Final answer:
The main differences between agave harvesting for aguamiel and tequila come down to the timing and method of extraction, and the subsequent processing of the sap or 'piña'.
Step-by-step explanation:
The difference between the harvest of agave for aguamiel and for the production of tequila lies in the processing of the agave sap. Native populations have been harvesting agave plants for hundreds of years, using the sap as a source of nutrition and fermenting it to create different alcoholic beverages.
For aguamiel, the sap is extracted from the core of the agave plant before it flowers. This sap is sweet and can be consumed in its natural form or fermented to produce an alcoholic drink called pulque. To harvest for aguamiel, the central part of the agave is carved out, creating a well from which the sap is collected daily.
In the case of tequila, the plant is allowed to mature for several years before the entire agave 'piña' or core is harvested after the plant has ceased its growth just prior to flowering. The 'piñas' are then baked to convert complex carbohydrates into simple sugars, crushed to extract the juices, and those juices are subsequently fermented and distilled to make tequila.