Royal icing is a decorative icing made from egg whites and confectioners’ sugar. In professional bakeshops, it is used to decorate cakes, pastries, and candies, but at home, it is primarily used to decorate rolled out sugar or gingerbread cookies.
We explain how to make and use traditional royal icing here, but there is a second method for preparing the icing that makes it food-safe (meaning, no raw egg whites) and a sturdy for cookies that you may be shipping or delivering for the holidays.
Meringue powder is a mixture of dehydrated egg whites and stabilizers. When combined with water and confectioners’ sugar, it makes a simple royal icing that is easy to use and easy to store.
To prepare royal icing from meringue powder, combine 3 tablespoons of meringue powder and about 4 cups of confectioners’ sugar (from just about one 32 oz bag) in the bowl of a stand mixer. Blend them to combine, then add water until it reaches the correct consistency for your use. Start with about 1/4 cup and then add more 1 tablespoon at a time. Never increase the speed over a gentle low, because any added air bubbles will appear in your finished cookies.
For piping cookie outlines or décor, you’ll want your royal icing to be stiff enough that it doesn’t spread once piped, about the consistency of Nutella. It shouldn’t be dry, and you’ll see that it’s glossy if it’s properly hydrated. It should be easy to pipe from a piping bag; if it’s not, return it to the bowl and add a bit more water. It is easier to add more water than to take it away, so hydrate slowly.
For royal icing that you’ll use to flood cookies—meaning, to cover the entire cookie within the outlines—you’ll add a bit more water, until the icing runs off the spoon like hot fudge.
If you plan to use icing for piping outlines and flooding, take out about 1/3 of the piping icing and transfer to another bowl to color, if you’d like, before thinning the remaining icing. You’ll use more for flooding than for piping outlines.
Once your royal icing is prepared, the rules for traditional royal icing apply. Use it the same way, and be sure to keep your icing tightly covered, both in the bowl and in piping bags. Use plastic wrap to keep the tips of the piping bags covered while not in use.
Meringue powder is easy to find. Look at your local baking store, craft store, or online.