In the bowl of a stand mixer fitted with the paddle attachment, or in a bowl using a handheld mixer, begin to beat the egg whites and sugar on low speed. Be sure the bowl and beaters are free of any fat and that there is no egg yolk in the whites. After 30 seconds or so, scrape down the bowl with a rubber spatula and gradually increase the speed of the mixer to medium. Beat until the mixer thickens and stiffens, about 3 minutes.
STORING ICING: Keep Royal Icing in an airtight container. To prevent a crust from forming while using the icing, keep the container covered with a damp towel or plastic wrap. Royal Icing will keep refrigerated for up to 2 days. Before reusing, lightly beat with a whisk or fork.
Yield: 2 1/2 cups icing to cover about 4 to 6 dozen 3-inch cookies
*RAW EGG WARNING
Food Network Kitchens suggest caution in consuming raw and lightly-cooked eggs due to the slight risk of Salmonella or other food-borne illness. To reduce this risk, we recommend you use only fresh, properly-refrigerated, clean, grade A or AA eggs with intact shells, and avoid contact between the yolks or whites and the shell.