Tequila is made from the blue agave plant, which is native to Mexico. The process of making tequila starts with the harvesting of ripe blue agaves, which are then sliced and crushed to extract their juice or 'must.' The must is then fermented in large tanks for a few days before being distilled twice. After distillation, many producers age their tequilas in white oak barrels for further flavour refinement. In order for something to be officially labelled as tequila, it must be made using at least 51% agave sugar. However, if you want to buy good tequila, the best way to ensure quality is to buy tequila that is 100% agave.