Perfect Swiss Meringue Buttercream

Ingredients

• 6 egg whites (large, approximately 180g)
• 2 cup granulated sugar
• 1.5 cup unsalted butter (softened but still cool, cut into Tbsp size pieces)
• 2 tsp pure vanilla extract
• 0.125 tsp salt

Steps

1. 1

   Make sure all the tools you are using are completely cleaned, dried, and grease-free. A quick wipe with a little lemon juice or white vinegar is very helpful to ensure no residual fat remains.

2. 2

   Separate the eggs one at a time into a small bowl before placing each white into your heatproof mixing bowl. This prevents a single broken yolk from ruining the entire batch.

3. 3

   Whisk the granulated sugar into the egg whites.

4. 4

   Set the bowl over a saucepan filled with two inches of simmering water over medium heat, ensuring the bottom of the bowl does not touch the water.

5. 5

   Whisk the whites and sugar constantly until the sugar is dissolved and the mixture has thinned out, about 4 minutes. The mixture should reach 160°F (71°C) or feel completely smooth (no sugar granules) when rubbed between your thumb and finger.

6. 6

   Transfer the mixture immediately to the bowl of a stand mixer fitted with a whisk attachment.

7. 7

   Beat the mixture on medium-high speed until stiff glossy peaks form and the meringue is no longer warm to the touch, which typically takes 10-15 minutes (or up to 18 minutes on humid days).

8. 8

   If the meringue is not reaching stiff peaks, stop the mixer and place the bowl uncovered in the refrigerator for 10 minutes, then continue beating.

9. 9

   Ensure both the bowl and meringue have cooled to room temperature (around 70°F / 21°C) before proceeding, as warmth will melt the butter.

10. 10

    Switch the stand mixer to the paddle attachment.

11. 11

    With the mixer on medium-high speed, add the softened but cool butter 1 tablespoon at a time, waiting for each piece to fully incorporate before adding the next.

12. 12

    Turn the mixer down to medium speed and beat in the vanilla extract and salt for about 30 seconds until fully combined.

13. 13

    If the buttercream appears curdled or separated after adding butter, place the bowl back over the simmering water for 1-2 minutes until the edges melt, then re-whip on medium-high speed until smooth.

14. 14

    If the mixture is too thin or soupy, refrigerate the bowl for 20 minutes, then beat on medium-high speed until thickened.

Notes

To ensure success, avoid making this on particularly humid days. If the meringue won't reach stiff peaks, it is likely due to a trace of egg yolk or grease on the equipment. The 'melting the edges' trick is highly effective for fixing curdled buttercream and actually results in a creamier texture.

Nutrition per serving

• frosting
• dessert
• baking
• gluten-free
• vegetarian
• cake topping
• base recipe