Persian Sugar-Pickled Garlic

4 heads garlic
2 cups red wine vinegar
2 cups water
1 cup granulated sugar
6 whole cloves
2 tablespoons black peppercorns

Separate garlic cloves, but do not peel. Place all ingredients in a large heavy-bottom saucepan. Bring to a boil; cook for 10 minutes, stirring from time to time. Reduce heat to moderate and cook 5 minutes. Cool to room temperature.

Transfer to a large glass or ceramic jar large enough to hold garlic and the liquid. Tightly seal. Refrigerate at least 1 month before serving.