As much as I love a good meringue buttercream I must confess... I haven't made one in years. I know, I know! For a serious baker and culinarian, that's kind of crazy. But I have a good reason. In culinary school we literally had to make Swiss and Italian meringue almost every class while taking the cake decorating course. The thermometers had to be temped, the butter had to be cut, and the double boilers had to be rolling. I grew a serious appreciation for the buttercream, especially now. But I can't deny - the process is tedious!
In my opinion, there is no buttercream rose like a rose piped from a meringue frosting. The combination of egg whites and sugar bring a gloss and sheen that cannot be duplicated. So let me break it down; The two most commonly used meringue buttercreams are Swiss and Italian. In a Swiss meringue buttercream, pasteurized egg whites and sugar are heated over a double boiler to 160 degrees then whipped until fluffy and the bowl is cool to the touch. At that point butter and shortening are slowly incorporated and whipped until fluffy. In Italian meringue buttercream, you start by whipping egg whites and cream of tartar. Meanwhile, sugar and water is brought to a temp of about 235 degrees. That mixture is then drizzled into the egg whites, and whipped until the bowl is cool to the touch, lastly adding in pats of butter.
Both recipes very similar, and pretty tedious. One wrong temperature and your entire buttercream is thrown off - TRUST ME I can't tell you how many cartons of eggs I've gone through in my earlier years of baking, but it's all a part of the game. Needless to say, this MOCK meringue buttercream cuts out a lot of the finicky stuff, and still gives you a wonderful result. This is a perfect frosting for those who don't like overly sweet buttercreams, and can appreciate a silky texture.
A few tips:
It is 100% detrimental that you only use pasteurized eggs. This is a no-cook method. I have to say as a baker and a now Certified Food Protection Professional, consuming raw eggs can cause serious harm to your or a loved one. I can't stress this enough.
Everything should be brought to room temperature and butter should be cut into pats.