Sourdough Lemon Bars Recipe

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Sourdough lemon bars are bright, creamy, and delicious. The decadent lemon filling is made with sweetened fresh lemons and tangy sourdough discard. And it sits on a thick, buttery sourdough shortbread crust. These cheerful treats are perfect for sunny picnics and summer gatherings.

When it comes to summer food, give me ALL of the fruit, please! We devour sourdough peach cobbler and sourdough peach pie for as long as we can get our hands on South Carolina peaches. And of course, we devour sourdough lemon bars!

The fresh lemon juice, lemon zest, and sourdough starter are perfectly balanced with a little sweetness and a buttery shortbread crust.

These sourdough lemon bars are like a cold glass of lemonade on a hot day!

About This Recipe

• The filling is an adaptation of Brown-Eyed Baker’s Lemon Bars adjusted to include sourdough starter.
• The crust is an adaptation of Inspired Taste’s shortbread crust, but with a tangy sourdough twist. I also bake them in an 8″ x8″ baking dish to create a thicker crust.

Why You’ll Love This Recipe

Use Extra Starter: If you have extra starter, this is a great recipe for using it up. You can use an all-purpose starter or even a fresh-milled sourdough starter.

Simple Ingredients: This recipe uses only nine ingredients, most of which you probably have on hand.

Lightly Sweetened: I often find store-bought lemon desserts are too sweet. These sourdough lemon bars will satisfy your sweet tooth, but they have less sugar than most.

Summer Treat: Summer baking, in my opinion, is completely overlooked and underrated. The flavors and textures of summer sweet treats are a dream.

Key Ingredients

Butter: I used unsalted butter. Salted will work, but you may need to adjust the salt in the recipe.

Sourdough Starter: Active starter works best for this recipe. You can use an all-purpose starter, einkorn sourdough starter, or even a fresh-milled sourdough starter.

Lemons: A little lemon zest in the crust adds a bright flavor to the crust.

Vanilla: I use homemade vanilla extract. Store-bought is a great option, too.

Flour: I used all-purpose flour, but if you prefer fresh flour, you can use soft white wheat berries.

Eggs: Use large eggs. If you are using farm-fresh eggs, they can vary in size, so adjust as needed. If you are confident in accurately rehydrating freeze-dried eggs, they will work, too.

Whole Milk – Milk makes these sourdough lemon bars creamy and decadent.

Get the full list of ingredients and measurements on the printable recipe card below.

How to Make Sourdough Lemon Bars

Step 1: Gather the ingredients. Preheat the oven to 350° F and line an 8″ x8″ baking dish with parchment paper.

Step 2: Add the butter and sugar to the bowl of a stand mixer. Mix with a paddle attachment on medium speed until light and fluffy, about 2 minutes.

Add the sourdough starter, lemon zest, vanilla, and salt. Mix for another minute or so until fully combined with the butter mixture.

With the mixer on low, add the flour. Mix until just combined. Then, use your hands to form the dough into a loose ball.

Step 3: Transfer the dough ball to the parchment-lined baking dish, and use your fingers to shape it into an even layer.

Step 4: Use a fork to pierce the crust a few times. This will prevent it from puffing up while baking. So don’t skip this step!

Pop the baking dish into the freezer for about 5 minutes to chill. This will help create a really lovely texture (if you are in a pinch, you can skip this step).

Bake for 25-30 minutes or until the edges are lightly browned.

Step 5: Meanwhile, whisk the eggs in a small bowl until the yolks and whites are combined. Add the sugar and mix thoroughly.

Pour in the sourdough discard and whisk until completely combined. Make sure there are no clumps of discard.

Add the lemon zest, lemon juice, and milk. Mix thoroughly. Set aside.

Step 6: Drop the oven temp to 325° F.

Give the lemon filling a stir, then pour it over the warm, lightly baked shortbread crust.

Bake 30-35 minutes or until the filling has set, the edges are lightly golden brown, and the center doesn’t jiggle.

Step 7: Place the whole baking dish on a wire rack and allow the lemon bars to cool to room temperature, usually about an hour.

Cover with plastic wrap and refrigerate for at least 2 hours before serving (I recommend keeping them in the fridge until thoroughly chilled).

Dust with powdered sugar just before serving.

Tips for Sucess

• Bake times may vary depending on your oven. Keep an eye on your lemon bars. If they need more time, check on them every 5 minutes until they finish.
• An active sourdough starter contains more flour, which can help thicken the lemon curd. However, it also has less sour sourdough flavor, so it won’t outshine the lemon.
• Use a 100% hydration starter (aka a starter fed equal parts flour and water). This ensures the proper liquid ratio in the filling.

Serving Suggestions

Fresh Fruit: Serve with fresh strawberries, raspberries, or blueberries.

Whipped Cream: Add a dollop of whipped cream with vanilla for a decadent touch.

Coffee: Serve with an iced coffee with a splash of brown sugar vanilla coffee creamer.

Ice Cream: Pair with a scoop of creamy vanilla ice cream or old-fashioned strawberry ice cream.

Dessert Spread: Create a summer dessert spread with sourdough lemon bars, sourdough peach pie, sourdough strawberry shortcake, and sourdough strawberry scones.

Storing

• Leftovers can be stored in an airtight container in the fridge for 3-5 days or frozen for up to 3 months.

Sourdough Lemon Bars FAQs

More Sourdough Recipes

If you tried this Sourdough Lemon Bars recipe or any other recipe on my blog, please leave a 🌟 star rating and let me know how it went in the 📝 comments below. Thanks, y'all!