Pour boiling water over the cranberries and let sit for 10 minutes. The skin should pop and split open although some may not. Pierce any that does not split.
To sweeten the craisins, make a solution of 1 part sugar to 2 parts water. Toss the cranberries in this solution. Omit this step if you want sugar free craisins.
Place the cranberries about 1/2 inch (6 mm) apart on the dehydrator trays
Dehydrate at 135°F (57°C) for 10 - 16 hours.
Let cool completely then store in airtight containers.