Italian Meringue Buttercream Frosting

If regular ol' buttercream frosting is crossed with whipped egg whites, then takes a trip to Southern Europe, what do you get?

Italian meringue buttercream frosting (aka Italian buttercream frosting). Yes, I know that was kind of labored, but work with me here.

What is meringue?

In general, a meringue is a mixture of whipped egg whites with sugar. There are three types of meringue: French, Italian, and Swiss. Each type varies based on preparation, texture, and stability.

The easiest type of meringue to make is a French meringue, i.e. egg whites beaten until fluffy and sweetened with sugar. When baked, French meringues are firm, yet fragile and crumbly. French meringues are used in desserts like Pavlova or Eton Mess, and also form the basis for French Macarons.

In Italian meringue, the sugar is boiled into a syrup before adding it to the whipped egg whites. As it's slowly added to the bowl, the egg whites cook, giving the resulting meringue a sturdier structure that's less brittle than French meringue. When baked, Italian meringues have a softer, marshmallowy texture. In fact, Marshmallow Creme (aka Marshmallow Fluff) is a form of Italian meringue. This Italian merigue method can also be used as the base for buttercream frosting.

There's also Swiss meringue, where the egg whites and sugar are slowly heated together so that the sugar dissolves egg whites. Then the mixture is whipped until light and fluffy. It's texture is softer, yet denser than an Italian meringue, and can be used in the same ways as the others. In terms of structure, Swiss meringue falls between the French and Italian versions.

What is Italian buttercream frosting?

So we've talked about the Italian meringue, now it's on to buttercream frostings.

The easiest frosting to make is a buttercream frosting (aka American Buttercream). That's just butter that's been whipped until it's light and creamy, then sweetened with powdered sugar. Flavored with vanilla extract, and you get vanilla butter frosting. Adding melted chocolate gives you chocolate buttercream frosting, which is a dream unto itself.

So why do you need to go to the extra trouble of making an Italian meringue first?

Well, while American buttercream is luscious, it can also be cloyingly sweet, and even gritty if the sugar isn't fully incorporated into the butter.

With an Italian meringue buttercream recipe, the meringue adds its sweetness without being overpowering, resulting in frosting that's smooth and creamy without being overly sweet. Also, the sugar is cooked in, so there's no risk of grittiness at all.

How to make Italian meringue buttercream

The method for making an Italian buttercream frosting recipe goes in two stages, make the Italian meringue, then beat in butter.

For an Italian meringue, you need to work concurrently to heat the sugar syrup and beat the egg whites. Ideally you want the whites to be whipped to stiff peaks just as the syrup comes to temperature.

Step 1: Make the sugar syrup

As with making caramel, sugar can crystalize if stirred while boiling. Give the sugar and water a quick stir just to moisten the sugar, then leave it to boil.

Heat the sugar syrup to firm-ball stage, between 248°F to 250°F (photo 1). It's best to use a digital thermometer or candy thermometer to be precise. If the syrup is done before the meringue is ready, add a very small amount of hot (not cold) water to lower the temperature slightly.

Step 2: Whip the egg whites

As soon as the sugar syrup starts to boil, it's time to start whipping your egg whites. When they're fluffy, add the cream of tartar and 1 tablespoon of sugar, then whip them to stiff peaks (photo 2).

Don’t overwhip or the meringue can start to separate. If it’s ready before the sugar is to temperature, turn the mixer to the lowest speed and let it continue to run.

Step 3: Slowly stream in sugar syrup

When the syrup and meringue are both ready, pour the hot syrup into the meringue in a thin, steady stream along the side of the bowl while the mixer is running (photo 3). This is now Italian meringue, and will be beautifully thick and glossy.

Continue beating until the bottom of the bowl feels cool to the touch. The meringue needs to be completely cooled before adding in the butter.

Step 4: Add the butter and flavoring

Italian buttercream is an emulsion, like Hollandaise sauce or Caesar dressing. You need to achieve a stable mixture of fat and water. In this case, you want the butter to be at room temperature so it will mix in easily, but not too soft that it melts before it's incorporated.

After the meringue has cooled completely, slowly add the butter two tablespoons at a time (photo 4). Make sure the butter is almost completely incorporated before adding more.

Flavoring your Italian Buttercream

After all the butter is added and the frosting is smooth, add your flavors and colors. If you want to color your buttercream, gel food coloring works best so you don't water down your frosting.

Here are some flavor ideas to try...

• Vanilla: 1 tablespoon vanilla extract
• Chocolate: 1 cup (170g) melted chocolate or chocolate ganache
• Lemon: ¼ cup lemon curd or 2 tablespoons lemon juice with 1 teaspoon vanilla extract
• Mint: 1 teaspoon mint extract
• Vanilla Orange: 1 teaspoon Fiori di Sicilia or to taste
• Coffee: Dissolve 1 tablespoon of espresso powder in 2 teaspoons boiling water and let cool.
• Kahlua or another liqueur: 2 to 4 tablespoons or to taste. Remember though, the buttercream is no longer kid-friendly.

Questions asked and answered

Here are some questions that you might have...

Pro Tip: Troubleshooting Buttercream

Even if you're really careful and precise while making an Italian buttercream recipe, things can go wrong.

I'm of course not speaking from personal experience. ( * cough * )

Here are a couple of tips for correcting any mishaps.

• If the buttercream looks curdled or runny, the butter has melted because the meringue is too warm. Place the mixing bowl in the refrigerator for about 15 to 20 minutes, then return to beating until the buttercream is smooth.
• If the butter doesn’t mix well into the meringue, either the butter or the meringue are too cold. Hold a heating pad set to medium-high onto the bowl while beating. You can also use a hair dryer set to warm, blowing around the bottom of the bowl.

It's worth the effort

Italian meringue frosting is creamy on the tongue, but doesn't feel like your tongue is coated in butter. Sweet but not cloying, it will enhance whatever you're using it for.

Here I've spread Vanilla Italian buttercream on a simple chocolate cake that's been filled with Chocolate Italian buttercream. It's a blank canvas just waiting for decoration.

Silky smooth, easy to spread and pipe, this frosting is perfect for your next cake, batch of cupcakes, or as a filling for macarons.

Italian Meringue Buttercream Frosting is greater than the sum of its parts!