Since it’s so sweet, it’s hard to add flavors like fruit preserves or caramel to American buttercream. It also tends to be a little grainy, but it has a classic buttery flavor.
The egg whites are safe to eat since you heat them with sugar. Swiss meringue buttercream is a great choice if you want to flavor it with jam, caramel, flavor extracts, or melted chocolate. It’s also perfect for frosting and piping since it’s so smooth.
Italian meringue buttercream is a great choice if you want to prep the cake in advance. The meringue helps stabilize the buttercream so you can frost and store your cake for up to 3 days in advance. [5] X Research source
Let the cake layers cool to room temperature and wrap them in plastic wrap before you stick them in the fridge. You can chill them overnight as long as they’re wrapped well.
You may have heard of a crumb coat—this is just a super-thin coating of buttercream that traps loose crumbs. It also gives your buttercream something to really stick to. If you’re frosting a chocolate cake, you might want to do an extra crumb coat since dark cake crumbs can show up easily in light-colored buttercream.
Remember, you’re covering the cakes that have a crumb coat. If you’ve got a turntable, you can also hold a flat scraper vertically against the side of the cake. Slowly rotate the turntable so the scraper smooths the buttercream.
If you don’t want to buy a cake comb, look for things you already have in your kitchen. Drag the tines of a fork along the sides to make thin ridges or swirl the back of a spoon along the frosting to make fun swoops.
To practice your piping skills, lay a piece of parchment paper on a baking sheet and try out different tips before you decorate the cake itself.
To chill your cake, put it into the fridge without a cover or plastic wrap until the frosting hardens a little. Then, cover it with plastic wrap and refrigerate your frosted cake for up to a day or two. Your cake will dry out the longer it’s in the fridge. While Italian and Swiss meringue buttercreams have egg whites, they’re safe to keep at room temperature since you heated them thoroughly.
Keep in mind that slices of frosted cake won’t last as long since they’ll dry out. If you make your cake in advance, don’t start cutting into it unless you’re ready to serve.
