In Search Of The Real
Key Lime Pie

by Gorgia Orcutt

By our unofficial tally, if you draw a line from Fort Myers to Boynton Beach, you’ll discover that 98.2% of all restaurants south of the line, large or small, fancy or not, list key lime pie on their menus. (For every 50 miles you travel north of the line, the figure drops by about 1%.) These aren’t just random musings. On July 1, with Governor Bush’s signature, key lime pie became legally recognized as Florida’s Official State Pie.

That’s no surprise. The perfect marriage of a refreshingly puckery sweet-tart flavor and a cold, creamy texture gives this dessert the haunting ability to possess anyone who tastes it. Likened to biting into a cool breeze, it has inspired a long list of bakers in Florida and elsewhere to make and ship pies across state lines, to say nothing of giving rise to a brisk business in spin-offs: key lime pie cocktails, liqueur, jelly beans, nutrition bars, cookies, candles, shampoo, tee-shirts, and jewelry among them. Yet there is a dark side to it all. Serve a Floridian something that falls short of his or her idea of what key lime pie ought to look like and taste like and you’ll never hear the end of it.

What really, is the true version? And, if we can agree on the recipe, can’t we stray from tradition without undermining the original? Yes and no. For starters, a true key lime pie can only be made with freshly squeezed juice from thin-skinned, walnut-sized key limes picked when they’re at the peak of perfection. Put on your glasses if necessary when buying them and choose only green or yellowish fruits with a fine leather-like grain to their skin. Avoid any that are blotchy, hard, or shriveled. Bottled juice or larger Persian or Tahiti limes commonly found in supermarkets won’t deliver the classic limey flavor or authentic 1950’s greenish-yellow color so important to pie perfectionists.

Beyond the limes themselves, you’ll find, as we did on a recent sampling tour around the Fort Myers area, that chefs love to tinker and there are dozens of versions of key lime pie to be tasted. To set the record straight, here’s a bit of background, and a recipe for your files.

In the Beginning…

Agricultural history credits Dr. Henry Perrine as being one of the first proponents of key lime growing in Florida, despite some rocky adventures. Born in New Jersey in 1797, Perrine tried in 1821 to cure his malaria by drinking a Peruvian bark cocktail, and accidentally ingested some arsenic left behind in the beaker. Suffering poor health as a result, he moved to Mississippi, where he rallied sufficiently to be appointed U.S. Consul in the Yucatan. During his ensuing ten-year stay in Mexico, he shipped citrus seeds to his friend, postmaster Charles Howe, on Indian Key. According to his plant inventory, these included citrus aurantifolia, which today we call Key Limes. Although killed in the Second Seminole War in 1840, Perrine’s interest in growing tropical plants in Florida inspired a number of small scale commercial growers to raise the thorny, scrubby trees, which grow true from seed, can be easily propagated from cuttings, produce fruit all year round, and are well suited to the climate and rocky, alkaline soil of the Keys. By 1883 key limes were commercially grown in Orange and Lake counties, and small plantings were scattered elsewhere.

But nasty weather played a large role in the key lime’s commercial future. When the hurricane of 1906 destroyed local pineapple plantations, South Florida growers expanded their key lime production, especially in the Keys and the islands off Fort Myers. From 1913 to 1923 key limes were pickled in salt water and shipped to Boston to serve as a snack for school children. Small scale operations lasted for two decades, until a second hurricane in 1926 wiped out most of the crop. Citrus growers and small farmers looking for some extra income succumbed to the charms of the new hybrid seedless Persian or Tahiti lime (citrus latifolia) which, although sadly lacking in fragrance and flavor, is virtually thornless and easier to pick, with a thicker rind that holds up better for shipping. In 1949, the invention of limeade concentrate created a ready market for the larger limes. Up until Hurricane Andrew in 1992, which took out the trees once again, 90% of US supermarket limes were grown in Florida. Key limes endured, but as a backyard crop or a funky tree in the neighborhood. The Upper Florida Keys Chamber of Commerce launched campaigns in 1954 and 1959 to encourage nurseries to sell key lime trees and urged residents to plant them so the Florida crop wouldn’t disappear, but today, most key limes sold in the United States come from Mexico.

Back to that Pie

With key limes easy to find and canned, sweetened condensed milk, which didn’t need refrigeration, locally available by 1890, cooks in Southern Florida figured out how to combine the two and create a winning pie, probably by the turn of the century. According to New York food historian, John Mariani, the earliest published recipe for Key Lime Pie shows up in the 1949 edition of The Key West Cookbook, published by the Key West Women’s Club. It calls for 4 eggs, 1 can of condensed milk, and 1/2 cup of lime juice, poured into a baked pie shell and topped with meringue. (The meringue uses 2 of the 4 remaining egg whites, is beaten until stiff, combined with 1 tablespoon of sugar and 1/2 teaspoon of baking powder and browned in a ‘slow’ oven.)

Today most purists insist that a true key lime pie must be made with only five ingredients: crushed graham crackers and butter for the crust, and egg yolks, sweetened condensed milk, and juice from fresh key limes for the filling. Sneaking in a bit of grated zest just passes under the radar. And the topping? There are two camps, one insisting on whipped cream, the other on baked meringue, to make use of those remaining egg whites. Whipped cream is easy, since you can top individual pieces as need be. Meringue is finicky and downright emotional, prone to weeping, sweating, and collapsing when overcooked or exposed to high humidity. And it doesn’t keep very well, making leftovers problematic. It does, however, elevate the pie to something special and elegantly Southern.

Blurring the edges in home and restaurant kitchens are the results of recipes and experiments that stray from the traditional. We can choose to love or hate those that rely on cream cheese, yogurt, unflavored or flavored gelatin, pudding mixes, frozen or prepared whipped topping, tofu, vegan soy spread and, horrors—green food coloring. Some versions use cinnamon-flavored graham cracker crumbs or ginger snaps or chocolate cookie crumbs or plain pie pastry, which is probably what was used prior to the arrival of Honey Maid Graham Crackers in 1925. Today you can also find mousse-like mixtures served crustless in ramekins or dessert glasses, drizzled with mango sauces or garnished with berries.

However you may feel about these variations, one thing is for certain: if your Mama used Cool Whip, you may have to, too.

Further Considerations

•Names to remember: Use ‘Mexican’ or ‘West Indies’ limes if you can’t find walnut-sized fruits labeled as Key Limes. They are all virtually the same. Most are grown today in Mexico, India, Eqypt and the West Indies. Look for them in small farmer’s markets, roadside stands, and in Middle Eastern and Mexican grocery stores. The larger seedless limes available in the supermarket are called Persian or Tahiti limes, and their flavor doesn’t compare.

•Key limes are small, seedy and a pain to juice. If you have a steady supply, invest in a good squeezer that will extract the juice but leave the bitter pith behind. Amazon.com features a number of models. One of the best, recommended by Mexican food authority Rick Bayless, is a cast aluminum version made in Mexico, which sells for under $10, available from www.gourmetsleuth.com.

•If you find yourself with a bumper crop of key limes, juice them all before they spoil and freeze the juice in ziplok bags in 2/3 cup amounts premeasured for pies. The juice will keep in the freezer for 3 months.

•If you can’t get your hands on real key limes, go ahead and make the pie with the juice from about 4 freshly-squeezed Persian limes. Add 1 tablespoon of lemon juice to create a more complex sour flavor or use half lime, half lemon juice.
•Add a bit of lemon juice as well to freshen the flavor if you use bottled lime juice, which can have a slightly off taste otherwise. Read the labels carefully. Several brands say that they come from Key West but don’t claim to be made from Key limes. Don’t use Rose’s Lime Juice, which is sweetened, and made for mixed drinks.

•Add 1/4 to 1/3 cup of granulated sugar to the crushed graham crackers before baking to sharpen the contrast between the filling and the crust.

•Beat one of the leftover egg whites until foamy and brush the inside of the graham cracker crust before baking it to keep the crust from getting soggy after you add the filling.

•In the old days, key lime pie wasn’t baked. The high acidity of key limes may in fact kill any salmonella that could be lurking in the eggs and when combined with the sweetened condensed milk it causes the filling to thicken slightly. But just to be safe the American Egg Board recommends cooking the filling to a temperature of 160o before adding the whipped cream. This will also ensure that the filling isn’t too runny.

•Garnish slices of pie with thin key lime slices or a sprinkling of freshly grated nutmeg.

•If you have some space, grow your own key lime tree. Dwarf varieties are available as well as the standards which can reach 12 feet. Add a bit of lime to raise the soil pH but don’t overfertilize or you won’t get any fruit. Old timers used cured seaweed as a mulch to keep the weeds down. •

from the September-October 2006 issue

A true key lime pie can only be made with freshly squeezed juice from thin-skinned, walnut sized key limes picked when they're at the peak of perfection.

Key Lime Pie
from Cooking USA
by Georgia Orcutt and John Margolies
Chronicle Books

10 whole graham crackers
6 tablespoons butter, melted

3 egg yolks
2 teaspoons finely grated key lime zest (optional)
1 can (14 ounces) sweetened condensed milk
2/3 cup freshly squeezed lime juice
(from about 12 key limes)
Whipped cream for garnish

Heat the oven to 350o. Grease a 9-inch pie pan. To make the crust: Place the graham crackers in a heavy-duty plastic bag and crush with a rolling pin, or crumble them into a food processor and pulse until ground into fine crumbs. Place the crumbs in a mixing bowl and drizzle with the melted butter. Stir with a fork until evenly damp. Press the mixture into the bottom and sides of the prepared pie pan. Bake for 6-8 minutes, or until slightly brown and firm. Set aside to cool.

To make the filling: Combine the egg yolks and lime zest, if using, and beat with an electric mixer on medium speed for several minutes until smooth. (Use the whisk attachment if you have one.) Add the condensed milk and continue to beat for 4 minutes, until the mixture thickens. Reduce the mixer speed and trickle in the lime juice, beating just until smooth. Pour the mixture into the prebaked pie shell and bake for 12 minutes, or until the filling is set and doesn’t jiggle. Cool on a rack and then chill for at least 2 hours. Freeze for 30 minutes before serving. The pie can also be wrapped with plastic wrap and frozen whole; let it sit at room temperature for about 20 minutes before serving. Garnish each serving generously with whipped cream.

Serves 6 to 8.