Gather the ingredients.

Combine the water and piloncillo or brown sugar in a pot or 2-quart mason jar. Stir to dissolve the sugar. If you are using piloncillo, it will take longer to dissolve; stir the water occasionally with a wooden spoon and break the piloncillo up as it softens.

Cut off the crown from the pineapple and discard. Wash the outside of the pineapple with water.

Peel your pineapple on a cutting board. Cut a slice off the top of the fruit, another slice off the bottom, and then slice the peel off in strips—or use your favorite method, as long as you end up with a peeled pineapple.

Place the pieces of peel into the pot. Add the stick of cinnamon.

Cut the fruit of the pineapple into slices or chunks, reserving the fibrous core. Store the fruit for another use.

Add the core, whole or in chunks, to the pot and stir.

Cover the pot with a dish towel, and set it on the kitchen counter at room temperature—it should be easily accessible but also out of the way. The towel will keep out any foreign matter while allowing air to reach the mixture, to ensure a successful fermentation.

After 24 to 36 hours, check your tepache. If you see a bit of frothy white foam on the surface of the water, it’s fermenting. You can drink it as is, or let it continue to brew another day or so. If you do not see any white froth, cover the pot again and check it after another 24 hours; the time necessary for fermentation will vary according to the room temperature, ripeness of the pineapple, and other factors.

Once your tepache has reached the desired level of fermentation, strain out, and discard all the solids.

Transfer the liquid to a pitcher and refrigerate.

Before serving, take a test drink. Add more water or sugar to taste; it's not uncommon to dilute with more water.

Serve over ice, if desired. Enjoy.