Perhaps my favorite feature of real buttercreams, aside from their fundamental deliciousness, is the extent to which they can be manipulated. For the creative baker, there’s virtually no end to it. A complete catalog is impossible, though I’ll do my best to summarize some of the most common variations.
Extracts are obvious, and there are more of them on the market than you might think. All kinds of fruit and candy flavors are available, though to my mind very few of them are truly great for buttercreams. Exceptions are of course vanilla, then hazelnut, almond, coconut, peppermint, cinnamon, butterscotch, maple, and citrus flavors like lemon and orange (though for a true citrus flavor you’ll want to add some real citrus zest as well, plus maybe a couple of tablespoons of juice).
Liquers and spirits are another natural fit. Add up to three or four tablespoons of just about anything. Classics include kirsch, rum, brandy, bourbon, Amaretto, Kahlua, Grand Marnier and many others.
Then of course there are chocolates of various kinds, in pretty much any combination you can think of. Melted, they can be added to any finished buttercream, up to about six ounces for a French buttercream, eight for a meringue buttercream (in general, the darker the chocolate the better). In that family of flavors is of course coffee. A couple of tablespoons of espresso powder dissolved in a teaspoon of boiling water makes a fabulous coffee buttercream (or mocha when added to a chocolate buttercream).
Fruit flavors are another classic buttercream compliment. I already discussed citrus flavors, but berry purées like raspberry and strawberry work great too. About half a cup does the trick. You can also use jam, but you’ll need to heat it slightly to get it to a pourable consistency.
If you really want to get jiggy widdit, a quarter cup of peanut butter can be added to a recipe of meringue buttercream…though I confess I’ve never tried it (seems a bit much to me).
That’s about all I can think of for the additives — though that’s not even getting into the manipulations of the base ingredients that are possible. You can swap out your sugar syrup and use honey or maple syrup instead, or use brown sugar or maple sugar instead of white. You can supplement your syrups with a few tablespoons of dark caramel or caramel syrup — even molasses. There’s really no end to it.
I should say at this point that while all these ideas will flavor your buttercream, very few will color it in a manner befitting, say, an orange or a raspberry icing. For that you’ll need to add colorings. In my experience (though as I said, I’m no decorator) paste colors provide more intensity, though liquids, especially for the novice, are easier to control.
So then…what are you waiting for? Go nuts!