Thoroughly wash the pineapple. Cut off the crown and base, then peel the skin, keeping the peels as intact as possible. You can also include a few chunks of the pineapple fruit if desired.

In a large glass jar or food-grade bucket (at least 1.5-gallon capacity), combine the pineapple peels (and fruit chunks if using), piloncillo (or brown sugar), cinnamon sticks, and cloves.

Pour the filtered water over the ingredients, ensuring all the pineapple peels are submerged. Use a small plate or a fermentation weight to keep them under the water if they float.

Cover the jar loosely with a clean cloth or cheesecloth, secured with a rubber band, to protect it from insects while allowing airflow. Do not seal tightly as gases will build up.

Place the jar in a cool, dark place (room temperature is fine, around 68-75°F / 20-24°C) to ferment for 2-3 days. The fermentation time will depend on the ambient temperature and your desired level of fizziness and tartness. You should see small bubbles forming on the surface.

Taste the tepache periodically after 24 hours. It should be slightly sweet, tangy, and lightly fizzy. If it tastes too sweet, let it ferment longer. If it tastes too vinegary, it has fermented too long.

Once it reaches your desired flavor, strain the tepache through a fine-mesh sieve into clean bottles or jars. Discard the pineapple peels and spices.

Chill the tepache in the refrigerator before serving. It can be stored in the refrigerator for up to a week.