The separation of volatile from the nonvolatile substances in tepache comes from the fermentation stage, this is what is known as distillation. In Tepache are found solid (non-volatile) and liquid (volatile) matter which must be separated by distillation. In the liquid part are found alcohols, ketones, ethers, etc. In the solid part are found fats, minerals, fibers, etc.
By submitting Tepache to heat it causes the evaporation of alcohol and impurities, leaving it separated from the solid materials. If these gases are collected and returned to their natural state, an alcohol is obtained that in the case of agave is called mezcal in states with Designation of Origin.
The distillation process is carried out in a still, several theories explain the use of the still for distilling the fermented agave, although two are the best known, one mentions that it was the Spaniards (who inherited it from the Arabs) who introduced it to our territory and one theory holds that the Filipinos were the ones who introduced the Chinese still. Several types of stills exist but all do the same, distil.