Key Lime Pie

Granny always felt at home in South Florida and the Key Lime Pie was a big reason why. This tart and creamy delight turns fresh Key lime juice and zest into a firm custard filling. Topped off with a sweet homemade whipped cream to complement the citrus flavor, the Key Lime Pie is like a trip to the beach.

Although regular limes will make a fine pie, Key limes are valued for their unique and intense flavor profile. Common in in the Caribbean, they may be harder to find in other regions but this hybrid citrus fruit is worth the search. Unlike regular limes, these appear yellow when ripe and have a stronger acidic taste. Thy're what makes a Key Lime Pie so special – that perfect balance of sweet custard and tart citrus.

Key Lime Pie - Green with Envy

The Key Lime Pie, a beloved American dessert, has a history as rich and tangy as its flavor. The pie is named after the small Key limes, which are more aromatic than the common Persian limes, and which have yellow juice. The filling in a Key lime pie is typically yellow because of the egg yolks.

The origins of the Key Lime Pie are somewhat disputed, but it's generally agreed that the pie was probably derived from the "Magic Lemon Cream Pie" published in a promotional brochure by Borden, a producer of condensed milk, in 1931. The recipe was altered with local ingredients, and it's described as "a stunning reminder of how deeply America's traditions are shaped by advertising".

A "Tropical Lime Chiffon Pie", using condensed milk and egg yolks, is documented in a 1933 Miami newspaper article. An "icebox lime pie", was mentioned as a specialty of the Florida Keys in 1935, and a recipe under the name "Key Lime Pie" was published in 1940.

The Star Ingredient: Key Limes

Key limes (Citrus aurantiifolia), also known as Mexican limes or West Indian limes, are a distinct variety that plays an essential role in the pie's authentic flavor profile. Significantly smaller than standard Persian limes found in most grocery stores, Key limes typically measure only 1-2 inches in diameter and have a thin, yellowish-green rind when ripe.

These special limes have a fascinating history that traces back to Southeast Asia, where they originated. They were brought to North Africa and the Middle East by Arab traders, then introduced to Europe during the Crusades. Spanish explorers brought them to the Caribbean and Florida in the 1500s.

Key limes earned their name from their abundant growth throughout the Florida Keys, where they thrived in the tropical climate and limestone soil. For generations, Key lime trees were commonly found in backyards across the Keys, making the fruit readily available to local households.

What makes Key limes distinct is their unique flavor profile—more aromatic, more acidic, and with a more complex bouquet than common Persian limes. They contain more seeds, have a stronger aroma, and provide a distinctive tartness that defines authentic Key Lime Pie. The juice of Key limes is actually pale yellow rather than green, which explains the traditional yellow color of a proper Key Lime Pie filling.

Unfortunately, a hurricane in 1926 and subsequent commercial development largely wiped out commercial Key lime plantations in Florida. Today, most Key limes in American markets are imported from Mexico and Central America, though some dedicated growers in South Florida still cultivate them on a smaller scale.

The Classic Recipe

The pie is made of lime juice, egg yolks, and sweetened condensed milk. It may be served with no topping, topped with a meringue topping made from egg whites, or with whipped cream; it may be cooked in a pie crust, graham cracker crust, or no crust. The filling is made similarly to a Magic Lemon cream pie, by simply mixing the ingredients without cooking: the proteins of the egg yolks and condensed milk and the acidic lime juice curdle, thickening the mixture without baking. Today, Key lime pies are usually baked to pasteurize the eggs and thicken the filling further.

In 2006, Key Lime Pie was designated as the official Florida state pie. So, the next time you enjoy a slice of this tangy, sweet pie, remember the rich history and cultural significance that it carries.

For purists, using actual Key lime juice rather than standard lime juice is essential for an authentic pie. The difference in flavor is noticeable—where standard limes provide simple tartness, Key limes offer a more complex, aromatic profile that balances perfectly with the sweetened condensed milk. Many Florida locals will insist that a proper Key Lime Pie should never contain food coloring—the natural yellow hue of the filling is the hallmark of authenticity.