Looks a lot like Italian meringue buttercream doesn’t it? In fact it is very similar, though a bit denser. Like Italian buttercream, it’s excellent both for spreading and piping, since (as you can see) it stands up quite well on its own. The advantage SMBC has over IMBC is that it’s somewhat easier to make, nearly as sturdy and 100% food safe. The formula goes like this:
4 egg whites
1 cup sugar
1/4 teaspoon cream of tartar
1 pound soft unsalted butter
Begin by combining the whites, sugar and cream of tartar the top of a double boiler set over simmering water.
Give them a good whippin’ with a whisk to combine them, and keep it up intermittently while the mixture warms.
In about 5-7 minutes’ time, your mixture should have reached 160 degrees Farhenheit (don’t worry, your whites won’t cook, the sugar will keep all those little proteins from clenching up). What’s so important about this temperature? It’s the degree at which Salmonella bacteria are killed.
So then, having created your egg white “syrup”, pour the contents of the double boiler into the bowl of a stand mixer fitted with a whip.
Turn the mixer on high. In a few minutes the mixture will turn white and start to build up into a foam.
In about 6-8 minutes, the meringue will come to stiff peaks, about like so:
Now then, all you need to do is add the butter. Switch to the paddle (beater) attachment and turn the mixer to medium high. Beat in the butter a piece at a time.
Ah yes! Here it is, the grainy “curdled” texture I was telling you about in my Italian meringue buttercream post. My butter pieces were a little cool in the center, and now I’m paying the price with this chunky, almost cottage cheese-looking buttercream.
No matter, just turn the machine up to high and beat those curdles right on out.
Much better. Again, this is the point where you incorporate your flavors and/or colors. A teaspoon or more of vanilla should again be your starting point. After that the sky is pretty much the limit.