Classic Key Lime Pie Recipe

I developed a Classic Key Lime Pie Recipe that uses just five pantry staples and one unexpected step to set the filling perfectly.

I love how a Classic Key Lime Pie tastes like sunlight, tart and bright in every bite. I wanted an Easy Classic Key Lime Pie that still feels special, and what grabs me first is the crunchy graham cracker crumbs crust paired with that sharp fresh key lime juice filling, it’s such a small miracle.

Folks call it a Simple Key Lime Pie or they search for a Classic Key Lime Pie Recipe and expect perfection, but honestly I mess up sometimes, and sometimes those mistakes are the best part, makes you curious enough to try it yourself.

Ingredients

• Crunchy, mostly carbs and sugars, small amount of fibre, makes crust sweet.
• Adds richness and mouthfeel, pure fat, no protein, helps crust bind.
• Very sweet, lots of sugar and calories, adds creaminess and body its rich.
• Provide fat and protein, help set filling, give silky texture.
• Tart and tangy, high in vitamin C it cuts sweetness, bright citrus punch.
• Concentrated oils, bold aroma, tiny bit of fibre, amps citrus flavor.
• Whipped for topping adds fat and silkiness, more calories but luxurious
• Sweetens filling and crust, mostly simple carbs, adds structure when crisped.
• Tiny amount boosts flavors, balances sweet and tart, no real nutrition.

Ingredient Quantities

• 1 1/2 cups (150 g) graham cracker crumbs (about 10 whole crackers)
• 1/3 cup (67 g) granulated sugar
• 6 tablespoons (85 g) unsalted butter, melted
• pinch of salt (about 1/8 tsp)
• 1 (14 oz / 396 g) can sweetened condensed milk
• 4 large egg yolks, room temperature
• 1/2 cup (120 ml) fresh key lime juice
• 1 tablespoon finely grated lime zest
• 1 cup (240 ml) heavy cream, cold (optional)
• 2 tablespoons powdered sugar (optional)
• extra lime zest or thin lime slices for garnish (optional)

How to Make this

1. Preheat oven to 350°F (175°C). In a bowl mix 1 1/2 cups graham cracker crumbs, 1/3 cup sugar, pinch of salt and 6 tablespoons melted butter until crumbs look evenly moistened.

2. Press crumbs firmly into the bottom and up the sides of a 9 inch pie pan, pack it tight so the crust holds together. Bake crust 8 to 10 minutes until set and lightly golden, then let cool on a rack.

3. In a clean bowl whisk 1 (14 oz) can sweetened condensed milk with 4 room temperature egg yolks until smooth and slightly glossy. Don’t rush this, but don’t overwhip either.

4. Gradually add 1/2 cup fresh key lime juice while whisking so the mixture thickens and becomes a pale green. Stir in 1 tablespoon finely grated lime zest.

5. Pour the filling into the cooled crust and smooth the top. Bake at 350°F for about 10 to 12 minutes, just until the edges are set and the center has a slight jiggle.

6. Remove from oven and cool to room temperature on a rack, then chill the pie in the refrigerator at least 3 hours or overnight to fully set and develop flavor.

7. If you want whipped cream: beat 1 cup cold heavy cream with 2 tablespoons powdered sugar until soft to medium peaks form. Dollop or pipe over chilled pie.

8. Garnish with extra lime zest or thin lime slices for color and a little extra zing. Run a knife around the edge before slicing to get clean pieces.

9. Store covered in the fridge for up to 3 days. If you want, let slices sit 10 minutes at room temp before serving so flavors open up a bit.

Equipment Needed

1. 9-inch pie pan
2. 2 mixing bowls (one large, one medium)
3. Measuring cups and spoons
4. Rolling pin or food processor (to crush graham crackers)
5. Whisk
6. Rubber spatula
7. Microplane or fine grater for zest
8. Electric hand mixer or stand mixer (optional, for whipped cream)
9. Oven mitts and a cooling rack
10. Sharp knife and pie server for clean slices

FAQ

Classic Key Lime Pie Recipe Substitutions and Variations

• Graham cracker crumbs → Digestive biscuits or plain shortbread, use equal weight (about 150 g). Crush like you would graham crackers, crust will be a bit richer with shortbread but still great.
• Unsalted butter → Melted coconut oil or a vegan buttery spread, use same volume (6 tbsp / 85 g). Refined coconut oil keeps flavor neutral, remember it firms up when chilled so crust can be a touch more brittle.
• Sweetened condensed milk → Make a quick stovetop swap: simmer 2 cups (480 ml) whole milk with 2/3 cup (135 g) sugar, stir until reduced by about half and slightly thick, cool and use 1:1. For dairy free try full-fat canned coconut milk reduced with 1/3 cup sugar until slightly thickened.
• Egg yolks → For an egg free version, blend about 12 oz (340 g) silken tofu until silky and fold into the lime/condensed milk mix, or thicken with a cornstarch slurry (3 tbsp cornstarch + 3 tbsp cold water) whisked into warm filling until it thickens, then cool. Texture wont be identical but it sets nicely.

Pro Tips

1) Pack the crust like you mean it. Use the bottom of a measuring cup to press the crumbs firmly into the pan so the crust doesnt crumble when you slice it, and let it cool completely before you pour the filling or it gets soggy.

2) Bring the yolks to room temp and add the lime juice slow. If you dump the acid in too fast the mix can seize up, whisk slowly until it thickens, and if it still looks grainy strain it through a fine sieve before baking.

3) Don’t overbake the pie. Take it out when the edges are set but the center still has a slight jiggle, carryover heat will finish it, and chilling it overnight makes the texture much better.

4) For brighter lime flavor use a microplane for zest and reserve a bit for garnish. Fresh key limes are best, but any fresh lime will beat bottled juice every time.

5) Chill everything for the whipped cream and for slicing. Cold bowl and beaters make fluffier cream, stop at soft to medium peaks so it doesnt turn to butter, and heat a knife under hot water and wipe it between cuts for clean slices.