Crusting buttercream is a special type of frosting that can be applied smoothly and dries to a harder consistency than typical frosting. Crusting buttercream is an excellent alternative to fondant when cake decorating, which many people think has an odd flavour and texture. With crusting buttercream, you get all of the flavour of more traditional frostings while still achieving a smooth, even surface for decorating.
Traditional Crusting Buttercream
This type of crusting buttercream is close to noncrusting buttercream frosting recipes. This recipe uses butter, shortening, icing sugar and water to create a crusting buttercream that is firm enough to make decorative flowers with. Start by blending together a stick of room-temperature unsalted butter and 1 1/2 cups of shortening. Alternate adding 0.907kg. of sifted icing sugar and 1/4 cup of water. Frost your cake, and let it sit for 10 to 15 minutes. Then use a paper towel to smooth out the frosting.
Flour-Based Crusting Buttercream
This recipe differs from other buttercream recipes in that it uses flour to stabilise the frosting and give it a firm but spreadable consistency. Start by creaming together 1 1/2 cups of shortening and 1/2 cup of plain flour. Then alternate adding 0.907kg. of sifted icing sugar and 1/4 cup of very hot water. Frost your cake, and then smooth out the frosting to get the perfect surface for decorating.
There are dozens of flavour variations that can be used on crusting buttercreams to make them better fit the flavour profile of the cake, although there is certainly nothing wrong with using just the base recipe. Common additions are vanilla extract and almond extract, both of which would be suitable for a number of different cake flavours. There are also fruity extract flavours available such as lemon, coconut, orange, cherry and raspberry. More complex flavour options include butter pecan, rum, bourbon, champagne and mint.
Crusting buttercream frosting can easily be coloured to suit your needs with the right combination of food colouring. The key to colouring your frosting is to add a drop or two of food colouring at a time until you achieve the right colour. You can always add more, but there is no way to fix going too far. Depending on your decorating plans, you may prefer a completely white crusting buttercream. To achieve this, you can use colourless butter, which can be purchased at health food stores, and if you add any flavour extracts, make sure they are clear.