In a medium saucepan combine all ingredients except rhubarb. Bring to boiling; reduce heat. Cover and simmer for 25 minutes, stirring occasionally. Add rhubarb; cover and simmer for 10 minutes. Uncover and simmer until thickened, about 5 minutes more if using fresh rhubarb or about 15 minutes more if using frozen rhubarb. Let cool. To store, cover and chill in the refrigerator up to 1 week. Makes about 2-3/4 cups.