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THE UNDERSTORY: The Tequila Agave

Blue Agave.  Photo Credit: Stan Shebs [CC BY-SA 3.0]

By Susan Starr.

At our January meeting, Jeff Chemnick took us on a photographic tour of the plants of the Sierra Madres, which included many beautiful shots of agaves. I wondered, as I had many times before, why tequila only comes from the Blue Agave (Agave tequiliana ‘Weber’ var. azul). Other agave varieties are used in making alcoholic beverages. Why is only the Blue Agave suitable for tequila?

Pulque and Mescal

The two major categories of alcoholic drinks produced from agaves are pulque and mescal. Pulque, I learned, is made from the fermented juice or sap of the maguey plant (Agave americana). The Maya, Aztecs, Huastecs and other cultures in ancient Mesoamerica consumed it on feast days and as part of ritual ceremonies. Pulque production begins when the maguey plant is ready to flower. The center, called a piña, begins to swell and elongate, gathering up stored sugar (fructans) to create a flower stalk. Growers cut off the stalk, leaving a depression in which the sap (known as aquamiel or honey water) collects. The sap is fermented and then drunk as pulque, a beverage relatively low in alcohol (6%).

Agave Piña. Photo credit: Stan Shebs [CC BY-SA 3.0]

When the Spanish arrived, they introduced distillation to remove impurities and increase the alcoholic content of fermented beverages. The result was mescal, a class of liquor that includes tequila. Drinks labeled mescal can come from many types of agave. Espadin (Agave augustifolia (Haw) var. espadin), the predominant variety in Oaxaca, is most commonly used. Mescal is made from the cooked piña, not from the agave sap used for pulque. The piña is stripped of leaves, cut in half, roasted in pits in the ground, crushed, combined with water, and the resulting liquid allowed to ferment before being distilled. Heat hydrolyzes the fructans stored in the agave stems releasing fermentable sugars and producing alcohol.


Tequila also comes from the cooked piña, so it is considered a kind of mescal. Here is what makes it distinctive:

  • It is cooked in ovens rather than pit-roasted, so it lacks mescal’s smoky flavor.

  • It comes from the Blue Agave. Each agave genus has a distinctive taste, reflecting the organic compounds found in the piña. The taste of the Blue Agave has been described as “herbal” and “citrusy.”

  • Blue Agaves, particularly those growing in Jalisco, have some of the highest concentrations of fructans among agaves. This reduces the time needed for distillation and contributes to tequila’s distinctive flavor.

  • The Consejo Regulador del Tequila which regulates tequila production, requires that only liquor made from the Blue Agave can be called tequila, and tequila can only be produced in certain municipalities, most of which are in Jalisco.

The Blue Agave has several other highly desirable characteristics: it has a relatively short time to maturation (5 to 9 years), it pups more readily than other species, and it produces heavily. A single plant can yield from 2 to 5 liters of tequila, enough to fill 3 to 6 bottles.

In the same way different grapes yield different wines, agaves produce a variety of beverages that differ in taste and quality. Because of its chemistry, and also by regulation, the Blue Agave is the only one that can produce the drink we call tequila. However, a wide variety of agaves can be used to create alcoholic drinks to enjoy. ¡Salud!

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