This Swiss meringue buttercream recipe is a dream. It is creamy, smooth, not-too-sweet, and whips up light, airy, and luscious. A perfect accompaniment to cakes and cupcakes!
2cupsunsalted butterat cool room temperature and cut into tablespoon-size pieces
2teaspoonsvanilla extract
Pinchsalt
Instructions
Place the egg whites in a heatproof mixing bowl (the bowl of your stand mixer would be ideal, but another heatproof bowl will work). Fill a medium saucepan with 1 to 2 inches of water and place over medium-low heat for a slow simmer.
Add the sugar and whisk together. Place the bowl over the saucepan and whisk constantly until the sugar is completely dissolved and the mixture reaches 160 degrees F on an instant-read thermometer. This can take anywhere from a few minutes up to 10 minutes.
Remove the bowl from the saucepan and place on your stand mixer fitted with a whisk attachment (you can also use a hand mixer if that’s all you have). Whip on medium-high speed until stiff, glossy peaks form, about 10 to 15 minutes. (If you have stiff peaks but your bowl or the meringue is still warm to the touch, place the bowl in the refrigerator for 10 minutes or so to cool down before you add the butter.)
Switch to the paddle attachment and beat on medium-high speed while adding the butter one piece at a time, waiting for each piece to fully incorporate before adding the next.
Once all of the butter has been incorporated, reduce the mixer speed to medium and add the vanilla extract and salt. Beat for 30 seconds, stop and scrape down the sides and bottom, then beat for a final 30 seconds.
The Swiss meringue buttercream can keep at room temperature, covered, for up to 2 days, or in the refrigerator for up to 5 days.
Notes
Yield: This recipe makes approximately 5 cups of frosting. This is enough to fill and frost a 9-inch layer cake, to frost a 9x13-inch cake, to lightly frost 24 cupcakes, or generously frost 12 cupcakes.
Does SMBC harden? No, this type of buttercream will not form a "crust" as traditional American buttercream does. You can use this frosting for piping detail, filling cakes or cookies, and can even be used underneath fondant.
How does it hold up in the heat? Like most butter-based frostings, this is fine at room temperature but will begin to get quite soft once you hit 80 degrees or so, and once you get much warmer than that, it can melt.
Chocolate Swiss Meringue Buttercream - To make a chocolate version, I use the same method from my favorite chocolate frosting - melt and cool 8 ounces of semisweet chocolate, then beat it into the buttercream when you add the vanilla and salt.
More Flavors - I recommend keeping 1 teaspoon of the vanilla and then swapping out the other teaspoon for another extract flavor, if you desire.
Coloring the Frosting - Tinting this buttercream is easy! I recommend gel food coloring always so as not to introduce too much extra liquid (I use and recommend this AmeriColor soft gel color set); add it on low speed after you beat in the vanilla and salt.
Make-Ahead and Storage Instructions - You can keep the frosting at room temperature for a few. hours after making it before using it. After that, it can be refrigerated in an airtight container for up to 1 week; be sure to re-whip before using it to get it back to that silky consistency. Baked goods with Swiss meringue buttercream can be left at room temperature, covered, for up to 2 days.
Freezing Instructions - Swiss meringue buttercream can be frozen in an airtight container for up to 6 months. Thaw overnight in the refrigerator then re-whip to achieve a smooth consistency.