Coffee Swiss Meringue Buttercream

Ingredients

• 10 g (1 1/2 Tablespoon) instant coffee granules
• 30 g (2 Tablespoons) warm milk
• 5 large egg whites
• 250 g (1 1/4 cup) granulated sugar or soft brown sugar
• 340 g (1 1/2 cups) unsalted butter, room temperature, cut into cubes
• 1 teaspoon vanilla paste or extract
• 1/4 teaspoon of salt

Instructions

1. 1

   Dissolve the instant coffee in warm milk in...: Dissolve the instant coffee in warm milk in a small bowl and set aside.

2. 2

   Bring a medium saucepan with 1-2 inches of...: Bring a medium saucepan with 1-2 inches of water to a simmer.

3. 3

   Combine egg whites and granulated sugar in the...: Combine egg whites and granulated sugar in the metal bowl of a stand mixer or other metal bowl. Balance the bottom of the bowl over the simmering water. Whisk continuously as the egg whites warm up, ensuring all the sugar has dissolved or the temperature reaches 160°F (71°C) on an instant-read thermometer. Be sure to keep stirring to prevent any egg whites from overcooking on the edges of the bowl.

4. 4

   Once the sugar has dissolved, place the bowl...: Once the sugar has dissolved, place the bowl in your stand mixer fitted with the whisk attachment. Beat on medium-high speed until the stiff peaks form and the meringue cools to room temperature.

5. 5

   Next, gradually add the softened butter to the...: Next, gradually add the softened butter to the meringue, a few pieces at a time, with the mixer still on medium-high speed.

6. 6

   At this stage, the frosting may appear to...: At this stage, the frosting may appear to separate or curdle – don't panic! Just continue beating the mixture until it becomes a thick and cohesive buttercream. This process can take time, so don't give up if it seems slow - it will come together.

7. 7

   Once the mixture is thick and cohesive, beat...: Once the mixture is thick and cohesive, beat in the coffee mixture, vanilla, and salt until the frosting is thick and fluffy. At first, the coffee will look like it doesn't want to mix into the frosting, but it will.

8. 8

   Switch to the paddle attachment and beat on...: Switch to the paddle attachment and beat on low for 10 minutes to knock out the larger air bubbles in the buttercream.

9. 9

   The frosting can be made in advance and...: The frosting can be made in advance and stored in the refrigerator or freezer. It will need to be re-whipped before using. See the notes below.