Hello! I’m Cassandre, and today on Caramel Loafing, I’m sharing the perfect sweet-tart dessert for spring and summer: a classic Key Lime Pie.
When the days get longer and the weather warms up, our taste buds crave something refreshing to replace the heavy comfort foods of winter. And what’s more refreshing than citrus? Lemons and limes are wonderfully versatile—too sour to eat alone but magical in sweet or savory dishes. From marinades and salad dressings to drinks and desserts, citrus adds a bright pop to everything. On Caramel Loafing we’ve shared plenty of lemony bakes, like Lemon Pound Cake, Lemon Bars, and French Lemon Sponge Cake, plus zesty drinks like a Virgin Mojito or refreshing Lemon Sorbet. But today, we’re serving up a true American classic: the Key Lime Pie.
Traditionally, a true Key Lime Pie is made with key limes—small, thin-skinned limes from Mexico that grow abundantly in Florida. Their aroma is extra bright and floral. If you can’t find them (they’re pretty rare outside Florida and the U.S. East Coast), don’t worry—regular yellow lemons, limes, or even a splash of calamansi juice can bring that fresh citrus kick. Just imagining the scent is pure therapy!
Unlike a French lemon tart (tarte au citron) that uses custard for the filling, a classic Key Lime Pie relies on sweetened condensed milk instead. You’d never guess there’s condensed milk inside—it tastes light and bright and is surprisingly easy to make. If you’re a citrus fan, you must try this!
Key Lime Pie Recipe & Method
Ingredients
Pan size: Round springform pan, base diameter 14 cm (5.5 in), top diameter 16 cm (6.3 in), height 2.5 cm (1 in)
Makes about 5–6 servings.
Need a different size? Use our handy Pan Size Converter.
☞ Crust
- Digestive biscuits: 9 pieces, about 134g (4.7 oz)
- Unsalted butter, melted: 54g (1.9 oz)
- Sugar: 8g (0.3 oz)
☞ Lime Filling
- Lime zest: 1.2g (about 1 tbsp / 0.04 oz)
- Egg yolks: 30g (1.1 oz)
- Sweetened condensed milk: 178g (6.3 oz)
- Lime juice: 55g (1.9 oz)
☞ Topping
- Heavy cream: 100g (3.5 oz)
- Powdered sugar: 9g (0.3 oz)
- Fresh lime zest, for garnish
Curious about the nutrition? Use our Nutrition Calculator for detailed info.
How to Make Key Lime Pie
- Make the crust: Crush the digestive biscuits and sugar into fine crumbs. Mix in the cooled melted butter until evenly combined. Press the mixture into the tart pan, working up the sides first, then smoothing the base until compact and even.
- Pre-bake: Preheat the oven to 347°F (175°C). Bake for 10 minutes, then let the crust cool completely.
- Make the filling: Beat the egg yolks with an electric mixer on medium speed until thick and pale (about 3–4 minutes).
- Add the condensed milk and lime zest; mix on medium speed for 1–2 minutes until fully combined.
- Pour in the lime juice and mix on low speed until smooth and glossy.
- Pour the filling into the cooled crust. Bake at 347°F (175°C) for 10–11 minutes, or until the filling is set and doesn’t jiggle.
- Cool to room temperature, then chill in the fridge for at least 2 hours or overnight for best flavor.
- Whipped cream topping: Whip the heavy cream with powdered sugar until soft peaks hold their shape. Dollop generously on top of the pie and finish with a sprinkle of fresh lime zest—or enjoy plain for a simpler treat!
Watch the full tutorial: Key Lime Pie Video
Key Lime Pie FAQs & Tips
Key Lime Pie is simple to make, but here are a few common questions and tips to help you get it just right:
Which limes are best for Key Lime Pie?
Authentic Key Lime Pie uses key limes—small, thin-skinned, and super aromatic, mostly grown in Florida. If you can’t find them, regular yellow lemons, Persian limes, or even a mix of the two will work beautifully. Some recipes even add a splash of calamansi juice for an extra fresh citrus note—feel free to get creative!
No tart pan? What can I use instead?
Traditionally, Key Lime Pie is baked in a ceramic or glass pie dish. If you don’t have one, a tart pan with a removable bottom works perfectly too. Just make sure your pan isn’t too deep—a shallow dish keeps the crust-to-filling ratio balanced and prevents the filling from tasting overly sweet or tart.
Do I have to use sweetened condensed milk?
Yes—this is the key ingredient that replaces the custard used in a French lemon tart. Sweetened condensed milk gives the filling its signature creamy texture and balances the citrus tang. Don’t worry if you’re not a fan of condensed milk: you won’t taste it at all in the final pie!
Can I make the crust without sugar?
Absolutely. The small amount of sugar in the crust just helps it hold together firmly after baking, but you can leave it out if you’d like a slightly less sweet base. The texture will still be deliciously crumbly.
Is Key Lime Pie very sweet?
It strikes a beautiful balance—sweet enough to tame the tartness of the citrus. The sugar is important because citrus desserts need enough sweetness to balance the acidity. If you want to adjust the overall sweetness, try making the crust slightly thicker or topping your pie with plenty of whipped cream for extra balance.
Any tips for zesting limes?
When zesting, use a light hand—only remove the colorful outer layer. If you scrape too deeply into the white pith, you’ll add bitterness. For the filling, yellow zest blends nicely, while a sprinkle of green lime zest on top adds a fresh, vibrant touch.
How long does Key Lime Pie keep?
After baking, cool the pie to room temperature, then chill it in the fridge for at least 2 hours or overnight. It’s best enjoyed within 2–3 days when stored covered in the refrigerator. Avoid freezing, as the texture can change.