Key lime pie
Key lime pie is an American dessert made of key lime juice, egg yolks, and sweetened condensed milk in a pie crust. The traditional conch version utilizes the egg whites and has a meringue topping. The dish is named after the small Key limes (Citrus aurantifolia 'Swingle') that are naturalised throughout the Florida Keys (Quays). Their thorns make them less tractable, their thin yellow rind makes them more perishable, but they are more tart and aromatic than the common Persian limes seen year round in most U.S. grocery stores.
During mixing, a reaction between the condensed milk and the acidic lime juice occurs which causes the filling to thicken on its own without requiring baking. Many early recipes for key lime pie did not instruct the cook to ever bake the pie, relying on this chemical reaction (called souring) to produce the proper consistency of the filling. Today, in the interest of safety due to consumption of raw eggs, pies of this nature are usually baked for a short time. The baking also thickens the texture more than the reaction alone.
In 1965, Florida State Representative Bernie Papy, Jr. introduced legislation calling for a $100 fine to be levied against anyone advertising key lime pie that is not made with key limes. The bill did not pass. As of July 1, 2006, key lime pie is the Florida state pie.