Slowly blend all ingredients together in an electric mixer. Then beat at medium speed about 5 minutes until the icing forms stiff peaks. If necessary, add more sugar to stiffen or a few drops of water to soften.

Use immediately or store in an airtight container at room temperature for up to two weeks. Stir to restore to original consistency, but do not beat again. When working with Royal Icing, cover the bowl with a damp cloth to prevent drying.

To cover a cookie, thin some of the icing with a few drops of water. Use a #2 tip for piping, a #3 tip for floodwork on small cookies, and a #5 tip for floodwork on large cookies. Smooth out floodwork with a metal offset spatula. While not in use, the pastry tip should be wrapped in a damp paper towel to prevent caking. Allow at least 1/2 hour for piping to dry and 24 hours for large areas of floodwork.