Combine sugar, water, vinegar, and pickling spice in a nonreactive saucepan over medium-high heat; bring to a boil. Reduce heat, and cook until reduced by half. Strain vinegar mixture through a sieve over another medium nonreactive saucepan; discard solids. Add fresh cranberries to strained mixture, and place pan over medium heat. Bring mixture to a simmer, and cook just until the cranberries begin to pop (about 5 minutes), stirring occasionally. Remove from heat; cool. Chill at least 24 hours.