Meringue is the puffy heart of every sweet soufflé, the airy start to classic buttercream, the basis of seven-minute frosting, the secret to flawless macarons, the chewy-crisp foundation of pavlova, and the fluffy cloud atop a lemon pie. While there are countless applications for meringue, there are only three main ways of making it—French, Italian, and Swiss.
French meringue starts with raw egg whites, whipped until they're foamy enough to hold soft peaks. That indicates that a minor protein called conalbumin has begun to coagulate, uncoiling and interlinking to entrap a network of air bubbles and water droplets. Sugar is then sprinkled in bit by bit, keeping the water content in check but inhibiting volume overall. Because it's raw, French meringue is particularly fragile, easy to over-beat and quick to collapse over time. It's typically used when baking can mitigate those risks—folded into a cake batter or piped out as meringue cookies, for example. Though it's technically the easiest to make, it's also the easiest to mess up due to the risk of over-beating.
Italian meringue begins the same way, but with the addition of a 240°F (116°C) sugar syrup to also coagulate a more abundant, heat-sensitive protein called ovalbumin. This doesn't fully cook the egg whites, but the double whammy of coagulation makes for a particularly stable foam. Because of the dense sugar syrup, Italian meringue is heavy and thick, like shaving cream. It's the silky, stable foundation of nougat, and the go-to choice of many pastry chefs for topping fancy tarts that need to survive several hours in a pastry case. It can be something of a pain to make, as it requires pouring a dangerously hot syrup into the heart of a whirling mixer, and then you're left to scrub a syrup-crusted pot.
Swiss meringue—which is most commonly used for preparations, like buttercream and baked Alaska, that don't require the loft of a French meringue or the stability of an Italian—combines the granulated sugar and egg whites up front, whisking them together over a water bath to about 140°F (60°C), then whipping them until stiff. I find it to be truly the easiest of the three, since you just warm it and whip it, with a big margin of error when it comes to timing.
Tragically, the Swiss method of front-loading the egg whites with sugar interferes with the coagulation of both conalbumin and ovalbumin, producing a meringue that's less fluffy than French and less stable than Italian. The worst of both worlds.
But it doesn't have to be that way! There exists a version of Swiss meringue—mine—that can deliver the best of both worlds, as stable as Italian, yet even lighter than a French meringue made with the same ratio of ingredients. The secret is to cook the Swiss meringue all the way up to 175°F (79°C) and whip at the highest speed possible. Check it out.
That's my Swiss meringue, whipped up and scraped out onto a piece of parchment, left uncovered at room temperature overnight, then cut open with a wet knife. No weeping, no crusting, no major collapse. And, as fate would have it, my experiment spanned two rainy days in Manhattan.
Sugar may delay coagulation, but it's worth taking care when heating egg whites to a temperature as high as what my recipe calls for. An extra-roomy water bath helps in this regard. When a mixing bowl completely covers a pot of water, it's effectively a lid, trapping all of the steam and encouraging the water to boil hard. A bigger pot with more water allows you to maintain a low simmer and a steady supply of steam. All you need is a ring of crumpled tinfoil to keep the bowl afloat.
By using a flexible spatula instead of a whisk, it's easy to scrape the bowl and prevent a thin film of egg whites from splashing up and cooking around the side of the bowl. A spatula is more efficient for scraping the bottom of the bowl as well, ensuring you won't find an egg white omelette there.
Since you're able to scrape the bowl, there won't be any unincorporated sugar crystals lurking around the sides (which can lead to a grainy meringue). As the gritty, gloppy, translucent egg-white-and-sugar mixture cooks, it slowly turns opaque, with a thin but foamy consistency.
Once the egg white mixture hits 175°F, I transfer the bowl to a stand mixer and whip it at high speed until it's glossy, thick, and stiff—about 5 minutes on a stand mixer, depending on its horsepower. Recipes that involve a lower cooking temperature generally call for beating the meringue until it's cool to the touch, but the higher cooking temperature used in my method means the meringue will still be a little warm when it hits peak volume.
So, instead of using temperature as your guide, watch the splashes of meringue that climb higher and higher along the sides of the bowl, and stop whipping as soon as you notice it's no longer growing. When the meringue's just right, it will seem to really fill the bowl, and it'll hold stiff peaks when tested.
It can take a little practice to whip the meringue just right, but it's far better to have a Swiss meringue that's sliiiiiightly under-whipped. It may be just shy of perfection, but it'll still have loads of air bubbles trapped inside, keeping it fluffy, light, and stable. Whipped past its prime, however, Swiss meringue will begin to deflate, becoming dense and gooey and eager to ooze out of shape, making it useless for piping as cookies or topping a pie.
My Swiss meringue isn't just extra fluffy and stable, it's darn tasty, too. Like many other recipes, mine includes cream of tartar. Not because it improves volume or stability (I didn't see any measurable improvements in side-by-side tests), but because its acidity adds a nice counterpoint to the meringue's sweetness. As does a generous pinch of salt. There are also vanilla seeds so the meringue tastes like more than sweetened air, with a flavor and aroma that will complement almost any dessert.
But the real game-changer is my favorite thing in the world—lightly toasted sugar. With its mellow sweetness and subtle depth of flavor, it brings the meringue into perfect balance. And, if you don't feel like investing a few hours to lightly caramelize a whole bag of sugar, you can quick-toast what you need for my meringue in just 30 minutes.
Whether you spread this meringue between layers of chocolate cake, like a seven-minute frosting; pile it over a lemon pie; swirl it over ice cream for baked Alaska; or just bake it off in simple kisses, its superior flavor, stability, and fluffitude will improve your favorite recipes.