Swiss Meringue Buttercream: A Step-by-Step Tutorial

In the bowl of a stand mixer, combine the egg whites, sugar, and salt. Place the bowl over a pot of simmering water. Whisk constantly (I use a hand mixer) until the sugar is dissolved and the mixture reaches about 150ºF.

Take the bowl and attach it your mixer, fitted with the whisk attachment. Whisk the egg white mixture until it reaches room temperature and stiff peaks have formed, about 5-10 minutes. At this point the mixture will be thickened and white.

With the mixer on low speed, add the butter, 2 tablespoon as a time. Once all the butter is added, raise the speed to medium high and mix until the mixture starts to come together. Remove the whisk attachment and replace with the beater attachment. Beat until the buttercream comes together fully and is smooth. This can take time, sometimes 2 minutes, and sometimes up to 10 minutes. Don’t worry if you think you did something wrong, it will come together and create a smooth and creamy buttercream.

Once the buttercream is silky and smooth, mix in the vanilla. At this point, you can color the buttercream any color you like. I prefer using gel food coloring instead of the liquid kind.

Swiss Meringue Buttercream can last months in the refrigerator. Just place it in a sealed container, and then keep it in the refrigerator until ready to use. When you need to use it again, remove it from the refrigerator and place it on the counter until it reaches room temperature. This will take a few hours, depending on how much buttercream you have. You can also microwave it for a quick 30 seconds (or a little bit longer or shorter, depending on how much buttercream you have) until it is soft, but not liquid. Place the buttercream in the bowl of a stand mixer and beat until it is smooth again, around 3-5 minutes.

Recipe adapted from Martha Stewart.