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Why There’s a Worm in Your Tequila Bottle

Mezcal mexican drink and orange with worm salt
Marcos Castillo/Shutterstock

Whether you’ve ever been challenged to eat the worm in the bottom of a tequila bottle yourself or simply watched someone else do it, you might be wondering what the deal is with the worm in the first place. But if you’re looking for the truth about the worm in your tequila, I have some sobering news for you: The truth is, there isn’t one.

Or at least, there shouldn’t be a worm in your tequila bottle; if there is, then the tequila itself is probably, well, let’s call it a little suspect. The worm, you see, is only found in bottles of tequila’s close relative, mezcal—and what’s more, it isn’t even a worm at all.

Here’s what you need to know about mezcal worms, from what they are to how they got there and what the heck happens if you eat one, anyway.

Mezcal vs. Tequila

Before we can talk about the worm, we need to talk about the differences between mezcal and tequila. Both spirits are distilled from the agave plant—a genus belonging to the Asparagaceae family of plants that’s native to hot, arid climates in the Americas. (Yes, agave and asparagus belong to the same family.) The process for making both is also similar: It starts with harvesting the agave and extracting and cooking the piña, or heart of the plant; then a mash is made from the cooked piña, which is subsequently distilled (usually twice).

But here’s the important thing to remember: Tequila is a type of mezcal—that is, all tequilas are mezcal, but only some mezcals are tequilas.

For one thing, mezcal can be made from a wide variety of agave plants— you’ll find citations for anywhere from 11 types of agave to 50 being used for distilling mezcal. Tequila, however, can only be made from one type of agave: Weber blue agave, known scientifically as agave tequilana Weber. This decision was made due to some of the Weber blue’s more unique characteristics, according to Patrón’s director of production, Antonio Rodriguez. “The Weber blue agave was selected to be the go-to agave for tequila because of its higher sugar concentration compared to other agave plants, as well as its reproduction method, life cycle, and strength of the plant,” Rodriguez told Vinepair in 2017.

Mezcal and tequila also differ in taste—mainly because of differences in how the piña is cooked in the production of each. For mezcal, the piña is typically roasted, which tends to impart a rich and smoky taste to the finished spirit. For tequila, however, the plant is steamed, resulting in a milder flavor. (The variety of agave used also affects the taste, however, so given that tequila is made from only one type of agave, while mezcal has a whole host of options, you can see how there might be more variations in flavor for one over the other.)

Furthermore, production of tequila and mezcal are each limited to specific areas. Jalisco, Nayarit, Tamaulipas, Michoacán, and Guanajuata are the only the only Mexican states where tequila is permitted to be made; meanwhile, mezcal is made in Durango, Guanajuato, Guerrero, San Luis Potosi, Tamaulipas, Zacatecas, Michoacán, Puebla, and Oaxaca. The vast majority of mezcal—around 85 percent of it—comes from Oaxaca.

So, What About the Worm?

And, of course, there’s the worm, or the gusano, as it’s known. That’s another one of the differences: Contrary to popular belief, worms come not in tequila, but in mezcal—and even then, only some mezcals have worms. When there is a worm in the bottle, it’s referred to as mezcal con gusano—literally, “mezcal with worm.” It’s usually added at the end of the production process.

Typically, the gusano is one of a few varieties of edible caterpillar or insect larva that feed on agave plants. They’re usually either white or red; when they’re white, they’re the larvae of the Aegiale hesperiaris butterfly, while the red variety is the larvae of the Comadia redtenbacheri moth. Occasionally you’ll find not caterpillars, but Scyphophorus acupunctatus, or agave snout weevils, in your mezcal—but this type of weevil is particularly destructive to agave plants, and, when found in mezcal, is generally agreed to be the mark of a cheap spirit.

Exactly how the mezcal gusano became a Thing, however, is up for some debate. As the exhaustive tequila- and mezcal-centric website In Search of the Blue Agave chronicles, an awful lot of folklore has sprung up around the gusano over the years, most of which has never been born out by the historical record. Claims that it’s a continuation of a tradition begun during the Aztec Empire or that innkeepers once used the gusano to test whether their mezcal had enough alcohol in it to pass muster remain unsubstantiated.

The most likely explanation is that it’s a marketing gimmick: In 1950, the mezcal brand Gusano Rojo was registered by Jacobo Lozano Páez, an art student/liquor store employee turned mezcal producer who—the story goes—found early in his mezcal-making career that the larvae that sometimes made its way into the mezcal during the production process changed the flavor of the spirit. Accordingly, he began bottling and selling mezcal con gusano, marketing it under the names Gusano Rojo (“red worm”) and Gusano de Oro (“gold gusano”). From there, the gimmick simply took on a life of its own.

The Gusano Rojo brand is still in production today; it’s been owned by several different companies and distillers over the years, including Nacional Vinícola and, most recently, Mezcales de Gusano. But you can still get it, and there’s still a gusano lurking at the bottom of every bottle.

Can I Eat the Worm?

Good news if you’ve ever been challenged to eat a mezcal worm: They’re edible. In fact, the gusano appears on its own throughout Mexican cuisine. It’s also called the maguey worm, and you can eat it fried, roasted, crushed up into salt and sprinkled on everything from limes to tacos, and more.

When it comes to the mezcal gusano in particular, popular lore insists that it has abilities that verge on magical if you eat it. Consuming one is said to function, alternately, as a psychedelic, an aphrodisiac, or simply as a thing that will make you even drunker than you already are. In truth, the gusano is none of these things; sometimes, a worm is just a worm.

However, recent research has found that the gusano does have a bit of an effect on the mezcal itself: According to molecular biologist Antonio De León Rodríguez of the Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), who has spent much of his career studying mezcal and tequila and spoke to Vice about his research in 2014, mezcals con gusano “have a greater amount of unsaturated compounds and unsaturated alcohols such as…cis-3-Hexen-1-ol.”

As Alexandra Ossola observed at Vice, this compound often smells like cut grass to humans, which can, in turn, affect how we experience both the scent and taste of mezcal; furthermore, it is a pheromone that can affect some insects and mammals, although it hasn’t been seen to have the same effect on humans. Either way, though, it might be interesting to compare tastings of mezcals con gusano and mezcals without the worm; you may find you prefer one variety over the other.

Of course, it’s worth noting that these days, the gusano tends mostly to appear in bottom shelf mezcal; the high-end stuff is usually gusano-free. But if you find yourself in the presence of a bottle of mezcal con gusano, go ahead and enjoy yourself—worm and all.


Lucia Peters Lucia Peters
Lucia Peters is a writer and editor based in Washington, D.C. Her work has appeared at Bustle, The Toast, Crushable, The Gloss, and others. She also writes and manages The Ghost In My Machine, where she haunts readers several times weekly with spooky stories of the strange and unusual. Her first book, Dangerous Games To Play In The Dark, was published by Chronicle Books in September of 2019. Read Full Bio »