How is it different from the traditional buttercream? Well, the traditional buttercream has a soft crunch to it because of the inclusion of icing sugar. However, Swiss Meringue buttercream has a very light, airy and slippery kind of texture. It just dissolves in your mouth and yes, it has a lot of butter. It is a very good choice for piping since it remains stable at room temperature.
For Swiss Meringue Buttercream, a candy thermometer makes life easier since you need to heat up the egg whites and the sugar till it reaches 80 degrees C. However, if you do not have one(like me), this buttercream can still be made very successfully. Just ensure that you read and follow the steps carefully. This was my second attempt at making this frosting since the first one failed miserably.
NOTE: The leftover cream can be frozen for upto a month. Before using, bring it to room temperature and beat with the paddle attachment on low speed until smooth again, about 5 mins.
Makes enough buttercream for piping 24 cupcakes.
185 grams / 6.5 ounces egg whites
240 grams / 8.5 ounces granulated sugar
450 grams / 16 ounces unsalted butter(yes 450 gm) at room temperature.
60 grams / 2.1 ounces fresh strawberries coarsely chopped and pureed (for the strawberry version)
Combine the egg whites and the sugar in the bowl of a stand mixer and set it over a pan of simmering water.
Whisk constantly until the mixture reaches 80 degrees C / 176 degrees F (on a candy thermometer) and the sugar has dissolved completely.(Note: If you do not have a candy thermometer, constantly whisk and heat the mixture until bubbles start to appear on it and it becomes frothy. Rub a little mixture between your fingers, it should fell warm(not hot) and completely smooth).
Attach the bowl in the stand mixer with the whisk attachment. Starting on minimum and gradually increasing the speed to high, mix until stiff peaks form. Have patience here. For the initial 4-5 mins, it would seem as if nothing is happening but eventually the egg whites start foaming up, the only condition is that you have not under heated or over heated the mixture in which case, you have to start all over again with a new batch of egg whites.
Reduce the mixer speed to low, add the butter and mix.
Do not panic since the mixture seems curdled at one point. Keep mixing and it will eventually come together to form a smooth and delicious looking buttercream. In the photograph below, you can see red puree besides the ready buttercream. It is strawberry puree and after mixing it the result is a Strawberry Meringue Buttercream.