Overview of Blue Agave
The Blue Agave, A. tequilana, is a domestic species of agave that is descended from Agave angustifolia (Gentry 1982). Blue agave is culturally and economically significant because it is the only species of agave that can be used to produce tequila which is certified by the Mexican government (NOM-006-SCFI-2012). Its sap is the main and defining ingredient of all forms of the alcoholic beverage and, “By federal law in Mexico, A. tequilana Web var. azul is the only variety of agave permitted for the production of any tequila (Gil Vega et al. 2001).”
Many botanists acknowledge that the separation of Blue Agave as its own species is nominal (Lopez et al. 2003; Valensuela Zapata & Nabhan 2003; Franck 2012; Garcia-Mendoza & Chiang 2003; Gentry 1982). However, Gentry and others have been reluctant to synonymize it with the wild species A. angustifolia because the tradition of maintaining separation is important to the tequila industry (Valensuela Zapata & Nabhan 2003). The tequila industry relies on the species classification of A. tequilana to provide commercial distinction between tequila and other mezcals and does not allow any other varieties besides agave tequilana var. azul for pure tequila (NOM-006-SCFI-2012; Valensuela Zapata & Nabhan 2003).
The sap of Agave tequilana is sweet and edible. It has been used since Pre-Columbian times, along with other agave species, to make alcoholic beverages and traditional medicines (Vargas-Ponce et al. 2009; Mohr 1999). Various indigenous Mesoamerican cultures have considered agaves to be sacred plants because they supplied many products necessary to everyday life and there (Bye 1993). In part because of this, there is an agave goddess in the Aztec pantheon named Mayahuel that is particularly associated with the traditional alcoholic beverage pulque, which blue agaves and their species of origin were likely used to produce (Vargas-Ponce et al. 2009; Bye 1993).
Today, the market for pulque has shrunk considerably and most Blue Agave is grown for tequila production (Mohr 1999). The tequila industry has grown substantially in the last 15 years, featuring a 19.82% yearly increase between 1995 and 2008 (Valenzuela 2011).The industry has seen as switch to intensive cultivation of Blue Agave in monoculture plantations since the beverage gained worldwide popularity in the 1980s (Dalton 2005). In the past 10 years especially, this has resulted in environmental impact in the form of soil erosion as well as soil, air and water pollution as well as the displacement of traditional food crops and Agave landraces in the zone designated Appellation of Origin for Tequila (Zizumbo-Villarreal et al. 2013).
Gloves should be worn when handling Blue Agave. All tissues of A. tequilana have calcium oxalate crystals, which are sharp at both ends and cause irritation and persistent rashes when they come in contact with the skin. In tequila distilleries 5/6 of workers that handle the stems and 1/3 of workers who harvest agave experience irritation characteristic of contact dermatitis (Salinas et al. 2001).
- Bye, Robert (1993). The Role of Humans in the Diversification of Plants in Mexico. in “Biological Diversity of Mexico: Origins and Distribution” TP Ramamoorthy, Robert Bye, Antonio Lot and John Fa eds. Oxford University Press.
- Centro de Información de la Dirección General de Normas de la Secretaría de Economía (2012) NOM-006-SCFI-2012. Catálogo de Normas Oficiales Mexicanas.
- Dalton, Rex (2005). Alcohol &science: Saving the Agave. Nature 438 (22 December): 1070-1071.
- Franck, Alan R (2012). Guide to Agave, Cinnamomum, Corymbia, Eucalyptus, Pandanus and Sanservieria in the Flora of Florida. Phytoneuron 2012-102:1-23
- Garcia-Mendoza, Abisai & Fernando Chiang (2003). The Confusion over Agave vivipara L. and A. angustifolia Haw., two distinct taxa. Brittonia 55(1) 2003: 82-87
- Gentry, HS (1982). Agaves of Continental North America. University of Arizona Press.
- Gil Vega, Katia, González Chavira, Mario, Martínez de la Vega, Ocatavio, Simpson, June & Vanemark, George (2001) “Analysis of genetic diversity in Agave tequilana var. Azul using RAPD markers.” Euphytica 119:335-341.
- Lopez, Mercedes G. Norma A. Mancilla-Margalli, Guillermo Mendoza Diaz (2003). Molecular Structures of Fructans from Agave Tequilana Weber Var. azul. Journal of Agricultural Food Chemistry. 51(77): 7835-7840.
- Mohr, Gary M. Jr. (1999) "Blue Agave and Its Importance in the Tequila Industry," Ethnobotanical Leaflets, 1999(3): Article 2.
- Salinas, ML., Ogura T. and Soffchi L (2001). “Irritant contact dermatitis caused by needlelike calcium oxalate crystals, raphides, in Agave tequilana among workers in tequila distilleries and agave plantations.” Contact Dermatitis vol 44: 94-96.
- Valensuela Zapata, Ana Guadalupe & Gary Paul Nabhan (2003). Tequila: A Natural and Cultural History. University of Arizona Press.
- Valenzuela, Ana (2011). “A new agenda for blue agave landraces: food, energy and tequila.” Vol 3(1)
- Vargas-Ponce, Ofelia, Daniel Zizumbo-VillarrealMartínes-Castillo, Jaime, Coello-Coello Julián & Colunga-GarcíaMarín, Patricia. (2009) “Diversity and structure of landraces of agave grown for spirits under traditional agriculture.”
- Zizumbo-Villarreal, Daniel, Vargas-Ponce, Ofelia, Rosales-Adamer, Jesús J, Colunga-GarcíaMarin, Patricia (2013). “Sustainability of the traditional management of Agave genetic resources in the elaboration of mescal and tequila spirits in western Mexico” Genetic Resources and Crop Evolution. Vol 60(1).