Too little cornstarch, too much lemon juice and insufficient cooking time are the likely culprits when a luscious lemon pie begins to puddle. Cornstarch is the binder that gives the pie its firm shape. But even the correct amount of cornstarch won’t prevent watery pie if you add too much lemon juice, under-cook or over-cook the pie, all of which can break the bonds that keep moisture distributed evenly throughout the filling. By mixing the ingredients in a precise order then cooking them without pause, you can set the lemon filling and meringue properly.

Things You'll Need

Progress from dry ingredients to cold, wet ingredients to warm, wet ingredients as you mix the lemon filling. Stir together granulated sugar, cornstarch and salt in a large saucepan. Use two units of cornstarch for every five units of sugar in your recipe. Whisk cold water and the lemon ingredients into the dry blend. The amount of cold water and lemon juice should each equal the amount of cornstarch in the filling. For example, if you use 1/2 cup of cornstarch add 1/2 cup of cold water and 1/2 cup of lemon juice. Whisk in the egg yolks then the butter. Continue whisking as you add the hot water. The volume of hot water in your mixture should equal the volumes of cornstarch, cold water and lemon juice combined.

Cook the lemon filling on the stovetop over medium-high heat until it begins to gently boil, approximately 6 to 8 minutes. Stir the filling constantly to prevent it from scorching. Reduce the heat to medium when the filling begins to bubble. Cook it 1 more minute then remove it from the stove.

Pour the filling into a pie crust immediately after you remove it from the stove. Scoop the uncooked meringue on top of the steamy lemon mixture. The steam from the hot filling penetrates the meringue, causing moisture to bead on top of ‘tthe pie. If the filling is only warm when you add the meringue the heat isn’t intense enough to penetrate the topping, and collects between the two layers in a watery puddle.

Bake the pie immediately in a 325-degree-Fahrenheit oven to set the pie before the filling or meringue can start to break. The steam beads on top of the meringue will evaporate or brown on the surface. Remove the pie from the oven when the meringue begins to brown, after approximately 20 to 25 minutes. Cool the pie at room temperature for 3 hours then transfer it to the refrigerator. Serve the pie within one day of making it.


  • Some recipes suggest using a kitchen torch to set the meringue without baking the pie. However, baking is a more effective way to set the meringue and cook the moisture out of the filling and meringue.