Long-Fermented Sourdough Blueberry Lemon Crumble Muffins
There’s something magical about the slow fermentation process- how time transforms simple ingredients into something richer, more flavorful, and irresistibly tender. These long-fermented sourdough lemon blueberry crumble muffins are the perfect example of that magic.
It all started when I thought, what if I turned my lemon poppy seed muffins into lemon blueberry? That bright citrus zing with juicy bursts of blueberries felt like the perfect match. And just like that, these muffins were born: a long-fermented batter that creates a pillowy, moist crumb with the addition of sour cream and sweet honey, and a crunchy fermented streusel topping for that bakery-style finish.
Why You’ll Love This Recipe:
These muffins seriously deliver on blueberry flavor and that perfect balance of lemon makes them even more decadent. Mix up a simple crumble topping to add crunch to the top, and you’ll be in heaven. Perfect for summer baking (or anytime) and with an optional overnight fermentation step, these muffins aren’t just delicious- they’ll fit your busy schedule and be easy on the stomach with the extra fermentation.
Why Use Sourdough Starter in Muffins?
Using sourdough discard in muffins adds a slight tang, enhances moisture retention, and makes the crumb softer and more tender. The fermentation process also helps break down gluten, making these muffins easier to digest.
Do I have to long-ferment these Muffins?
No! You can mix up this batter if you want muffins quickly. Just skip the fermentation step!
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Tools You’ll Need:
• Standard 12-cup muffin tin- for baking muffins. I love these pans from USA Bakeware linked here.
• Muffin liners- to avoid burned edges. I love these bakery style parchment muffin liners linked here.
• Kitchen scale (optional)– for accurate measuring, especially helpful with sourdough baking.
• 1/4 cup scoop – for scooping batter. I love this scoop for muffins linked here.
• Whisk + spatula- for combining ingredients.
• Mixing bowls- for mixing batter and crumble.
• Hand mixer or sturdy whisk- for mixing batter and filling.
• Cooling rack– to cool muffins.
Gather Your Ingredients:
Sourdough starter- (flat or past peak, can be cold or room temperature). Adds depth of flavor, moisture, and just a whisper of tang—without making these muffins “sour”. Key for fermentation.
Avocado Oil- Adds moisture and keeps the muffins soft and tender. You can substitute for any neutral cooking oil.
Sour Cream– Adds moisture and tang to balance sweetness and enhance tenderness of the crumb. You can also substitute for full-fat Greek yogurt.
White sugar– Boosts sweetness and supports the rise and golden color.
Whole Milk- you can use whole milk or substitute with buttermilk in the muffins.
Honey- adds sweetness and moisture to the muffins.
Vanilla extract– Enhances the flavor and brings warmth.
Unsalted butter– Binds the crumble to give it crisp buttery texture and gives muffins moisture and flavor.
Eggs (room temperature)– provide structure and lift with moisture, works as a binder for ingredients.
All-purpose flour- Gives the muffins structure while keeping it soft and cakey. You’ll also use flour in the crumble.
Baking powder + Baking soda– Ensures the right rise and bakery-style domes for the muffins.
Salt- Balances sweetness and enhances all the other flavors.
Lemons- You’ll use both the lemon zest and the juice in the muffins to give them a bright citrus flavor.
Blueberries– adds pockets of jammy blueberry to the muffins. I prefer to use smaller blueberries such as wild blueberries because the distribute more evenly.
Now let’s make some muffins!
Instructions
Step 1: Mix the Muffin Batter
In a large mixing bowl add honey, white sugar, sourdough discard, sour cream, milk, vanilla extract, avocado oil, melted butter, eggs, lemon juice and lemon zest. Whisk ingredients together until blended.
In a separate bowl, whisk together the flour, baking powder, baking soda, and salt.
Add the dry ingredients to the wet, whisking together until no streaks remain. It’s important to not overmix the batter, as this will make the muffin tough.
Overnight Ferment Option: At this point you have the choice to ferment the batter overnight. If you choose to ferment, cover the bowl with plastic and transfer to the refrigerator overnight. Please note that if you choose to ferment the crumble as well you’ll mix this at this time and allow to rest overnight.
Step 2: Mix the Crumble
Combine flour, sugar, and salt in a bowl. Add softened (not melted) butter and discard. Use your fingers or a fork to mix until a crumbly texture forms.
Overnight Ferment Option: Cover and let crumble sit at room temperature overnight.
Note: If you choose to make these muffins same day, you can skip the fermentation step.
Step 3: Add Blueberries
If batter was fermenting in refrigerator overnight, allow to rest at room temperature for an hour to warm up. If you’re not fermenting the batter, skip this step.
Weigh out frozen blueberries and allow to rest in a bowl of warm water to thaw. After 5-10 minutes, strain blueberries from water and transfer to a bowl lined with a paper towel to absorb any excess moisture (you can also just strain and blot). After water has been absorbed, remove the paper towel and toss the blueberries in 2 Tablespoons of flour.
Add blueberries to the muffin batter, gently folding into the muffin batter until blueberries are distributed evenly.
Step 4: Bake Muffins
Preheat your oven to 425°F (175°C).
Line a 12-cup muffin tin with parchment papers, and lightly spray with oil to avoid muffins sticking to the parchment.
Divide the batter evenly into the muffin cups, filling each about 3/4 full. This is typically roughly 1/3 cup for a regular sized muffin, I love this scoop here for easy consistent measuring https://amzn.to/41GFGKg.
Spoon 1 big spoonful of crumble on top of each muffin.
Bake for 5 minutes at 425 F, then drop the heat to 350 F and bake 22-25 minutes, or until a toothpick inserted into the center comes out clean. Let the muffins cool in the pan for 5 minutes, then transfer them to a wire rack to cool completely.
Note about baking temperatures: Baking for 5 minutes at a higher heat gives muffins a more domed, bakery-style appearance. If you would like to skip this step, you can bake your muffins at 350 F for 25-28 minutes or until a toothpick comes out clean.
Yields 12 large muffins or 16 regular muffins
Storing Tips:
Room Temperature– Store muffins in an airtight container on counter for up to 5 days.
Freezer– Freeze muffins in an airtight container for up to 3 months. Allow to thaw and gently reheat in oven or microwave to serve.
These long-fermented sourdough lemon blueberry crumble muffins are sure to be a hit. Drop a comment and leave a review if you loved this recipe! Happy baking!
FAQ’S:
Can I make these without the overnight fermentation?
Absolutely. They’ll still be moist and flavorful baked right away, but fermentation deepens the flavor and improves rise.
Can I use fresh blueberries?
Yes! Coat them in flour like the frozen blueberries and fold into the batter. I recommend using smaller blueberries, larger varieties tend to sink and can cause a gummier crumb.
Long-Fermented Sourdough Blueberry Lemon Streusel Muffins
Equipment
- Standard 12-cup muffin tin – for baking muffins.
- Muffin liners – to avoid burned edges.
- 1/3 cup scoop – for scooping batter.
- Whisk or hand mixer – for mixing batter.
- Spatula – for folding blueberries.
- Mixing bowls – for mixing wet and dry ingredients and crumble.
- Cooling rack – for cooling muffins and avoiding soggy bottoms.
Ingredients
Wet Ingredients:
- 1/4 cup (85g) honey
- 3/4 cup (150g) white sugar
- 1/2 cup (120g) sourdough discard or starter
- 1/2 cup (120g) full-fat sour cream or plain whole milk Greek yogurt
- 2/3 cup (150g) whole milk or buttermilk
- 4 tbsp (60g) unsalted butter, melted
- 1/4 cup (60g) avocado oil or neutral oil
- 2 large eggs room temperature (soak in warm water for ten minutes if needed)
- 2 teaspoons vanilla extract
- 1 Tablespoons (8g) zest of 2 lemons
- 3 Tablespoons (45g) fresh lemon juice
Dry Ingredients:
- 3 and 1/4 cups (400g) all-purpose flour
- 2 1/2 tsp baking powder
- 1/2 tsp baking soda
- 3/4 tsp salt
Mix-In's:
- 1 3/4 cup (250g) 250g frozen wild blueberries
Fermented Crumble:
- 1/2 cup (75g) all-purpose flour
- 1/2 cup (100g) granulated sugar
- 2 tbsp (30g) 2 tbsp sourdough discard
- 2 tbsp (30g) unsalted butter softened not melted
- 1/8 teaspoon sea salt
Instructions
Step 1: Mix the Muffin Batter
- In a large mixing bowl add honey, white sugar, sourdough discard, sour cream, milk, vanilla extract, avocado oil, melted butter, eggs, lemon juice and lemon zest. Whisk ingredients together until blended.1/4 cup (85g) honey, 3/4 cup (150g) white sugar, 1/2 cup (120g) sourdough discard or starter, 1/2 cup (120g) full-fat sour cream, 2/3 cup (150g) whole milk or buttermilk, 4 tbsp (60g) unsalted butter, melted, 1/4 cup (60g) avocado oil, 2 large eggs, 2 teaspoons vanilla extract, 1 Tablespoons (8g) zest of 2 lemons, 3 Tablespoons (45g) fresh lemon juice
- In a separate bowl, whisk together the flour, baking powder, baking soda, and salt.3 and 1/4 cups (400g) all-purpose flour, 2 1/2 tsp baking powder, 1/2 tsp baking soda, 3/4 tsp salt
- Add the dry ingredients to the wet, whisking together until no streaks remain. It’s important to not overmix the batter, as this will make the muffin tough.
- Overnight Ferment Option: At this point you have the choice to ferment the batter overnight. If you choose to ferment, cover the bowl with plastic and transfer to the refrigerator overnight. Please note that if you choose to ferment the crumble as well you’ll mix this at this time and allow to rest overnight.
Step 2: Mix the Crumble
- Combine flour, sugar, and salt in a bowl. Add softened (not melted) butter and discard. Use your fingers or a fork to mix until a crumbly texture forms.1/2 cup (75g) all-purpose flour, 1/2 cup (100g) granulated sugar, 2 tbsp (30g) 2 tbsp sourdough discard, 1/8 teaspoon sea salt, 2 tbsp (30g) unsalted butter
- Overnight Ferment Option: Cover and let crumble sit at room temperature overnight.
- Note: If you choose to make these muffins same day, you can skip the fermentation step.
Step 3: Add Blueberries
- If batter was fermenting in refrigerator overnight, allow to rest at room temperature for an hour to warm up. If you’re not fermenting the batter, skip this step.
- Weigh out frozen blueberries and allow to rest in a bowl of warm water to thaw. After 5-10 minutes, strain blueberries from water and transfer to a bowl lined with a paper towel to absorb any excess moisture (you can also just strain and blot). After water has been absorbed, remove the paper towel and toss the blueberries in 2 Tablespoons of flour.1 3/4 cup (250g) 250g frozen wild blueberries
- Add blueberries to the muffin batter, gently folding into the muffin batter until blueberries are distributed evenly.
Step 4: Bake Muffins
- Preheat your oven to 425°F (175°C).
- Line a 12-cup muffin tin with parchment papers, and lightly spray with oil to avoid muffins sticking to the parchment.
- Divide the batter evenly into the muffin cups, filling each about 3/4 full. This is typically roughly 1/3 cup for a regular sized muffin, I love this scoop here for easy consistent measuring https://amzn.to/41GFGKg.
- Spoon 1 big spoonful of crumble on top of each muffin.
- Bake for 5 minutes at 425 F, then drop the heat to 350 F and bake 22-25 minutes, or until a toothpick inserted into the center comes out clean. Let the muffins cool in the pan for 5 minutes, then transfer them to a wire rack to cool completely.
- Note about baking temperatures: Baking for 5 minutes at a higher heat gives muffins a more domed, bakery-style appearance. If you would like to skip this step, you can bake your muffins at 350 F for 25-28 minutes or until a toothpick comes out clean.
- Yields 12 large muffins or 16 regular muffins
