Have you ever tasted a cake or cupcake from a bakery and wondered how they got their frosting to be so incredibly light and fluffy? It's highly likely the bakers were using a meringue buttercream. Many buttercream recipes geared toward home cooks use butter and confectioners' sugar. While this is an easy, foolproof technique, the results are often extremely heavy, cloying, and overly rich. Meringue buttercream uses plenty of butter, but it also uses egg whites that have been whipped into an airy, delicate meringue. It's a slightly more advanced recipe, but it is so worth learning how to make it. Once you learn how to make an Italian meringue buttercream, you'll never want to use anything else.
This recipe yields enough buttercream for a triple layer cake.
Things You'll Need
5 large egg whites
1 1/2 cups granulated sugar
1/4 cup + 2 tablespoons water
1 pound unsalted butter, cubed and at room temperature
Optional: food coloring, flavoring such as extracts, liqueurs, melted chocolate
Do not use egg whites sold in a carton for this recipe. Use only fresh egg whites, preferably pasteurized.
Step 1: Beat the eggs to a soft peak.
Place the egg whites in a stand mixer fitted with the whisk attachment. Begin mixing on medium speed to form a soft peak (there's no need to rush this process).
Step 2: Cook the sugar syrup to the soft boil stage.
Meanwhile, place the sugar and water in a small saucepan. Cover, and turn the heat to medium-high. Remove the cover once steam has formed (this will help prevent the sugar from crystalizing). Clip a thermometer to the side of the pan, and cook until the syrup reaches the soft boil stage, 235 to 240 degrees F.
Step 3: Slowly add syrup to the egg whites.
Carefully and slowly pour the syrup down the side of the mixing bowl to incorporate it into the egg whites as they mix. Working slow will prevent the eggs from scrambling. This step cooks the eggs to make them safe for consumption.
Step 4: Mix on high speed while the meringue cools.
Turn the mixer to high speed. Continue mixing until the meringue reaches room temperature, approximately 15 to 20 minutes.
Step 5: Slowly add the butter.
Once the meringue has cooled, turn the mixer to medium. Slowly add the butter, one piece at a time, periodically scraping down the the bowl. Again, patience is key. Note: the meringue will deflate slightly as you add the butter. This is normal, so don't panic! It will be quite thick once all of that butter is added.
Step 6: Add optional ingredients, if using.
Now is the time to get creative. Meringue buttercreams can take a surprising amount of liquid, at least 3 to 4 tablespoons if you work slowly. Some of my favorite additions include pure vanilla extract, Grand Marnier Liqueur, pureed strawberries, and melted unsweetened chocolate (that has been cooled to room temperature). Make sure that anything you add is at room temperature.
Meringue buttercream is best enjoyed at room temperature; it firms up quite a bit when chilled. You can store buttercream at room temperature for 2 days, in the refrigerator for 1 week, or in the freezer for 2 to 3 months.
Troubleshooting "Broken" or Curdled Buttercream
I've had buttercream break/curdle on me countless times when adding the butter. Don't panic if this happens; it can always be fixed. Meringue buttercream breaks when the temperatures of the meringue and butter aren't properly lining up. This rarely happens if I let the butter come to room temperature overnight as opposed to giving it only a few hours (or using the microwave).
The fastest, most foolproof way to fix broken buttercream is to scoop a couple tablespoons into a small ramekin and microwave it for 7 to 10 seconds. Next, add it back to the buttercream with the mixer running on high speed. You can repeat this process a few times if necessary. That should fix the ingredients and you'll be good to go!