Key Lime Pie

Violet’s Key Lime Pie for non-American households

(American substitutions in italics)

This delicious tart (“pie” to Americans) is a light and luscious summer dessert treat. Originally invented in the Florida Keys (small islands off the southern tip of Florida), it is properly made with the small Key Limes once plentiful in the area. Unfortunately, these limes are not available any more due to a hurricane that destroyed the original key lime plantations…there are a few small commercial growers but mostly, key limes are now found only in back gardens and not available for purchase. The pie is just as delicious and refreshing when made from the limes you get from your grocery store though, but it must be made with sweetened condensed milk, not plain evaporated milk. A proper Key Lime pie, by the way, is yellow in colour, not green!

Ingredients
1/2 cup fresh lime juice—4 or 5 limes (12 or more key limes)
2 to 4 teaspoons grated lime zest
4 egg large yolks (3 jumbo)
1 – 385 g (14 ounce) can sweetened condensed milk
1 packet Woolworths “home made” shortbread biscuits (shaped like sticks)
    OR enough digestive biscuits or ginger biscuits to make 2 cups of crumbs
    OR (2 cups graham cracker crumbs)
(3 tablespoons granulated sugar—for use with graham crackers only)
3 tablespoons butter, melted (may need more with graham crackers)

Preparation
Start with the crust:
Preheat oven to 190C (325F)
Using a food processor or blender, process the biscuits or graham crackers into fine crumbs. Pour crumbs into a bowl (if using graham crackers, add sugar) and add butter. Mix with fork and then fingers. Add a little more butter if necessary to moisten the crumbs enough to hang together.

Now, press crumb mixture into pie dish. Be sure to build up the sides as the crust will shrink while baking.

Bake in the centre of the oven for 10 to 12 minutes, then remove and cool to room temperature.

Filling
While the filling is baking, zest the limes.

Slice zested limes in half and remove all seeds. Squeeze limes until you have ½ cup of juice.

Separate the eggs, setting aside the yolks. If you are going to make a meringue with the whites, make sure there is not even a trace of yolk in the whites or they won’t whip.

Whisk, or beat on high speed, the yolks and lime zest together for about 2 minutes. Beat in the juice for one minute and then slowly add the condensed milk. Incorporate the milk into the egg mixture thoroughly, then set aside to thicken at room temperature.

When the crust has cooled to room temperature, pour in the filling and spread evenly.

Because the acid in the lime juice “cooks” the egg yolk (by a process known as “souring”), unless salmonella in the eggs is a concern, the filling does not need to be baked. In the original Key Lime Pie, the filling was not baked and there is considered by some to be a significant texture difference between the two methods. (If you live in America, however, or any other place that has a concern with salmonella in their eggs, you must now bake the pie for 15 minutes at 325F—190C—to make sure the salmonella is killed. Cool to room temperature and then follow the remaining instructions.)

If you are going to put a meringue topping on the pie, now is the time to do it. Otherwise, place the room-temperature pie in the refrigerator until well chilled (at least 3 hours)

Topping
There are 3 schools of thought regarding toppings on the pie: plain, whipped cream or meringue. Meringue is the most cost effective because you have egg whites left over and by making a meringue, they will not go to waste.

Meringue
3 to 4 egg whites
A scrupulously clean (and devoid of any kind of oil) deep bowl
3 tsp castor (granulated) sugar
½ tsp cream of tartar (optional)

Pour eggs into bowl with cream of tartar. Whisk briskly (or beat on high speed) until foamy. Sprinkle in 1 tsp sugar. Continue whisking until soft peaks begin to form. Sprinkle in 1 tsp sugar. Continue whisking until peaks become somewhat firm. Add remaining sugar and whisk in. Pour meringue onto top of pie, swirling to make peaks. Put into oven and bake up to 6 minutes or until peaks start to brown. Remove from oven, cool to room temperature, then refrigerate for 3 hours or more.

Photo of authentic Key Lime Pie by Marc Averette