2 pounds powdered sugar
½ teaspoon cream of tartar
2/3 cup pasteurized egg whites
1 teaspoon vanilla
Food coloring, optional
Mix the powdered sugar and cream of tartar in a stand
mixer bowl. Add the egg whites. Mix on low until the
frosting comes together.
Turn the mixer on to high speed and mix for two minutes.
The frosting will be very thick and turn a crisp white color.
Stir in the vanilla.
At this stage, the frosting can be used to decorate gingerbread houses.
Royal Icing Outline Consistency:
Place 1 cup of the frosting in a bowl. Stir in ¾ teaspoon water and add food coloring if desired. Place half of the frosting in a decorating bag or plastic bag. Use this frosting to outline areas to be filled in with the Flood Consistency Royal Icing.
Royal Icing Flood Consistency:
Stir in water (about 2 teaspoons) to the leftover ½ cup of tinted frosting. Place the frosting in a decorating bag or plastic bag. Use this frosting to fill in the areas outlined with the Outline Consistency Royal Icing.