Swiss Meringue Buttercream Frosting

Swiss meringue buttercream frosting is silky smooth, not too sweet and pipes beautifully onto cakes and cupcakes. This frosting is surprisingly light in texture, but holds its shape perfectly. Learn all the tips and tricks to making perfect Swiss meringue buttercream!

Prep Time45

Total Time45

Course: Dessert

Cuisine: Swiss

Keyword: Swiss Meringue Buttercream Frosting

Servings: cupcakes

Author: Fiona Dowling

Ingredients

6 large egg whites discard the yolks
2 cups granulated sugar (400 grams)
2 cups unsalted butter (454 grams) softened but not starting to melt or become greasy - I only take the butter out of the fridge once I take the meringue off the heat
2 teaspoons vanilla extract
1/2 teaspoon salt

Instructions

Prep

Separate the eggs. This is easiest to do when cold. I recommend separating the eggs about 20 minutes before getting started.
Wipe down your bowls, whisk and whisk attachment with vinegar to ensure that there is no residue from butter or oil. Dry thoroughly with paper towel or fresh dish cloth (do not use a dish cloth that you have previously used - as it may reintroduce grease into the bowl).

Make the Frosting

Whisk together the egg whites and sugar in a bowl.
Transfer the bowl to over the top of a saucepan over low to medium heat with about 1/2 to 1 inch of simmering water in the pan. Ensure that the bottom of the bowl is not touching the water. Gently whisk for about 4-6 minutes, or until there are no sugar granules remaining. When you rub the hot mixture between your fingers, you shouldn't feel any granules. It should reach 160F or 70C on a candy thermometer.
Take the butter out of the fridge and cut into cubes (about 1-2 tablespoons each). Transfer the mixture to the bowl of your stand mixer with the whisk attachment. Start on a low speed and gradually increase to medium speed. Whisk for about 10-20 minutes, or until stiff peaks are formed. If you lift the whisk attachment out of the bowl - the meringue should stand straight up. If it drizzle or flops over - you aren't done whisking yet.
Ensure the meringue and bowl are no longer warm to the touch. Change the mixer to the paddle attachment. Beat in the butter one cube/nob at a time. Do not add the next nob of butter until the previous has been incorporated.
Then mix in the salt and vanilla extract.
If you frosting is too thin/soupy - place the bowl in the fridge for about 20 minutes, then continue mixing. If the frosting starts to curdle (ie look like cottage cheese) - place it back over the simmering water for about 30 seconds or until the sides are just starting to melt. Then beat on a low speed until smooth. You may need to repeat this process a few times.

Notes

Yield: This frosting recipe makes enough for:
- 24 cupcakes with a generous amount of frosting
- 9-inch layer cake
- 8-inch layer cake - you will have some leftover if you only do a 2 layer cake
Mixers: This recipe can be made without a stand mixer, however it will take much longer for stiff peaks to form. You will also need a very large bowl.
Storage: Store frosted cakes and cupcakes covered at room temperature for up to 1 day. Leftovers can be stored in the fridge for up to 4 days. Frosting can be frozen in an airtight container for up to 3 months. Thaw in the fridge. Then place on the kitchen counter at room temperature for about 30 minutes.
Humidity: Like all frosting recipes - heat and humidity will impact the results. I do not recommend ever making frosting on a hot and humid day if you do not have air conditioning or wish to have it turned on.
Nutrition: Details provided are an estimate only and based on the frosting being divided between 24 cupcakes (not including the cupcake)

Nutrition