The Tart Flavor of the Tropics

At the risk of sounding older than I really am, I can recall the days before limes became mainstream, when fresh limes were hard to come by at the supermarket and most cooks made do with the juice in a green fruit-shaped squeeze bottle.

That was before French nouvelle cuisine made lime the chic souring agent of the 1980s, before a sparkling glass of Perrier (and later San Pellegrino), with its obligatory wedge or slice of lime, became the fountain of youth for health-conscious Americans.

How we cooked without fresh lime boggles my imagination. Without it, there would be no daiquiris, no ceviche, none of a dessert near and dear to my Floridian heart: key lime pie. In this age of low-fat cooking and reduced sodium, fresh lime juice is a miracle worker, adding flavor and piquancy (not to mention loads of vitamin C and potassium) without cholesterol, calories or fat. A lemon is merely sour, while a lime offers both tartness and a perfumed tropical taste.

Say “lime” to most people and they’ll think you mean a dark-skinned seedless Persian lime. Florida is partial to the key lime, a small roundish yellow-green fruit with a bracingly bitter, mouth-puckeringly tart juice. Also known as Mexican lime or West Indian lime, the key lime was cultivated extensively in the Florida Keys in the 19th and early 20th centuries. Many Floridians still have key lime trees in their backyards.

The key lime remains the preferred lime throughout the Caribbean and Central and South America. But it isn’t for everybody. The trees are full of thorns, and the fruits are full of seeds. The juice has a bitter aftertaste that can be off-putting, although it’s perfect for balancing the cloying sugariness of the sweetened condensed milk in key lime pie. Key limes are acidic, but because they’re picked at a riper stage than Persian limes, they also have a touch of sweetness.

Key limes are available irregularly year-round; peak season is winter and spring. Most of the key limes sold in North America these days come from Haiti and are distributed by the Florida fruit magnate J.R. Brooks. But you don’t have to live in Florida to enjoy them. I’ve found net bags of key limes in cities as far-flung as Boston, Seattle and Houston.

Floridians use key limes for many preparations, including old sour (a hot sauce concocted from key lime juice, bird peppers and salt) and conch salad (a sort of ceviche made with a giant sea snail).

But the most famous use for the key lime, a use that almost serves as its raison d’e^tre, is Florida key lime pie. This pie is surprisingly simple and easy to make. The filling contains only four ingredients: key lime juice and peel, sweetened condensed milk and egg yolks. Old-timers don’t even bother to cook the filling.

Most cooks serve this filling in a graham cracker crust, but there all agreement ends. Floridians are sharply divided on the proper topping. Some argue for meringue, which has the advantage of using up the egg whites. Others insist on whipped cream to echo the creaminess of the filling.

Lore holds that key lime pie was invented at the end of the Civil War, the result of combining the indigenous citrus fruit with a newly invented convenience food--sweetened condensed milk. But no one has ever found a 19th century key lime pie recipe.

Food historian Merle Evans believes that what was to become Florida’s signature pie originated in the 1930s, the result of a campaign by Borden Co. to persuade Americans to use sweetened condensed milk for pie making.

“As fresh milk became more widely available in the United States,” Evans says, “the company sought new ways to market its canned products.” According to Evans, a 1928 “Borden Condensed Milk Magic Recipes” booklet contained a recipe for lemon pie made with sweetened condensed milk. Lime pie recipes began to circulate in the 1930s. The earliest Florida key lime pie recipe that Evans found appeared in a Key West Women’s Club cookbook in 1939.

Here’s my recipe for this Floridian favorite. It differs from the traditional recipe in that the filling and topping are cooked.

KEY LIME PIE

CRUST

1 1/2 cups cinnamon graham cracker crumbs

1/3 cup butter, melted

Mix together crumbs and melted butter in mixing bowl with fingertips or fork until moist and crumbly. Press mixture into bottom and sides of 8-inch pie pan, using back of large spoon to obtain smooth crust. Bake at 350 degrees until firm and lightly browned, about 10 minutes. Remove from oven and cool.

FILLING

3/4 cup fresh key lime or regular lime juice

2 teaspoons grated lime peel

4 egg yolks

1 (14-ounce) can sweetened condensed milk

Whisk lime juice, peel, egg yolks and sweetened condensed milk in bowl until smooth. Pour filling into crust. Bake pie at 350 degrees until filling is cooked and set, 10 to 15 minutes. (An inserted skewer will come out clean and hot to the touch.)

MERINGUE

4 egg whites

1/2 teaspoon cream of tartar

3/4 cup sugar

3 tablespoons water

1 teaspoon grated lime peel

Beat egg whites and cream of tartar in bowl at low speed. Gradually increase speed to medium and beat until frothy. Continue to beat at this speed while you cook sugar.

Bring 1/2 cup sugar and water to boil in covered saucepan. Uncover pan and cook to softball stage. (239 degrees on candy thermometer. If you don’t have candy thermometer, drop tiny spoonful of sugar mixture--it should look thick and syrupy--into bowl of cold water. When cooked to proper consistency, syrup will form soft, pliable ball. Continue cooking until this consistency is reached.)

When syrup is ready, increase mixer speed to high and beat egg whites to soft peaks. Add remaining 1/4 cup sugar and beat until whites are glossy and firm but not dry, about 8 minutes. With mixer running, pour hot sugar mixture and lime peel into egg whites and continue beating until cool.

Preheat broiler (rack should be set about 6 inches below it). Spread or pipe meringue in decorative swirls or rosettes on top of pie. Run pie under broiler to lightly brown meringue, about 2 minutes. Cool. Cover and refrigerate until serving time.

Makes about 6 servings.

Each serving contains about:

546 calories; 351 mg sodium; 231 mg cholesterol; 22 grams fat; 80 grams carbohydrates; 11 grams protein; 0.17 gram fiber.

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Note: Although many recipes call for uncooked eggs, the U.S. Department of Agriculture has found them to be a potential carrier of food-borne illness and recommends that people avoid eating raw eggs, including whites, as called for in this recipe.