Sourdough Blueberry Muffins with Crumb Topping

I can’t contain my excitement for these sourdough blueberry muffins with crumb topping. They’ve become my latest baking obsession!

Seriously, I’ve made them three times in two weeks!

They offer a rich and tender texture, bursting with the sweetness of blueberries. And the buttery crumble on top? It’s a fun, irresistible surprise that adds a satisfying crunch! 

Better still, the sourdough starter adds such a fantastic depth of flavor. 

I bet nobody will be able to put their finger on what makes these so good. And I won’t tell if you don’t!

The Secret to Perfectly Moist Sourdough Blueberry Muffins Every Time

There’s nothing better than a warm homemade muffin straight from the oven with a cup of sweet vanilla coffee. 

These are a great way to use discard after feeding your sourdough starter! Not only does this reduce waste, but it also adds a unique tangy flavor to the muffins.

The key to achieving the ideal moist texture in sourdough blueberry muffins lies in a few crucial techniques:

1. Folding. This is crucial for achieving light and fluffy muffins. But we’re not folding anything like a piece of paper and dropping it in the pot! Instead, we’re very gently stirring the wet and dry ingredients together. Over-mixing the batter is the main reason for tough, dense muffins. So, be sure to stop stirring as soon as you don’t see any streaks of flour.

2. Acid + Fat = Moisture. The combination of sourdough discard, buttermilk, and melted butter provides the perfect balance of acidity, fat, and moisture. 

3. High oven temp. Start these off at a higher temp than usual to give them a quick rise (oven spring). That helps the crust, too. Then, reduce the heat to finish baking. 

4. The toothpick test. It’s so easy to overbake muffins. So, check on them early and take them out as soon as a toothpick inserted into the center comes out clean or with just a few moist crumbs. The residual heat means they keep cooking on the counter. 

Elevate Your Sourdough Muffin Game with Crumb Topping

This isn’t just true of these blueberry muffins! Crumb tops make any muffins infinitely more delicious!

The light spice and buttery texture plays so well against the tender muffin. 

But, like the muffin itself, there’s a right and wrong way to do it. Here are my two top tips:

1. Rub cold butter into the dry ingredients with your fingers. If you mix it too much (into a smooth dough), it won’t be a crumble top anymore. 

2. Be generous with the crumble. If you only add a few crumbs, they’ll get swallowed up in the batter. 

Ingredients

Other than the sourdough discard, this looks like any other muffin recipe.
Here’s what you need:

• All-Purpose Flour: You can use cake flour if you like, but all-purpose or plain flour works just fine.
• Granulated Sugar: For sweetness. White sugar gives the muffins a nice crust on the top. 
• Baking Powder and Baking Soda: So they rise. 
• Salt: Enhances all the flavors.
• Vegetable Oil or Melted Butter: For moisture and richness. Use whichever you have on hand, but know that muffins made with oil will stay tender longer. 
• Large Egg: To bind the batter and help with rise. 
• Sourdough Starter Discard: Our tangy star! It adds tangy flavor and helps create a moist, tender crumb.
• Buttermilk: Brings a wallop of moisture and a subtle tang.
• Vanilla Extract: For sweet warmth.
• Fresh Blueberries: You can use frozen, but fresh is best!
• Lemon Zest: For a bright, citrusy note that complements the blueberries.
• Crumb Topping: A quick blend of flour, sugar, cinnamon, and butter. 

How to Make Bakery-Style Sourdough Blueberry Muffins at Home

Ready to get baking? Here are the steps:

1. Prep the oven and muffin tin. Preheat the oven to 425°F (220°C). Line a 12-cup muffin pan with paper liners or grease well.

2. Make the topping. In a small bowl, mix the flour, sugars, and cinnamon. Rub the butter into the dry ingredients with your fingers or a pastry cutter. Refrigerate until ready to use.

3. Mix the dry ingredients. In a large bowl, whisk together the flour, sugar, baking powder, baking soda and salt.

4. Mix wet ingredients. In a separate bowl, whisk the oil, egg, sourdough discard, milk, vanilla and lemon zest (if using) until smooth.

5. Make the batter. Pour the wet ingredients into the dry ingredients and mix gently with a spatula until about halfway combined. Then, gently fold in the blueberries until no streaks of flour are visible.

6. Fill the muffin cups. Divide the batter evenly between the prepared muffin cups, filling each one almost to the top. Generously sprinkle the crumb topping over each muffin.

7. Bake the muffins. Bake for 8 minutes at 425°F, then reduce oven temperature to 350°F (175°C) and continue baking for 12-15 minutes or until a toothpick inserted into the center comes out clean. Do not open the door during the bake.

8. Cool and serve. Let the muffins cool in the pan for 10 minutes before transferring to a wire rack to cool completely.

Tips and Tricks for the Ultimate Sourdough Blueberry Muffin Recipe

Elevate your sourdough blueberry muffins from good to great with these expert tips and tricks:

• Use room temperature ingredients. Bring the eggs, milk, and sourdough starter to room temperature before mixing to ensure a smooth, evenly blended batter.
• Don’t overmix the batter. Gently fold the wet and dry ingredients together until just combined. A few lumps are okay.
• Toss blueberries with flour. Coat the berries in a light dusting of flour before adding them to the batter. This prevents them from sinking to the bottom during baking.
• Use a large scoop or ice cream scoop. It makes portioning easy and helps ensure they’re all the same size.
• Start with a high oven temperature. Baking the muffins at 425°F (220°C) for the first 10 minutes helps create tall, domed tops. Then reduce to 375°F (190°C) to finish cooking through.
• Don’t overbake. Check your muffins a few minutes early and remove them from the oven as soon as a toothpick inserted into the center comes out clean or with just a few moist crumbs.
• Experiment with add-ins. While blueberries are classic, try mixing in other berries, nuts, or even white chocolate chips for delicious variations.
• Embrace imperfection. Rustic, craggy tops and slightly irregular shapes are part of the charm of homemade muffins. Don’t stress about making them look perfect!
• Add glaze. Want extra sweetness? Mix some powdered sugar with milk or water and drizzle it over cooled muffins.

Why Should You Add Sourdough to Blueberry Muffins? What Does It Do?

We’ll talk about how to add discard to muffins below. But why do it in the first place?

1. Flavor: Sourdough adds a subtle tangy flavor that complements the sweetness of the blueberries and enhances the overall taste of the muffins.

2. Texture: Sourdough starter helps create an incredibly moist and tender crumb in the muffins. It provides a softer, fluffier texture compared to regular muffins.

3. Easier to Digest: The natural fermentation process of sourdough breaks down some of the gluten and makes the flour easier to digest. Fermenting the batter overnight allows even more breakdown of phytic acid for better digestibility. Just mix up the batter, cover it, and pop it in the fridge until baking.

4. Extends Shelf Life: The acidity from the starter acts as a natural preservative and helps keep the muffins fresher for longer.

5. Prevents Food Waste: Adding sourdough discard to muffins is a great way to use up the portion of starter that is discarded when feeding it, reducing waste. 

How to Add Sourdough to Blueberry Muffins

Discard is the portion of sourdough starter removed before feeding. There’s nothing wrong with it, but the starter needs fresh food to feed.

And using discard in recipes like this prevents waste and adds flavor.

You can use recently fed, active starter, or unfed sourdough discard in muffin recipes. 

Fed Starter:

If using fed starter, it’s best to use it when it’s at peak activity, 4-12 hours after feeding. 

At this point it will be bubbly and pass the float test (a spoonful will float in water).

Unfed Starter:

Unfed discard can be used straight from the fridge. 

Collect discard in a jar and store in the fridge for up to 2 weeks to use in recipes. 

Let it come to room temp first for best results.

Active Starter:

If you don’t want the hassle of making and feeding starter, or if you don’t make sourdough bread a lot, you can maintain a small starter. 

Keep only what you need and build it up as needed for baking. This avoids excess discard.

How to Use:

In general, you can add up to 200-250 grams of starter/discard to a recipe by replacing an equal amount of the flour and liquid called for in the original recipe. 

Don’t use more than this, or it may negatively impact the texture.

The starter enhances the flavor and tenderizes baked goods like muffins, pancakes, etc. However, it doesn’t necessarily leaven the baked goods on its own, so recipes still need baking soda/powder.