Italian Meringue Buttercream

This is an absolutely lovely buttercream. It is smooth, light, incredibly soft, and creamy but quite stable. It pipes like a dream and holds up well in warm weather (especially if you make the white chocolate variation in the notes). It is not nearly as sweet as buttercream that is made with confectioners sugar.

It can be a bit fussy if you don’t have the temperature correct. Have all your ingredients at room temperature and read the notes before you begin. The temperature of the butter is especially important (see notes).

Make sure the meringue cools down to room temperature before you add the butter. All that said, this really isn’t as challenging as I make it sound. Make sure the temperature is correct in every step and you will nail this.

4.74 from 19 votes

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Prep Time: 20

Cook Time: 15

Additional Time: 15

Total Time: 50

Servings: -1/2 cups

Calories: 97kcal

Author: Dahn Boquist

Ingredients

⅓ cup water
1-½ cups sugar divided
5 egg whites room temperature
¼ teaspoon cream of tartar
1 pound 2 cups butter, softened but slightly cool
1 teaspoon vanilla extract
¼ teaspoon salt

Instructions

Make the syrup:

Place 1-¼ cups of sugar and the water in a saucepan. Stir to combine then stop stirring.
Bring to a boil over medium-high heat and attach a candy thermometer to the side of the pot. You will let the syrup boil until it reaches between 238°F to 245°F.

Whip the egg whites:

While the syrup boils, place the egg whites and cream of tartar in a mixing bowl. Stir to incorporate the cream of tartar and keep the mixer on low speed.
Keep an eye on the candy thermometer. When the syrup reaches 230°F to 235°F, switch the mixer to medium-high speed to whip the egg whites.
When the egg whites reach soft peaks, slowly add the remaining 1/4 cup sugar and continue beating until they reach stiff peaks.

Pour the syrup into the egg whites:

As soon as the syrup reaches between 240°F to 245°F, remove it from the stove and slowly drizzle the syrup into the meringue. Keep the mixer on medium to medium-high speed while you drizzle in the syrup.
Once all the hot syrup is added, beat the mixture on high speed for 2 minutes.
After 2 minutes, beat on low speed until the mixture comes to room temperature. It can take about 15 to 20 minutes for the mixture to cool down. You can stop the mixer and place the meringue in the fridge but the texture of the buttercream always seems to be slightly fluffier if you keep the beaters going while the meringue cools down.

Add the butter:

Place the mixer on medium speed and add the butter 1 to 2 tablespoons at a time. Beat for about 3 to 5 seconds after each addition. After a few tablespoons of butter, the mixture will start to look thin and sloppy but just keep beating and slowly adding the butter.
When all the butter is added, beat in the salt and vanilla. Continue to beat the buttercream until it is light and fluffy.
At this point, you can use the buttercream as it is or you can add flavorings. See below for variations.

VARIATIONS:

White Chocolate buttercream:

Melt 8 ounces of white chocolate slowly over a double boiler. Let the chocolate come to room temperature then beat it into the buttercream. Since white chocolate has a higher melting point than butter, adding white chocolate to the buttercream will make it more stable in extremely hot weather. Perfect for a summer wedding cake!

Chocolate Buttercream:

Melt 6 ounces bittersweet chocolate, let it cool, then beat it into the buttercream. Adding bittersweet chocolate to the buttercream will make it more stable in hot weather.

Tipsy buttercream (with alcohol):

Add up to 3 ounces of liqueur such as Grand Mariner, Amaretto, Chambord, or Cointreau.

Fruit flavored buttercream:

Add ¾ cup of fruit puree or lemon curd. You can also add 1/2 cup to 3/4 cup of jam or jelly but the buttercream will be slightly sweeter if you use jam.

Notes

This recipe works best if you have a stand mixer but you can do it with a handheld mixer as well, it just takes a bit more coordination.
Make sure the butter is room temperature or about 68°F to 70°F. If your house is warm then don’t let the butter sit out too long or it will get too soft. You will know it is at the right temperature if it is still firm but soft enough to leave an indent if you push your finger into the cube of butter. If the butter is too soft or if the egg whites are too warm when you add the butter, it will not emulsify into the egg whites and it will be a wet, sloppy mess. The correct temperature of your ingredients is essential to success.
Make sure the syrup reaches at least 238°F on the candy thermometer. 240°F to 243° seems to be the sweet spot for the meringue. It can get as hot as 250°F but if it gets any hotter than that then the buttercream will have a grainy texture.
When you drizzle the hot syrup into the meringue, try to keep it from falling on the beaters or it will fling syrup all over the sides of the bowl. If you can’t manage to pour the hot syrup into the meringue without getting it on the beaters or the side of the bowl then stop the mixer, pour a small amount of syrup in, then immediately start the mixer back up for 5 seconds. Continue to stop/pour/beat until you add all the syrup.

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