Royal icing has a thick and creamy consistency and spreads like soft cream cheese. Egg white power is a favorite substitute for meringue powder when making royal icing because it’s easier and safer. While the risk is slight, it is possible for raw egg whites to contain food-borne pathogens, such as Salmonella. Fortunately, chefs can prepare royal icing with little or no risk by employing meringue powder or dried and pasteurized egg whites. The resulting dessert will have a longer shelf life. Cake icing made with fresh egg whites will only keep for a week, while sugary confections made with egg white powder can keep for up to two weeks in a refrigerator.