A silky, intensely sharp lime custard in a buttery graham cracker crust topped with whipped cream, the most refreshing and perfectly balanced pie from the Florida Keys and one of the great American desserts.
About This Recipe
Key lime pie is the most perfectly balanced pie in the American tradition. The filling has a tartness that is almost aggressive in the best possible way, a genuinely sharp, bright acidity from the key lime juice that is immediately bracing and then immediately pleasing. Against the sweet graham cracker crust and the lightly sweetened cream on top, this sharpness finds its equilibrium and produces a dessert that is simultaneously rich and refreshing, sweet and sour, simple and somehow complex.
The filling requires only three ingredients: condensed milk, egg yolks, and lime juice. The condensed milk provides sweetness and richness. The egg yolks provide the fat that gives the filling its silky, custardy texture. The lime juice provides the acidity that reacts with the proteins in the condensed milk to thicken the filling without any cooking. In the oven the filling sets completely to a smooth, trembling custard that holds a clean edge when sliced.
Key limes, the small, yellow-green limes native to Florida and the Caribbean, produce a more aromatic, more intensely flavoured juice than the standard Persian limes available in most supermarkets. Outside Florida, bottled key lime juice is the practical alternative and produces a very good result. In the absence of key lime juice, regular fresh lime juice produces a slightly less complex but equally tart and delicious pie that is entirely authentic in spirit.
History and Origins
Key lime pie originated in the Florida Keys in the late 19th century, where the combination of locally grown key limes, condensed milk (which did not require refrigeration in an era before electric refrigerators were common), and egg yolks produced a practical and delicious dessert. The pie became an official Florida state pie in 2006. It is one of the most recognised regional American desserts and one of the most frequently searched pie recipes.
Why It Is Good For You
Limes are rich in vitamin C, citric acid, and flavonoids with antioxidant properties. The egg yolks provide choline and vitamin D. The condensed milk provides calcium. Key lime pie is a relatively moderate dessert in terms of caloric density compared to cream-heavy pies.
Key Lime Pie
4
servings30
minutes40
minutes300
kcalIngredients
•tFor crust: 200g graham crackers or digestive biscuits crushed, 80g unsalted butter melted, 2 tbsp sugar
•tFor filling: 4 large egg yolks, 400g tin condensed milk, 120ml fresh lime juice or key lime juice, zest of 3 limes
•tFor topping: 200ml double cream, 2 tbsp icing sugar, extra lime zest
Directions
- Preheat oven to 175C. Mix crushed biscuits with melted butter and sugar. Press into a 23cm tin.
- Bake crust for 8 minutes until set. Cool slightly.
- Whisk egg yolks until pale. Beat in condensed milk then lime juice and zest.
- Pour filling into warm crust.
- Bake for 15 to 17 minutes until filling is set with a slight wobble in the centre.
- Cool completely then refrigerate for at least 2 hours.
- Whip cream with icing sugar to soft peaks. Serve pie slices topped with cream and extra lime zest.
Notes
- Use fresh lime juice only. Bottled lime juice lacks the aromatic quality that makes this pie distinctive.
The filling sets primarily through the reaction of the acid with the condensed milk. The oven heat firms it further.
The pie must be completely chilled before slicing. Warm key lime pie filling is too soft to slice cleanly.
The colour of the filling is naturally pale yellow-green. Any vivid green colour indicates artificial colouring.
Make Ahead Tips
Key lime pie keeps refrigerated for up to 4 days and is consistently better the next day than the day it is made. This is an ideal make-ahead dessert. Add whipped cream topping just before serving.
Storage and Serving
Refrigerate for up to 4 days. The lime flavour deepens and the filling firms over the first 24 hours. Serve cold. Add cream topping just before serving as it weeps if added too far in advance. Freeze for up to 3 months without the cream topping.
Variations and Substitutions
Replace lime with lemon for a lemon pie version. Add a tablespoon of rum to the filling. Make a coconut key lime pie by adding 60g of desiccated coconut to the graham cracker crust. Top with toasted meringue instead of cream for a more dramatic presentation.
