The Real Difference Between A Florida Key Lime And A Regular Lime

What will happen if you substitute regular limes in Key lime pie?

The Difference Between Key Limes and Regular Limes

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They say you should eat several servings of fruit every day. And lime is a delicious citrus fruit. So, when you're craving a slice of Key lime pie, there's no reason not to give in. Right? Right!

Key lime pie is a dessert prepared with lime, of course, egg yolks, and sweetened condensed milk. You can serve the pie plain, but many prefer it with an egg white meringue topping or whipped cream. You can also bake it in a traditional pie crust, graham cracker crust, or no crust. It all depends on the baker's preference. With these options, you might still wonder about substituting regular limes for Key limes in your pie. Here's what you need to know.

What Is Key Lime?

Named for the Florida Key limes used in the original recipe, Key lime pie is a Southern classic and has even been declared the official Florida state pie. Though the lime is strongly associated with the Florida Keys, and its popular name even comes from this association, the Key limes are actually native to tropical Southeast Asia. Its other names include West Indian lime, bartender's lime, Omani lime, or Mexican lime. And in the Philippines, it is called dayap or bilolo.

Key limes have not been grown commercially in the United States since 1926, when a hurricane devastated Miami, Florida, the Bahamas, and the Gulf Coast. The storm wreaked catastrophic damage on commercial lime crops in the Florida Keys. Thornless Persian limes replaced commercial lime crops, which are hardier than Key limes—Key limes are now imported from Central or South America.

So what happens if you want a slice of sweet-tart Key lime goodness but have yet to make it to the Florida Keys to stock up on their local limes? Can you run to the Piggly Wiggly for a regular lime instead? Does a lime pie made with Piggly Wiggly limes not have the same flavoring as a Key lime pie? Will people snub your pie at the potluck if you make it with the supermarket variety?

Key Limes Vs. Persian Limes

Key limes tend to be small and seedy, with a distinctive lime flavor that is tart but not too acidic. They also have a distinct aroma, far more aromatic than common limes. Grocery store limes, generally speaking, are Persian limes, the most widely commercially cultivated variety of lime. They are larger and more tart than their Florida cousins. Persian limes are a hybrid cultivated from Key lime and lemon, also known as seedless lime, Bearss lime, and Tahiti lime. Key limes are smaller and contain more seeds than Persian limes. And while Persian limes have thick, bright green skin, a Key lime's skin is thin and tends to be a little on the yellow side. The juice from Key limes is also more yellow.

As for whether they have a different taste—significant enough to tell the difference when used in your homemade lime pie—the food testing pros over at Cooks Illustrated claim a slight difference in flavor. They write, "sampled plain, the Key lime juice tasted slightly less tart and bracing than its Persian counterpart." They have even gone so far as to run a lab test on the lime juices, confirming that the juice from the Persian limes has a lower pH and higher acidity than the Key lime juice.

That distinction also held true when they whipped up a batch of Key lime bars. They found that the bars made with Persian limes were more tart than those made with Key limes. Of course, this isn't that significant of an issue for some. Plenty of people like a dessert with a bit of bite and will appreciate the extra acidity that comes from Persian limes.

The main difference is that it requires more aromatic Key lime juice to make the famous pie sing. It is worth the elbow grease to get that authentic floral Key lime flavor—unless you can't find Key limes. Then swap them out for whatever you see at the grocery store and dig in because you want to get your recommended servings of fruit, don't you?

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