Recipe Review

I Tested the Internet’s Favorite Key Lime Pie Recipes and the Winner Blew Me Away

published Aug 19, 2023
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four key lime pies recipes labeled in their dishes, each with a slice missing and another one separated from the rest of the pie on a marble surface
Credit: Photo: Alex Lepe; Food Styling: Brett Regot

In the world of desserts, Key lime pie is relatively easy to make. There’s no pastry dough to fuss with; instead, you have the ease of a pat-into-place crumb crust. The filling is most often a whisk-together affair, and the topping almost always consists of whipped cream (homemade is ideal). Within that winning formula are little nuances that make all kinds of Key lime pie recipes unique. 

Quick Overview

So, What’s the Best Key Lime Pie on the Internet?

Alex Guarnaschelli’s key lime pie is the very best recipe we tested. Adding sour cream to the filling provided a touch of a creaminess without overpowering the classic tang.

But which nuances have the best payoff? To find out, I searched online for popular recipes that each offer something a little different. To my delight, they were all very good. Let me repeat that: Every one of these Key lime pie recipes is delicious and worth making. But, thanks to a unique ingredient, one edged out the rest to earn the top prize.

Why You Should Trust Me as a Tester 

Beyond being a recipe developer and food writer, I have always been (and will forever be) on Team Fruity Dessert — the tangier the better. Key lime pie is one of my all-time faves, and I took my Key lime research and taste testing very seriously. 

Meet Our 4 Key Lime Pie Contenders

The four recipes in this showdown have more similarities than differences. They all involve graham cracker crusts, but a couple add some extra oomph with special additions. Each one uses a filling made with fresh lime juice and sweetened condensed milk, but some include egg yolks, while others include additional dairy products. Most of the pies are baked, but one uses a no-bake filling.

  • Once Upon a Chef adds a little more richness to the crust by incorporating brown sugar with the graham cracker crumbs and butter. The filling differentiates itself with the addition of plain Greek yogurt.
  • Sally’s Baking Recipes adds a little tropical flair with the addition of macadamia nuts in the crust. Also noteworthy: This was the only recipe that specifically called for Key lime zest and juice. 
  • Ina Garten’s version is unique to this showdown in three distinct ways: It calls for an electric mixer, the filling is not baked, and it gets frozen instead of chilled in the fridge. 
  • Alex Guarnaschelli has perhaps the easiest of these recipes to make; this one adds a whiff of lemon zest to the crust and a bit of sour cream to the filling.

How I Tested the Key Lime Pie Recipes

  • The ingredients: In the interest of parity, I used the same brand of common ingredients. Those included Honey Maid graham crackers, Land O’Lakes butter, and Eagle Brand sweetened condensed milk. I purchased a giant bag of Persian limes and used them for three of the four recipes; for the remaining recipe, I used fresh Key limes. 
  • The pie dish: For the one pie that specified a deep-dish pie plate, I used my ceramic dish; for all others, I used sturdy disposable aluminum pans. 
  • The timeline: I made all four pies in the morning of the same day, chilled/froze them for several hours, and then tasted them all side-by-side in what can only be called a Key lime pie lover’s ultimate fantasy.
Credit: Photo: Alex Lepe; Food Styling: Brett Regot

1. The Creamy, Cheesecake-Like Riff: Once Upon a Chef’s Key Lime Pie 

As noted above, this recipe uses a little brown sugar in the graham cracker crust for rich caramel notes. The filling layer is quite thick, which is why the recipe smartly specifies using a deep-dish pie pan. It consists of two whole cans of sweetened condensed milk, a cup of plain Greek yogurt, a tablespoon of lime zest, and 3/4 cup fresh lime juice (from regular/Persian limes). A simple sweetened whipped cream topping crowns the finished pie. 

With the large amount of sweetened condensed milk and the hefty amount of yogurt, the pie takes on a cheesecake-like vibe and a milder lime flavor. I wanted more tang, but if you prefer a Key lime pie with a softer edge, this thick, creamy, less-puckery version is perfect for you. (And with an average five-star rating and more than 1,000 comments, you would be far from alone.)

Credit: Photo: Alex Lepe; Food Styling: Brett Regot

2. The Nutty Twist: Sally’s Baking Recipes’ 7-Ingredient Key Lime Pie

The crust for this pie includes a half-cup of macadamia nuts, which get pulsed with the graham crackers in a food processor into coarse crumbs. A little granulated sugar and melted butter round out the crust before it’s patted into the pie dish and baked. Surprisingly, this was the only recipe in this showdown that called for using Key lime juice and zest (a full cup of the juice and a teaspoon of the zest), along with two full cans of sweetened condensed milk and four egg yolks. The pie is baked until the filling almost sets, and the recipe suggests garnishing the pie with lime zest and/or slices, macadamias, whipped cream, or meringue. I went with whipped cream.

In the finished pie, the flavor difference of real Key limes was subtle, but it was there; the pie filling had more floral notes and a bit of pleasant bitterness. For me, the macadamias in the crust felt incongruous somehow with the pie; they felt dense and a little too hearty (I might have enjoyed a softener nut like cashews or pine nuts instead). But overall, the pie was wonderfully tangy and satisfying.

Credit: Photo: Alex Lepe; Food Styling: Brett Regot

3. The Frosty Riff: Ina Garten’s Frozen Key Lime Pie

Ina’s version of Key lime pie is all kinds of different from the rest. The filling is the only one that requires an electric mixer. You’ll use it to beat six extra-large egg yolks with sugar for several minutes, until the mixture is thick (it looks similar to pound cake batter at this point). You’ll then mix in one can of sweetened condensed milk, a couple of tablespoons of lime zest, and 3/4 cup fresh lime juice. You’ll spoon this mixture into the baked pie crust (a deep-dish pie pan might work best, as my filling threatened to overflow) and then freeze it. The pie gets topped with sweetened whipped cream and frozen for several hours. 

I used eggs with orange yolks so the filling had a deep sunny-gold hue, and it was wonderfully rich, even when frozen. I’m not opposed to raw yolks, but you could always use pasteurized eggs if you’re concerned.

The pie is bracingly tart, just the way I like it, but admittedly a bit too intense for some folks. Freezing the pie enhances the zesty, refreshing nature of the filling. But the slices do melt fairly quickly and can get quite messy. (The Kitchn’s studio had trouble photographing a slice for this reason!) Those are the only “ticks” against this otherwise amazing recipe.

Credit: Photo: Alex Lepe; Food Styling: Brett Regot

4. The Classic Version with Extra Creaminess: Alex Guarnaschelli’s Key Lime Pie

As I mentioned at the top of this article, all four of these recipes are quite good. As it happens in shows like Top Chef or Project Runway, determining a winner came down to tiny details. Alex Guarnaschelli’s recipe offered the best of all the components: a crust with a little extra flair, a fantastically tart and creamy filling, and the ideal topping.

For starters, the crust is an otherwise standard graham cracker version, but with a little bit of lemon zest for a bright lift. The filling uses not-quite two cans of sweetened condensed milk, a couple of tablespoons of lime zest, 3/4 cup fresh lime juice, and (here’s the differentiator) 1/2 cup of sour cream. That little bit of extra dairy has a big effect, lending loads of creaminess without detracting from the zippy lime flavor. And, as it turns out, the topping of unsweetened whipped cream, which is a suggestion and not part of the actual recipe, is exactly the right finishing touch, as it balances the sweetness of the filling while contributing that rich counterpoint you expect.