History
Key lime pie was likely invented in the late 19th century in the Florida Keys, where the small, intensely tart key limes (Citrus aurantiifolia) grew wild and sweetened condensed milk (invented by Gail Borden in 1856) was the only available shelf-stable dairy on the islands. The chemistry of the dish is unique: the citric acid in lime juice causes the condensed milk to thicken without heat, so the original 19th-century version was uncooked, set by acid alone. Modern food safety requires a low-temperature bake. Joe's Stone Crab in Miami Beach has served the dish since 1913 and is the most-cited Miami canonical address. The Florida Keys grow few commercial key limes today; most are now imported from Mexico and the Dominican Republic. Some Miami spots use Persian limes for accessibility, but purists demand authentic key limes (smaller, yellower, more aromatic).
Make it at home
Yield Serves 8Hands-on 25 minTotal 4 hrDifficulty Easy
Ingredients
- For the graham-cracker crust: 250g graham cracker crumbs (about 14 cracker sheets), 80g granulated sugar, 120g unsalted butter (melted)
- For the filling: 4 large egg yolks, 1 can (397g) Eagle Brand sweetened condensed milk (the canonical Florida brand), 125ml fresh key lime juice (from about 25 key limes; substitute with bottled key lime juice or a 50-50 blend of Persian lime juice and lemon juice for a closer match if key limes are unavailable), zest of 4 key limes (or 2 Persian limes)
- For the topping: 500ml heavy whipping cream, 30g icing sugar, 1 tsp vanilla extract
- Garnish: thin slices of fresh key lime, additional lime zest
Method
- Heat the oven to 175 degrees Celsius (160 fan).
- Combine graham cracker crumbs, sugar and melted butter in a bowl; press firmly into the base and 4cm up the sides of a 23cm pie plate. Bake 10 minutes until pale gold and fragrant; cool 10 minutes while you make the filling.
- Whisk the egg yolks in a large bowl until thick and pale yellow (about 90 seconds).
- Whisk in the sweetened condensed milk slowly, then the lime zest.
- Pour in the key lime juice gradually, whisking constantly. The mixture will thicken visibly as the acid reacts with the milk; this is the structural step.
- Pour the filling into the warm crust, smooth the top.
- Bake at 175 degrees Celsius for 12 to 15 minutes until the centre is just set with the slightest wobble; the surface should not crack or brown.
- Cool to room temperature, then refrigerate at least 3 hours (and up to 24 hours) until completely chilled.
- Just before serving, whip the cream with icing sugar and vanilla to stiff peaks.
- Cover the pie generously with whipped cream (the canonical Florida style is a full edge-to-edge layer, not just a centre dollop). Garnish with paper-thin lime slices and fresh zest.
- Slice with a hot wet knife. Serve cold.
Tip from the editors. Real key lime juice is essential; Persian lime alone tastes flat. If you cannot source key limes, the Nellie and Joe's brand of bottled key lime juice is the canonical Florida pantry substitute. Use Eagle Brand condensed milk if possible; other brands have different sugar levels and the chemistry varies.
This is the TableJourney editorial recipe, modelled on the canonical bistro / counter version. The first place to try the dish in its city of origin is below.