For the Love of Mezcal: Debunking Methanol Myths

Screen Shot 2017-07-26 at 2.42.13 PMBy Alvin Starkman, M.A., J.D.

When trying to understand the relationship between the Mexican agave-based spirit mezcal, and methanol poisoning, it’s hard to separate fact from fiction from fear-mongering. One finds lay literature without references backing up claims and allegations regarding the likelihood of hangovers, headaches and much more serious effects (blindness and death); it’s cloaked in words including “likely” and “probably.” And it ignores aspartame.


Is it appropriate to equate mezcal, which has been produced essentially safely and without incident by families in Oaxaca for generations, with American moonshine and deaths due to deliberately adulterating a spirit for purely profit motive, with concoctions created by naive youth, or with third-world country reports where ignorance of safe spirit production results in imprudent means of production or the use of equipment which contaminates? The alarmists draw their data from such sources.

For a quarter century I’ve been drinking mezcal sold at small, family owned artisanal distilleries without incident. And so have my friends and compadres, hundreds of thousands of villagers who patronize their neighborhood producers, and more recently visitors to Oaxaca anxious to sample and take home at an accessible price quality they cannot find at their local bars or retailers.

To augment my understanding I rely on online sources such as International Center for Alcohol Policies, UPI, Methanol Institute, National Institute of Health / U.S. National Library of Medicine, World Health Organization, as well as my social anthropology background. My Darwinian academic training led me to an Internet search enabling me to prove a reasonable hypothesis, and put into perspective the tall tales I’d been reading — that mezcal not certified by a regulatory agency is fake, illegitimate, results in hangovers, and may even lead to blindness or death from methanol poisoning. Have imbibers been extremely lucky all these years, decades and perhaps even millennia?

Just as early Zapotec natives learned to dye with the cochineal insect, and presumably through trial and error that the mineral alum served as the best mordent, it is suggested that the Spanish and indigenous peoples of Mexico similarly learned how to distill safely. Wool dyed red with cochineal dramatically faded from the sun or washing, until a reliable fixer was found; and likely hundreds of years ago both natives and Spanish succumbed to unwise distillation practices, until they learned to remove methanol from the spirit, and distill using clay, copper and other “safe” metal compounds.

Methanol Explained

Our bodies contain methanol, from eating fruits and vegetables. It is absorbed through the gastrointestinal tract and the skin, and by inhalation. It is metabolized in the liver, converted to formaldehyde and then to formic acid. As a building block for many biological molecules, formate is essential for survival. On the other hand, high levels of formate buildup after excessive methanol intake can cause toxicity. Methanol is considered a cumulative poison due to the low rate of excretion once absorbed.

Methanol is used for industrial and automotive purposes: antifreeze, canned heating sources, copy machine fluids, de-icing liquids, fuel additives, paint remover, shellac, and windshield wiper fluid. This is known as denatured alcohol. Government actually dictates the inclusion of high levels of methanol in such products, wanting to ensure that the public buys its liquor (in which levels of methanol are controlled, as opposed to other alcohols), in order to maintain healthy tax revenue.

But Government rules do not prevent consumption of denatured alcohol or its being used to fortify other beverages. The literature on non-commercial alcohol, which is sometimes referred to as unrecorded alcohol, cites these “surrogates” or non-beverage alcohols as one of three categories of drinks which potentially create health risks. They are drunk alone (i.e. the classic skid row cases) and used as “cocktails” when they are added for example to fruit juices. The other two are “counterfeit” products and illicit mass-produced drinks, and traditional drinks produced for home consumption or limited local trade (licit or illicit). Artisanal mezcal falls into the second part of this third category. So yes, there is the possibility of health problems arising as a consequence of consuming mezcal with higher than “safe” levels of methanol.

Screen Shot 2017-07-26 at 2.42.35 PMHealth Risks in Mexico and Internationally                                             ­

In central Mexico, much more than anything else, the singular health problem related to mezcal and other traditional alcohol consumption is alcoholism resulting in liver cirrhosis. In an article centering on global methanol poisoning outbreaks, World Health Organization cited examples of adulterated, counterfeit and informally produced spirits in Cambodia, Czech Republic, Ecuador, Estonia, India, Indonesia, Kenya, Libya, Nicaragua, Norway, Pakistan, Turkey and Uganda. Mexico is conspicuously absent from the list.

An article analyzing the quantification of selected volatile constituents in the Mexican spirits sotol, bacanora, tequila and mezcal, while methanol was the most problematic compound and at times the samples taken were far above the levels recommended by international as well as national standards, two points are particularly noteworthy: methanol levels were not of toxicological relevance, and other legally obtained drinks such as German fruit spirits were found to have significantly higher methanol levels.

In “Noncommercial Alcohol: Understanding the Informal Market,” International Center for Alcohol Policies reported that much of the perceived health risk stems from patterns of drinking such as chronic consumption and binging, use of low quality ingredients, adulteration, and lack of control during production or storage. In Russia and other republics in the former Soviet Union, samagon is cheap and easy to make using household equipment. Kenya’s poor fortify their grain spirit, chang’aa, with surrogates. Brazil’s national drink cachaca or pinga is sometimes fortified using industrial alcohols, some of which are noted above.

What about the United States’ renowned moonshine, typically made using corn mash as the main ingredient? Poorly produced moonshine is contaminated mainly from materials used in still construction, such as employing car radiators as condensers (caked glycol from the antifreeze or lead from the connections). In addition, methanol can be added to the spirits to increase strength and improve profits.

The 1994 report of poisoning from ingesting mezcal produced in the state of Morelos cites the spirit having been deliberately spiked with methanol. It is suggested that this was an aberration, though of course noteworthy. Somewhat surprisingly there was relatively little reported about the incidents, and they have not to my knowledge received attention in the broader English literature centering upon methanol poisoning. Here in Oaxaca an unscrupulous distiller might get away with it once, but never again; villagers have their own way of meting out justice.

As suggested, methanol is not the only potentially harmful constituent. Lead as well as other toxic metals can poison not only as a consequence of employing unsuitable distillation equipment but also through the use of a contaminated water source. Volatile compounds such as acetaldehyde can be produced due to fault in production technology or microbiological spoilage. There have been occurrences of fruit and sugarcane spirits containing the carcinogen urethane.

When is Methanol Safe?

What is the safe maximum level of methanol ingestion? In 1981 aspartame was approved for dry goods, and two years later for carbonated beverages. It is made up of three chemicals: aspartic acid, phenylalanine, and 10% is methanol. The absorption of methanol into the body is sped up when “free methanol” is ingested, and this form of the chemical is created from aspartame when it is heated to above 86 degrees Fahrenheit (i.e. when making sugar-free Jello). In 1993 the FDA approved aspartame as an ingredient in numerous food items that would normally be heated to above that temperature.

The EPA recommends consumption of no more than 7.8 grams of methanol daily. While the amount of aspartame in a diet soda can vary, it has been reported that a single can produces 20 mg of methanol in the body. It is no wonder that aspartame accounts for over 75% of the adverse reactions to food additives reported to the FDA. Chronic illnesses can be triggered or worsened by ingesting aspartame. The range of afflictions reported is alarming.

The current regulation for the maximum amount of methanol in mezcal is .3 of a gram per 100 ml. It is an arbitrary standard. Query how much mezcal one must ingest to reach the EPA maximum limit of methanol of 7.8 grams daily. The FDA states that as much as .5 of a gram per day of methanol is safe in an adult’s diet. Should the Mexican standard be higher, or lower?

No wonder the study referenced earlier identifying volatile constituents in Mexican spirits did not find toxicological relevance in the face of analyzing samples far above recommended levels.


Confusion exists in the literature regarding recommended maximum methanol levels and when health risks kick in, both dealing specifically with Mexican spirits, and where they are noted merely tangentially or not at all. However there is consistency:

  1. There is a paucity of reliable research and literature stemming in part from the fact that statistics regarding non-commercial spirits are essentially non-existent for various reasons (i.e. unrecorded since no precise reliable quantitative figures exist);
  2. There is a lack of collaboration between local authorities, NGOs and international experts;
  3. Methanol poisoning is relatively rare in circumstances where traditional, safe distillation processes that have been passed down through generations are practiced (i.e. throughout Mexico, current United States moonshine operations, etc.; subject to 1., above);
  4. There are umpteen other reasons why there are health risks associated with both licit and illicit spirit production;

There is a concern that strict government controls encourage the consumption of non-commercial or informally sold alcohol and increase harm;

  1. Quality artisanal non-commercial traditional spirits are essentially safe, both aside from and notwithstanding the issue of methanol;
  2. They often constitute an important part of local culture, often with ceremonial significance (i.e. consumed in a plethora of rite of passage events), and provide a source of national pride.

Aside from my Darwinian suggestion that the days of dangerous mezcal production have long passed, and acknowledging the issue of still construction, it is noteworthy that almost all artisanal distilleries in Oaxaca consist of either copper alembics or similar production equipment made in equally standardized and carefully monitored factories; or clay pots. In both cases they are essentially free of harmful levels of compounds.

If there is a lesson to be learned, it is perhaps that one should never drink artisanal mezcal, commercial or otherwise, while consuming government authorized products containing aspartame.

Alvin Starkman operates Mezcal Educational Excursions of Oaxaca (, a registered trademark. He is authorized by the Mexican government to teach about the culture of mezcal and pre-Hispanic beverages.

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