So our local newspaper proclaims! Tequila is an alcoholic beverage prepared from the leafless cores of various types of agave in statutorily-defined areas of Mexico, where it is a native plant.  One USA botanical source lists over 1350 recorded names of species of agave, but the preferred species for top-quality tequila is the blue agave - Agave tequilana Weber (blue variety).  Even then, this particular agave has many subspecies and varieties. 

There are four main types of tequila, with varying percentages of alcohol.  Some may have involved the addition of non-agave sugars, colourings or flavourings such as caramel, and have been subjected to different periods and methods of aging.  The acknowledged best and clearest, but most expensive, white or “blanco” tequila, is aged for the least time - less than 60 days. Whether it or cheaper types will be the “new vodka” remains to be seen.

Tequila is familiar to drinkers in bars round the world as the basis of margaritas. Margaritas consist of white tequila, mixed with an orange liqueur such as Triple Sec, Cointreau or Grand Marnier, and lime juice (preferably from fresh limes). The rim of the glass can be moistened with lime juice and then dipped in salt.  A lime wedge set across the rim completes the presentation.  However, tequila does not contain the well-publicised preserved worm inside the bottle – this is found in a similar product called Mezcal, which is prepared from one or more other types of agave, to which is often added a preserved larva of one of at least two insect species found within the plant. Tequila and vodka are sometimes combined in cocktails, but which will be most popular and affordable in the long term remains to be seen. The traditional preparation of tequila did not include distillation, so the usual alcohol content was only 5%-7% or so.  However, when the Spanish Conquistadores arrived in Mexico, far from their ready supplies of familiar liquors, they introduced distillation and so a much stronger spirit could be produced. The Mexican legal limit to alcohol in tequila is 38%-55% but the lower end of this range is most common. Production is labour-intensive at times during the 8-12 years it takes the blue agave to approach maturity.  Offshoots arising from the base of the plant are taken to provide new plants. This is because the developing flower spike is cut off a few months before it is ready to emerge from the core, which subsequently swells and becomes sugar-enriched, a desirable quality for alcohol production.  The leaves are cut off during harvesting of the core, which can weigh over 50 kg. Shredding, roasting (or steaming) milling and fermenting are followed, in commercial production, by distillation and then blending to standardize the flavour of particular brands.

The high prices asked for bottled tequila do not reflect the poor cash return to the Mexican growers, who have suffered recent boom and bust periods, with some crops affected by serious epidemics of fungal and bacterial diseases.  The Mexican authorities seem to be just as protective as the wine-growers of the Champagne district of France of the name of their important local product, and the areas in which it can legally be grown. This, together with the lengthy period before a crop can be harvested, its size and quality depending on climate and soils, and the technicalities of processing, would surely discourage any serious tequila fancier from embarking on a do-it-yourself project.

It may be of interest that a rather similar member of the Agavaceae,  Furcraea foetida, a mistakenly-labelled, weedy species which grew in our back garden for about 25 years, allowed us to secure a current record in the Guinness Book of Records in 2002 for the tallest inflorescence ever recorded. It towered for almost 40 feet, on top of a further five feet or so of the substantial leafy base.  The long-awaited, sudden emergence of the flowering stem and the rate at which it grew each day were remarkable.  It beat the previous record, for an unrelated species, by about five feet, but we are sure there are still-taller relatives out there somewhere. Further information can be found in books such as:

Lawrence Kretchmer “Guide to Tequila” and Lance Cutler’s “The Tequila Lover’s Guide to Mexico”.

Also, a very exhaustive review with links to further information is available at: http://www.ianchadwick.cm/tequila/news.html.



Authored by: 
Dr Elwyn Hegarty - Plantchem Pty. Ltd
Sourced from: 
STFC June July 2004