3large egg whitesroom temperature, (or 1/2 cup liquid egg whites) NOTE: The 2X/3X above only updates the main amount, so if doubling your recipe and using liquid egg whites, use 1 cup liquid egg whites as a substitute for 6 large egg whites.
1/2teaspooncream of tartar
5cupspowdered sugar (also called confectioners' sugar)
Instructions
In a large bowl, using an electric mixer fitted with the whisk attachment (on medium speed), beat together egg whites and cream of tartar. Add powdered sugar, 1 cup at a time and beat for about 3-4 minutes or until mixture is thick and fluffy, and has fairly stiff peaks. Stop the mixer to scrape down the bowl periodically, as needed.
You may need to add more powdered sugar if your icing is too loose, do so by adding more powdered sugar in 1/4 cup increments, until desired consistency I achieved. Humidity/weather can also cause icing to be too loose/runny. You want to be sure you have stiff peaks, so increase powdered sugar until it's stiff. We find 4 1/2 - 5 cups to do the trick, but adjust accordingly. You want to be able to pull a knife through the icing and it doesn't run back together. This will ensure that it holds the shape you want when piped! If too thick to pipe, add just a teaspoon or two of water (at a time) to thin the icing out.
Since it dries quickly, keep the icing covered with a damp cloth while working. Ideally, use the royal icing right away. If I starts to set up while you are working on your gingerbread house, just give it a good stir to soften it back up.
Notes
This is the perfect royal icing for gingerbread houses. It makes a royal icing that hardens when dry and pipes pretty ruffled edges on your houses, it will hold it's shape and not be too runny or loose!