Pour water into a medium saucepan and place it over low-medium heat.
Add the whole cloves and cinnamon stick to the water, allowing them to infuse as the water warms. Gently stir with a wooden spoon to help release their flavors.
Grate the citrus zest directly into the pot, watching as the bright orange strips float on the surface and fill the air with citrus aroma.
Add the whole allspice and a pinch of freshly grated nutmeg for a warm, spicy scent.
Increase the heat slightly until the mixture begins to shimmer gently, then reduce to low to maintain a steady simmer without boiling rapidly.
Allow the mixture to simmer uncovered for 15-20 minutes, letting the spices bloom and the flavors meld. You’ll notice the liquid develop a warm aroma and a slight sheen on the surface.
If desired, stir in a teaspoon of vanilla extract for an added layer of aroma and subtle sweetness.
Remove the saucepan from heat and strain out the spice remnants using a fine sieve or cheesecloth, leaving behind a clear, fragrant broth.
Pour the hot, aromatic broth into cups, and garnish with a strip of citrus zest or a cinnamon stick if desired.
Sit back and enjoy the warm, spiced aroma that fills the room, perfect for chilly autumn days.