Wash a 1-gallon glass jar (or nonreactive container) and utensils with hot, soapy water, then rinse well and let air-dry; this helps avoid unwanted microbes.
Rinse and scrub the pineapple, trim off the crown, peel the skin in wide strips, remove the core, and cut the flesh into 1-inch chunks; reserve peels, core, and chunks.
Bring 2 cups of the water to a simmer in a small pot, remove from heat, and stir in the piloncillo until fully dissolved; stir in the remaining 6 cups water to cool the mixture to room temperature.
Put the prepared peels, core, and chunks into the jar, add the cinnamon stick and whole cloves, then pour in the cooled piloncillo mixture until solids are submerged (use a clean weight to keep them under the liquid).
Cover the jar with a clean cloth or coffee filter secured with a rubber band and ferment at room temperature (70–80°F/21–27°C) until lightly bubbly, fragrant, and sweet-tart, 24–48 hours; it is ready when small bubbles rise and the taste is pleasantly tangy, not vinegary.
Strain through a fine-mesh sieve lined with cheesecloth into a pitcher; for natural fizz, funnel into swing-top bottles leaving 1 inch headspace, seal, and leave at room temperature 12–24 hours until lightly carbonated, then refrigerate to chill and slow fermentation.