Makes about 3 cups
2 large egg whites
2 teaspoons fresh lemon juice
3 cups confectioners (powdered or icing) sugar, sifted
In the bowl of your electric mixer (or with a hand mixer), beat the egg whites with the lemon juice until combined. Add the sifted powdered sugar and beat on low speed until combined and smooth. The icing needs to be used immediately or transferred to an airtight container as royal icing hardens when exposed to air. Cover with plastic wrap when not in use.
Royal Icing Using Meringue Powder
4 cups confectioners' (powdered or icing) sugar
3 tablespoons meringue powder
1/2 teaspoon extract (vanilla, lemon, almond)
1/2 - 3/4 cup warm water
In the bowl of your electric mixer (or with a hand mixer), beat the confectioners' sugar and meringue powder until combined. Add the water and beat on medium to high speed until very glossy and stiff peaks form (5 to 7 minutes). If necessary, to get the right consistency, add more powdered sugar or water. To cover or 'flood' the entire surface of the cookie with icing, the proper consistency is when you lift the beater, the ribbon of icing that falls back into the bowl remains on the surface of the icing for a few seconds before disappearing.