Key lime pie is the official dessert of the Florida Keys in the United States. While it of course can be made year-round, people often serve it in the spring or summer because of its citrus flavor. The light but filling pie is a nice choice for meals that aren't too heavy--like ones that have fish or salad as the main course--and afternoon gatherings like teas and lunches.
While key lime pie has a sweet taste because of the sweetened condensed milk in the recipe, it also has a noticeably tart flavor that's more intense than a lemon-flavored pie.
People might assume that the pie's filling would be green because of the lime juice, but it's actually a pale yellow and its topping is white. Some add food coloring to give it a green tint or decorate each slice with a sliver of sugared lime.
Two different toppings are used for key lime pie. One is the meringue-style topping that is also used for lemon meringue pie, and another is whipped cream. The topping can cover the whole surface of the pie or may only be used to form a rim around the top of the dessert.
Key lime pies always have a cream filling that is fairly dense. The recipe for the filling typically consists of egg yolks, lime zest, lime juice and sweetened condensed milk that are blended together, baked in an oven and chilled before serving.
This dessert can be made with either a graham cracker or a pastry crust. Restaurants favor the graham cracker recipe, as do people who don't have the time or skill to bake a pastry crust.
The pie has a combination of textures. A graham cracker crust is crumbly, and a pastry crust is flaky. The filling can range from creamy to spongy, depending on the ingredients' portions. The topping for a meringue-covered pie is a foam that dissolves on the tongue, but ones with whipped-cream toppings have a smooth texture.