Classic Lemon Bars
Lemon bars are a sweet, tart lemon custard on a tender shortbread crust. They are a bake sale favorite for a reason: bright, buttery and simple.
- 1 h 5 minTotal time
- 16Servings
- 215kcal / serving
- 3 gProtein
The filling uses fresh lemon juice and zest for real flavor, and the crust is pressed in by hand. They cut into 16 neat squares once chilled.
The science: why this works
- Pressing the buttery dough into the pan and prebaking it gives a crisp base that does not go soggy.
- Pouring the filling onto the hot crust helps it start setting right away and bonds to the crust.
- Fresh lemon juice and zest give far more flavor than bottled juice.
- A small amount of flour in the filling helps it set firm enough to slice.
- Chilling the bars before cutting gives clean edges.
How the filling sets
Egg proteins unwind and link together as they heat, trapping the lemon juice and sugar in a soft gel. The flour helps hold it together. The filling is done when it no longer jiggles in the center, about 160°F (71°C).
Learn: Lemon curd: gentle heat →Why prebake the crust
Raw dough would absorb the wet filling and turn gummy. Baking the crust first sets the starches and dries the surface, so it stays tender and crisp under the custard. The crust should be lightly golden before the filling goes on. A prebaked crust also lifts out cleanly, so the bars slice into neat squares.
Learn: Choosing the right flour →Why zest and juice both
Most of the lemon aroma lives in the oils of the zest, not the juice. The juice gives sourness. Using both gives the bars both the tart bite and a fragrant, lemony smell. Zest the lemons before juicing them, since a juiced lemon is hard to zest.
Learn: Citrus oil is in the zest →Classic Lemon Bars
1 h 5 min · 16 servings · American · Dessert
Ingredients
Makes 16 servings
- 230 gunsalted butter, softened (1 cup)
- 65 gpowdered sugar (1/2 cup), for crust
- 280 gall-purpose flour (2 1/4 cups), divided
- ¼ tspfine salt
- 300 ggranulated sugar (1 1/2 cups)
- 4large eggs
- 180 mlfresh lemon juice (about 4 to 5 lemons)
- 1 tbsplemon zest
- Powdered sugar, for dusting
Method
Tips for the best result
- Zest the lemons before juicing them.
- Cool completely before cutting, since warm filling is too soft.
- Dust with powdered sugar just before serving, or it melts into the surface.
Mistakes to avoid
- Overbaking makes the filling rubbery and browned, so pull the pan when the center no longer jiggles.
- Using bottled lemon juice gives a flat flavor, so squeeze fresh lemons.
- Cutting while warm smears the filling, so chill the bars first.
Variations and swaps
- Add 1 tbsp of lime zest and swap half the lemon juice for lime juice.
- Add a pinch of ground ginger to the crust.
- Make them with Meyer lemons for a softer, floral flavor.
- Swap powdered sugar in the crust for 50 g granulated sugar for a slightly crisper crust.
- Swap 60 ml of the lemon juice for orange juice to soften the tartness.
- Swap salted butter for the unsalted butter and omit the added salt.
Storing and reheating
Refrigerate the bars in an airtight container for up to 5 days. Freeze cut bars for up to 2 months and thaw in the fridge. Dust with powdered sugar just before serving.
Classic Lemon Bars: questions
How do I know when lemon bars are done?
The edges are lightly golden and the center no longer jiggles when you gently shake the pan. It firms more as it cools. Overbaked bars turn rubbery and brown.
Why are my lemon bars runny?
They were underbaked or cut before they were cool. Bake until the center is set and chill for at least 1 hour before slicing.
Can I use bottled lemon juice?
You can, but fresh juice tastes much brighter. Bottled juice is often flat or bitter. You need about 4 to 5 lemons for 180 ml of juice.
Why did my lemon bars turn brown on top?
The filling baked too long or the oven was too hot. Check at 22 minutes and use an oven thermometer to confirm 350°F (175°C).
How do I get clean cuts?
Chill the bars thoroughly and use a sharp knife, wiping it clean with a damp cloth between cuts.
