How to Make a Perfect Swiss Meringue Buttercream: the Foolproof Method That Works Everytime!

Swiss meringue buttercream (SMB) is a favorite for cake decorators, and it’s easy to see why. With its silky texture and a flavor that’s not too sweet, this frosting is perfect for frosting cakes and cupcakes. Unlike other frostings, it’s smooth, creamy, and light—just the right balance to complement your baked goods without overwhelming them.

What Is Swiss Meringue Buttercream?

Swiss meringue buttercream is a type of frosting made by combining egg whites and sugar, heating the mixture, and then whipping it into a meringue. Once that’s done, it’s blended with butter and flavorings like vanilla. What makes it stand out is its incredible texture—creamy, smooth, and stable enough to hold up under fondant. It spreads beautifully over cakes, making it the go-to choice for many decorators.

Ingredients

To make Swiss meringue buttercream, gather these ingredients:

• 300 grams of egg whites
• 400 grams of sugar
• 1 teaspoon of vanilla sugar (or vanilla extract)
• 400 grams of unsalted butter, at room temperature

Method

Start by combining the egg whites and sugar in a heatproof bowl. You’ll need to heat this mixture, so place the bowl snugly over a pot of simmering water (this is called a bain-marie). Make sure the water doesn’t touch the bowl. Keep whisking constantly to ensure the sugar dissolves fully and the egg whites don’t cook. This is crucial for getting a smooth buttercream.

Once the sugar dissolves completely (you can check by rubbing the mixture between your fingers—it should feel smooth), remove the bowl from the heat. Using a stand mixer or hand mixer, whisk the mixture on high speed for about 10 minutes until the meringue forms stiff peaks and cools down significantly. Add in the vanilla sugar or extract and give it a quick mix to incorporate. Next, add the room-temperature butter, a little bit at a time, while continuing to mix. If the mixture looks curdled, don’t worry—just keep mixing! It will eventually turn into a smooth, glossy buttercream. Continue to beat until the frosting reaches the perfect thick and creamy consistency. Once it’s ready, you can use it to decorate cakes and cupcakes.

How to Make It White

Want a whiter buttercream? It’s easier than you think. Use very pale butter and add a tiny bit of purple or blue food coloring to balance out any yellowish tones. You can also use clear vanilla extract instead of regular vanilla to avoid darkening the frosting.

Storage and Shelf Life

Swiss meringue buttercream is pretty easy to store. At room temperature, it’ll stay good for about a day—just make sure it’s not too hot or humid. For longer storage, pop it in the fridge, where it will stay fresh for up to 2 weeks, or freeze it for up to 3 months. When you’re ready to use it, let it come to room temperature and give it a quick rewhip to restore that creamy texture.

Swiss Meringue Buttercream vs. Regular Buttercream

The big difference between Swiss meringue buttercream and American buttercream lies in how they’re made and their texture. American buttercream is simply butter mixed with powdered sugar, which makes it sweeter and denser. Swiss meringue buttercream, on the other hand, is lighter and smoother thanks to the meringue base, making it perfect for those who want a less sugary frosting.

Common Mistakes and Fixes

• Buttercream is too runny: If your buttercream is too runny, it’s probably because the meringue was too warm when you added the butter. No worries—just chill the mixture for 20 minutes and then rewhip it.
• Buttercream curdles: If your buttercream looks curdled, that’s usually because the butter was too cold. Keep mixing, and it should come together beautifully.
• Too buttery or heavy: If it’s a bit too rich for your taste, try adding a pinch of salt or a few drops of lemon juice to cut through the richness and lighten the flavor.