Key Lime Pie Factory-Style Key Lime Pie

Key lime pie is a chilled Florida dessert with a crisp graham cracker crust and a bright, creamy filling made with lime juice, egg yolks, and sweetened condensed milk. This factory-style version uses a brief bake to set the filling, then a long chill for neat slices and a balance of tart citrus and sweetness.

Ingredients

1½ cups (150 g) finely crushed graham cracker crumbs
⅓ cup (67 g) granulated sugar
6 tablespoons (85 g) unsalted butter, melted
4 large egg yolks, at room temperature
1 can (14 oz / 397 g) sweetened condensed milk
½ cup (120 ml) Key lime juice, freshly squeezed or bottled
1 tablespoon (6 g) finely grated Key lime zest, plus a little extra to garnish
1 cup (240 ml) cold heavy cream
2 tablespoons (15 g) powdered sugar
½ teaspoon (2.5 ml) vanilla extract

Instructions

Heat the oven to 350°F (175°C). Set a 9-inch (23 cm) pie plate on a baking sheet. If using fresh Key limes, zest them before juicing; strain the juice to remove seeds and pulp. A microplane makes fine zest that blends evenly into the filling.
Stir the graham cracker crumbs and granulated sugar together in a medium bowl. Pour in the melted butter and mix until the crumbs are evenly moistened and hold together when pressed. Tip the mixture into the pie plate and press it firmly across the bottom and up the sides, keeping the thickness even. Bake for 8 minutes, then set the crust aside while you make the filling. Leave the oven on.
Whisk the egg yolks in a bowl for about 1 minute, until slightly thickened. Whisk in the sweetened condensed milk, lime juice, and zest until smooth. Pour the filling into the warm crust and smooth the top. The lime’s acidity helps thicken the condensed milk, but the pie still needs baking and chilling for a properly set filling.
Bake for 10 minutes, until the edges look set and the center still has a slight, gentle wobble when the plate is nudged. The filling contains egg, so check the center with a food thermometer: the USDA FSIS safe minimum for an egg dish is 160°F (71°C). Avoid baking until the center is completely firm, which can make the texture less creamy. Set the pie on a rack to cool for 1 hour.
Once the pie has cooled, cover it without letting the covering touch the surface and refrigerate for at least 4 hours, or until thoroughly cold and firm. Do not leave it at room temperature for more than 2 hours in total, including the cooling period.
Just before serving, whip the cold heavy cream with the powdered sugar and vanilla until it holds soft-to-medium peaks. Spread or pipe the cream over the pie, then finish with a little extra lime zest. Slice with a clean knife, wiping it between cuts for tidy portions.

Tips

Choose your limes: Key limes are small and aromatic, but regular Persian limes work well if Key limes are unavailable. Their juice is usually less delicate and can taste sharper, so zest lightly and taste the filling before baking if you prefer a gentler tartness.
Use bottled juice carefully: Bottled Key lime juice is a convenient option and gives consistent acidity. Use plain, unsweetened juice, not a sweetened lime drink or cordial.
Pack the crust firmly: Press the crumbs into the pie plate with the flat bottom of a measuring cup. Loose crumbs can crumble when sliced; excessive pressure is not necessary, but an even, compact layer helps it hold together.
Watch the set, not just the clock: Ovens and pie plates vary. The center should have a slight wobble after baking and become firm during refrigeration. Check temperature without touching the crust or plate with the thermometer probe.

Serving Suggestions

Serve the pie well chilled, with a modest layer of whipped cream so the citrus filling remains the main feature. A few curls of lime zest or a very thin lime wheel make a simple garnish. For a richer dessert plate, add fresh berries; their mild sweetness complements the tart filling without requiring a sauce.

For clean wedges, use a sharp knife warmed under hot water and dried before each cut. Keep the pie refrigerated until close to serving time, especially on a warm day, and return leftovers to the refrigerator promptly.

Variations

More tart: Reduce the condensed milk by about 2 tablespoons (30 g) and increase the lime juice by the same volume. The filling may be a little softer, so give it the full chilling time before slicing.

Gingersnap crust: Replace the graham cracker crumbs with 1½ cups (150 g) finely crushed gingersnaps. Their spice adds warmth and makes the crust a little more assertive; keep the butter and sugar amounts as written, adjusting only if the crumbs seem unusually dry or sweet.

Individual pies: Divide the crust among 8 small oven-safe tart dishes or ramekins and press it into the bottoms. Bake the crusts for about 6 minutes, add the filling, and bake until the edges are set and the centers gently wobble; check that the filling reaches 160°F (71°C). Small portions may cool and chill faster, so begin checking after 2 hours in the refrigerator.

Skip the topping: The pie is complete without whipped cream. For a lightly browned meringue topping instead, use a recipe that cooks the egg whites to a safe temperature; do not rely on brief torching alone to make raw egg whites safe.

Storage and Reheating

Refrigerate the pie within 2 hours of baking and keep it covered at 40°F (4°C) or colder. For best texture, serve within 3 days; discard it after 4 days. Store whipped cream separately if you want it to keep its shape, and top each slice just before serving. This dessert is served cold, so reheating is not recommended.

To freeze, wrap the cooled, un-topped pie tightly and freeze for up to 1 month for best quality. Thaw it overnight in the refrigerator, not on the counter, then add freshly whipped cream. Freezing may slightly soften the crust.

Frequently Asked Questions

Can I make key lime pie ahead of time?
Yes. Bake and chill it a day ahead, then keep it covered in the refrigerator. Add the whipped cream shortly before serving for the best texture and appearance.

Do I need to use Key limes?
No. Persian limes are a practical substitute and are easier to juice. The result will still be a lime pie, though the citrus aroma and tartness may differ slightly.

Why is my filling runny?
It may not have baked long enough to reach the safe temperature, or it may not have chilled for long enough. Confirm the center reaches 160°F (71°C), then refrigerate for at least 4 hours before slicing.

Can I use a store-bought crust?
Yes. Use a 9-inch graham cracker crust and follow the package guidance for pre-baking. Fill and bake as directed here, checking the filling’s temperature and allowing the full cooling and chilling time.

Can I make it without baking?
This recipe is not designed as a no-bake pie. Lime juice thickens the condensed milk, but it does not make raw egg yolks safe; baking the filling to 160°F (71°C) is important. For a no-bake version, use a recipe made with pasteurized eggs or no eggs.

How do I keep the crust from crumbling?
Crush the crackers finely, measure the butter accurately, and press the mixture into a compact, even layer. Let the baked crust cool slightly before filling, and chill the finished pie thoroughly before cutting.

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Safety notes: safe minimum internal temperatures from USDA FSIS; raw and undercooked fish guidance from the U.S. FDA. Food safety notes

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