini chocolate chips until evenly distributed.
5. Optional: For a thicker batter and deeper developed flavor, let the batter rest at room temperature for up to one hour so the flour can hydrate and the sourdough flavor can mellow.
6. Preheat the oven to 350°F (175°C). Line a muffin tin with paper liners or grease the cups. Fill each cup nearly to the top for tall domes.
7. Bake for 15–20 minutes, until the muffin tops spring back when touched and a toothpick inserted near the center comes out clean or with a few moist crumbs clinging.
8. Allow muffins to cool in the pan for a few minutes, then transfer to a wire rack to finish cooling. Serve warm, split and buttered if desired.