Before you can dehydrate the cranberries, prepare them by blanching them. Wash the cranberries and set aside. Fill a pot with 6 C. water and bring to a boil.
Once the water comes to a boil, add your cranberries. Boil for 1 - 1 1/2 minutes. They should "pop" (or split open). You may have a few duds that don't, but don't worry.
Drain the cranberries in a colander. Gently wrap them/dry them in a clean dish towel to rid them of excess water.
Lay your cranberries out on the dehydrator trays, evenly spaced. The cranberries that didn't pop will need to be pierced with a sharp knife.
Cranberries can take up to 14 hours to dry at 135 degrees F. After 8 hours, check on the cranberries to determine their dryness. They may need more time (up to 6 additional hours).
Cranberries need to cool before you can check to ensure they are completely dehydrated. Turn off the dehydrator and open the top to let them cool for 20-30 minutes.
After the cooling period, check the cranberries by cutting or tearing in half and checking for moisture. If there is no moisture, they are fully dehydrated.
Once dehydrated, store the cranberries in an air tight glass jar or BPA-free food storage container. Fill the jars only 1/2 - 2/3 full and shake them several times a day for one week to redistribute the berries and any moisture they may contain.
If (after a few days) you notice moisture on the jar(s), you may need to add the berries back to the dehydrator for a short time. Once dehydrated, store away from light or heat.