Key Lime Pie Recipe
Key lime pie is an iconic pie closely associated with Florida and was officially named Florida’s State Pie in 2006. It is also an incredibly simple pie to make and remains one of the most searched-for recipes all year long. Its predecessor, sour orange pie, is still a niche Florida favorite, but it has never reached the national popularity that key lime pie enjoys. With only three ingredients in the filling and baked in a graham cracker crust, key lime pie is a perfect beginner-friendly dessert if you are just getting started with making pies.
Table of Contents
What is Key Lime Pie?
Key lime pie is a rich, sweet and sour lime custard baked in a graham cracker crust. The filling is made with just three ingredients: lime juice, condensed milk, and egg yolks. Although it is most often seen in a graham cracker crust, key lime pie also works well in any type of crumb crust including Oreo crust, Biscoff cookie crust, and vanilla wafer crust.
There are also a few different ways to top key lime pie. Some people serve the pie as is with no topping at all, while others like it best with whipped cream or meringue. All three choices are delicious, let us know which one is your favorite!
Key lime pie is so popular that it has spawned a whole variety of other adjacent pies, from other citrus pies made in a similar way, like meyer lemon pie, to other takes on key lime pie, like key lime cheesecake pie.
What are Key Limes?
What is the Difference Between “Regular” Limes and Key Limes?
The limes typically sold in American grocery stores are Persian limes. Persian limes are actually a hybrid fruit, as most citrus varieties are, and are a cross between key limes and a standard lemon. They are larger than key limes and some people say they have a less intense lime flavor.
Key limes are much smaller and can taste noticeably stronger. They are originally from Southeast Asia and are grown primarily in Florida, California, and Mexico today. The name key lime comes from the period when they were mainly grown in the Florida Keys. To get the one cup of lime juice needed for this recipe, you will need to juice about 18 to 20 key limes compared to 5 or 6 regular limes.
Can You Use Regular Lime Juice in Key Lime Pie?
Purists will say you need real key lime juice for a key lime pie, and it is definitely worth trying if you can get enough key limes. However, key lime pie is still delicious with regular lime juice. If you want to increase the intensity of the lime flavor, bring the lime juice to a boil first with zest from one of the limes to help bring out the lime aromatics.
History of Key Lime Pie
The history of key lime pie is debated among a small subset of Floridians and pie aficionados. For decades, the lore has claimed that a Florida millionaire from the 1800s, William Curry, had a servant named Aunt Sally who began making the pie in the late 1800s. However, there is no real proof of this story, and the first published recipes for key lime pie appear in the 1930s.
Stella Parks, the author of BraveTart, has attempted to trace the history of the pie and credits the original key lime pie to Borden, a condensed milk company, which tested recipes in a New York kitchen in 1931. This aligns with how several national favorites gained popularity. For example, pecan pie, which originally appeared in Texas, only surged in popularity and became a Southern favorite when Karo, the corn syrup company, began printing a recipe on their label.
A number of people have tried to dig up old key lime pie recipes from Florida residents, including written home recipes, and the oldest that can be found outside of Borden’s was published in 1933.
However, making pies from citrus has a long tradition in Florida since citrus has always grown well there. The truly Floridian predecessor of key lime pie is sour orange pie, made with Seville oranges. These oranges are not very sweet and are generally used to make marmalade. The first sour orange pie recipes appeared in the 1870s.
Today, key lime pie is one of the most well-known and popular pies in America. It is consistently the most searched-for pie on Google all year, only overtaken by massively popular favorites like pumpkin pie during Thanksgiving. Its popularity is likely helped by how simple the pie is to make.
Step-by-Step Key Lime Pie Recipe
Crust:
Key lime pie is most often served in a graham cracker crust. You can sometimes find pre-made graham cracker crusts at the grocery store, or you can make your own since it is one of the easiest crusts to prepare at home. You can find my recipe for graham cracker crust here. If you live somewhere where graham crackers are not commonly sold, a Digestive biscuit crust is a great substitute. You can also branch out and try making this pie in another type of crumb crust.
Key Lime Pie Filling Recipe:
Key lime pie filling is one of the easiest pie fillings you can make. You don’t need any special equipment, and it only requires three ingredients.
Ingredients
- 28oz Sweetened Condensed Milk (795g)
- 1c Lime Juice (237mL)
- 5 Egg Yolks
- Zest from one lime (optional)
Optional Step: To give your pie a more intense lime flavor, in a small pot on medium heat, combine the lime zest and lime juice and bring the juice to a boil. As soon as the juice reaches a boil, remove it from the heat. For an extra smooth custard, you can strain out the zest.
1.
Preheat your oven to 325°F (165°C).
2.
In a large mixing bowl, combine the sweetened condensed milk and egg yolks. Using a whisk or even a fork, mix until fully combined.
3.
Add the lime juice, and once again mix until fully combined.
4.
Pour the filling into your prepared graham cracker crust.
5.
Bake for 25 to 30 minutes, or until very tiny cracks begin to appear around the edges of the pie. (To be quite honest, baked and unbaked key lime pies look very similar. But after 30 minutes at the correct temperature, the pie should be done).
6.
Chill the pie for at least 3 hours in the refrigerator so the filling can fully set before serving.
Homemade Whipped Cream Topping:
Ingredients
- 1½ c Heavy Whipping Cream, cold
- ¼c Powdered Sugar, sifted (60g)
- ½t Vanilla Extract
1.
In a stand mixer fitted with the whisk attachment, combine the cold heavy cream, sifted powdered sugar, and vanilla extract. Whip on medium-high speed until stiff peaks form and the cream holds its shape.
2.
Spread the whipped cream evenly over the chilled key lime pie using an offset spatula or the back of a spoon. For a more decorative look, transfer it to a piping bag and pipe rosettes or swirls across the top.
Pro-Tip: Sifting your powdered sugar is an important step to prevent clumps in your whipped cream. You can shake the powdered sugar through a fine-mesh sieve to sift it.
How to Separate Eggs for Key Lime Pie:
Key lime pie filling requires egg yolks rather than whole eggs. If you have never separated eggs before, this can seem like an odd or intimidating task. However, once you get the hang of it, it becomes quite easy.
You can separate eggs with a special egg separator tool that is very affordable online. Or you can use the egg shell itself or clean hands to separate the whites from the yolks.
The most important part is to cleanly crack the eggs so the yolk does not break when the egg is opened. Then either crack the egg into an egg separator, or, using clean hands, lift the yolk out of the bowl and allow the egg whites to slip through your fingers.
How to Top Key Lime Pie:
Key lime pie can be served with no extra toppings, or you can finish the pie with either whipped cream or toasted meringue.
- Whipped Cream: Make a batch of freshly whipped cream, or buy whipped cream from the grocery store and top your baked and chilled key lime pie. You can spread whipped cream over the entire top of the pie or pipe pretty patterns on the surface. Try sprinkling extra lime zest on top for color and added flavor.
- Toasted Meringue: Toasted meringue also pairs well with key lime pie. It doubles as a convenient way to use the egg whites left over from using only egg yolks in the filling, although five egg whites will make much more meringue than you need. You can find instructions for how to make a meringue topping for a pie here.
Variations of Key Lime Pie:
With how popular key lime pie is, many variations of the pie have been created. They generally fall into two categories. Some pies are very similar to this key lime pie but use other fruits, while others are different types of pies that are flavored with lime juice.
Other Citrus Pies Like Key Lime Pie:
These pies tend to be made with a very similar recipe but swap the lime juice for other fruit juices. They work best with other citrus fruits. Even if you do not see a recipe listed here, you can experiment by replacing the lime juice with another citrus juice of your choice.
- Meyer Lemon Pie: Meyer lemon juice is a great replacement for lime juice in key lime pie. The sweet and sour nature of meyer lemons lends itself exceptionally well to this type of dessert.
- Lemon Pie: Although the flavor and aromatics of lemons and limes differ noticeably, lemons are similarly sour. Lemon juice creates a deliciously creamy lemon pie. In some ways, it acts like a simpler version of lemon curd, making an easy dessert similar to lemon meringue pie.
- Sour Orange Pie: Sour orange pie is actually the predecessor to key lime pie, though it has never gained the same recognition. Some bakeries in Florida still sell this pie. While regular orange juice is much sweeter than lime juice, Seville oranges have a sour flavor that creates a sweet and sour filling. This is an excellent pie worth trying.
- Orange Pie: Although oranges are much sweeter than limes, you can make this pie with regular orange juice as well. Keep in mind that the final product will have no sourness to balance the sweetness. You can lower the sweetness by using a mix of orange juice and lemon juice or by making the sour orange pie described above.
- Grapefruit Pie: Grapefruit juice is extremely sour and not very sweet. Using grapefruit juice in place of lime juice in this recipe can create a delicious grapefruit-flavored dessert where the sourness of the grapefruit juice is balanced by the sweetness of the condensed milk.
Other Key Lime Flavored Pies:
- No-Bake Key Lime Pie: Cream cheese replaces the egg yolks in this recipe, creating a quick, no-bake version of key lime pie.
- Key Lime Cheesecake Pie: Add more depth of flavor and tartness by turning key lime pie into a cheesecake.
- Frozen Key Lime Pie: An extra chilled version of key lime pie that is perfect for summer gatherings.
- Key Lime Mousse Pie: A lighter, fluffier take on a classic key lime pie.
How to Store Key Lime Pie:
Key lime pie is most delicious when served chilled, and it needs to be chilled for a few hours after baking so the custard filling can fully set. Store your key lime pie in the refrigerator, so you can serve a slice at any time. The pie keeps well in the refrigerator for 3 to 5 days. The filling will remain stable, but after a few days the graham cracker crust will begin to soften and the whipped cream topping will no longer hold up.
Key lime pies also store very well in the freezer. In fact, they are often sold whole in the frozen section of grocery stores. Bake your pie as usual, and instead of storing it in the refrigerator, place it in the freezer wrapped in plastic and sealed in a freezer bag to prevent freezer burn. Do not top the pie with whipped cream or meringue until you are ready to serve it, since the toppings do not freeze well. When you are ready to enjoy your key lime pie, thaw it in the refrigerator for a couple of hours and then cut your slices.
We’d love to see your key lime pie creations! If you give this recipe a try, tag @doggone_baking on social media so we can share in the baking fun.
Key Lime Pie
Ingredients
Crust
Key Lime Pie
- 28 oz Sweetened Condensed Milk (795g)
- 1 cup Lime Juice (237mL)
- 5 Egg Yolks
- 1 tsp Lime Zest
Whipped Cream
- 1½ cups Heavy Whipping Cream (355mL)
- ¼ cup Powdered Sugar, sifted (30g)
- ½ tsp Vanilla Extract
Instructions
Make the Key Lime Pie
- Preheat your oven to 325°F (165°C).
- In a large mixing bowl, combine the sweetened condensed milk and egg yolks. Mix until fully combined.
- Add the lime juice, and once again mix until fully combined.
- Pour the filling into your prepared graham cracker crust.
- Bake for 25 to 30 minutes, or until very tiny cracks begin to appear around the edges of the pie.
- Chill the pie for at least 3 hours in the refrigerator so the filling can fully set before serving.
Finish with Whipped Cream
- In a stand mixer fitted with the whisk attachment, combine the cold heavy cream, sifted powdered sugar, and vanilla extract. Whip on medium-high speed until stiff peaks form and the cream holds its shape.
- Spread the whipped cream evenly over the chilled key lime pie using an offset spatula or the back of a spoon. For a more decorative look, transfer it to a piping bag and pipe rosettes or swirls across the top.
