Lemon Bars - From Scratch Recipe

When life gives you lemons, make lemon bars! My original plan was to make these for a get together over the weekend with new students. However, Jeff convinced me students would prefer chocolate chip cookies and we should have the whole pan of lemon bars to ourselves. I didn't take much convincing.
 

Never having made the lemon curd filling before and I was a little nervous because it calls for the use of a candy thermometer. Although I have one I'd never used it. It's actually Jeff's grandma's I believe. And I think it has Mercury in it. I mentally created a "just in case it breaks" plan in my head and then started cooking. In hind site, I should probably just get rid of the old mercury thermometer and get a digital one. If you're not convinced read this Cleaning Up Houshold Spills of Elemental Mercury.

If you don't use an ancient candy thermometer this is a pretty easy recipe. A little extra work will ensure curd that sets and tender crust. Many lemon bar recipes call for baking the lemon curd on the crust in the oven, which resulted in under cooked lemon and rubbery crust. Cook's Illustrated found the crust didn't get soggy if the crust was pre-baked and the curd was cooked on the stove. Then the curd goes into the crust and a final baking in the oven brings it all together!

Lemon Bars

Crust

1/4 cups unbleached all-purpose flour
1/2 cup confectioners’ sugar

1/2 teaspoon salt

8 tablespoons unsalted butter, softened but still cool, cut into 1-inch pieces

Lemon Curd Filling

7 large egg yolks, plus 2 large eggs
1 cup plus 2 tablespoons granulated sugar
2/3 cup lemon juice (from 4-5 medium lemons), plus 1/4 cup finely grated zest
Pinch of salt
4 tablespoons unsalted butter, cut into 4 pieces
3 tablespoons heavy cream

1. Fold two 16-inch pieces of parchment paper lengthwise to measure 9 inches wide. Fit 1 sheet in the bottom of the greased pan, pushing it into the corners and up the sides of the pan (overhang will help in removal of baked bars). Fit the second sheet in the pan in the same manner, perpendicular to the first sheet. Butter the parchments to ensure a no stick situation. 


2. Place the flour, confectioners’ sugar, and salt in a food processor and process briefly. Add the butter and process to blend, 8 to 10 seconds, then process until the mixture is pale yellow and resembles coarse meal, about three 1-second pulses. Sprinkle the mixture into the prepared pan and press firmly with your fingers into an even layer over the entire pan bottom. Put the crust in the refrigerate for 30 minutes.
    
3. Prebake the crust: Adjust an oven rack to the middle position and heat the oven to 350°F. Bake the crust until golden brown, about 20 minutes. Set aside to cool.
   
   
4. In a medium bowl, whisk together the yolks and whole eggs until combined, about 5 seconds. Add the granulated sugar and whisk until just combined, about 5 seconds. Add the lemon juice, zest, and salt; whisk until combined, about 5 seconds. Transfer the mixture to a medium saucepan, add the butter pieces, and cook over medium-low heat, stirring constantly with a wooden spoon, until the curd thickens to a thin sauce-like consistency and registers 170°F on an instant-read thermometer or candy thermometer, about 5 minutes. Immediately pour the curd through a single-mesh stainless steel strainer set over bowl. Stir in the heavy cream; pour the curd into the warm crust immediately.
   
   
     
5. Bake until the filling is shiny and opaque and the center 3 inches jiggle slightly when shaken, 10 to 15 minutes (Mine actually took longer more like 30 minutes).
    
6. Cool on a wire rack to room temperature, about for at least 45 minutes. Cut into at least 16 pieces because these bars are rich!