You can learn a lot from the label of a mezcal bottle, but you should still know what questions to ask. (Deb Lindsey /For The Washington Post)

The wall behind the bar at Espita Mezcaleria, where Josh Phillips serves as general manager, is lined with mezcal. Every bottle is a source of pride for Phillips — a certified master mescalier — and beverage director Megan Barnes, who, he says, spends “an ocean of time” researching the producers.

Phillips moves from the flavor notes in tepeztate mezcals (“almost all of them have some note of pepper”) to the cultivation of tobala, an agave that grows largely in the wild. At one point, he smiles sheepishly and tells me to open the list of WiFi networks on my phone, to figure out which one belongs to his cantina in the District’s Shaw neighborhood.

I scan networks of nearby places before I spot it: MezcalDOisStupid, a reference to the “Denominacion de Origen” rules that define mezcal.

Sign of an agave nerd, I think.

Happily, those nerds are increasing in number. Consumers have become more informed about agave spirits, says David Suro-Piñera, president of Siembra Spirits and owner of Tequilas restaurant in Philadelphia. “When I opened the restaurant 30 years ago, people were looking for the worm in the bottle,” he says. “People thought there was a cactus in the desert of Sonora and someone was extracting the tequila ready-made out of that plant.”

Now, he says, more people are engaged “not just in spirits, but they want to know how their craft beer is made, where the lettuce and the chickens are coming from, how the textiles in their clothes were made.”

These origin questions are at the heart of the agave spirits category. But do consumers know what to ask? Where can they get good information about the production processes that affect the flavor of the spirit, fair pay for agave crop workers, the pressures on particular agave varietals?

Sustainability is a big part of the discussion right now. Unlike grapes or grain, agave plants take years to mature. The agave tequilana, or blue agave plant, required for tequila matures fastest, but even that can take five years; espadin, the most common in mezcal, takes up to eight years. Other species can take decades, and some of those — rare, wild, hard-to-get — are highly sought after in the growing mezcal market. Once an agave is harvested, that’s it.

Mezcal is an old spirit being buffeted by contemporary market forces. Young entrepreneurs from Mexico and elsewhere and big multinationals are dipping toes into the category. The new players are sure to spur changes, and not everyone is excited about the possibilities of change.

To ensure mezcal doesn’t become a victim of its own success, advocates want to see producers become more transparent and consumers become more demanding. If the spirit and its makers are to flourish, and if agave species are to do the same, more consumers need to become agave nerds. Or, barring full-blown nerddom, at least develop a deeper understanding of how to choose from among the latest enticing bottles from Mexico.

The tequila example

The D.O. that Phillips’s WiFi network references is a set of rules that define mezcal, much like those that define Champagne as unique to a region of France. The rules specify that mezcal can be made only in Mexico, in nine Mexican states. The D.O. for tequila, mezcal’s best-known offspring, is even narrower, allowing production in fewer states and using only tequilana Weber; mezcal allows use of multiple agave species.

Most agave nerds wouldn’t quibble with the D.O.’s definition of mezcal as uniquely Mexican. Some, including Phillips, would disagree with its state restrictions; after all, agave distillates have been made for centuries across Mexico. But the rules protecting mezcal omit many states that share that heritage.

Beverage director Megan Barnes does extensive research on all the mezcals carried at Espita Mezcaleria in the District’s Shaw neighborhood. (Rey Lopez/Espita Mezcaleria)

Agave spirits lovers spend a lot of time keeping an eye on the regulations that govern the category. To understand why, you have to understand the history of the most famous one, tequila.

Technically a kind of mezcal, tequila has changed over the decades due to market forces. Its popularity and the capital that poured into the category drove most distillers making the spirit to do so faster, using more industrial processes to meet demand, altering the very nature of the spirit.

While some tequilas are still made in traditional ways, many are now made using industrialized processes that, critics argue, minimize the unique characteristics of agave spirits. Such bottlings are sometimes dismissed as “aga-vodkas”: smoother, softer, their agave nature muted, some adulterated with sweeteners or flavorings.

The majority of mezcals are made much as they have always been: by small, family producers, the agave hearts roasted in underground pits, crushed by mallet or a tahona (a stone wheel) and distilled in clay or copper stills.

As interest in mezcal grows, there’s an ongoing battle to define what it is and to shape what it might become. Many mezcal lovers want to make sure that it doesn’t go the way of tequila.

Agave spirits should be understood “as what they are: a cultural element, not a merchandise,” says Pedro Jimenez, director of Mezonte, an organization in Guadalajara devoted to the preservation of agave spirits, via email. He fears that entrepreneurs eager to capitalize on the trend see mezcal “as if it was a Coke or pizza. A commodity. And mezcals are nothing near to that. . . . The essence of them is the contrary. It’s diversity, it’s tradition, time, culture, local identity.”

Others would argue that tequila is a massive success story — worth more than $1 billion to Mexico — and have fought to ensure that any regulation of the category protects the distillers making more industrialized versions of mezcal and producers who may want to expand and modernize.

Small producers’ protection

Over the past several years, two proposed regulations seen as particularly threatening to smaller producers appear to have been defeated. And in February, a new regulation establishing three categories of mezcal passed, designating categories for “mezcal,” “artisanal mezcal” and “ancestral mezcal.” By codifying traditional mezcal practices, the new rule supports the ability of small producers (who already use processes that qualify as “artisanal” or “ancestral”) to stand out, marketing their mezcals as special, heritage spirits in a liquor market that’s been shifting toward just such higher-quality, more expensive products.

That marks a big shift, says Sarah Bowen, author of “Divided Spirits: Tequila, Mezcal and the Politics of Production.” In years of studying the issue, she found that “laws that regulate tequila and mezcal had always gone in one direction — allowing for more industrialization . . . and they’ve always been pushed by the big distilleries and the multinationals.” Bowen views the proposal as a break “in the other direction.”

Though many say setting the classifications is a good step, it won’t cover every component that needs protection. It’s complicated: There’s mezcal itself, a traditional spirit with a deep cultural history. There are the agave species, some of which, if the boom grows, may be depleted. Finally, there are the jimadors harvesting the agaves, the mezcaleros making mezcal and their communities, who live at poverty levels unimaginable to the affluent (mostly American) consumers snapping up their products.

In protecting authentic mezcal, there may be danger, Bowen says, of “locking people into museums of production.” She says it’s critical that U.S.-based advocates work to amplify the voices of Mexican farmers and producers, allowing them to define their own processes.

Labels matter

At bars specializing in agave spirits, customers can ask the staff about how they select stock. Phillips will vouch for everything Espita carries; he has an extensive list of conditions a bottle has to meet to make it onto the bar’s wall.

Suro-Piñera is pushing the agave spirits industry toward greater traceability and transparency, and he wants consumers to push as well. A Siembra Spirits label lists not only the distillery and the kind of agaves used, but the mezcalero, the strain of yeast used in fermentation, where the agave was grown and how it was cooked, down to the name of the lead jimador and the type of cut he made preparing the piña, or heart. “The juice inside this bottle should taste like this technical data,” he says.

In fact, much can be gleaned from many mezcal labels. To make use of this data, though, consumers need to understand it, or at least do some on-the-spot googling. The average consumer, after all, won’t know that certain agaves have more sustainability issues, or that a certain producer doesn’t pay its agave suppliers fairly. This transparency-without-comprehension factor has caused some to criticize the approach as over-labeling; one tequila maker sniped in a Facebook discussion that it’s “gobbledygook.”

Several sources, though, argued that more data on a label is inherently better, telling consumers that the producers are not trying to hide anything.

Steve Olson is a wine and spirits educator and cooperating partner in the Del Maguey line of mezcals, one of the earliest brands to make a splash in the U.S. cocktail scene, and one that is focused on sustainability and conditions in the producers’ communities. He says that in the past there has been discussion of ratings that might simplify the issue.

“Imagine a 12- to 15-point system where everything a producer does right is a point”: responsible waste disposal, humane use of working animals, use of organic and sustainable agaves, and so forth, he says. Each bottle would get a numerical score, so a consumer who cares about these issues could do better than guess without having to do hours of research.

A system like this could be implemented by mezcal’s regulatory council, the Consejo Regulador del Mezcal, Olson says, or voluntarily by producers who want to steer the industry in the right direction.

In the meantime, savvy consumers can help by asking questions of producers and bartenders and demanding transparency — before the growing demand for mezcal pushes the spirit into a shape that may not be authentic or sustainable.

“If we don’t take a look at it now,” Olson says, “it may already be too late.”

Allan is a Hyattsville, Md., writer and editor. Follow her on Twitter: @Carrie_the_Red.