Wash the pineapple thoroughly to remove any dirt or pesticides. Carefully peel the pineapple, reserving the peels. You can use the fruit for another recipe.

In a large glass jar or food-grade bucket (at least 2-liter capacity), combine the pineapple peels, piloncillo (or brown sugar), cinnamon stick, and whole cloves.

Pour in the filtered water, ensuring all the pineapple peels are submerged. If they float, you can use a small plate or weight to keep them under the water.

Cover the jar opening with a clean cheesecloth or a thin kitchen towel, secured with a rubber band. This allows air circulation while keeping out insects.

Place the jar in a warm spot, away from direct sunlight, to ferment for 2 to 4 days. The ideal temperature is room temperature (around 68-75°F or 20-24°C).

Check the tepache daily. You'll notice small bubbles forming on the surface, and the liquid will develop a sweet, slightly tangy, and yeasty aroma. A thin layer of white foam or scum is normal; skim it off if desired. Discard immediately if you see any signs of black, blue, or green mold.

Once the tepache smells pleasantly sweet and mildly acidic and has a good amount of fizz (usually after 2-3 days, but can be up to 4), it's ready.

Strain the liquid through a fine-mesh sieve into clean glass bottles or jars, discarding the pineapple peels and spices. Do not press the solids.

Seal the bottles or jars and refrigerate immediately to slow down or stop the fermentation process. This will keep your tepache fresh and prevent it from becoming too alcoholic or vinegary.

Serve the tepache very cold, over ice. For an authentic street-style touch, rim your glass with chili powder (like Tajín) or garnish with a fresh pineapple slice. Enjoy!