Lemon Blueberry Sourdough Muffins

There's something almost magical about opening my fridge and finding a jar of sourdough discard staring back at me, begging not to be tossed. One Saturday morning, instead of composting it, I decided to bake muffins and grabbed every bright lemon in the fruit bowl. The kitchen filled with this incredible tang before anything even hit the oven, and I knew I'd stumbled onto something special. These lemon blueberry muffins became the reason my neighbor keeps asking what smells so good when the oven's on.

I made these for my book club last month, and honestly, the muffins disappeared before the actual discussion started. One friend came back for thirds and confessed she'd never thought to use her sourdough starter discard this way, which felt like passing along a quiet kitchen secret. Now she texts me photos of her batches, and it's become this unspoken thread between us.

Ingredients

• All-purpose flour (1 cup, 120 g): This is your structure, keeping the muffins from becoming gritty or too crumbly.
• Whole wheat flour (1 cup, 125 g): Brings an earthiness that complements the lemon without overpowering it; swap it for all-purpose if you want something lighter.
• Granulated sugar (1 cup, 200 g): Sweet but not cloying when balanced with lemon juice and the tang of sourdough.
• Baking powder (1 tsp) and baking soda (1/2 tsp): The pair that works together; baking soda reacts with the lemon juice and sourdough acid, giving you lift without that metallic aftertaste.
• Salt (1/2 tsp): A pinch of salt makes the lemon brighter and the blueberries pop.
• Eggs (2 large): Bind everything and add richness.
• Vegetable oil or melted butter (1/2 cup, 120 ml): Oil keeps these incredibly tender; butter works too if you want a slightly richer flavor.
• Sourdough discard (1 cup, 240 g): The star ingredient that adds complexity and keeps the crumb moist longer than a regular muffin.
• Whole milk (1/2 cup, 120 ml): Creates a tender crumb and plays nicely with the sourdough.
• Vanilla extract (1 tsp): A small amount rounds out the flavors without making them taste vanilla-forward.
• Lemon zest (from 1 large lemon) and lemon juice (2 tbsp): Both matter; zest gives aromatic brightness, juice adds tang and reacts with the baking soda for lift.
• Fresh or frozen blueberries (1 1/2 cups, 225 g): Keep them frozen if using; they release less liquid and stay intact instead of bleeding through the batter.
• Crumb topping flour (1/2 cup, 65 g), light brown sugar (1/3 cup, 65 g), cold unsalted butter (1/4 cup, 60 g cubed), salt (pinch), and lemon zest (from 1/2 lemon): Together these create that buttery, sandy texture that makes every bite feel indulgent.

Instructions

Heat your oven and prepare:

Preheat to 375°F and line your muffin tin with paper liners or grease it well. Cold batter goes into a hot oven, so don't skip this step.

Mix your dry team:

Whisk together both flours, sugar, baking powder, baking soda, and salt in a medium bowl until everything is evenly distributed. This is where the leavening agents spread out, ensuring even rise.

Combine the wet ingredients:

In a large bowl, whisk eggs, oil, sourdough discard, milk, vanilla, lemon zest, and lemon juice until everything is incorporated and the mixture looks fairly smooth. The sourdough might look a bit lumpy, and that's fine.

Bring it together gently:

Fold the dry mixture into the wet ingredients until just combined; overmixing develops gluten and makes muffins tough and tunneled. Lumpy batter is your friend here.

Add the blueberries:

Gently fold them in so they stay whole and scatter throughout rather than sinking to the bottom. If you're using frozen berries, don't thaw them first.

Fill the cups:

Divide batter evenly, filling each cup about 3/4 full; this gives the muffin room to rise without spilling over the tin.

Make the crumb topping:

Combine flour, brown sugar, cold butter cubes, salt, and lemon zest in a small bowl. Use your fingertips or a pastry cutter to work the cold butter in until the mixture looks like coarse breadcrumbs; this contrast in texture is what makes it special.

Crown each muffin:

Sprinkle the crumb topping generously over each muffin so some pieces stick out and get crispy in the oven.

Bake until golden:

Bake for 22 to 25 minutes, until a toothpick inserted into the center comes out clean and the tops are golden brown. The timing depends on your oven, so trust your eyes more than the clock.

Cool with patience:

Let them rest in the pan for 5 minutes so they set, then transfer to a wire rack to cool completely. This prevents them from steaming themselves into a gummy texture.

Save

My daughter dunked a warm muffin in her Earl Grey tea one morning and called it "accidentally elegant," and now that's exactly how I serve them when friends visit. That one small moment turned these muffins into something bigger than breakfast.

Why Sourdough Discard Belongs Here

Using sourdough discard in muffins isn't just a way to avoid waste; it's an upgrade to the entire eating experience. The fermentation in the discard adds a subtle complexity that store-bought baking can't achieve, and it keeps the muffins tender and moist for days without any added preservatives. There's also something satisfying about turning something you'd normally throw away into something your family actually looks forward to.

The Lemon Factor

Lemon zest and juice work differently in this recipe, and understanding both makes a difference. The zest carries the aromatic brightness that makes people pause and sniff before they bite, while the juice adds a subtle tang and actually reacts with the baking soda to create lift. If you use only juice or only zest, you lose half the story.

Storage and Serving Wisdom

These muffins keep well in an airtight container for up to four days, though they're honestly best on day one or two when the crumb topping still has some crispness. Warm them briefly in the oven if they've been sitting in the fridge, and consider a small pat of butter on top of a warm muffin as non-negotiable.

• Store in an airtight container at room temperature for up to two days, or refrigerate for up to four days.
• Freeze muffins individually wrapped in plastic wrap and placed in a freezer bag for up to three months; thaw at room temperature or warm gently in the oven.
• A quick pass under the broiler for 30 seconds will revive the crumb topping if it softens after a day or two.

Save

There's something quietly wonderful about a muffin that tastes thoughtful without being fussy. These ones do that, and they've become my way of saying hello to friends and family.

Recipe FAQs

→ Can I use all-purpose flour instead of whole wheat flour?

Yes, substituting whole wheat flour with all-purpose flour will result in a lighter texture without compromising flavor.

→ How does sourdough discard affect the muffins?

Sourdough discard adds a subtle tang and enhances the crumb structure, making the muffins moist and flavorful.

→ Can I add nuts to the crumb topping?

Yes, adding chopped nuts to the crumb topping provides extra crunch and complements the blueberry-lemon flavors.

→ What is the best way to store these muffins?

Store muffins in an airtight container at room temperature for up to 2 days, or refrigerate for longer freshness.

→ Can frozen blueberries be used directly?

Yes, use frozen blueberries without thawing to prevent the batter from becoming too wet.