Key Lime Pie

Key lime pie is a tart custard of key lime juice, sweetened condensed milk and egg yolk, baked into a graham cracker crust until just set. It comes from the Florida Keys, built specifically around the key lime — a small, intensely sour, pale-fleshed lime that grows there and is too sharp to eat on its own, which is exactly why condensed milk's sweetness became the fix rather than an afterthought.

What it really is

Graham crackers, crushed fine and bound with melted butter, press into a pie dish and bake briefly until they set into a firm shell. Egg yolks whisk with sweetened condensed milk and key lime juice — the acid in the lime juice is strong enough to thicken the mixture almost on its own — and the filling bakes just long enough to set fully without curdling, then chills until fully cold before it's cut. The colour is naturally a pale, egg-yolk yellow; a bright green filling means dye and food colouring, not real key lime juice.

Key limes are what make it a key lime pie, not limes in general. Regular Persian limes, the common green ones found in most supermarkets, are larger and less acidic, and a pie made with them is a reasonable substitute but not the genuine article — a distinction worth being upfront about if key limes aren't what's actually in the kitchen.

How it's served

• Cold, straight from the fridge, cut into wedges.
• With whipped cream on top, sometimes torched meringue instead.
• As a dessert, rarely served any other way.

How to write it on the menu

• Say if it's made with real key lime juice or standard lime juice, since the difference matters to people who know the dish.
• Flag the wheat in the graham cracker crust, the dairy in the condensed milk, and the egg.
• Note if the topping is whipped cream or meringue, since both are traditional but change the dish's finish.