This Swiss meringue recipe is ideal for topping pies. By heating the egg whites and sugar before whipping, the meringue becomes food-safe, stable, and easy to work with. It spreads or pipes smoothly and toasts evenly.
Set up a double boiler by filling a pot with 1 to 2 inches of water and placing a heatproof bowl on top. The bowl should be slightly larger than the pot, with its bottom hovering just above the water. Bring the water to a boil over medium heat.
In the heatproof bowl, whisk together the egg whites, sugar, and optional cream of tartar. Keep the bowl over the double boiler and whisk gently until the mixture reaches 160°F (71°C), using a candy thermometer to check the temperature.
Immediately transfer the mixture to a stand mixer fitted with a whisk attachment. Whip on high speed until stiff peaks form.