Dehydrated White Onion Leave a Comment / Preserving / By Amanda and Tim / January 9, 2020 February 9, 2020I like to have a few of these on hands. If ever I’m out of onions, I’ll always have some. I cut them up in various ways, cubed, sliced thin and big. Dehydrate on trays at 135F about 10-12 hours. Timings always vary as per size of onion or dehydrator being used. Love our dehydrator. It’s half the price to leading brands but works just as good!