Place the piloncillo on a board and, using a serrated knife, slice the sides downward from top to bottom, and then finely chop the sugar. (Alternatively, you can use a box grater and grate on the large holes.) Add the chopped piloncillo to a 2-liter or 2-quart glass jar or other nonreactive container. Add 4 cups of the filtered water. Stir vigorously with a wooden spoon until most of the sugar dissolves, about 1 minute. It’s OK if all the sugar doesn’t fully dissolve at this point.

Trim off and discard the top and bottom of the pineapple. Stand the pineapple on a cutting board and, using a knife, work around the pineapple to cut the peel off in strips. Set the fruit aside to eat later.

Stir the piloncillo water again to dissolve the sugar. Add the pineapple peel to the liquid and pour in the remaining 2 cups of filtered water. Add any add-ins you like. All of the ingredients should be covered by the liquid. If the pineapple peels pop up, you can place one peel on top of the others to keep everything submerged as best as possible. Place a clean cloth on top of the jar. You can secure the cloth with a rubber band or string, or just rest it on top. Place the jar in a secure, warm, dark place to ferment. Try not to move the jar around.

Check on the tepache daily. Around day 2 or 3, depending on the environment, you should see some frothing on the top. This is a sign that it’s fermenting. Taste a little bit of your tepache to see if it has fermented to your liking. If it’s not yet fermenting, or not at the stage you prefer, cover and continue to let it ferment.

When it has fermented to your liking, which may take up to 5 to 7 days, strain using a fine-mesh strainer, discarding the peels, core and any spices. Transfer the tepache to a pitcher or bottle and refrigerate.

To serve, pour over ice and add more water to dilute and sugar to sweeten as desired. Tepache will keep in the fridge for up to 5 days.