I absolutely love this 3 Ingredient Key Lime Pie recipe. It is one of the best! The key lime pie filling is made using three main ingredients: sweetened condensed milk, lime juice concentrate, and egg yolks.
The three ingredient key lime pie filling is smooth, sweet, and a little tart. It is an easy summer dessert that is sure to impress. The sweet and tart filling makes this Key Lime Pie a refreshing summer dessert recipe. In fact, Key Lime Pie is a classic American dessert and even the official state pie of Florida. Key Lime Pie would also make a great PI day pie recipe, which is on March 14th every year.

The base of the 3 Ingredient Key Lime Pie is a pre-made graham cracker crust. Using a pre-made graham cracker crust is one of the reasons why this key lime pie recipe is so easy to make. A made-from-scratch graham cracker crust tastes better (arguably), but I would much rather use a pre-made graham cracker crust!
Pies are considered one of the most traditional American desserts. My favorite types of pies are pies that use a graham cracker crust and have a smooth, mousse like filling. It's no wonder this one of my favorite pies. This pie would pair well with Crispy Panko Coated Chicken Legs.
Another reason I love this quick and simple key lime pie recipe is I don't have to hand-squeeze limes. I like to skip over some of the more tedious aspects of cooking if there is an easier way to achieve the desired result. In this case, using lime juice concentrate is an easy alternative to hand-squeezing limes. The pie still achieves a tart lime flavor in a shorter amount of time.
📖 Recipe
3 Ingredient Key Lime Pie
Equipment
- Mixing bowl
- Hand or stand mixer
- Zester
Ingredients
- 1 pre-packaged graham cracker crust
- 4 egg yolks
- 1 can (14 oz) sweetened condensed milk
- ½ cup lime juice concentrate
Instructions
- Preheat the oven to 325 degrees.
- Whip the egg yolks at high speed until fluffy, about 5 - 6 minutes. Slowly add the sweetened condensed milk. Continue to whip until thick, about 3 - 4 minutes. On low speed, slowly add the lime juice concentrate just until blended.
- Pour the mixture into a pre-packaged graham cracker crust and bake for 15 minutes, or until the filling has just set.
- Cool the key lime pie on a wire rack for about 30 minutes and then refrigerate until completely cooled. Top with sliced limes and whipped cream, if desired.
Notes
- Place the graham cracker crust on a baking sheet before baking to make it easier to get the pie in and out of the oven.
- When the key lime pie is ready to be removed from the oven, it should be slightly firm to the touch. The pie filling will continue to firm up as it cools. It will also become firmer during refrigeration.
Can you use regular limes instead of key limes for Key Lime pie?
You can find Key Lime juice concentrate at most grocery stores. I personally don't bother with trying to specifically find lime juice concentrate that says "Key Lime" on the bottle. I use any lime juice concentrate I can find. If you have the option to grab "Key Lime Juice from Concentrate" then go for it! Otherwise, don't worry too much about being that specific.
If you happen to enjoy juicing limes, juice enough limes to fill a half a cup and substitute fresh lime juice for lime juice concentrate.
What are the ingredients in the 3 Ingredient Key Lime Pie filling?
Many Key Lime Pie recipe options are available. The ingredients are all a little different. Every single Key Lime Pie filling contains lime juice (either fresh or from concentrate). That is how the pie gets its tangy lime flavor, of course!
The other pie filling ingredients other than lime juice tend to vary. I've seen recipes that use sour cream, cream cheese, sweetened condensed milk, whipped cream (Cool Whip), or different combinations of them all. This 3 Ingredient Key Lime Pie recipe uses sweetened condensed milk and egg yolks.
Three Ingredient Key Lime Pie Filling
- Lime juice concentrate
- Sweetened condensed milk
- Egg yolks
You do not have to add any other sweetener to the recipe since the sweetened condensed milk already contains sugar. The egg yolks help bind the filling together.
Key Lime Pie recipes without eggs tend to be no-bake Key Lime Pie recipes. Eggs shouldn't be eaten raw so you have to bake this Key Lime Pie.
Frequently Asked Questions
Should you refrigerate Key Lime Pie?
Yes. You should refrigerate key lime pie. The filling is made with both sweetened condensed milk and eggs. It should be kept cold.
How long can Key Lime Pie sit out?
The pie should not sit out on the counter more than two hours at room temperature. If the dessert is kept outside on a hot summer day, I wouldn't let it sit out longer than it takes to serve it.
Does Key Lime Pie need to be baked?
Not every Key Lime Pie needs to be baked. However, since this recipe uses eggs in the filling, it must be baked.
Lauren
One of my favorite dessert recipes to make!
Elly
This is a fantastic 3 ingredient key lime pie! I love how it uses lime juice concentrate.