Swiss Meringue Buttercream - Small and Large Batch

Batch for 6-inch double layer cake:                                                          

6 egg whites

1 cup/200g sugar

Pinch of salt

1 pound unsalted butter, cubed, softened (room temperature works too, but takes longer to come together)

3 teaspoons clear vanilla extract

Large batch (make once for 3-4 large tiers, or make 2-3 times for many-tiered cakes):

12 egg whites

2 1/2 cups/500g sugar

1/4 tsp salt

5 cups unsalted butter, softened

1 tbsp clear vanilla extract

  1. Set a saucepan filled one-third full of water over medium-high heat and bring to a simmer.
  2. Whisk together the egg whites, sugar, and salt in a large heatproof bowl ( I suggest a stainless bowl). Set over the simmering water and whisk until the mixture is hot to the touch and the sugar has dissolved (120-140 degrees on a candy thermometer, to be sure).
  3. Transfer the mixture to the bowl of a stand mixer fitted with the whisk attachment.
  4. Beat on low speed for 2 minutes. Increase to medium-high until stiff peaks are formed.
  5. Continue beating at medium-high speed until the mixture is fluffy and has cooled (the mixing bowl should feel cool to the touch).
  6. Turn the mixer off and switch from the whisk attachment to the paddle. Turn the mixer on medium-low and add the butter, a few cubes at a time, beating until well incorporated before the next addition.
  7. Add the vanilla extract.  Divide batter and tint with food coloring, if desired.  
  8. Beat until the frosting is thick and completely smooth.
  9. Store in an airtight container until ready for use.