Key Lime Crème Brûlée Recipe

Preheat and prepare ramekins

Preheat the oven to 325°F (163°C). Arrange four 6-ounce (180 ml) ramekins in a deep roasting pan or baking dish large enough to hold them with space between. Have a kettle of hot water ready to create a water bath (bain-marie).

Infuse cream with key lime zest

In a medium saucepan, combine the heavy cream, whole milk, and the 2 tablespoons key lime zest. Warm over medium heat until just below simmering — small bubbles will appear at the edges but do not boil — about 5 to 7 minutes. Remove from heat and cover. Let the mixture steep for 15 minutes so the lime zest infuses the cream.

Whisk eggs and sugar

While the cream steeps, whisk together the 5 egg yolks, 1 whole egg, and 1 tablespoon granulated sugar in a medium bowl until the mixture lightens slightly in color and becomes smooth, about 1 to 2 minutes. Whisk in the pinch of fine sea salt.

Temper the eggs

Strain the warm cream through a fine mesh sieve into a heatproof measuring cup to remove the zest solids. Gradually add about 1/3 cup of the warm cream to the egg mixture while whisking constantly to temper the eggs and prevent scrambling. Continue adding the remaining warm cream slowly in a steady stream while whisking until fully combined.

Add flavor and combine

Stir in the 1 teaspoon vanilla extract and the 3 tablespoons fresh key lime juice into the custard mixture. Taste and adjust: the lime should be bright but balanced with cream. If the curdles formed during tempering, strain the custard again through the fine mesh sieve into a clean bowl or measuring cup to ensure a silky texture.

Fill ramekins

Divide the strained custard evenly among the four prepared ramekins. Place ramekins back into the roasting pan.

Bake in a water bath

Pour hot (not boiling) water into the roasting pan until it reaches halfway up the sides of the ramekins. Carefully transfer the pan to the oven and bake at 325°F (163°C) until the custards are just set around the edges but still slightly wobbly in the center, about 32 to 40 minutes depending on oven and ramekin size. Check at 30 minutes for doneness.

Cool and chill

Carefully remove ramekins from the water bath and transfer to a wire rack. Let them cool to room temperature for 30 to 45 minutes, then cover with plastic wrap and chill in the refrigerator at least 3 hours, preferably overnight, to fully set and develop flavor.

Prepare sugar mixture

Mix the 3 tablespoons granulated sugar with the optional 1 tablespoon demerara or turbinado sugar in a small bowl. The coarser sugar adds a crunch but is optional if you prefer a smooth glassy top.

Caramelize the sugar

Remove chilled custards from the refrigerator and let sit at room temperature for 10 minutes. Evenly sprinkle about 3/4 tablespoon to 1 tablespoon of the sugar mixture over each custard to form an even layer. Using a kitchen torch, hold the flame about 2 to 3 inches from the sugar and move in small circular motions until the sugar melts, then watch for it to bubble and turn a deep amber color to form a crisp caramelized crust, about 1 to 2 minutes. If you do not have a torch, preheat the oven broiler on high, place the ramekins on a baking sheet, and broil 3 to 6 inches from the heat for 2 to 4 minutes, watching constantly to avoid burning.

Set the crackle

Allow the caramelized tops to cool untouched for at least 2 minutes so the sugar hardens into a glassy shell. For the best crack, chill the brûléed custards for another 10 to 15 minutes before serving, if time allows.

Garnish each brûlée with a thin key lime slice or wedge, a light dusting of extra grated key lime zest, and a small mint leaf if desired. Serve immediately so the contrast between cool creamy custard and warm crisp top is enjoyed. Each ramekin serves one.