Cook's Illustrated

The Best Lemon Bars

Published May 1, 1998.

Most lemon bars are too sweet and have a thick, soggy crust. We developed a recipe that delivers a fresh, lemony filling paired with a thin, crisp crust.

The Problem

Lemon bars are a casual treat to make without a lot of fuss. Still, they have their requirements, and we wanted to learn how to make the best lemon bars possible with a simple and straightforward recipe.

The Goal

The filling should be light and very lemony, the crust tender, ready to melt in you mouth. We also wanted everything to come together in a way that made it possible to cut up the bars cleanly and serve them neatly.

The Solution

We tackled the crust first, knowing that our basic ingredients would be flour, butter, and sugar and that the outcome should be more like a cookie or a shortbread than a pastry-type crust. White granulated sugar is often the first bakers turn to for the sort of crust we were after, but we discovered that confectioners' sugar gave us the most tender texture. The addition of a little cornstarch also helped move the crust in the melt-in-your-mouth direction. To ensure an evenly baked crust and prevent sogginess, we found it necessary to prebake before adding the filling. To make the filling lemony enough to satisfy us, we ended up using the juice from three or four lemons, plus some zest. Arriving at a smooth and pleasant texture involved eggs, a little flour for thickening, and, somewhat unexpectedly, milk, which seemed to balance the flavor with the texture.

list of recipes
America's Test Kitchen

America’s Test Kitchen is a 2,500-square-foot kitchen located just outside of Boston. It is the home of Cook’s Country and Cook’s Illustrated magazines and is the workday destination for more than three dozen test cooks, editors, and cookware specialists. Our mission is to test recipes until we understand how and why they work and arrive at the best version. We also test kitchen equipment and supermarket ingredients in search of brands that offer the best value and performance. You can watch us work by tuning in to America’s Test Kitchen (www.americastestkitchen.com) on public television.