Baking & Pastry > Frosting & Icing > Buttercream Frosting > Swiss Meringue Buttercream Recipe

Classic Swiss Meringue Buttercream

Learn how to make a perfect Swiss Meringue Buttercream (SMBC). This frosting is silky smooth, not too sweet, and the perfect complement to cakes and cupcakes. This recipe provides a detailed guide for consistent results.

Prep Time
20 minutes
Cook Time
10 minutes
Servings
Enough for a 9-inch cake or 12 cupcakes
Ingredients
  • 5 large Egg Whites
  • 1 cup Granulated Sugar
  • 1 cup (2 sticks) Unsalted Butter
  • 1 teaspoon Vanilla Extract
  • 1/8 teaspoon Pinch of Salt

Prepare the Meringue

In a heatproof bowl (such as stainless steel or glass) set over a saucepan of simmering water (double boiler), combine the egg whites and granulated sugar. Make sure the bottom of the bowl doesn't touch the water. Stir constantly until the sugar is completely dissolved and the mixture is hot to the touch (about 160°F or 71°C). You can test this by rubbing a little of the mixture between your fingers; it should feel smooth, with no gritty sugar particles.

Whip the Meringue

Remove the bowl from the heat and transfer it to a stand mixer fitted with the whisk attachment. Beat on medium-high speed until stiff, glossy peaks form and the bowl is completely cool to the touch. This may take 5-10 minutes. The meringue should be thick and stable. It's crucial that the bowl is cool, otherwise the butter will melt when added.

Add the Butter

With the mixer on medium speed, add the softened butter one tablespoon at a time, allowing each piece to incorporate fully before adding the next. The mixture may look curdled or separated at first – don't panic! Continue mixing, and it will eventually come together into a smooth, silky buttercream. If it doesn't come together after all the butter is added, continue mixing on medium speed for a few more minutes. If the buttercream seems too soft, chill it in the refrigerator for 10-15 minutes, then beat it again until smooth.

Flavor and Finish

Once the buttercream is smooth and stable, add the vanilla extract and salt. Mix until combined. You can also add other flavorings at this stage, such as extracts, citrus zest, or melted chocolate. The buttercream is now ready to use. It can be stored in the refrigerator for up to a week or in the freezer for up to three months. Bring to room temperature and re-whip before using.

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FAQ

  • Why is my buttercream curdled?

    Curdling often happens when the butter is too cold or too warm. Make sure the butter is softened but still cool to the touch. If it curdles, keep mixing! It will usually come back together. If not, try chilling the bowl for 10-15 minutes and then re-whipping.
  • Why is my buttercream soupy?

    Soupy buttercream can happen if the meringue is too warm when you add the butter. Make sure the bowl is completely cool to the touch before adding the butter. If it's already soupy, chill the bowl for 10-15 minutes and then re-whip.
  • Can I use salted butter?

    While you can use salted butter, unsalted butter is preferred because it allows you to control the salt level in the buttercream. If using salted butter, omit the pinch of salt in the recipe.