Pillowy Key Lime Pie

This is key lime pie the way Florida natives make it, before the rest of the country started topping it with whipped cream. The original is finished with a tall, baked meringue that crowns the bright green-yellow custard filling and turns golden in the oven. The combination of sharp key lime and sweet, cloud-like meringue is unbeatable.

Using both key lime juice and regular lime juice is the smart compromise. True key limes are smaller, more aromatic, and harder to find outside Florida. The ⅔ cup of key lime juice plus ⅓ cup of regular lime gives you proper key lime authenticity with the more available regular limes filling in for volume. Don’t use bottled lime juice if you can avoid it; fresh juice has dramatically better flavor.

The magic is in the no-bake filling. Five egg yolks beaten with sweetened condensed milk and lime juice create a thick, creamy custard through a simple acid-cooking reaction. The lime juice’s acidity “cooks” the proteins in the milk and yolks, producing a set custard without any heat. This is the same chemistry as ceviche.

Sealing the meringue edges against the pie shell is non-negotiable. Meringue that doesn’t touch the crust pulls away during baking, weeping juice and shrinking. Pressing the meringue all the way to the crust edges locks it in place and prevents the cosmetic disaster.

Pro Tips

• Beat the egg whites in a clean, grease-free bowl. Even a trace of fat prevents proper foaming.
• Add the sugar gradually, after soft peaks have already formed. Too early and the whites won’t reach full volume.
• Bake the meringue topping just until golden brown peaks form. Overbaking can produce “weeping” beads of sugar syrup on the surface.
• Cool at room temperature first, then chill. Going straight to the fridge can cause the meringue to weep.

Variations

• Top with sweetened whipped cream instead of meringue for a modern presentation.
• Use a graham cracker crust for the most authentic Florida version.
• Add 1 teaspoon of finely grated lime zest to the filling for added brightness and visual flecks.
• Garnish with thin lime slices or candied lime peel for presentation.