In a large pot, combine the ginger, peppercorns, clove, cardamom, and cinnamon. Add 12 cups water. Bring the pot to a boil and then turn the heat to medium and let it cook, bubbling gently, for 25 minutes with the lid off.
Turn off the heat, add the tea bags, and let it steep for 5 minutes.
Scoop out the tea bags and add the sugar (if using). Stir well so that the sugar dissolves.
Using a fine mesh strainer, strain the tea into a large bowl or pitcher. Serve immediately by filling a mug 2/3 of the way and then topping off with your favorite type of milk, or bring to room temperature and then store in the refrigerator for up to a week.