Italian meringue buttercream is the ultimate light and silky-smooth frosting for cakes, cupcakes, cookies, and more. My favorite of all the buttercreams, it is unfortunately known to be the “intimidator.” But with the tips outlined here in this post, there is no reason for you to be shrieking away from this satiny, lightly sweetened buttercream any longer!

Italian buttercream is a mixture of sugar, egg whites, and butter. Although it is known as the most difficult of buttercreams to make, it is the most stable. A standard ratio for buttercream is one part egg, two parts sugar, and three parts butter.

Questions About Italian Meringue Buttercream: Answered

Why is my buttercream curdled?
- The buttercream may curdle at some point, especially when adding the butter to the meringue. Continue adding more butter until it comes together.
- The butter needs to be at room temperature. If your butter is too hot, the buttercream will become soupy. If the butter is too cold, the buttercream will curdle.
Why is my buttercream soupy?
- The butter needs to be at room temperature.
- Under-beating the eggs before adding the sugar.
- The sugar mixture needs to come to 240° F.
- Having any grease or water on the bowl or beaters.
- Use room temperature eggs.
Can I fix deflated buttercream?
- Place the buttercream in the refrigerator for 15-20 minutes then beat it again until it becomes smooth.
Why does buttercream have so many air bubbles?
- Whipping the buttercream at too high of a speed will incorporate too much air and cause air bubbles.
Why is the Italian buttercream grainy?
- Do not stir the sugar water mixture when bringing to temperature.
- Make sure to add corn syrup to help prevent crystallization.
Why did the buttercream break?
- Adding the butter too quickly will make the buttercream break. Add one to two tablespoons at a time.

How to make Italian Meringue Buttercream

Have the eggs and butter at room temperature. If you forgot to take the butter out, do not melt it, wait until the butter comes to room temperature. If you forgot to take the eggs out of the refrigerator, place them in a bowl of hot water for five minutes.

Set up a double boiler and have the water at a simmer. Cut the butter into one tablespoon portions.

Add the sugar to the top of the double boiler, then add the water and take a spatula or clean finger and gently mix them together, keeping the sugar away from the sides of the pot. Add the corn syrup. Place the thermometer in the mixture and bring to 240° F. DO NOT STIR.

In a stand mixer with a whisk attachment, mix the egg whites and cream of tartar, whip until a soft peak.

Remove the sugar mixture from the heat and very slowly and steadily start adding the sugar mixture to the egg whites with the beaters running at a slow speed. Pour the sugar mixture down the side of the mixing bowl and not directly into the egg mixture. As soon as the sugar is all added, turn the speed up to medium high and whisk until the bottom of the bowl has cooled. This may take 10-15 minutes.

Once the meringue has completely cooled, begin adding the butter one or two tablespoons at a time. Once the butter is all added, add the shortening and any flavorings or extracts. Continue to whip for about 5 minutes or until you hear a hollow slapping.

Reusing Buttercream

You can leave the buttercream out at room temperature for up to three days. If doing so, I recommend placing plastic wrap directly on top of the buttercream to help prevent the growth of bacteria and the possibility of it turning rancid, especially in hot conditions. Use a paddle attachment to cream the buttercream before re-using.

Buttercream can be frozen for three to six months. Store in an air-tight container. When ready to use, bring to room temperature and re-whip.

Why Choose Italian Meringue Buttercream

Italian Buttercream is especially great for making super sharp edges on cakes.
It holds up well in humid and hot conditions.
This buttercream has a silky-smooth texture with a hint of butter flavor that is lightly sweetened.
Has a nice white sheen.