Swiss Meringue Buttercream

Recipe from Epicurious.com, originally from The Well-Decorated Cake by Toba Garrett

12 oz. (336 g) egg whites (10 large eggs or about 1 1/2 c.)
3 c. (680 g) granulated sugar
3 lbs (1.36 kg) unsalted butter, room temperature
2 Tbs. lemon extract, almond extract, orange extract, or vanilla extract, or up to 3 fl oz. (90 ml) light rum, framboise, pear William, or kirsch

Lightly whisk egg whites and sugar together over simmering water until mixture reaches 140 degrees Fahrenheit or is hot to touch.

Pour hot whites into a room-temperature bowl and whip with a wire whip until double in volume on medium-high speed. When the mixer stops, the meringue should not move around in the bowl. Meanwhile cut up the butter into 2-inch pieces (the butter should be slightly moist on the outside but cold inside).

On your mixer, remove the whip and attach the paddle. Add half the butter into the bowl immediately and pulsate the mixer several times until the meringue has covered the butter completely. To pulsate the mixer, turn it on and off in a jerky motion. This forces the butter on the top to the bottom of the bowl. Add the balance of the butter and pulsate mixer several times. Slowly increase the mixer's speed, starting with the lowest speed and increase the speed every 10 seconds until you reach medium-high speed.

Continue beating until the mixture begins to look light and fluffy. Stop the mixer and scrape the bowl. Reduce speed to low. Add flavoring and continue to beat on low speed for 45 seconds. Then beat on medium-high speed for an additional 45 to 60 seconds.

Leftover buttercream can be placed in plastic containers with lids and kept in the freezer for up to 3 months. Defrost completely (several hours) and rewhip before using.

Yield: 2 1/2 quarts (2.37 L)