Whether you’re a buttercream beginner or cake decorating pro, this straightforward Swiss meringue buttercream recipe will be your new go-to. Made with whipped egg whites, Swiss meringue buttercream is airier and more stable than American buttercream (made by whipping softened butter with powdered sugar) but has a lush mouthfeel that can’t be beat. This silky, spreadable frosting glides smoothly onto layer cakes, sheet cakes, or cupcakes.
To make Swiss meringue buttercream, you’ll cook egg whites and sugar over a double boiler, whisking constantly until it reaches 140°. Don’t have an instant-read thermometer? Rub the egg whites between your fingers—when ready, you shouldn’t feel any sugar granules. You’ll then whip the egg whites to a froth in the bowl of a stand mixer before incorporating the butter and flavorings. Switching from the whisk to paddle attachment at the final stage helps remove any air bubbles. Troubleshooting tip: If the meringue looks soupy once you start incorporating the butter, the egg whites were too warm. Stick the bowl in the refrigerator for 15 minutes, then rewhip.
In hot weather, you can make this frosting even more stable by swapping out a portion of the butter for hi-ratio shortening (a variety emulsified with water). Use about 2 lb. 10 oz. butter and 6 oz. (710 g) shortening.
Customize this versatile frosting recipe however you please, adding flavored extracts, vanilla bean paste, or melted chocolate or cocoa powder to make chocolate buttercream. You can also use gel food coloring to dye it any color of the rainbow, or load it into a pastry bag and use piping tips to make myriad designs.
This Swiss meringue buttercream recipe yields 2½ quarts, which is more than enough for two 2-layer cakes; if only icing one cake, halve the recipe or freeze the extra). Store the icing in an airtight container in the fridge for up to 1 week or freeze for up to 3 months.
This recipe was adapted for style from ‘The Well-Decorated Cake’ by Toba Garrett. Buy the full book on Amazon.