Swiss Meringue Buttercream with Variations
This ultra-smooth buttercream is our go-to frosting, especially for piped designs.
- Yield: Makes about 6 cups
Source: Martha Stewart Living Special Issues
- 1 1/2 cups sugar
- 6 large egg whites, room temperature
- 2 cups (4 sticks) unsalted butter, room temperature, cut into pieces
- 1 teaspoon pure vanilla extract
Whisk together sugar and egg whites in a heatproof mixing bowl set over (not in) a pan of simmering water. Whisk until warm and sugar is dissolved (mixture should feel completely smooth when rubbed between your fingers), 2 to 3 minutes. Remove from heat.
With an electric mixer on medium speed, whisk egg-white mixture 5 minutes. Increase speed to medium-high, and whisk until stiff, glossy peaks form and meringue has cooled (test by feeling bottom of bowl), about 6 minutes.
Reduce speed to medium. Add butter, 1 piece at a time, beating well after each addition. Beat in vanilla. Buttercream can be refrigerated up to 3 days or frozen up to 3 months in an airtight container. Bring to room temperature and beat on low speed until smooth before using.