Fermentation is a natural, metabolic process caused by yeast and bacteria that converts sugars to alcohol, gases and acids. The crushed, cooked agave is shoveled by hand into large wooden or plastic vats and water from a local source (spring, river, or well) is added.

Unique, wild yeasts are living in an around us all the time. They float into the open-air palenques colonizing the fermentation vats and naturally begin the fermentation process of the sugary liquid within. This natural fermentation, completely unaided by added yeast or enzymes, typically lasts 8-10 days. The fermenting agave juice warms and bubbles as the sugars are converted.

When most of the sugar has been converted to alcohol and the yeast eventually starves itself to death, the fermentation is complete. The liquid is now quite dry and mildly alcoholic between 4 and 7% ABV.