In a 4-quart Dutch oven combine apple cider, cranberry juice, guava juice, lime juice, ginger, cinnamon, and allspice. Bring to boiling; reduce heat. Simmer, uncovered, for 5 minutes, stirring occasionally. If desired, sweeten to taste with honey.
To serve, pour into mugs. If desired, garnish with lime slices and kumquats. Makes 8 to 10 servings.