Lemon meringue pie is a custard pie which is topped with a frothy layer of meringue. Many people think of lemon meringue pie as a classic Southern American dessert, thanks to its abundance in the American South, but it also shows up in other regions of the country and the world. When well made, a lemon meringue pie showcases the tangy, intense flavor of lemons, balancing it out with naturally sweet and fluffy meringue. Many diners offer lemon meringue pie, and you can also make lemon meringue pie at home. It is not terribly difficult to make, although the kitchen can get a bit messy during the process.
The custard used in lemon meringue pie is a form of lemon curd, made by cooking eggs, sugar, and lemon juice together over a double boiler before adding in lemon zest and unsalted butter. Many people also add cornstarch to ensure that the filling thickens. There is some dispute over the amount of sugar to use. Some people like a more tangy lemon curd, allowing the natural citrus flavor of the lemons to come through, while others prefer a sweeter filling which is less mouth puckering.
The meringue topping is made by beating egg whites and sugar together, and then spreading the meringue over the custard filling before baking. As the pie is baked, the meringue sets, turning a creamy color. Making a good meringue is a bit tricky; meringue tends to collapse, be uncooked in the middle, or become weepy. You may want to consult the wiseGEEK article on making a perfect meringue pie to learn more about meringue.
The foundation of a lemon meringue pie is, of course, the crust. Some people like to cheat with their crust, and this can have unfortunate results. The ideal lemon meringue pie crust is light and flaky, so that it will not distract from the texture and flavor of the pie. Stiff, cardboardy crusts should be avoided, and the crust should be precooked before the lemon filling is added, to ensure that it does not become soggy. Crumbly crusts like graham cracker crust can be used, although you may find that they clash with the meringue.
Classic lemon meringue pie is served on its own, without any adornment, because the meringue and the lemon curd are considered to be enough. However, some people like to serve lemon meringue pie with a tuile cookie or mint garnish, and adventurous cooks may shave some chocolate over their lemon meringue pie before service.