Why It Works
- An ample amount of fresh lemon juice and zest in the curd gives the filling the brightest and tangiest lemon-forward flavor possible.
- Honey adds a subtle floral flavor to the filling.
- Straining the lemon filling removes lumpy bits, keeping the filling silky-smooth.
- Coating the flour with melted butter limits gluten development, resulting in a crisp and tender crust.
When I was a kid, one of my favorite treats was a lemon stick—a candied lemon straw pierced into a cut lemon half. Every sip through the candied straw brought a jolt of fresh lemon juice so intense it always made me pucker. I haven’t eaten lemon sticks since I was a child, but as an adult I satisfy my craving for that sweet-tart jolt by making lemon tarts professionally and at home. To me, a great lemon tart should make your mouth pucker so much that your eyes open wide too, and that’s what I was aiming for when I developed this recipe: a filling that’s sweet, yes, but also has a powerful fresh lemon punch.
In this recipe, the lemon curd is intensely bright tasting, sharp, and tangy with a silky smooth texture that’s creamy and dense enough to hold together once the tart is sliced. The filling’s velvety texture is countered by a crunchy shortbread-like crust. Not only does this tart taste fantastic (if I do say so myself), the whole thing requires just 15 minutes of active prep time, followed by 40 minutes of baking (that includes baking the tart crust and cooking the lemon curd), and an hour of resting. Here’s how to do it.
How to Make an Intensely Tart Lemon Curd Filling
I’ve professionally baked and eaten a lot of lemon tarts over the years and the biggest problem with most of them was that they simply were not lemony enough. These subpar tarts were cloyingly sweet or unpleasantly eggy. A great lemon curd needs to celebrate the fruit’s fresh flavor, and the first way to ensure this is to use more lemon than you would expect. Through testing many rounds of curds, I found that to achieve a supremely tart tart, you need to use an aggressive amount of both lemon zest and lemon juice.
The other way to get the sharpest lemon flavor possible is to cut down on the amount of sweetener used in the filling, and to use honey instead of granulated sugar. In my research, most recipes call for at least a full cup of granulated sugar to sweeten the curd filling. I tried this standard at the start of recipe testing, but the result was a cloyingly sweet and dull lemon filling. I tested again using less sugar, going all the way down to a half cup. With less sugar, the flavor was sharper and closer to that pucker-worthy lemon filling flavor I wanted. But the filling still didn’t taste as vibrant as I wanted. The solution was using honey instead of granulated sugar in the lemon filling. Honey’s mild floral flavor pairs perfectly with the sharp lemons and adds a subtle depth of flavor to the curd.
The other ingredients in the curd are fairly straightforward. A combination of three whole eggs and a full six eggs yolks thickens and emulsifies the curd, giving it its signature creamy but sliceable texture. Using extra yolks also means you don’t need to thicken the filling with cornstarch or flour, which can add an unwelcome grainy texture. After the curd is cooked and strained, a few tablespoons of butter are whisked in for a hint of richness to balance the sharp lemon flavor. The whole process of making the curd takes about 10 minutes.
Pair It With an Easy Pat-in-the-Pan Shortbread-Style Crust
Once you have your tart filling prepped, all you have to do is pour it into a prepared tart shell. While you can use a store-bought shell or a classic French pâte sucrée—which requires a stand mixer and hours of chilling before rolling the dough out—my go-to is the simple pat-in-the-pan crust I’ve included here. (The tart shell is great for other fillings too). This buttery, shortbread-like shell is the perfect container for the tart lemon filling. It’s sturdy when handled but tender once bitten into and the buttery flavor pairs perfectly with the bright lemon.
The tart crust takes only a few minutes to prepare and you can make the lemon curd while the crust bakes. The hardest part of this recipe might be the fact that you need to wait at least an hour for the tart to fully cool and the curd filling to set before slicing and serving.