Ingredients in most Key lime pie recipes include a creamy base such as cream cheese or Greek yogurt, Key lime or lime juice and sweetened condensed milk. Most recipes contain egg yolks, butter, graham crackers and sugar.
The basic ingredients of a Key lime pie remain largely the same regardless of recipe variation, but many of the secondary ingredients are different. However, people who want fewer calories can change the basic ingredients. For example, while the basic recipe calls for a cream or cream cheese base, the light version of the recipe with less calories replaces the fattier cream cheese with reduced-fat Greek yogurt. Sweetened condensed milk is another basic ingredient, although some recipes call for fat-free sweetened condensed milk. However, not all recipes call for egg yolks, although most do. A few recipes require a minimal amount of sugar, while the lighter version requires fat-free whipped topping instead.
Key lime pie recipes differ mostly in the crust. One recipe requires a combination of butter, bread crumbs and cookie crumbs for the crust while another crust is made with only cookies and butter. A third recipe has a much more elaborate crust made of graham cracker crumbs, brown sugar, grated white chocolate, butter and canola oil.