• In a small saucepan, combine the citrus zest, cinnamon stick, coriander seeds, nutmeg, allspice, cloves, ginger, tamarind pod if using, water, sugar, and brown sugar.Bring to a gentle simmer over medium-low heat. Simmer for 15 to 20 minutes, stirring occasionally, until the sugar is fully dissolved and the mixture smells warm and cola-like.Remove from heat and strain through a fine-mesh strainer into a jar. Press lightly on the solids to extract the liquid, but do not force pulp through.Stir in the vanilla extract.Let cool completely before using.

To Serve

• 1 part syrup3 to 4 parts club soda or sparkling waterServe over ice

Storage

• Refrigerator: 2 to 3 weeksFreezer (in cubes): 3 to 6 months

Optional Ginger Bug Version

• 1/4 cup syrup 2 to 3 cups water 2 to 4 tablespoons active ginger bug

Note on Tamarind

• Tamarind is optional in this recipe, but it brings a deeper, more traditional cola flavor that is hard to replicate with citrus and spices alone. It adds a subtle tang that is softer and more rounded than lemon or lime, along with a natural richness that almost leans caramel-like.

  When used, tamarind helps bridge the gap between the bright citrus notes and the warm spices, creating a more layered and balanced syrup. It gives the finished cola a fuller, more complex flavor that tastes closer to what people recognize as a classic cola profile, without relying on artificial ingredients.

  If you do not have tamarind, the recipe will still work beautifully. The result will be slightly brighter, more citrus-forward, and a bit lighter in overall depth, but still very good and completely usable.