Sourdough Lemon Bars
Sourdough lemon bars are made with fresh lemon and sourdough discard for a sweet, tangy, irresistibly delicious treat. Easy to make and perfect for any occasion!
Sourdough lemon bars are a classic dessert perfect for spring and summer. The sweetness of the sugar and the tart lemon juice create the perfect balance of flavors!
We've added sourdough discard to the buttery shortbread crust to reduce food waste, and that little hint of sourdough flavor is so yummy!
Like our sourdough lemon crinkle cookies, sourdough lemon cake, and lemon poppy seed muffins, this sweet treat is easy to make, and you'll love the bright lemon flavor!
Carmyn's notes
Sourdough lemon bars are one of my all-time favorite desserts! I love their bright, zesty, and perfectly sweet flavor, plus the subtle hint of sourdough in the crust adds something special.
For foolproof sourdough lemon bars, keep these tips in mind:
- Fresh lemon juice is a MUST! Bottled or concentrated juice just doesn’t compare and will alter the flavor. Stick to fresh for the best taste.
- Line the baking pan. The delicate filling makes parchment paper essential—it allows you to lift the bars out easily without breaking them.
- Use a sharp, clean, slightly damp knife. Running a sharp knife under warm water before cutting (and re-dampening it after each slice) ensures clean, precise edges.
- Don’t worry if the filling wobbles! A slight jiggle is normal when they come out of the oven. They’ll continue to set as they cool and firm up in the fridge. Make sure the filling is completely set before slicing!
Enjoy these tangy, sweet, and buttery treats! xx
Ingredients & Equipment Needed
- Sourdough Shortbread Crust: All-purpose flour, powdered sugar, sourdough starter discard, melted unsalted butter, vanilla extract, and salt combine to create a delicious buttery crust to hold the lemon filling.
- Lemon Filling: For this zesty, sweet lemon filling, you'll need fresh lemon juice plus their zest, whole eggs, granulated sugar, and flour. Use Meyer lemons for a sweeter, less acidic taste.
- 9x13 Baking Dish: A metal baking dish heats more evenly, prevents overbaking, and creates a crispier crust than glass. A glass baking dish can be used.
- Parchment Paper: Use high-quality parchment paper to easily lift the sourdough lemon bars from the pan without breaking them.
Step by Step Instructions with Photos
Heat your oven to 350°F(176°C) and line a 9" x 13" baking dish with parchment paper.
Step 1
Whisk the flour, powdered sugar, and salt in a large mixing bowl until thoroughly combined.
Step 2
Add the sourdough discard, melted unsalted butter, and vanilla extract and mix together until the dough just comes together. Do not overwork to avoid gluten development.
Step 3
Transfer the dough to the baking dish and use your hand to press it into a flat, even layer.
Optional: For a long fermentation, cover the pan and refrigerate the uncooked dough for up to 48 hours. Remove the cover and bake straight from the fridge for 25 minutes.
Step 4
Bake for 20 minutes or until the surface is light golden brown. While the crust bakes, make lemon filling.
Step 5
Beat the eggs in a large bowl. Add the sugar, lemon juice, lemon zest, and flour and mix until smooth.
Step 6
Pour the lemon mixture onto the warm crust, then carefully return the pan to the oven and bake for 25 minutes.
Step 5
The filling should wobble slightly but not appear wet on the surface.
Remove the pan from the oven and allow it to cool for 1 hour before refrigerating for at least 6 hours for the filling to set.
Step 6
Before serving, dust the top with powdered sugar and cut into bars with a sharp, clean knife.
How to Store
Storage: Keep sourdough lemon bars in an airtight container in the refrigerator for up to one week.
Freezing: Wrap individual bars in plastic, layer them with aluminum foil, and store them in the freezer for up to three months.
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Sourdough Lemon Bars
INGREDIENTS
Sourdough Shortbread Crust
- 2¾ cups (330 g) all-purpose flour
- 1 cup (120 g) powdered sugar
- ½ teaspoon salt
- ¼ cup (62 g) sourdough discard
- 1 cup (226 g) melted unsalted butter
- 1 teaspoon (5 g) vanilla extract
Lemon Filling
- 3 cups (600 g) sugar
- 8 eggs
- ½ cup (60 g) all-purpose flour
- 1 cup (240 g) fresh lemon juice + zest from the lemons (about 5 large lemons, NOT bottled lemon juice)
INSTRUCTIONS
- Heat the oven to 350°F and line a 9x13 metal baking dish with parchment paper.
- In a large mixing bowl, whisk together 2¾ cups (330 g) all-purpose flour, 1 cup (120 g) powdered sugar, and ½ teaspoon salt until fully combined. Add ¼ cup (62 g) sourdough discard, 1 cup (226 g) melted unsalted butter, and 1 teaspoon (5 g) vanilla extract and mix together until the dough just comes together. Do not overwork the dough.Optional: For a long fermentation, cover the pan and refrigerate the uncooked dough for up to 48 hours. Remove the cover and bake straight from the fridge for 25 minutes.
- Transfer the dough to the baking dish and press it out to a flat even layer. Bake for 20-25 minutes or until the surface is a light golden color.Optional: For a long fermentation, cover the pan and refrigerate the uncooked dough for up to 48 hours. Remove the cover and bake straight from the fridge for 25 minutes.
- In large bowl, beat 8 eggs with a whisk. Add 3 cups (600 g) sugar, 1 cup (240 g) fresh lemon juice + zest from the lemons, and ½ cup (60 g) all-purpose flour and mix until smooth.
- Pour the filling onto the warm crust, then carefully return the pan to the oven and bake for 25 minutes. The filling should wobble slightly but not appear wet on the surface.
- Remove the pan from the oven and let the bars cool for 1 hour before refrigerating for at least 6 hours to fully set. Do not skip the cooling and refrigeration steps—allowing the lemon bars ample time to set is essential for the perfect texture.
- Before serving, dust the surface with powdered sugar and use a sharp, clean knife to cut into bars.
NOTES
Tips:
-
- Fresh lemon juice is a MUST! Bottled or concentrated juice just doesn’t compare and will alter the flavor. Stick to fresh for the best taste.
-
- Line the baking pan. The delicate filling makes parchment paper essential—it allows you to lift the bars out easily without breaking them.
-
- Use a sharp, clean, slightly damp knife. Running a sharp knife under warm water before cutting (and re-dampening it after each slice) ensures clean, precise edges.
-
- Don’t worry if the filling wobbles! A slight jiggle is normal when they come out of the oven. They’ll continue to set as they cool and firm up in the fridge.
- Don't skip chilling in the fridge: Proper chilling is key to allow the lemon filling to set, achieving the perfect texture.
Hello! Is it necessary to leave the uncooked dough to ferment or is it okay to just bake it right away?
Hi Bonnie, you can bake it right away.
my shortbread is floating ....
I'm currently baking it so as far as taste goes I cannot say. (it does smell delicious tho)
But yeah, my shortbread crust is floating in the lemon filling.
This is a chocoflan like situation and I know it shouldn't be...
any tips?
Hi Anna, two things could have happened here. I'm thinking either the crust was not pressed firmly enough in the pan or the dough was over mixed.
Curious if you or anyone else here has tried this with duck eggs? I'm wondering what amount of eggs to use, since duck eggs are larger than chicken.
These are so so so lemony. I used 8 lemons and all of them got zested. Fabulously easy! We had family over and they all loved these A LOT!!
I made these for Easter and they turned out AMAZING. Sending it to all my friends who bake. I even rushed the cooling and put them in the freezer and they still turned out beautiful.
Yes delicious but could use overnight setting up in my fridge.
I want to use some sweet limes from my garden and they are not as sour. Can I reduce the amount of sugar without affecting the result?
Hi Bek, I haven't tried reducing the sugar in this recipe but upon a little research it looks like you may be able to reduce the sugar by a third and still get a good result.
why is baking in a non-glass dish essential?
Hi Dani, you can use a glass baking dish. That was supposed to have been taken out of the post. It has been corrected.
These are amazing!!
Glad you enjoyed them!