Fondant is one of the cake decorator's best friends, a form of icing that can be rolled and shaped rather like modeling clay. Sheets of rolled fondant give cakes an unmatched smooth, velvety finish, and a skilled decorator can turn small pieces of colored fondant into decorative accents that are limited only by the imagination. Fondant's naturally matte surface is one of its few limitations. To give the fondant a sheen, or to give floral decorations a more realistic appearance, you can use steam.
The Virtues of Steam
Steam makes an immediate difference in the appearance of fondant. Instead of its usual soft, matte appearance, steamed fondant displays a slick, shiny surface similar to molded chocolate. If your fondant shows fingerprints, cornstarch or powdered sugar from the rolling process, a quick blast of steam will make all of those disappear. An entire decorated cake can be steamed by putting it in a large countertop steamer, but that glosses the whole cake. Steaming by hand lets you control the entire process.
The implement most cake decorators use is the type of small, electric steamer, the type used for steaming the wrinkles out of clothing. They rather resemble a miniature vacuum cleaner, with a flexible hose and a T-shaped wand at the end. The only difference is that instead of the vacuum's canister, the hose leads to a small water reservoir and heating unit. By carefully angling the wand, and by lingering over some areas but only lightly touching others, you can apply varying amounts of steam to the cake wherever they're wanted.
Wherever the fondant is steamed, its surface becomes shiny. For example you might steam Santa's boots or belt to make them shiny, while shielding the red suit with a spatula or sheet of foil to keep it matte and velvety-looking. If you use luster dust on your decorations to give them a more realistic appearance, steaming will "set" the dust and prevent it from rubbing off. Steaming also deepens the colors slightly. The shininess of steaming is temporary and will fade over a day or so, but can be refreshed by steaming the cake again. Don't over-steam a single area, or it might soften enough to droop and lose its shape.
Although you can steam the whole cake after it's decorated, sometimes it's more practical to steam the decorations separately before adding them. You can lay them out on a baking sheet and steam them with a fabric steamer, or steam them individually over a pot of simmering water. Put a colander or wire strainer over the pot, and place one or two decorations at a time on small squares of parchment paper. Place them in the colander and cover the pot for 30 to 60 seconds with a lid. Remove the lid, wave the steam away, and remove your decorations.