Italian Meringue Buttercream

Italian Meringue Buttercream is a creamy, rich-yet-fluffy frosting made by incorporating a hot sugar syrup into beaten egg whites, then gradually adding butter until it all comes together. Less dense and sweet than a traditional American-style buttercream—which is made primarily with butter and powdered sugar—it spreads beautifully onto cakes, cupcakes, and other baked treats. It also holds up better in warmer temperatures than other types of buttercream, making it an ideal option for outdoor parties. Though it may sound intimidating, with the right equipment and instructions, it’s easier than it looks and produces an all-around great base to dress up with additional flavors and colors.

Ingredients for Italian Meringue Buttercream

Sugar: You'll need white granulated sugar for this recipe. A mixture of the sugar and water is boiled until it reaches what is known as the "soft-ball stage," which means that if a drop of the mixture were added to a bowl of cold water, it could be rolled into a soft ball. At this point, enough water has evaporated to reach a certain concentration of sugar suitable for making fudge, fondant, pralines, and, of course, meringue.

Cream of tartar: This white, powdery substance is a byproduct of winemaking. It is often used to stabilize whipped egg whites and keep them from deflating, though it can also be used to add tanginess to a recipe, stabilize whipped cream, and retain the color of boiled vegetables.

Egg whites: This recipe calls for five egg whites, which are whipped until stiff (with a little help from the cream of tartar above). To separate egg whites, use two egg shells, an egg separator, or your hands. Use up leftover egg yolks to make an emulsified sauce like mayonnaise or aioli, spaghetti carbonara, or as an egg wash for baked goods.

Butter: The final step in making our Italian Meringue Buttercream recipe is to beat in cold, unsalted butter bit by bit until a smooth and creamy frosting forms. We recommend cutting the butter into small pieces to make it easy to add gradually, then popping it back into the refrigerator until ready to use. This will help ensure it stays nice and cold and doesn't melt when added to the other ingredients.

Equipment for Italian Meringue Buttercream

For Italian meringue buttercream success, it's crucial to have the following pieces of equipment at the ready:

Small saucepan: You'll need a small saucepan (ideally 1-quart in size) to boil the sugar syrup on the stove. Using too large of a saucepan for this step will make it difficult to get an accurate temperature reading, so use the smallest one you have.

Candy thermometer: A candy thermometer is essential for knowing when the sugar syrup you're cooking for the meringue reaches the appropriate temperature. While you can also use an instant-read thermometer for this step, we don't recommend using an analogue meat thermometer as it is not designed to reach such high temperatures.

Electric mixer: You'll need to use an electric mixer to whip the egg whites while drizzling in the sugar syrup, and then subsequently incorporating the butter. A stand-mixer is ideal as it will free up both your hands, but a handheld mixer will also work. We do not recommend trying to make this recipe by hand.