This classic key lime pie with meringue is out of this world. It has a buttery graham cracker crust, a silky smooth key lime pie filling, and it's topped with a toasted meringue that just makes this pie *mwah* chef's kiss.
Why you will love this classic key lime pie recipe
- The graham cracker crust. Ah - a graham cracker crust. My absolute favorite! This buttery graham cracker crust is pre-baked in the oven so it gets a nice golden brown color.
- The key lime pie filling. The key lime pie filling is super silky and smooth, you won't be able to stop at one slice! It is made from key lime zest, lime juice, sweetened condensed milk and yogurt.
- The meringue. I ADORE a toasted meringue. It's easy to make, and pairs perfectly with this pie. It doesn't have to be toasted, but if you have a lighter or a kitchen torch, I highly suggest it. It tastes like a toasted marshmallow!
- Key limes: of course! The star ingredient. We use a combination of key lime zest and key lime juice to give the filling that perfect lime flavor. If you only have regular limes, that works too! It is still delicious.
- Sweetened condensed milk: we use sweetened condensed milk as the sweetener. It also leads to an incredibly silky smooth consistency.
- Yogurt: yogurt adds to the creamy consistency. I like to use full-fat yogurt, but low-fat or non-fat work, too!
- Graham crackers: graham crackers are needed for the crust. We use about 17-18 full graham cracker sheets.
- Unsalted butter: unsalted butter is mixed with the graham cracker crumbs to give it that wet sand consistency.
- Granulated sugar: a little bit of granulated sugar is added to the graham cracker crust mixture to sweeten it up. It also aids in that toasted, golden brown color.
- Egg whites: egg whites are a crucial ingredient in the meringue - whipping the egg whites is what gives us those luscious stiff peaks.
- Make the crust. Whisk together the graham cracker crumbs and granulated sugar. Pour in the melted butter and mix until the mixture resembles wet sand. Press into your pan and bake for 10 minutes at 350F.
- Make the filling. Whisk together the key lime zest, lime juice, yogurt and sweetened condensed milk until smooth. Pour the filling on your pre-baked crust and bake for an additional 10 minutes.
- Make the toasted meringue. Whisk the egg whites, granulated sugar, cream of tartar and vanilla extract in a bowl over 2 inches of boiling water (or use a double boiler) until thin and frothy on top. Remove from the heat and beat on high speed for 5-6 minutes until stiff peaks form.
- Serve. Once the pie is cool, top with the meringue and toast it with a lighter/kitchen torch. This isn't necessary, but definitely recommended. Enjoy!
Can I use salted butter?
If salted butter is all you have for the filling, then sure! It works just the same.
Can I use regular limes?
Yes! While the name of this dessert indicates key limes, regular limes taste just as delicious.
Why is my pie bitter?
A bitter key lime pie is most likely from zesting the lime pith. The pith is that white layer in between the peel and the fruit. It has a very bitter flavor, so try not to get any of that while you are zesting.
How do I zest a lime?
Zesting a lime is super easy. Make sure to wash your lime and then, well, zest! If you don't have a zester, you can use a fine cheese grater or microplane. Scrape the lime against your zester (CAREFULLY - I have cut my hands many, many times) until you see the white part of the lime. Rotate the lime while repeating this until you have gone all the way around.
Why is my meringue not forming stiff peaks?
A common reason why a meringue won't form those beautiful stiff peaks is most likely because grease or fat got into the meringue mixture. Any fat from the egg yolks or grease residue left on the bowl you are using can prevent stiff peaks from forming. Make sure to separate one egg at a time and wipe your bowl down thoroughly before using.
Other reasons could be that you simply have not beaten it long enough, or you forgot to add the cream of tartar. Cream of tartar stabilizes the egg whites by preventing the egg proteins from sticking together, thus speeding up the whipping process and leading to a soft and pillowy meringue.
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Classic Key Lime Pie With Toasted Meringue
- 2 cups (260 grams) graham cracker crumbs about 17-18 full sheets
- ⅓ cup (66 grams) granulated sugar
- 7 tablespoons (99 grams) unsalted butter melted
- 2 tablespoons key lime zest
- ½ cup (120 mL) key lime juice
- ½ cup (120 grams) yogurt greek or regular works, I use greek!
- 2 14 oz cans sweetened condensed milk
- 4 egg whites
- 1 cup (200 grams) granulated sugar
- ½ teaspoon cream of tartar
- ½ teaspoon vanilla extract
- Preheat oven to 350F. You can use either an 8 inch or 9 inch springform pan or a pie pan for this. If using a springform pan, line the bottom with parchment paper.
- Make the graham cracker crumbs. In a food processor, pulse the graham cracker sheets until they turn into fine crumbs. If you do not have a food processor, put the graham crackers in a zip lock bag and gently hit them with the back of a wooden spoon until they are in crumbs.
- In a medium-sized bowl, whisk together the graham cracker crumbs and granulated sugar. Add the melted butter and mix with a rubber spatula or wooden spoon until the mixture is combined and resembles wet sand.
- Firmly press the mixture up the sides and into the bottom of your pan. I like to work my way around the sides with my fingers first, then pack down the bottom. Then I like to use a measuring cup to firmly press it into place. Once you are happy with the crust, pre-bake it for 10 minutes. It will turn golden brown. Remove from the oven.
- While the crust is baking, prepare the filling.
- Combine the lime zest, lime juice, yogurt and sweetened condensed milk and whisk until you have a smooth and creamy mixture. Pour the filling on top of the pre-baked crust and bake for an additional 10 minutes. The mixture will be slightly jiggly in the middle when you pull it out of the oven. Let the pie cool completely in the pan.
- If you are using a springform pan, this is where I would remove the sides. However, if you are using a regular pie pan, you can leave it be.
- While the pie is baking/cooling, make the meringue.
- Fill a sauce pan with about two inches of water and bring it to a gentle simmer.
- Separate the yolks from the egg whites and make sure NONE of the yolk gets into your egg white mixture. Any fat can prevent your meringue from setting up and getting those stiff peaks.
- In a heat proof bowl, place the egg whites, sugar, cream of tartar and vanilla extract. Place the bowl on the sauce pan over the simmering water but do NOT let the bottom of the bowl touch the simmering water. If you think there is too much water, pour a little out. You can also use a double boiler if you have one.
- Continuously whisk while the mixture heats up. It will start out thick but will thin out as you keep on whisking. Whisk for about 4-5 minutes until the mixture is thin and frothy on top. If you have a thermometer, it should be around 160 degrees Fahrenheit.
- Remove from the heat. Using a handheld mixer or in the bowl of a stand mixer fitted with the whisk attachment (preferred method), beat on high speed for 5-6 minutes until luscious, puffy, stiff peaks form.
- Top the pie with the meringue. If you have a kitchen torch, I highly suggest toasting the meringue once it is on the pie. Enjoy! Store in an airtight container in the fridge.
Tried this recipe? Make sure to rate and review and tag @sturbridgebakery on Instagram!