Drying
Royal Icing has the ability to dry smooth and hard, which makes it the perfect canvas for intricate designs. Once you pipe your RI, you can set it out to dry. Shortly after piping it will form a thin crust on the surface, but it will stay wet underneath for several hours. This medium is fully dry when it is firm to the touch; if your fingernail pokes through, it hasn’t dried completely.
When left at room temperature, RI will take ca 6-8 hours to dry – or even a full day. There are a few things that could alter that time:
- The consistency: the thicker the icing, the quicker it will dry. For flood consistency icing (thinner icing), the drying time is longer.
- Environmental factors such as ambient temperature, humidity and wind. In a high humidity environment, water vapor gets absorbed into porous surfaces. High humidity prohibits icing from quickly drying, leading to damp icing.
Note:
Don’t keep the cookies in an airtight container. The humidity trapped inside the container will make the cookies soggy. The icing needs to be exposed to the air to dry.
Watch this video by Haniela to see how long it takes for RI to dry on cookies:
How to speed up the drying process?
- Leave your cookies at room temperature with low humidity and expose them to as much airflow as possible. Place a fan nearby to increase the airflow (at least 1 meter away from the cookies so the airflow doesn’t cause the icing to change shape). Be aware that wet icing is extremely fragile and pliable before it sets, so additional wind can affect its texture.
- Dry your icing in an oven. Preheat it to run at lower temperatures (95-105°F or 35-43°C) or to the lowest possible setting. Remember that running a convection oven (with fan running) heats up a bit more than a conventional oven. Carefully move your cookies to the middle shelf and leave the door slightly open. Too high temperature will cause the icing to ripple or crack from the heat. Leaving the door off helps with air flow and allows moisture to exit the oven.
- Use a dehydrator.It's easier to control than the oven, so you don't have to worry about overheating the icing. This appliance will 'dehydrate’ the frosting by removing the moisture. It also generates an airflow that helps the icing to dry puffier and shinier. Dehydrators are also great for getting that first layer of the royal icing cookie to dry quickly, so you need to wait shorter between your first and second layers of icing. The temperature setting is 95-105°F or 35-43°C. See also paragraph "Dehydrator/Drying tool" in Must-haves section.
Note:
There are basically two kinds of dehydrators you can use for cookies decorated with RI - a stackable version that has a fan on top, or a dehydrator with sliding trays that has a fan in the back (see the picture below).
