Southern Sweet Potato Souffle With Vanilla And Nutmeg
A light, egg lightened Southern sweet potato souffle flavored with vanilla and freshly grated nutmeg. Whipped egg whites make it spoonable and fluffy instead of dense, with no marshmallows and no streusel.
Servings 8 servings
Ingredients
For the Souffle
- 3 lb sweet potatoes about 4 medium, roasted and peeled to yield 4 cups mashed
- 6 tablespoons unsalted butter melted
- ¾ cup light brown sugar packed
- ½ cup heavy cream
- 4 large eggs separated
- 1 tablespoon vanilla extract
- ¾ teaspoon freshly grated nutmeg plus more for the top
- ¼ teaspoon ground cinnamon
- 1 teaspoon fine salt
- 1 teaspoon baking powder
- ⅛ teaspoon cream of tartar optional, for the whites
- 1 tablespoon softened butter for the baking dish
Instructions
Roast and Mash the Sweet Potatoes
- Heat the oven to 400 degrees F. Scrub the sweet potatoes, prick each one several times with a fork, and set them on a foil lined baking sheet.
- Roast for 55 to 70 minutes, until a knife slides through the thickest part with no resistance and the skins have started to weep sugar.
- Cool until you can handle them, then peel the skins away with your fingers. Mash the flesh well in a large bowl or push it through a ricer, and measure out 4 cups. Do not use a food processor, it turns sweet potato gluey.
Build the Base
- While the mash is still warm, beat in the melted butter and the brown sugar.
- Add the heavy cream, egg yolks, vanilla, nutmeg, cinnamon, salt, and baking powder. Beat with a hand mixer on medium for about 1 minute, until glossy and slightly paler.
- Taste and adjust the salt now. It should taste slightly saltier than you expect, because the whipped whites will dilute it. Let the base cool to just warm before adding the whites.
Whip and Fold the Whites
- Put the egg whites and the cream of tartar in a scrupulously clean glass or metal bowl. Whip on medium high to soft peaks, the stage where a lifted beater pulls up a peak that flops at the tip. Do not whip to stiff peaks.
- Stir one third of the whites into the base vigorously to loosen it.
- Fold in the remaining whites in two additions with a rubber spatula, cutting down through the center, sweeping along the bottom, and turning the bowl a quarter turn each time. Stop as soon as the white streaks disappear.
Bake
- Heat the oven to 350 degrees F and butter a shallow 2 quart oval baking dish, about 2 inches deep, right up the sides.
- Scrape the mixture in and level the top gently with the back of a spoon without packing it down. Grate a little extra nutmeg over the surface.
- Bake 40 to 45 minutes, until the top has puffed and cracked lightly, the edges have pulled slightly from the dish, and the center jiggles as one soft mass. Do not open the oven in the first 25 minutes.
- Rest 10 minutes before serving so the custard finishes setting.
Notes
- Roast, never boil: boiled sweet potatoes carry water into the mash and water is what makes a souffle dense and weeping.
- Soft peaks only: stiff whites break into dry clumps instead of folding, and leave white streaks in the bake.
- Go shallow: a 2 inch deep oval baker cooks evenly. A deep casserole dish sets the top before the center cooks.
- Make ahead: the base holds covered in the fridge up to 2 days. Whip and fold fresh whites on the day you bake.
- Fresh nutmeg: grate it from a whole nutmeg. Preground loses its oils within months.