Shelf life of Royal Icing
HTC....If you use Wilton Meringue Powder to make your icing I know that it has at least a 3 month shelf life and some would claim a year. The reason is that it is essentially powdered egg whites and for you to make the same recipe at home you would be using raw eggs and raw egg whites. Therefore you can extend your shelf life using this product. If you do not keep this product cool and covered it will get very hard, quickly! So check your Wilton supplier and they will give you the "official" shelf life. Pst :D
Life is short...Eat dessert first!