Italian Meringue Buttercream refers to a type of frosting made from sugar, egg whites, and butter. It’s light, fluffy, and never cloying. This recipe includes options for vanilla, chocolate or strawberry buttercream, as well as suggestions for additional flavors.
Place the sugar, water and corn syrup in a medium-sized saucepan (do not stir). Cover and turn the heat to high. Once the liquid begins to simmer and steam develops, remove the cover (this helps prevent crystallization). Using a digital or candy thermometer, cook the sugar to the soft boil stage, 235-245 degrees F.
While the sugar is cooking, whisk the eggs on high in a stand mixer fitted with the whisk attachment, until a soft peak has formed.
Turn the mixer speed down to medium-low and very slowly pour the syrup down the side of the bowl into the egg whites (this will “cook” the egg whites, making them safe to consume. Don’t pour the hot syrup directly into the meringue or you’ll have scrambled egg whites.
Once the syrup is completely incorporated, turn the speed to high. The meringue will continue to form a stiff peak as it cools down. Mix on high until the meringue comes to room temperature, approximately 15-20 minutes.
Once at room temperature, slowly begin incorporating the soft butter on medium speed. Once all of the butter has been added, turn the mixer speed up to medium-high and slowly add the vanilla and any additional flavors (see variations).
If not using immediately, store the buttercream in an airtight container in the refrigerator, then bring to room temperature before using. Briefly whisk or place back in the stand mixer with the whisk attachment to make sure it’s nice and fluffy before frosting. Buttercream can also be frozen for up to 3 months (I like using gallon sized freezer bags).
This recipe yields enough buttercream to frost one 8 or 9-inch triple layer cake.Corn syrup is optional in meringue buttercream. It helps prevent the sugar syrup from crystallizing.I typically melt small quantities of chocolate in the microwave. Coarsely chop the chocolate and place in a small microwave-safe bowl. Microwave in 20 second increments, stirring each time, until the chocolate is smooth and shiny. Cool to room temperature, stirring periodically.I recommend using gel food coloring, which has a much more vibrant color with only 1-2 drops. It's available online and in specialty shops.Meringue buttercream can take a decent amount of additional liquid for flavoring, up to 1/4 cup. The key is to add slowly and make sure the ingredients are at room temperature to avoid breaking the buttercream.Additional flavor ideas:
Other fruit purees or nectars! Don't use anything sweetened.