Combine plums and water in a Dutch oven, and bring to a boil. Reduce heat, and simmer, uncovered, 20 minutes or until tender. Stir in sugar, juice, ginger, and rind. Cook over medium heat 40 minutes, until thick or a candy thermometer reaches 210°. Stir mixture occasionally. (Do not overcook or mixture will scorch.) Cool. Discard lemon rind. Store in an airtight container in the refrigerator up to 2 weeks.