[H]ave you ever juiced a key lime? You can get blood more easily from a turnip or paint from a marble. Yet, I spent an afternoon recently wrangling with these tiny green but potent creatures, feeling oversized myself, giant wooden reamer in hand, as I violated nearly a dozen limes for the mere 1/2 cup of juice i needed for a pie.
I had never made a true key lime pie — just a cheesecake from their slightly larger cousin, the Persian lime, which is more readily available. The purchased key lime pies I had eaten carried an air of falsity in flavor, along with an unnatural mint green color. True key limes (also known as Mexican limes or West Indian limes for their areas of propagation) only come around every so often, bearing bright green thin skin and the yellow juice that made that pie from the Florida Keys famous. These were on sale at my local market, so I but two bags of the little devils, envisioning a dessert that would carry me away to beachside climes.
The recipe itself looked like a snap. It would figure that some element of it would end up more arduous, that being said juice extraction. My extra-large hands — and wooden reamer — brutalized limes about the size of a pecan in the shell (an inch or so). Those first few hard-won drops gave me a clear idea of what I was in for. I was not daunted. My technique improved. I employed all of the traditional methods of getting citrus to give up its liquid — rolling the fruit, microwaving it, etc. I discovered that a combination of heating the limes slightly and then slicing them lengthwise, rather than crosswise, was the best way to get the most yield. I ended up with quite a pile of husked key limes.
Putting the pie together — after all the juicing — could not have been easier. A simple graham cracker crust (I used cinnamon-flavored grahams) is first pressed into the dish and baked. For the filling, in addition to the juice, I added some zest for flavor and dynamic green flecks of color (the pie filling itself is a pleasant yellow). Merely blend sweetened condensed milk, egg yolks, juice and zest, then pour into the crust . A very short baking time (about 15 minutes), then a substantial chill (4 to 8 hours). Top with sweetened whipped cream.
Worth every drop of juice! For their tiny size, key limes pack a wallop of flavor, more tart and tangy than standard limes. The pie, with its cool, creamy texture and deep citrus pucker was like a sweet kiss from a far-off coast.
During the recent Florida Keys Days, the world’s largest key lime pie was created. At 1,000 pounds, its crust was made from 200 pounds of graham crackers; its juice from almost 6,000 key limes.
Any juicing complaints I had are now but a drop in the bucket.
Key Lime Pie
From Gourmet magazine
Makes one 9-inch pie
For crust
1 1/4 cups graham cracker crumbs from 9 (2 1/4-inch by 4 3/4-inch) crackers
2 tablespoons sugar
5 tablespoons unsalted butter, melted
For filling
1 (14-ounce) can sweetened condensed milk
4 large egg yolks
1/2 cup plus 2 tablespoons fresh or bottled Key lime juice (if using bottled, preferably Manhattan brand)
For topping
3/4 cup chilled heavy cream
Preheat oven to 350 degrees.
Stir together graham cracker crumbs, sugar, and butter in a bowl with a fork until combined well, then press mixture evenly onto bottom and up side of a 9-inch (4-cup) glass pie plate.
Bake crust in middle of oven 10 minutes and cool in pie plate on a rack. Leave oven on.

Whisk together condensed milk and yolks in a bowl until combined well. Add juice and whisk until combined well (mixture will thicken slightly).
Pour filling into crust and bake in middle of oven 15 minutes. Cool pie completely on rack (filling will set as it cools), then chill, covered, at least 8 hours.
Just before serving, beat cream in a bowl with an electric mixer until it just holds stiff peaks. Serve pie topped with cream.