How To Store Royal Icing
When you're decorating cookies, royal icing can be a fabulous way to pipe out picture-perfect designs. However, if you finish adorning your treats and still have quite a bit of icing left, you can save the sweet spread for future use.
Leftover royal icing should always be stored in an airtight container. This keeps the icing hydrated and protects it from bacteria, ensuring it won't absorb smells from other foods stored nearby. Additionally, where you keep the icing depends on whether it was made with meringue powder or egg whites.
Royal icing made with meringue powder, water, and powdered sugar combines ingredients that are all shelf-stable. Once it has been properly packed away, it can be left at room temperature for up to two weeks, since none of its components require refrigeration. However, if egg whites are used to make the icing, you'll need to refrigerate your leftovers, and the timeframe will be much more restrictive.
Keep egg white-based icing in colder temperatures
Royal icing made with powdered or fresh egg whites must be stored in the fridge to prevent bacteria growth, which can occur if eggs rest at room temperature for more than two hours. Once it's sealed in an airtight container, a layer of cling wrap can be placed over it to prevent a film from forming on top. Egg white-based icing will only last for about three to five days in the fridge.
For long-term storage, royal icing can be frozen. Scoop the icing into a resealable freezer bag, press out extra air, and seal it. The airtight bag helps prevent freezer burn from creeping in and altering the icing's texture. Once frozen, the icing should be used within three months.
When it's time to use the icing, defrost it in the fridge overnight, then allow it to come to room temperature before piping. Keep in mind that an extended storage period may cause the icing's ingredients to separate slightly. To remedy this, simply whip the icing together again with a whisk until it reaches the desired consistency.
How to use leftover royal icing
Leftover royal icing can easily be transformed into edible accessories for future baking projects. For the meringue-based variety, you can pipe out an assortment of decorations, like icing flowers, letters, or stars. You can even make your own sprinkles to incorporate into sugar cookies. This icing should be left to dry out completely on a piece of parchment paper at room temperature. After about six to eight hours of setting, they'll be solid and slightly crunchy to bite into.
These decorations should be stored differently than wet icing. Sprinkles can simply be placed in a jar and stored on a shelf. Piped icing embellishments should not be kept in airtight containers, as condensation can form and soften the decorations, ruining their shape. Instead, they can be stored in a cake box in a cool area. With proper storage, these piped decorations will remain fresh for up to two weeks, and can be used to adorn a variety of baked goods.