Swiss Meringue Buttercream

Heating the Egg White Mixture

Notes: It is essential to have a clean and dry bowl for this step. The egg whites cannot contain any egg yolk. If your equipment or bowl has grease on it, wipe it down with lemon juice or vinegar. Make sure the water in the pan does not touch the bottom of the bowl.

Ingredients

5 egg whites at room temperature

1 ½ cups granulated sugar (300g)

1 pinch kosher salt

Instructions

Add egg whites, sugar, and salt to a large bowl.

Give the mixture a brief whisk.

Place the bowl over a pan of simmering water.

Whisk the egg whites occasionally while it warms up. When the mixture has warmed, whisk it constantly until it reaches an internal temperature of 160ºF or is not grainy when rubbed between your fingers.

Whipping the Meringue

Notes: It's important that the mixture cools completely to room temperature before adding the butter in the next step. The goal is to achieve glossy, stiff peaks.

Instructions

Transfer the hot bowl to a stand mixer.

Mix with a whisk attachment on high speed until you get room temperature glossy peaks.

Finishing the Buttercream

Notes: It is entirely normal for the buttercream to look soupy or curdled after adding the butter. Continue to whip, and it will come together. If it stays curdled after 10 minutes, you can warm the edges of the bowl over the simmering water for a moment before continuing to mix.

Ingredients

2 cups unsalted butter (452g), at room temperature

1 tsp vanilla extract

Instructions

Switch to the paddle attachment.

While the mixer is running on low, add tablespoon-sized dollops of room temperature butter, letting each piece incorporate before adding the next.

Once all the butter is incorporated, add the vanilla extract and whip until combined and smooth.

Use immediately, or transfer to a piping bag or ziptop bag to store in the refrigerator or freezer.