A bright, intensely tart custard made from the juice of Key limes — smaller, more aromatic, and more acidic than Persian limes — combined with sweetened condensed milk and egg yolks, baked in a graham cracker crust. The chemical reaction between the acid of the lime juice and the condensed milk sets the custard without baking in the original versions. True to the Keys: simple, bright, and made from what was available.
Black fishing communities in the Florida Keys used Key limes — which grew prolifically on the islands — as a dietary staple from the late 19th century. The pie was a practical creation: no refrigeration required for condensed milk, limes grew everywhere, and the acid-set method meant the custard could be made without a precise oven. It belonged to the Keys before it belonged to restaurants.
Key limes have a higher vitamin C concentration than Persian limes and a distinctive aromatic profile from terpenes not present in larger limes. The citric acid supports kidney stone prevention with regular consumption. As a dessert, the primary nutrient contribution is vitamin C and calcium. A celebration food framed honestly.
Use fresh Key lime juice — bottled versions are acceptable but lack the aromatic terpenes that define the flavor. Whisk egg yolks with condensed milk until thickened, add lime juice and zest, pour into a graham cracker crust, and bake at 350°F for 15 minutes. The custard should be barely set — it firms on cooling. Serve cold, topped with fresh whipped cream, never meringue.
Free, no account needed to ask.