Dehydrated Grapes & Blueberries Leave a Comment / Preserving / By Amanda and Tim / January 9, 2020 February 9, 2020These two take a long time! You can just poke holes in each of them and keep them whole which makes them take even longer. I prefer to just cut in half.Dehydrate both at 145F grapes are larger so they will take longer. I use Dehydrating sheets also. Dehydrate for 12-15 hours.Dehydrators vary which means times will always very! Love these. Love our dehydrator. It’s half the price to leading brands but works just as good!