Fermentation is one of the most important stages of the process. In this stage the sugars are transformed into ethyl alcohol and others in smaller proportions. Fermentation is performed in big stainless steel containers and honeys, also known as must, are added. Then water, yeasts and nutrients for fermentation are added.
Fermentation time varies depending on environmental temperature and this, in turn, changes with each season. Under low winter temperatures, fermentation can be prolonged more than 24 hours. This process has a pattern similar to any organism development curve, representing firstly an exponential growth, then a second lineal phase and a late-stage decrease. Any product fermentation implies alcohol, carbon dioxide, water and energy released as heat. Must in plain fermentation is effervescent and motion ceases when yeast cells finish work. At that time the process ends and it is customary to say that must is dead; yeast has completed the sugar conversion into alcohol.
During distillation process, heat and pressure is applied, separating the enzymes in alcohol content products (Tequila) and vinasse; being the latter a waste product. Process is carried out in copper or stainless steel stills, and even in continuous distillation towers. Common stills consist of three parts: the pot or boiler, where must is deposited for heating; the column or capital, which collects and conducts the steams, and the coil, where the steams are cooled becoming liquid.
Boiling points of the different compounds and the diverse volumes and pressures of the still assist in the gases separation, and these are condensed into higher alcoholic content products. Two distillation processes are needed to produce Tequila: the first is called crushing and the second rectification.
Alcoholic content increases with rectification and undesirable products are eliminated, getting a high purity product. Tequila gotten from crushing or first distillation is called “Tequila ordinario” (standard Tequila). Tequila earned from second distillation or rectification is considered as “Tequila blanco” (white Tequila). In addition to vinasses, there are other sub products that can be gotten from distillation beginning and ending, known as “cabezas”(heads) and “colas” (tails), respectively. The last parts of the distillate to come through the still, usually recycled into a subsequent distillation