All four of the major parts of the agave can be eaten: flowers, leaves, stalks or basal rosettes and sap (Davidson 1999). The plants bloom every 8 to 12 years and each plant may produce several pounds of edible flowers. During inflorescence sap collects in the base of the flower stalk(Davidson 1999). The stalks the flowers grow on can be roasted and pulverized to extract the sap. Leaves can also be collected for eating in winter and spring when the plant is rich with sap. Species are grown for commercial sap production include: Agave tequilana, Agave salmiana and Agave Americana (Morales Areli et al. 2008).
Agave sap is rich in carbohydrates such as inulin, sucrose and fructose and also contains small amounts of amino acids and vitamins (Morales Areli et al. 2008). It is collected from many species but particularly A. tequilana, A.atrovirens, A. potatorum, and A. americana. The sap is commonly called “aguamiel” (honey water), “agave syrup,” and “agave nectar.” Although it has traditionally been harvested to make pulque or mezcal it can also be drunk on its own or used as a sweetening agent(Mata Pizón & Zolla 1994a). The sap, which is thinner and sweeter than honey, is produced as a commercial sweetener that can be added to mass produced cereals or sold in individual bottles to be used in home-cooking (Mata Pizón & Zolla 1994a; Mohr 1993).
Pulque is an alcoholic beverage that was religiously and economically significant in Mesoamerica in the pre-Columbian economy (Miller and Taube 1993). It is made by fermenting agave sap. Pulque was closely restricted under Aztec rule but it was secularized after the Conquest of Mexico by the Spanish and became widely consumed throughout the colonial period (Miller and Taube 1993).
Pulque can be made from many agave species: A. teometl Zucc., A weberi Cels., A. altísima Jacobi, A compilata Trel., A. gracillispina Englem., A. malliflia Trel., A. quitifera Trel., A. crassispina Trel., A. mapisaga Trel., A Americana L., A. salmiana Otto., and Salm A. atrovirens (Morales Areli et al. 2008). A key distinguishing feature between pulque and tequila is that pulque can be made from many different species of agave while tequila must be made from Agave tequilana var. azul to qualify as tequila (Miller and Taube 1993).
Mezcal (& Tequila)
Mezcal is a drink made from the cooked heart of certain agave plants. Because all tequila is mezcal but not all mezcal is tequila, many different species of mezcal may be made into agave.
Tequila is a variety of mezcal made from Agave tequilana var. azul, commonly known as Blue agave. Blue agave is made into tequila by cooking the sap out of the stems which is then fermented and distilled into liquor. Production is limited to 5 Mexican states with most of the production taking place in Jalisco, Mexico (Dalton 2005).
Biofuel Feed Stock Potential
It has been found in 14 different studies that 2 species of agave greatly exceed the yields of other biofuel feed stocks including corn, soybeans, sorghum and wheat. Agave is set apart from these crops because of its “high water use efficiency and ability to survive between rain falls (Davis et al. 2011).” Davis et al. suggest that abandoned agave farms in Mexico in Africa that had previously produced material for the natural fiber market could be converted into bioenergy cropland and that the biomass of agave could be co-harvested with sap in tequila production without additional land demands (Davis et al. 2011).