Whenever I’m in Florida, I eat Key Lime Pie all the time because I love it. There are lots of different versions: with or without whipped cream, with or without meringue, with a crust from graham crackers or with a baked crust, etc. I like all versions, because what defines key lime pie for me is the contrast between the velvety texture and the sour tanginess of the custard. It may be impossible to find key limes out of the US or Mexico, but it’s fine to substitute with regular limes (living in the Netherlands, I do too!). Since key limes have a higher acidity, you could substitute some of the key lime juice with lemon juice but you could also just try whether you like it with regular limes first. The stronger aroma of key limes cannot be replaced, but the pie is still good without it. I’d rather use freshly squeezed juice of regular limes than bottled key lime juice, as both the added preservatives and the fact that it’s not fresh strongly affect the flavor. Here’s my version, which is not traditional at all since I don’t use condensed milk nor graham crackers.
For a 24 cm (9″) springform pan, serves 8-10
For the crust
125 grams butter
125 grams white castersugar (or regular sugar)
3 grams (1/2 tsp) salt
1 egg, separated
1 Tbsp water
250 grams flour
5 grams baking powder
For the custard
175 grams sugar
4 large eggs
175 ml heavy cream
150 ml freshly squeezed (key) lime juice (juice from 3-4 limes)
grated zest of 1 (key) lime
pinch of salt
For finishing (optional)
Start with the crust, and allow at least 2 hours or overnight for the dough to rest.
Put butter, sugar, salt, egg yolk and water into your food processor fitted with a metal blade.
Process until mixed.
Add flour and baking powder and process until mixed.
Shape the dough into a disk, wrap in plastic and let it rest in the refrigerator for at least 2 hours or overnight.
Preheat the oven to 180C/350F.
Grease a 24 cm (9″) springform pan with butter and sprinkle with flour. (I like to use a Porsgrund springform that can also be used to serve the pie, but a regular springform pan will do just fine.)
Roll out the dough to a circle with a diameter of 32 cm (13″) and line the springform with the dough.
Line the dough with parchment paper and fill the pie with beans or ceramic balls. (I should buy additional ceramic balls, because it works better if the crust is completely filled.
Bake the crust like this (in Dutch we call this ‘blind baking’) for 20 minutes at 180C/350F.
Remove the parchment paper and the beans or ceramic balls. Lightly beat the egg white and brush the crust with it. Bake for another 15 minutes at 180C/350F.
The egg white helps to keep the bottom of the crust dry.
Meanwhile, zest 1 key lime. Juice key limes to obtain 150 ml of freshly squeezed juice.
Put the sugar and eggs into your mixer and mix until pale yellow and creamy, around 2 minutes.
Add the key lime juice, heavy cream, and a pinch of salt and mix.
Put the custard mixture into the crust and bake for 40 minutes at 180C/350F or until barely set.
Let the key lime pie cool completely, at least 1 hour. (If you cut it too soon, the custard has not set completely yet.)
If you like, you can sprinkle the pie with confectioner’s sugar or even decorate it with whipped cream. To make it easier to cut, you could freeze it for 15 minutes or so.
Key lime pie is outstanding with Moscato d’Asti, the slightly fizzy sweet and fresh dessert wine from Piemonte in Italy. Moscato d’Asti should be served cold, 5C/41F.