Cookie decorating is a popular and fun holiday activity for many families. Royal Icing is often the chosen frosting for decorating as it dries quickly and hard and it is easy for nearly anyone to achieve decorating success! Traditionally made from egg whites and powdered (confectioners’) sugar, it is an easy icing to prepare but should NOT be made with raw egg whites.
It is a well-known fact that eggs may contain a bacteria, Salmonella Enteritidis (SE), that can cause foodborne illness. Researchers say that if present, the SE is usually found in the yolk, but they can’t rule out the possibility of SE in egg whites. To eliminate risk and ensure food safety, one should replace the raw egg white with lightly cooked egg whites, use pasteurized egg whites, or meringue powder when making Royal Icing.
Lightly Cooked Egg Whites. Use the following method provided by South Dakota State University which can be used for Royal Icing and other frosting recipes calling for raw egg whites: In a heavy saucepan, the top of a double boiler or a metal bowl placed over water in a saucepan, stir together the egg whites and sugar from the recipe (at least 2 tablespoons sugar per white), water (1 teaspoon per white) and cream of tartar (1/8 teaspoon per each 2 whites). Cook over low heat or simmering water, beating constantly with a portable mixer at low speed, until the whites reach 160° F. Pour into a large bowl. Beat on high speed until the whites stand in soft peaks. Proceed with the recipe. Note that you must use sugar to keep the whites from coagulating too rapidly. Test with a thermometer as there is no visual clue to doneness. If you use an unlined aluminum saucepan, eliminate the cream of tartar or the two will react and create an unattractive gray meringue.
Meringue Powder. Meringue powder is available in specialty stores wherever cake decorating equipment is sold. Meringue powder is composed of cornstarch, dried egg whites, sugar, citric acid and some stabilizers. It’s perfect for making royal icing. Follow the instructions on the package to rehydrate and use.
Pasteurized Egg Whites. Pasteurized egg whites are of two types—pasteurized in-shell eggs or liquid pasteurized egg whites. Pasteurized in-shell eggs are available at some grocery stores. Shells of such eggs are stamped with a red or blue “P” in a circle. Whites of pasteurized shell eggs may appear slightly cloudy compared to fresh eggs. Liquid pasteurized egg whites are found in the refrigerated section of the grocery store in a milk-like carton usually near the regular eggs. According to the FDA, both of these products are safe to consume raw. Use these two products like raw whites is the recipe.
Keep unused icing covered at all times with a damp cloth or tightly wrapped to prevent drying and caking. For longer keeping time, store in the refrigerator for up to three days or freezer for up to three months. In addition to preventing food borne illnesses, refrigeration seems to help with separating. (If separation occurs–yellowish liquid on the bottom—just remix.).