Frostings 101

• Canned frostings are designed to replicate buttercream frosting, but they usually contain shortening rather than butter, along with cornstarch, powdered sugar and corn syrup. The simplest homemade buttercream frostings contain just a few ingredients -- butter, powdered sugar and perhaps vanilla and milk. For a richer flavor, you can also try Italian buttercream, which is made by beating butter into a meringue that has been stabilized with a hot sugar syrup. Swiss buttercream is created by heating egg whites and sugar to 160 degrees Fahrenheit before beating in the butter. Italian and Swiss buttercreams take more time, but they're by far, the richest, fluffiest frostings you'll find. Heating the ingredients also removes any risk associated with raw eggs.

Raw Egg Safety

• Raw eggs can carry pathogens, including the salmonella bacteria. If you use raw egg whites to fluff up canned frosting, you increase your risk of foodborne illness. Young children, the elderly, pregnant women and those with compromised immune systems are especially at risk. Raw eggs must be heated to 160 F to destroy bacteria, according to the U.S. Department of Agriculture. If you're worried about the risks associated with using raw eggs, opt for pasteurized, refrigerated egg whites or use meringue powder instead. You can also cook the eggs as you would for Italian or Swiss buttercream.

Mix It Up

• To fluff canned frosting with raw egg whites, beat the frosting lightly with a hand mixer first to soften it. Break the egg whites into a clean metal or glass bowl -- not plastic -- and mix them with a whisk until stiff peaks form. A bit of cream of tartar added to the whites can keep them from deflating. Carefully fold the egg whites into the canned frosting. If you beat the frosting too vigorously, the egg whites will lose volume.

Storing the Leftovers

• A cake frosted with canned frosting can safely be stored at room temperature, but once you add raw eggs, you should refrigerate any leftovers. Store leftover frosting in a covered container in a refrigerator set at 40 F for up to two weeks. To store leftover cake, place the cake in the refrigerator for 15 minutes to harden the frosting. Then wrap the cake in plastic wrap and keep it in the refrigerator. Use it within three or four days.