Royal icing is great for decorative baking. It’s a deliciously beautiful addition to any cookie, cake or other sweet treats. But it’s also one of the more fickle types of icing.
Due to its formula, it has a very short window of time that it can be used and doesn’t last long once it’s made. Here’s a basic guide:
- Egg-based royal icing: 1 week, refrigerated
- Meringue-based royal icing: 1 month, room temperature
- Either formula: Up to 2 hours if left in a piping bag
In this piece, we’ll discuss different types of royal icing, how long it lasts, and tips you can use to make your royal icing last as long as possible.
Looking directly for airtight containers? Check these ones out at Amazon, they are perfect for storing your baked goods.
The basics
Royal icing is a white type of decorating icing that hardens when it’s exposed to air over time. Most bakers give royal icing a touch of vanilla flavoring since that matches well with most other baking flavors.
You’ll mainly see it in three formulas. It is either based on raw egg whites, dried egg whites, or meringue powder. The royal icing made with egg whites tends to hold up better than the meringue formulas.
How long does it last?
While fresh royal icing will always give you the best results, egg white icing can last up to one week if refrigerated and stored properly. Meringue powder based royal icing lasts much longer, up to a month. 
You can find Wilton meringue powder at Amazon.
Either formula will only last a few hours in its piping bag and will deteriorate faster if it has a runnier consistency (i.e. more water in its mixture).
The reason it doesn’t last very long, whether it is stored correctly or not, is due to its formula. After a given period of time, the sugar and water ingredients separate. The watery, liquid part of the icing starts to pool up, leaving dry, cracked icing behind. The longer the icing sits, the more it separates.
But there is good news! Once the royal icing has dried as a decoration on your cookie, cake, etc., it lasts basically forever. The only thing you’ll need to look out for is potential breakage since it’s a very delicate substance.
Check out the MuYwa piping bag set at Amazon. Silicone, reusable plus piping tips
Storage tips
Storage is key when it comes to preserving royal icing. If you made a little more than you needed for your baking project and want to save it for another time, you’ll need to know how to store it properly to make it last as long as possible.
Airtight
The number 1 tip for storing royal icing is air-tight containers. As we mentioned before, exposure to air is what really causes separation and deterioration of royal icing, so you’ll want as little air as possible getting into your mixture.
These Prep Naturals meal prep glass containers work really well.
Grease-free
The second rule of royal icing storage is grease-free containers. If you’re making your own royal icing, you’ll need to make sure all of your mixers, bowls, and other baking utensils are grease free. Grease is a nightmare for royal icing and can completely discolor and disintegrate it.
This means you should stay away from containers made out of plastic. Plastic is a porous substance, which makes it very difficult to de-grease if you’ve used it before. Glass and stainless steel are much better types of containers to use when storing your royal icing.
These Pyrex mixing bowls come with lids—perfect for storing your extra icing. 
The paper towel trick
If your royal icing is meringue based, it can be stored at room temperature. But if it’s egg white based, it’ll need to be stored in the refrigerator. Either way, another pro tip is placing a slightly damp paper towel or plastic wrap directly on the surface of the royal icing and then covering it with the airtight lid. This will keep the top layer from crusting over.
Before you bake, you might want to check out my favorite rimmed baking sheets.
Revive your royal icing
If you want to reuse your royal icing, there are a few factors to consider. The first is which formula you used. If your royal icing is egg-based, make sure to return it to room temperature before you remix it. If it is meringue based, you may want to add 1-2 teaspoons of meringue powder as you remix to revive its consistency.
Also, depending on your desired consistency, you can always add a little bit more water to thin it out, or icing sugar to thicken it. Make sure to mix all the lumps out of the icing before reusing it. But be careful when remixing, since overmixing can lead to air bubbles. Using an electric mixer can remedy this issue.
Frequently Asked Questions
What is royal icing?
It’s a versatile frosting, often used to prepare cut-out cookies and decorate gingerbread houses. The old conventional royal icing involves the use of different ingredients such as water, sugar, and egg whites or meringue powder. You can add flavors with extracts and tint it with food color. As it dries, it becomes even harder, and thus it’s used for decorative purposes. You can make a simple royal Icing at home by using water, milk, and sugar or fruit juice.
How do I ice my cake with royal icing?
For a smooth and perfect finish, I would recommend you first apply a thin layer of royal icing, approximately 5mm thick, to smooth the surface of the cake. If you have a turntable, place the cake on top and put a scoop of icing on the cake. With the help of a spatula, spread the icing on top of the cake so that it extends over the sides. Without touching it, lean over the turntable and hold a metal ruler at 45 degrees and pull it in your direction to smooth the surface evenly. You can cover the sides of the cake with an even layer of the royal icing. You need to work quickly because royal icing can dry when exposed to air for a few minutes. Be cautious for the best results. You can trim the excess icing from the edge with the spatula.
How can I prevent my black icing from bleeding?
The icing may take longer to dry when it’s humid, and your icing can experience bleeding, especially when using dark colors, like dark red. I would advise you to wait for a few minutes for the dark color icing to rest overnight before using it on cookies. You can improve your icing by using corn syrup, which helps prevent bleeding.
The weather is humid today and I want to prepare royal icing. Will it dry?
I would recommend you use a dehumidifier to manage the wet, moist air. Also, you can speed the drying process by using the lowest setting on the oven for approximately ten minutes. This will help your icing develop into a nice crust. You can decorate it with a second layer because the icing may be still wet under the crust. Also, if you want to write on your cookies, you should wait until the icing has dried through completely.
How can I dry my cookies decorated with royal icing?
You can dry your cookies by exposing them to air. Place them on the try and let them air dry. You can also place a fan next to your cake or cookies. This helps in the drying process, and you can achieve an excellent smooth finish with the icing. Avoid covering the cookies and don’t put them in the fridge.
How can I make black royal icing?
If you’re starting with white icing, add a black gel food coloring (in this case I would recommend using the best brand you can find) until the icing turns dark gray. Cover the icing and let it rest overnight or for several days. This will allow the dye to mature and the color will deepen with time. You can add more food coloring if needed.
How can I prepare cookies with royal icing for shipping?
I would advise you to choose shapes that are not prone to break, such as squares, plaques or hearts. Shapes such as stars or long and thin shapes are likely to break when shipping. You should lay the cookies between bubble wrap and leave sufficient room between them so that they don’t come into contact with each other. Fill the corners thoroughly to hold the cookies firmly in the box so that they don’t shake when in transit. The walls of the box should be well protected with bubble wrap to prevent the cookies from touching the box directly.
What is meant by runouts, floodings, and flood-ins in relation to royal icing?
Flood-ins and runouts are methods used to produce desired shapes with royal Icing. It should be thinned down with a little bit of water to a more liquid consistency, i.e. it pours freely from the spatula when dipped and lifted in the icing.
To fill an outlined cookie with the desired shape, you use runny royal icing. For a perfect result, outline the cookie with proper royal icing and flood the inside with thinned royal icing. The floods in and runouts help in generating a smooth sheen surface with uniform colors, and you can pipe details on top or add decorations. It’s the simplest method for decorating a cookie. You need to bake the cookies and cool them down, and then you need to outline them and flood the icing with silver balls on top. Allow it to set, and they’re ready to eat!
What does brush embroidery mean with regard to royal icing?
This is when a decorator brush is used to pull the lines of the piped royal icing. It provides a smooth, streak effect that gives the cookies an outstanding look and has an embroidery effect on the design.
Conclusion
When used and stored correctly, royal icing is a great addition to your baking repertoire. It can create fun, intricate, beautiful designs to give your baking a personal and unique touch. And now that you know some of the ins and outs of this delicate type of icing, you’ll want to use it even more.
