Vanilla Swiss Meringue Buttercream Recipe by Joanne Chang

Joanne Chang is a Boston-based pastry chef and the co-owner of Flour Bakery. The award-winning pastry chef has a degree with honors in applied mathematics and economics from Harvard University in Cambridge, Massachusetts. Passionate about baking since her college days, Joanne left her consulting job to work in restaurants, eventually opening Flour Bakery in 2000. Since then, she expanded the bakery to eight more locations, opened a Taiwanese-inspired restaurant, won a reality TV cooking competition and a James Beard Award, and wrote five cookbooks.

Despite her long list of accolades, Joanne still delights in the alchemy of baking: simple ingredients that, when combined with the right techniques, transform into something magical. Learn to bake like a pro with Joanne Chang.

Swiss meringue, also known as meringue cuite, is a type of meringue made by beating egg whites and sugar together in a double boiler (a pan or bowl set above simmering water) until the sugar fully dissolves and the mixture is hot to the touch. It’s then removed from the heat and further beaten until it doubles in volume. The result is a foam of air bubbles enclosed in egg white and stabilized by sugar. If you want to bake the Swiss meringue cookies known as kisses, follow Chef Dominique Ansel’s recipe for Swiss meringues.

Swiss meringue buttercream is a type of frosting made from a base of Swiss meringue, plus plenty of butter. It’s one of several different styles of buttercream frosting used to frost cupcakes and layer cakes, along with American buttercream and Italian buttercream.

Swiss meringue can be intimidating since it requires whisking eggs over hot water on the stovetop, but with the right tools and techniques, it produces a silky, stable buttercream frosting. Here’s how to make Swiss meringue buttercream frosting perfectly, even if it’s your first time.

1. 1. Whisk the meringue thoroughly. Over-whipping the meringue won’t affect the final outcome of the product, so better to over-whip than under-whip. A good meringue has firm, stiff peaks.
2. 2. Use clean tools. When making the meringue, it is essential to use clean tools. If a drop of oil (or other fat) or egg yolk gets into the egg white mixture, the meringue will not whip properly. To avoid the yolks entirely, purchase a carton of pasteurized egg whites.
3. 3. Add a stabilizer. Some meringue recipes call for cream of tartar, which acts as a stabilizer. It isn’t necessary, but if you find your meringue turns soupy or curdles, consider adding a pinch of the stabilizer before whisking. Learn more about cream of tartar and its culinary uses.
4. 4. Invest in an instant-read thermometer. A digital thermometer will let you know when your meringue is the exact right temperature for transforming into buttercream frosting.
5. 5. Add other flavorings. If you’re looking to tone down the sweetness of a jam or marmalade (and thicken it up), stir it into your buttercream until everything is well combined. The result is a lovely pastel frosting. For a chocolate Swiss meringue buttercream, incorporate cocoa powder or melted chocolate. Amp up the vanilla flavor by swapping the extract for vanilla bean paste or achieve bright colors with gel food coloring.

Store vanilla Swiss meringue buttercream in an airtight container in the refrigerator for up to one week. Before using the buttercream, bring it to room temperature by letting it sit out for a few hours. Use the paddle attachment of your standing mixer to beat it until it is glossy again.

If the buttercream continues to look curdled after beating, it is still too cold, and you’ll need to continue beating until it comes together. You can warm a bit of buttercream in a saucepan on the stove and add it to the mixer with the firm buttercream to help smooth it out.