I used the Saharas and they are quite tempermental. If you have the plate that holds 4 units take it out and switch it for the one that holds 2; it offers better circulation. You will need to thaw label down, set a timer for ~10 gently mash the unit finger tips to loosen up any ice and disperse it, swap the units positions, and set for another 10minutes. We found that worked, but yes you are right you can not just set it and forget it. For large volumes we still used our water bath. I hope that helps. Sorry. They are so pretty and less up keep, but finicky.