Science, Tech, Math › Science Your Tequila May Contain Methanol Share Flipboard Email Print Bob Muschitz, Getty Images Science Chemistry Chemistry In Everyday Life Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated August 14, 2019 Happy Cinco de Mayo! If your holiday celebration includes tequila, you may be interested to know the American Chemical Society (ACS) has found that some tequila contains methanol, 2-methyl-1-butanol, and 2-phenylethanol. What are these chemicals? In case you're wondering, no, these are not good and desirable chemicals to drink. The 'alcohol' in alcoholic beverages that you drink is ethyl alcohol or ethanol (grain alcohol). Methanol (wood alcohol) and other alcohols are the types that can make you go blind and otherwise cause permanent neurological damage, not to mention give you a nasty hangover. The ACS purposely timed the release of the results to coincide with Cinco de Mayo, to raise awareness of the quality control issue. Tequila made from 100% blue agave tended to have higher levels of undesirable chemicals than other types of tequila (pure agave tequila is usually considered superior). What This Means Does this mean tequila somehow bad? No, actually tequila is one of the best-regulated alcoholic beverages in the world. The results not only point out a potential health hazard for this drink but also indicate other beverages are probably adulterated with contaminants. It's the nature of distillation. The process relies on boiling point differences between liquids, which means good control of temperature is key. Also, the first and last portion of alcohol that is distilled (the heads and the tails) contain other compounds besides ethanol. Not all of these molecules are bad, so a distiller may choose to retain a certain amount. Then, there is a risk of picking up contaminants during the aging process. It's tricky, which is why top-shelf tequila is likely way better than home-grown moonshine, as far as your health goes. Yet, it's possible to distill alcohol without unwanted compounds. Why does the problem persist? It's partly a matter of economics, where a distillery determines what level of contamination is acceptable. Increasing purity decreases yield which decreases profit. It's partly a compromise between making a product with premium flavor, color, and scent while keeping toxins to a minimum.