Do you need to let fondant dry?
If you're not short on time, this is reliable way to ensure you don't damage the fondant, but it requires a bit of planning. We'd recommend waiting a good 3-5 days to ensure the fondant is completely dry before decorating your cake with it.
How to Dry Fondant Fast. You can leave fondant out at room temperature, and it will normally dry in 24 to 30 hours. However, there may be times when you need to speed up the process.
It'll still take a few hours (up to overnight) to dry your fondant pieces, but the overall time will be shorter. A blow dryer is especially good for smaller pieces or for those that are already on a cake.
Your fondant needs to dry for at least 12 hours (24 hours is even better) before you try and paint on it.
Wrap 2x in plastic wrap and let it set at least 8 hours or overnight before using. When ready to use, knead the fondant until it's smooth and supple. Roll on a surface dusted with powdered sugar. When not using always keep the fondant covered so it doesn't form a skin.
Tip 1: Use Tylose Powder or CMC
However, it is also one of the easiest ways to make your fondant dry quickly and hard. The addition of Tylose powder creates more of a gum paste texture. Add about a teaspoon at a time. Adding too much tylose will make your fondant unworkable.
You can use edible food paint on anything, but it works best on a flat, light-colored surface that isn't super porous. Great examples are fondant cakes and cookies with royal icing. You can also paint on chocolate with a slightly different recipe.
Painting the fondant with egg whites is a quick and easy way to add a shiny appearance. Simply brush on the egg whites with a food-safe paintbrush and let it dry. (Depending on the humidity, this can take 1 to 2 hours.)
If you're using a layer cake and/or perishable fillings or icings, then you need to do everything just a day or two before the event. Fondant dries quickly, so while working with it, always keep excess well-wrapped in plastic, as well as the parts on the cake you are not working on.
Dry fondant with your oven light.
It's warm enough to dry fondant, but not so warm that the fondant will melt. Place your baking sheet or wire rack on the top rack of your oven with the light on. Larger pieces may need to dry for a few hours or possibly overnight, and smaller pieces may be done within an hour or two.
Can you put fondant in the fridge to harden?
Fondant does not dry in the refrigerator, it firms up. Once it comes to room temperature it will remain the same and will still need time to dry. Marshmallow fondant is a different beast, the normal marshmallow fondant recipe is usually soft and sticky.
The main reason fondant cakes sweat in the fridge is because the fridge is full of humidity and that immediately causes the fondant to start condensing. When you remove the fondant cake from the fridge, you also need to allow it to slowly adjust to room temperature before you unwrap the cake.