Why It Works
- Milk softens the sour edge of lime, for a filling that's creamy and tart but mellow.
- Using whole eggs keeps the custard light and the lime flavor fresh and bright.
- A few drops of rosewater bring a fresh aroma to the cooked custard filling.
- A crisp whole wheat crust gives the pie a hearty, graham cracker–like vibe.
- Oven-browned meringue puffs as it bakes, for a lighter texture than meringue browned with a torch.
This pie relies on the killer combo of citrus and dairy (think Creamsicle) for a mellow, sweet, and sour dessert. The crispy whole wheat crust underscores the zippy custard with its graham-like flavor, while fluffy peaks of toasted meringue recall those of a classic lemon meringue pie. It all comes together in a pie that tastes both familiar and distinctive at the same time.
- 1/2 recipe Whole Wheat Pie Crust, blind-baked according to recipe directions
- For the Filling:
- 9 ounces sugar (shy 1 1/3 cups; 255g)
- 1 1/2 ounces cornstarch (about 1/3 cup plus 1 tablespoon; 42g)
- 1/4 teaspoon (1g) Diamond Crystal kosher salt; for table salt, use about half as much by volume or the same weight
- 4 large eggs (about 7 ounces; 195g)
- 1/4 ounce lime zest (about 2 tablespoons; 7g), from about 4 limes (see note)
- 8 ounces fresh lime juice (about 1 cup; 225g), from about 8 limes (see note)
- 16 ounces milk, any percentage will do (about 2 cups; 455g)
- 1/4 teaspoon rosewater (optional)
- For the Topping:
- Swiss Meringue, full or half batch as desired
Getting Ready: In a 9-inch glass pie dish, prepare and blind-bake the whole wheat pie crust according to the directions in the recipe. This can be done up to a week in advance; crust can be held at room temperature if wrapped tightly in plastic.
For the Filling: In a 3-quart stainless steel saucier, combine sugar, cornstarch, and salt and mix until smooth, then whisk in eggs, lime zest, and lime juice, followed by milk. Cook over medium-low heat, whisking constantly but gently, until hot to the touch, about 5 minutes.
Increase heat to medium and continue whisking until thick, about 3 minutes longer. When custard begins to bubble, set a timer and continue whisking for exactly 2 minutes. (This is important to neutralize a starch-dissolving protein found in egg yolks.) Remove from heat and stir in rosewater, if using. Pour into prepared pie crust. For a silkier texture, first strain through a stainless steel sieve, pushing the thick custard through with a flexible spatula.
For the Topping: Adjust oven rack to lower-middle position and preheat to 375°F (190°C). Prepare Swiss Meringue as directed, making a half or full batch depending on your own personal preference for meringue. Transfer to a piping bag fitted with a large star tip. Starting at the very edge of the pie, pipe meringue kisses over surface of custard until completely covered. Alternatively, spread meringue over custard with the back of a spoon. Place on a wire rack set inside a half sheet pan (this setup minimizes heat transfer to the custard) and bake pie until meringue is well browned, about 15 minutes.
To Serve: Cool pie to room temperature, then cover loosely in plastic and refrigerate until no warmer than 60°F (16°C), about 3 1/2 hours. Cut with a wet chef's knife, rinsing the blade clean with cold water between slices. Wrapped in plastic, leftovers can be refrigerated up to 1 week.
You can zest and juice the limes right before making the pie, or do it up to 3 days in advance; combine and refrigerate in a nonreactive, airtight container until ready to use. If you like, save the leftover rinds to make a lime variation of Fresh Lemon Syrup. When working with citrus, it's vital to use nonreactive equipment throughout—a stray aluminum whisk, pot, or sieve is all it takes to give the custard a harsh, metallic flavor.