Add the water to a large pot and place over high heat to bring it to a boil.
While the water is heating, cut the oranges into wedges and smash and peel the garlic cloves.
Once the water is boiling, reduce the heat to medium-low. Add the kosher salt and brown sugar and stir until dissolved. Add the orange wedges, garlic, rosemary sprigs, and black peppercorns. Simmer for 10 minutes.
Remove the brine from the heat. Add the apple juice and apple cider vinegar. Add about 8 cups ice to reduce the temperature.
When you're ready to brine your turkey, add the turkey to the brine and add enough ice to bring the liquid level above your turkey so it's fully submerged. Brine the turkey overnight in the fridge.