This entire post is dedicated to my favorite buttercream of all time, the Swiss Meringue. This is my favorite not only because it looks the silkiest and smoothest out of all the buttercream versions, but because it isn’t as sweet the others. The base of this buttercream starts with egg whites. Lots and lots of egg whites.
Separate 10 egg yolks and egg whites, placing the whites into the bowl of a stand mixer and the yolks into a tupperware container filled with water so it can be saved for later use.
Measure out the sugar and add it into the bowl.
Over a double boiler on low heat, begin to whisk the egg whites and sugar. Be careful and keep the mixture moving as you do not want the heat to actually cook the egg whites and make an egg white scramble. Continue to gently whisk the mixture until you can pinch the warm liquid and do not feel any more grains of sugar.
Strain the mixture to remove any lumps in case any egg whites cooked. Return to the stand mixer bowl.
Begin to whip the meringue on high speed, trying to get it to cool. I placed a cold tea towel around the bowl to help it cool down faster.
Once it reaches a neutral/cooler temperature and is thick and glossy, you can slowly begin to add the butter a little at a time.
At first, the mixture will look soupy and deflated. Continue to add in the butter as you whip.
As you add the butter in, there is a possibility it may look like cottage cheese. This generally happens if the butter was added too early in the process when the mixture was not cool enough, but don’t worry, keep on mixing! The buttercream will quickly come together into this smooth and silky texture, ready to use!
Swiss Meringue Buttercream
recipe from Sweetapolita
10 egg whites
2 1/2 c sugar
3 c butter, cubed and cold
1 1/2 Tbsp vanilla extract
Over a low simmering double boiler, gently whisk the egg whites and sugar. Be careful to not allow any of the egg whites to cook to become an egg white scramble! When you are able to pinch the warm mixture and not feel any of the sugar grains, it is ready. Strain the mixture through a sieve into a stand mixing bowl to remove any cooked egg whites. Move the bowl over to the stand mixer and begin to whip until the mixture is at a neutral-cool to the touch. It helps to wrap the outside of the bowl with a cool tea towel to speed up the process. It can take anywhere from 7-15 minutes, depending on the temperature of your kitchen.
When it is cooled, slowly begin to add in the butter. Continue to mix it on high. It will go through different stages of soupy, then curdled (like cottage cheese), then finally, silky and smooth! If it takes too long between the curdled and silky stage (more than 5 minutes), place the bowl into the refrigerator for 10-15 minutes for the buttercream to firm up. Once it reaches the final stage, add in the vanilla, whip, then it is ready to be used however you like!