It took us a bit to get the hang of dehydrating, but I think we’ve finally got it down. For the most part, when your veggies or fruit feel crisp with a bit of leathery give they are done. Once they cool down they’ll harden a bit more. It’s like an optical illusion.
We’ve been drying our cayennes in a Salton food dehydrator at 50ºC for around 8 hours. Some recipes call for a higher temperature for a shorter period of time, but I find lower for longer works better.