mezcal worm in shot of mezcal with sliced oranges placed in background
Julie Hambleton
Julie Hambleton
March 2, 2024 ·  4 min read

Mezcal Worm in a Bottle: DNA Testing Yields Unexpected Results

Mezcal, the Mexican spirit that is gaining popularity in the United States, has a unique history. The worm in a bottle is just one of its many interesting characteristics. But why is that little worm inside the bottle, and more importantly, what species of worm is it? A new study has revealed just what species that Mezcal worm truly is.

DNA Testing Reveals Who The Mezcal Worm in a Bottle Really Is

A new study published in PeerJ Life & Environment looked to identify the species of larva found in bottles of Mezcal. All larvae appeared superficially very similar, with a distinct head capsule and prolegs that are characteristic of lepidopteran larvae. Some specimens were white, others were pinkish-red. The researchers performed DNA sequencing to determine the species. Of the 21 larvae subjected to DNA extraction, 18 yielded DNA sequences that were suitable for analysis. (1)

The study found that all larvae are a single moth species affirming the importance of C. redtenbacheri for the mezcal industry. Larvae of C. redtenbacheri are one of the most popular edible insects in Mexico. They are commonly eaten in tacos, soups, and salads. They are also sold dried for consumption as a snack. The lepidopteran larvae have the potential to provide a sustainable source of protein for both humans and livestock with minimal environmental impact. They are added to many Mexican foods and beverages because of their health benefits. Many also believe that they hold aphrodisiac properties.

Image Credit: Jose I. Martinez

What Is Mezcal?

Mezcal is a distilled alcoholic beverage that has been produced for centuries in Mexico. It is made from the heart of the agave plant, which grows primarily in the state of Oaxaca. There are two types of mezcal: de espadín and de maguey. De espadín is made from piñas (the core) from wild or semi-wild agave plants, while de maguey is made from mature agaves cultivated by local farmers. (2)

The distillation process for both types of mezcal is the same. The piñas are roasted in a pit or oven and crushed, releasing juice. This juice is then heated to create steam, which drives off alcohol and causes the liquid to become thick. The thick liquid is then poured into jugs called metates (“masa” means “cornmeal”) where it cools down and becomes a solid again. This process is repeated until the mezcal has a high alcohol content. The final product is then filtered and bottled or sold as unaged, white mezcal.

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Types of Mezcal

When it comes to drinking mezcal, there are also two different types: Blanco and Reposado (rested). Blanco mezcal is clear and unaged. It has a light, neutral flavor profile that makes it perfect for mixing in cocktails. Reposado mezcal, on the other hand, is aged in oak barrels for between two months and one year. The aging process allows it to develop a deeper color and smoother taste with notes of vanilla and spice.

Image Credit: Jose I. Martinez

Why Is There A Worm In Mezcal?

One of the most famous characteristics of mezcal is the worm that’s often found in bottles. The presence of a worm isn’t random, however; it has a deep history that dates back to pre-Hispanic times. Before mezcal became a popular spirit in Mexico, it was drunk as an everyday beverage. The worm at the bottom of the bottle was an indicator that the mezcal had been made properly and wasn’t poisoned by molds or other contaminants. Today, the practice of putting a worm in each bottle has become more ceremonial than anything else; it’s not necessary to have one present in order for your drink to be considered authentic.

The Difference Between Tequila and Mezcal

Tequila and mezcal are both made from agave, but they are very different spirits. Mezcal is made primarily in Oaxaca, while tequila comes from Jalisco; the two states have distinct climates, soil types and methods of production that affect their flavor profiles. Tequila is a distilled spirit made from blue agave (a type of succulent), while mezcal can be made from any species of the agave plant. Tequila has an ABV between 38% and 55%, while mezcal can have an ABV anywhere between 25% and 50%. (3)

Tequila is often described as having a “clean” taste, while mezcal has a more earthy flavor profile that includes smoky and spicy notes. Tequila can be flavored with fruits or spices after distillation, but it is not aged in wood barrels like mezcal.

Image Credit: Jose I. Martinez

Give Them Both A Try

If you are reading this thinking “but I don’t like Tequila!”, if you find yourself in Mexico, we encourage you to give these drinks a try, anyways. There are many wonderful Tequilas in Mexico (especially if you visit the town Tequila in Jalisco), and Mezcal is an entirely different experience altogether. Rumor has it, as well, that if you eat the Mezcal worm, you will find yourself feeling pretty good pretty quickly. We’ll let you be the judge on that one.

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  1. Mezcal Worm in a Bottle: DNA Testing Yields Unexpected Results.” Scitech Daily. PeerJ. March 8, 2023.
  2. What is mezcal, what does it taste like and how is it made?AZ Central. Daniel Gozalez. February 22, 2022.
  3. What Is The Difference Between Tequila and Mezcal?Mestizo Market. November 23, 2020.