Which agave cultivar is specified for tequila production under Mexico’s official rules?

Mexico’s official tequila rules specify Blue Weber agave, formally Agave tequilana Weber var. azul.

This cultivated variety is valued for its sugar-rich heart, which is harvested after years of growth. Producers cook the hearts, extract their sugars, ferment the resulting juice or mash, and distill it into tequila.

The word “blue” refers to the plant’s blue-green appearance, while “Weber” honors the botanist Frédéric Albert Constantin Weber, who classified the variety in the early twentieth century. The scientific name is often shortened in everyday writing to blue agave.

Other agave varieties are used for mezcal and other agave spirits, but using another variety does not satisfy tequila’s official raw-material requirement.