Place wine, cinnamon stick, cloves, peppercorns, star anise, and juniper berries in an airtight container and leave at room temp for 1 day.
Preheat an oven to 200C (400F).
Place apple and grapes on separate oven safe trays and lightly drizzle honey over each fruit.
Bake apples for 10 to 12 minutes or until they slightly soften.
Bake grapes for 3 to 5 minutes or until they just begin to wilt.
Remove from oven and let cool slightly.
Strain wine mixture, and place in large mixing bowl.
Add apple, grapes, and berries and whisk well, allowing fruits to break up.
Add all remaining ingredients and whisk extremely well.
Strain mixture through a fine mesh strainer and crush pulp in strainer to extract all liquid.
Place sangria into a pitcher, fill serving glasses with ice, and garnish each glass with an orange slice, and serve.