For 15 years, natural wine has been a contentious time bomb that has divided many in the wine community, creating conflicts fought with the sort of anger that stems only from extreme defensiveness.

Since 2003, when I first encountered what has come to be called natural wine at the seminal restaurant 360 in Red Hook, Brooklyn, I have been a fan, though a cleareyed one, I hope.

I believe in the promise and beauty of natural wines, while acknowledging that many examples are not good, as is true with all genres of wine. The truth is that natural wines have made all of wine better.

Natural wines could not have offered a more luminous contrast to the industrial practices of the wine industry, a business that marketed itself as pastoral. Many mainstream wines are made from chemically farmed grapes, then produced like processed foods, with the help of technological manipulations and artificial ingredients, to achieve a preconceived aroma-and-flavor profile.

Natural wines, made from organic grapes or the equivalent, and fermented and aged without additions, are unpredictable but alive, energetic, vibrant and surprising. It’s like comparing fresh cherries picked off a tree to red Life Savers.

The winemaking spectrum offers many shades and degrees. Not all conventional wines are processed wines. Not all wines called natural adhere to a strict “nothing added, nothing taken away” protocol.

But the appearance around 20 years ago of natural wines as a group challenged an industry dominated by a postwar promise of better living through chemistry and technology.

Back then, the prevailing wine culture was marked by increasing homogeneity. Wine was elevated to a luxury good, and grapes were placed in a caste system and ranked by their “nobility.”

Natural wine, on the other hand, promoted a diversity of styles. It resurrected and celebrated indigenous grapes and local traditions that had been forgotten or dismissed by wine authorities. It sought to knock wine off its pedestal with irreverence, presenting it as a delicious, fun drink that nonetheless packed emotional and cultural power.

Most of all, it reconnected wine to classic farming as it had been practiced for centuries before the rise of industry and technology. Wine as a product of the earth resonated with young people concerned with the environment, with health and with wellness in its full, and now fashionable, sense.

I’ve seen the audience for natural wines evolve from the nerdy inhabitants of a small, secret parallel universe to a curious, eager, ever-growing crowd. In the last few years, natural wine has been anointed the next big thing, the new “it” wine and all the other tiresome labels issued by professional trend spotters.

In this time, natural wines have stepped out of the underground into the sunshine. Natural wine bars are common in almost every big city, while even some high-end restaurants have devoted entire lists to natural wines.

This new popularity has forced the sort of reckoning that natural wine producers have for so long successfully avoided — namely, what exactly is natural wine and who is permitted to use the term?

In the past, it was the wine mainstream demanding a definition for natural wine, an entreaty that most producers blithely ignored. Definitions smacked of authority, orthodoxy and bureaucracy, exactly the binding forces that many natural wine producers have long viewed as inhibiting their freedom.

I always saw this refusal to be pinned down as a strength. Allowing natural wine to be strictly defined would set it up to be co-opted, the way many organic food companies are now largely profit-making subdivisions of Big Ag.

But the notion of natural wine producers as independent bohemian artisans is tough to maintain when the genre’s popular breakthrough radiates dollar signs, not only to corporate bean counters but also to small-business poseurs.

In a recent pandemic-era Zoom discussion of natural wine, Alice Feiring, a longtime proponent of natural wine and the author of the 2019 guide “Natural Wine for the People,” said she had changed her thinking on an official definition of natural wine.

“I haven’t seen the need for legislation, but that was before it became worthy of imitation,” she said.

In an Opinion article she wrote for The New York Times in December, Ms. Feiring warned that big wine companies were creating ersatz cuvées disguised as natural wines in order to capitalize on their growing popularity. But a threat comes from the small business side as well.

Jacques Carroget, of Domaine de la Paonnerie in the Loire Valley, led a group of natural wine producers that after a decade of work won approval last year for an official, though voluntary, certification of natural wine in France. Wines that join the approved trade syndicate and follow its rules governing viticulture and winemaking will be able to label their wines Vin Méthode Nature.

Mr. Carroget, who joined in the Zoom discussion, said the group was motivated by the discovery that some small producers who were purporting to make natural wines had in fact used grapes sprayed with chemical pesticides.

“We analyzed 34 natural wines and found two had residues, including a wine which came from a famous natural winemaker,” he said in an email from the Loire. “We do not want synthetic chemistry in natural wines.”

As long as natural wines were the province of a small number of producers, he said, he saw no reason for an official definition. “Alas, the business, the greed — when we see natural wine emerge from its niche, we find unacceptable abuses,” he said.

The Vin Méthode Nature charter requires its members to use only grapes that have been certified organic and harvested by hand. They must be spontaneously fermented with yeast found naturally in vineyards and wine cellars, and made without what the charter calls “brutal” technologies like reverse osmosis, thermovinification or cross-flow filtration.

Only small amounts of sulfur dioxide, an antioxidant and preservative, may be used, and two different labels will distinguish between wines made with or without even this low level of sulfites.

The use of sulfur dioxide has been a difficult issue in the natural wine world. Some producers and consumers adamantly oppose any additions, while others are more tolerant of minimal use. The effort to accept both points of view is unlikely to satisfy everybody.

Neither will the requirement that grapes be certified organic at a minimum. Many producers work organically, biodynamically or the equivalent, but avoid certification because of the expense and the paperwork. That is unlikely to change.

“I understand people’s concerns around stifling creativity and freedom by applying rules,” she wrote in an email from England, “but from my personal perspective I don’t think this is something to worry about as a definition won’t kill the spirit of natural wine.”

But she added that practical hurdles, like the difficulty of determining what sort of yeast was used for fermentation, might make it difficult to enforce a definition. In addition, she said, big companies might be able to make wines that conform to the letter of the law even if they do not reflect the spirit of natural wine.

“Will it actually result in a natural wine with the small imperfections that make it unique and the palpable energy from the men and women who made it?” she said. “Of course not. I hope that consumers will not be fooled either and they will continue to understand the difference between ‘establishment natural’ and ‘small, artisan-farming natural.’ ”

That, I think, is a crucial point and perhaps indicates that regulations will not change much of anything. Natural wine is as much defined by the intention of the producer as it is by adherence to a set of rules. Most consumers of natural wines have either educated themselves to know the difference, or put their trust in retailers, sommeliers and wine journalists to point them in the right direction.

Relying on a label to guide curious consumers shopping for wine is a halfway measure, just as produce labeled organic in a supermarket is a far cry from the carefully grown produce sold by farmers at the greenmarket.

I’ve always thought the best way to enlighten consumers is to require bottles to carry labels identifying the ingredients and processes used in producing the wine. Only then can they make educated decisions.

Aaron Ayscough, a blogger who is also the wine director at Tablerestaurant in Paris and is writing a book on natural wine, argues that labeling like “Vin Méthode Nature” asks a lot of small producers and nothing of large industrial producers.

“It’s fundamentally regressive, because it puts the financial and administrative burden of proof on small-scale, artisanal natural winemakers rather than on industrial wine producers,” he wrote in an email. “It would be way more effective to mandate that all wine producers, natural and conventional, list the ingredients and processes used in their winemaking, and let consumers make the verdict about what’s natural enough for them.”

He and I share that ideal, but Ms. Legeron rightly pointed out that wine labeling is little more than a dream right now.

“We are far off this being a reality, not least because some of the biggest players in our industry have no incentive for it to be otherwise,” she said. “So given this, I am definitely not averse to a certification system for natural wine, mainly because it will set basic minimums and help avoid abuse of the category and of the term.”

Ultimately, nothing is wrong with the French label, which is voluntary and available only to producers in France. But for people who have not educated themselves, it may merely provide the illusion of discernment. They may be buying wines that are made naturally according to a set of rules, but that are not in the end natural wines.

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