I am trying to dry sweet potatoe sticks (look like French fries). I’m drying them in a food dehydrator. When they are finished drying they come out looking like they have mold on them even though they are thoroughly dry. I use them for dog treats. Are they moldy or just discoloured? At what temperature should I use? Thanks for any tips.
If the discolouration is white, it's most likely sugar crystallising on the outside, so nothing to worry about. For the dehydrator, you can go fairly hot for sweet potatoes - I would use 80-90 °C for a few hours, and also cook (steam) the potatoes before drying. See this wikipedia page for reference.