Tequila is an alcoholic drink made from the distilled agave plant. The general group of alcoholic drinks made from this plant are referred to as mescal, of which tequila is a specific and regulated form.
Agave is not, as is commonly thought, a cactus, but is actually a large succulent more closely related to lilies. There are hundreds of species of agave, many of which are radically different from one another. One of the most well-known species is the century plant, often found in gardens throughout the world. Tequila is made from a species of agave called blue agave, or Agave tequilana.
The best tequilas are made solely from agave and are usually labeled as being 100%. Others may mix in some other bulk, such as sugar or corn, to supplement the agave, which is quite expensive. In order to be certified as tequila, however, at least 51% of the material used to make it must be agave.
Many archaeologists believe that the agave plant has been cultivated by humans for nearly 9,000 years. The first evidence for an alcoholic drink made from it dates back to the time of the Spanish Conquistadors nearly 500 years ago, who distilled the native pulque drink into a stronger liquor. By the 17th century, the beverage was being mass produced and sold throughout Mexico. The modern tequila has its origins somewhat later, around 1800, when it began to be mass produced using methods that are almost identical to those used by many modern producers. Some of these original batches have survived and are still available for sale.
In the past decade, tequila has seen increased international popularity, with worldwide sales skyrocketing. A wide range of top-end spirits have sprung up to take advantage of this popularity, and a number of large corporations have begun expanding their production. The popularized inclusion of a worm in the bottom of a bottle has its origins in the 1940s, when it was introduced as a marketing ploy. The worm is meant to be the larvae of a moth that sometimes infests the agave plant, whose presence denoted a lower quality product. In recent years, manufacturers have struggled to remove the myth of the worm from the minds of their drinkers, as they attempt to improve the image of the drink.