According to Deanna DeLong, author of How to Dry Foods (Canada, UK) cranberries are not the best candidates for drying because they take a long time. But Ocean Spray has clearly found success with its Crasins brand of dried cranberries.
DeLong says if you have the patience, the berries should be washed first to remove dirt or fungicide. Dipping them in boiling water to crack the skins is optional, but if you don’t, they take "forever" to dry.
They should be kept at a temperature of 140°F (60°C) until dry, and you’ll know they’re dry when they are shriveled and light in weight with no sign of moisture, although they will likely be a bit sticky. Once dry, they can be kept at refrigerator temperatures for 18 to 24 months or in a freezer for 5 to 8 years. So make a big batch!
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