Perfect Swiss Meringue Buttercream
Make silky Swiss meringue buttercream with egg whites, sugar, butter, and vanilla, plus troubleshooting tips for smooth, stable frosting every time.
Ingredients
- 5 large Large egg whites (approximately 150 g)
- 1 1/2 cups cups Granulated sugar
- 1 1/2 cups (340 g) cups Unsalted butter, softened but still cool, cut into tablespoons, softened but still cool, cut into tablespoons
- 2 tsp tsp Vanilla extract
- 1/4 tsp tsp Fine sea salt
Instructions
- Ensure the mixer bowl and whisk are completely clean and grease-free.
- Combine the egg whites and granulated sugar in the heatproof mixer bowl.
- Set the bowl over a saucepan containing approximately 1 inch of gently simmering water. The bottom of the bowl should not touch the water.
- Whisk constantly over the heat until the sugar is fully dissolved and the mixture reaches 160°F (71°C).
- Remove the bowl from the heat.
- Using the whisk attachment, whip on medium-high to high speed until the meringue is glossy, stiff peaks form, and the bowl is no longer warm, approximately 10 to 15 minutes. CRITICAL: Do not begin adding butter while the meringue is still warm.
- Switch to medium speed.
- Add the softened butter 1 tablespoon at a time, allowing each addition to incorporate.
- Continue until all butter has been added.
- If the buttercream temporarily appears curdled, soupy, or broken, continue mixing before assuming it failed.
- Add the vanilla and salt.
- Beat until smooth and silky.
- Optional: Switch to the paddle attachment and mix on low for 3 to 5 minutes to reduce air bubbles for cake finishing.
Chef's Notes
SWISS MERINGUE TROUBLESHOOTING: TOO SOUPY: Buttercream is likely too warm. Chill the mixing bowl for 10 to 15 minutes, then continue whipping. CURDLED / CHUNKY: Mixture is often too cool. Warm the outside/bottom of the bowl very gently, then continue mixing. BUTTER MELTING: Meringue was too warm or butter too soft. Cool before continuing. GRAINY MERINGUE: Sugar was not fully dissolved before whipping. FLAVOR VARIATIONS: Vanilla, Chocolate, Espresso, Strawberry, Lemon, Salted Caramel. The new Fresh Strawberry Buttercream is a separate canonical recipe and should be linked as the preferred full strawberry frosting. YIELD: Approximately 5 cups — enough for 24 cupcakes with moderate swirls, or one 8-inch two-layer cake. ALLERGENS: Egg, Milk/Dairy. CROSS-LINKS: Vanilla Bean Bakery Cupcakes, Strawberry Shortcake Cupcakes, Salted Caramel Espresso Cupcakes, Fresh Strawberry Buttercream.