It can be a hassle waiting for bath bombs to dry. The time it takes depends on the method you use for drying your bath bombs.
Air-drying takes about 6 to 8 hours. It's best done overnight, in a well-ventilated area to fully harden a bath bomb. You can significantly reduce this time to within 1 hour by drying bath bombs with an oven.
The air drying method is recommended as it doesn't force too much moisture out, which is known to result in stability problems.
Do you live in a humid climate and need to dry your bath bombs quickly? Try the oven-drying method. But be careful. Trying to rush the drying process may result in the bath bomb expanding so much that it spills out of the mold. Also, be careful to avoid crumbling the bath bomb.
Factors that affect how long it takes for a bath bomb to dry include:
Ingredient list: While you need wet ingredients like oils and water to make a bath bomb, avoid using an excess mixture rich in wet ingredients. Too much moisture at this stage is problematic. You want less moisture during production so that the drying process is quicker. Try to use as little of everything as possible. For the final mixing process, try to add witch hazel rather than water. Then use a few drops of essential oil (olive oil or coconut oil).
Temperature: If you use an oven, setting a lower temperature will dry the bath bombs slower. You have more control and can set the ideal time for drying.
Humidity: This is a common problem for many bath bomb makers. Low humidity and high humidity can lead to problems as the mixture can dry too fast before placing it in bath bomb molds.