Bon Appétit|Published: July 3, 2026|By Rachel Dolfi
A great key lime pie is a study in contrasts: tangy, silky custard; lightly sweetened whipped cream; and a crunchy graham cracker crust. Too often, the crust is defined by its crumbly, hard-to-slice nature. Adding an egg yolk helps bind the graham cracker crumbs, butter, and sugar into a sturdy, sliceable base. It also makes removing the first slice of pie a breeze, rather than a delicate balancing act.
If key limes or key lime juice isn’t available at your grocery store, Persian limes are a great substitute. You'll miss some of the floral aroma and subtle bitterness that make Key limes distinctive, but you'll still get a bright, tart pie. It’s best to make this dessert the night before, but 6 hours in the refrigerator will work as well. Top the pie with a velvety whipped cream and bright lime zest to finish it off, and dessert is served.
Tips for making Key lime pie
Can I use “regular” limes?
Absolutely. Key limes have a slightly more floral flavor and subtle bitterness, but Persian limes (the variety sold at most grocery stores) make an excellent substitute and are far easier to juice since they’re quite a bit bigger. Either way, fresh juice is strongly preferred to bottled versions. Want to try Key limes but can’t find them in your local market? Snag a bag online via sites like Etsy and Wee!.
Why add an egg yolk to the crust?
The yolk helps bind the otherwise standard graham cracker crust, creating a sturdier base that slices cleanly and holds its shape when served. It also helps the crust stay crisp.
How do I know when the pie is done baking?
The pie is ready when the edges are set, and the center still has a slight wobble. Give the pie plate a gentle shake: the filling should jiggle as one cohesive mass, not slosh. The pie will continue to set as it cools and chills, so resist the urge to bake until completely firm. Overbaking can lead to a less silky texture, while underbaking or insufficient chilling can result in a runny filling.
Why do I need to bake the crust first?
Prebaking helps the crust stay crisp and sturdy beneath the filling, preventing sogginess and improving texture. Here, it also cooks the egg yolk, helping to set the crust before the filling goes in.
Can I freeze this key lime pie?
Yes. Freeze the pie without the whipped cream topping for up to 1 month. Thaw overnight in the refrigerator—or serve frozen.
Recipe information
Total Time
1 hour (plus cooling and chilling)
Yield
8 servings
Total Time
1 hour (plus cooling and chilling)
Yield
8 servings
Ingredients
Crust
2
1
½
11
1
4–5
Filling and Assembly
6
1
2
⅔
¼
¼
1½
⅓
Need to make a substitution?
Preparation
Crust
Step 1
Place a rack in middle of oven; preheat to 375°. Combine 2 Tbsp. granulated sugar, 1 tsp. finely grated Key lime or regular lime zest, and ½ tsp. Diamond Crystal or ¼ tsp. Morton kosher salt in a small bowl and rub zest into sugar and salt with your fingers until mixture looks like wet sand.
Step 2
Transfer to a food processor, add 11 graham cracker sheets (about 6 oz.), and pulse to very fine crumbs. Add 1 large egg yolk and 4 Tbsp. unsalted butter, melted, and pulse until combined. Mixture should hold together when squeezed in the palm of your hand. If it doesn't, add 1 Tbsp. unsalted butter, melted, and pulse again to combine.
Step 3
Transfer mixture to a 9”-diameter pie pan. Using your hands and the bottom of a flat measuring cup, press mixture evenly and firmly into bottom and up sides of pan. Place pan on a rimmed baking sheet and bake crust until edges are golden brown, 12–14 minutes. (If crust slumps while baking, carefully press up sides again with measuring cup.) Transfer pan to a wire rack and let crust cool. Reduce oven temperature to 325°.
Do ahead: Crust can be baked 3 days ahead. Cool completely, then store, lightly covered with plastic wrap, at room temperature.
Filling and Assembly
Step 4
Gently whisk 6 large egg yolks, one 14-oz. can sweetened condensed milk, 2 tsp. finely grated Key lime or regular lime zest, ⅔ cup fresh Key lime or regular lime juice, ¼ tsp. Diamond Crystal or Morton kosher salt, and ¼ tsp. vanilla extract in a large bowl just to combine (be careful not to beat in too much air).
Step 5
Pour filling into cooled crust and bake pie until edges of filling are set but center still jiggles slightly when gently shaken, 20–22 minutes. Transfer pie to rack and let cool 1 hour, then chill, uncovered, at least 6 hours.
Step 6
Just before serving, using an electric mixer on medium-high speed, beat 1½ cups heavy cream and a large pinch of kosher salt in a medium bowl until medium peaks form. Add ⅓ cup (37 g) powdered sugar and beat, starting on low speed and moving up to medium-high as sugar is incorporated, until stiff peaks form.
Step 7
Scrape whipped cream into center of pie and spread out to edges with an offset spatula or a spoon, swooshing decoratively as desired. Scatter lime zest over.
Do Ahead: Pie, without whipped cream, can be baked 2 days ahead. After cooling, place toothpicks around perimeter of custard, then cover with plastic wrap (don’t let plastic touch custard) and keep chilled.
Photograph by Elliott Jerome Brown Jr., Prop Styling by Christina Allen, Food Styling By Mieko Takahashi
Crust
Step 1
Place a rack in middle of oven; preheat to 375°. Combine 2 Tbsp. granulated sugar, 1 tsp. finely grated Key lime or regular lime zest, and ½ tsp. Diamond Crystal or ¼ tsp. Morton kosher salt in a small bowl and rub zest into sugar and salt with your fingers until mixture looks like wet sand.
Step 2
Transfer to a food processor, add 11 graham cracker sheets (about 6 oz.), and pulse to very fine crumbs. Add 1 large egg yolk and 4 Tbsp. unsalted butter, melted, and pulse until combined. Mixture should hold together when squeezed in the palm of your hand. If it doesn't, add 1 Tbsp. unsalted butter, melted, and pulse again to combine.
Step 3
Transfer mixture to a 9”-diameter pie pan. Using your hands and the bottom of a flat measuring cup, press mixture evenly and firmly into bottom and up sides of pan. Place pan on a rimmed baking sheet and bake crust until edges are golden brown, 12–14 minutes. (If crust slumps while baking, carefully press up sides again with measuring cup.) Transfer pan to a wire rack and let crust cool. Reduce oven temperature to 325°.
Do ahead: Crust can be baked 3 days ahead. Cool completely, then store, lightly covered with plastic wrap, at room temperature.
Filling and Assembly
Step 4
Gently whisk 6 large egg yolks, one 14-oz. can sweetened condensed milk, 2 tsp. finely grated Key lime or regular lime zest, ⅔ cup fresh Key lime or regular lime juice, ¼ tsp. Diamond Crystal or Morton kosher salt, and ¼ tsp. vanilla extract in a large bowl just to combine (be careful not to beat in too much air).
Step 5
Pour filling into cooled crust and bake pie until edges of filling are set but center still jiggles slightly when gently shaken, 20–22 minutes. Transfer pie to rack and let cool 1 hour, then chill, uncovered, at least 6 hours.
Step 6
Just before serving, using an electric mixer on medium-high speed, beat 1½ cups heavy cream and a large pinch of kosher salt in a medium bowl until medium peaks form. Add ⅓ cup (37 g) powdered sugar and beat, starting on low speed and moving up to medium-high as sugar is incorporated, until stiff peaks form.
Step 7
Scrape whipped cream into center of pie and spread out to edges with an offset spatula or a spoon, swooshing decoratively as desired. Scatter lime zest over.
Do Ahead: Pie, without whipped cream, can be baked 2 days ahead. After cooling, place toothpicks around perimeter of custard, then cover with plastic wrap (don’t let plastic touch custard) and keep chilled.
