I am attempting to make some decorating pieces with isomalt. I found that the isomalt started to absorb water even before it completely cools down! So what I got was: molten isomalt -> warm isomalt (semi hardened, non-sticky) -> slightly warm isomalt (sticky). I first through the pieces was not cooled enough when i unmold it so I left the pieces overnight in a room with AC, only wake up to fine them extremely sticky.
Any feedback will be very helpful!
Are you cooking the isomalt in a pot on the stove or are you melting the pre-cooked isomalt stick?
If you're cooking it on the stove, I'd say that you've used too much water and perhaps aren't cooking it to a high enough temp (340F). You only need about 10% water (in weight) to dry isomalt. If the isomalt is the texture of wet sand when you start to cook it, it should be good to go.
If you're melting the pre-cooked isomalt sticks in the microwave, it needs to bubble well in order to be done.
Another option is that the hot/warm pieces in the cool/cold room simply developed condensation on them--a normal physical reaction. Placed under a fan or in a box with some desiccant, they should dry & be fine.
Isomalt actually does not need much water. I use 2oz for 1# and it comes out just fine. Granulated needs to be "wet sand", Isomalt does not. Cook it to 330ºF. Isomalt should not be absorbing moisture from the air. Invest in silica gel/limestone/de-humidifier that will collect moisture and keep your products dry.