Combine first 3 ingredients in a small nonaluminum saucepan. Bring to a boil; reduce heat and simmer, uncovered, until sugar dissolves, stirring occasionally.
Remove from heat and pour syrup mixture over cranberries in a medium-size heatproof bowl. Place bowl on a steamer rack in a large Dutch oven over simmering water. Cover and steam 30 minutes. Remove bowl of cranberries. Let cool completely without stirring.
Cover bowl with cheesecloth; let stand at room temperature for 3 days, stirring occasionally. (Mixture will become thick.)
Transfer cranberries, using a slotted spoon, to a large mesh wire rack placed over a wax paper-lined jellyroll pan. Store cranberry syrup in a glass container in refrigerator for another use. Let fruit dry, uncovered, for 2 to 3 days, turning occasionally. Reserve 1/4 cup Candied Cranberries for use in Pistachio Crunch.
Note: Candied Cranberries can be prepared and refrigerated up to 2 weeks ahead.