1 vanilla bean, split and scraped
2 cinnamon sticks
2-inch piece of ginger, peeled and sliced
5 whole cloves
2 star anise
24 green cardamom pods, split
1 black cardamom pod, split
2 tsp. black peppercorns
1/2 whole nutmeg, roughly chopped
1/4 tsp. fennel seeds
Bring about 1 quart filtered water to a boil, then pour over spices and cover in a separate container.
Let steep for 15 minutes, then strain to remove spices. Cover tea and keep chilled until used.
I blended in about 2 cups (473 milliliters) of this liquid in the 5-gallon (19-liter) batch. But you want to do it slowly, mix it well, and taste it. Different people have different tastes, so you're looking for a nice balance without being overpowering with the spices.