Key lime pie - two delicious recipes for the American classic Key lime pie.
Key lime pie is one of America's most popular classic sweet pies. As its name suggests, one of the main flavours and key ingredients in this dessert, is the lime, in particular those that grow abundantly in the Florida Keys region.
Key lime pie, which can be made with either a shortcrust pastry shell or a crushed biscuit base, was invented just before the turn of the 20th century. However, the first recorded recipe for the pie was in 1930.
During this time, fresh milk was not readily available and modern refrigerated delivery transport was not yet in use either, and so to make the filling, sweet canned milk was employed, another of the pie's main ingredients.
The Key lime is smaller in size than the common Persian lime that we usually use in our cooking, and its juice is more of a pale yellow colour than green. It is however, slightly more acidic than the Persian lime, which is mild and slightly sweet in flavour.
If you are unable to obtain fresh Key limes for your recipe, try using bottled Key lime juice instead. This can be found in many supermarkets in the US and it is a more than adequate substitute for the fresh fruit.
For home cooks in other parts of the world, the common Persian lime is always used instead of the Key lime with very good results.
The final main ingredient for the pie filling is the egg yolk. Generally four are used and it is the yolk that gives the filling its traditional yellow colour.
The distinctive thing about this pie is that in previous years no cooking was involved. This is because during the mixing process, a chemical reaction between the acid in the lime together with the condensed milk causes the filling to naturally thicken by itself. Nowadays, due to the worry of the possible food poisoning when consuming raw eggs, the pie is always cooked on a low temperature for a short while.
Some recipes use the remaining egg whites to make a meringue topping.
Below are our recipes for Key lime pie:
Key Lime Pie with Shortcrust Pastry
- 9-inch shortcrust pastry shell (See our page on shortcrust pastry)
- 1 can of condensed milk (400g /14oz)
- 240ml (8fl oz) of double cream
- 150ml (5fl oz) of freshly squeezed lime juice
- 4 egg yolks
- 1 tsp of grated zest of lime
- 1 tbsp of caster sugar
- Preheat the oven to a temperature of 180°C (350°F).
- In a large bowl, whisk together the condensed milk, egg yolks and a little of the lime zest.
- Pour in the lime juice and stir well.
- Pour the filling into the shortcrust pastry shell and spread with a knife so that it is smooth on top.
- Bake in the preheated oven for 20 minutes.
- Remove from the oven and transfer to a wire rack, allowing the pie to cool before refrigerating for 2 hours.
- In a separate bowl, whip the double cream and fold in the sugar and the rest of the lime zest.
- Serve slices of Key lime pie with a good dollop of the cream mixture on top.
Biscuit Base Key Lime Pie
- For the base
- 175g (6oz) of Digestive biscuits, crushed
- 85g (3oz) of butter, melted
- 55g (2oz) of caster sugar
- For the filling
- 240ml (8fl oz) of condensed milk
- 115ml (4fl oz) of freshly squeezed (Key) lime juice
- 85g (3oz) of caster sugar
- 3 large eggs, separated
- zest of 2 limes
- ½ tsp of vanilla extract
- Preheat the oven to180°C (350°F).
- Place the crushed biscuits into a mixing bowl and pour over the melted butter.
- Add the caster sugar and mix thoroughly by stirring.
- Transfer to a 9-inch pie case and spread evenly across the bottom and sides. Set aside.
- In a large mixing bowl prepare the filling by first of all whisking the egg yolks until pale and light.
- Add the condensed milk and continue to whisk.
- Finally pour in the lime juice and add the zest and whisk all of the ingredients together until the mixture is creamy and smooth.
- Pour the filling into the pie case.
- In a clean glass or copper bowl whisk the egg whites until they are almost stiff.
- Add the sugar and vanilla and fold into the white peaks, then whisk until stiff peaks form.
- Spoon over the filling.
- Place into the preheated oven and bake for 20 minutes or until the meringue has turned golden brown.
- Remove from the oven and allow to cool at room temperature before placing in the refrigerator to chill for several hours.