(NYTimes) - The task ahead of me was a two-day tasting marathon of wines with a welter of confusing labels: natural, organic, organic practice and biodynamic. But for Jean Bardet, a semiretired chef with two Michelin stars to his name, there was little confusion about the worthiness of such bottles.

“You have all these young people with rings in their noses who don’t know wine and say, ‘If it’s organic, it’s better,’ ” said Mr. Bardet, an expert on Loire Valley wines. “That’s crazy. Either wine gives pleasure and happiness or it does not. It’s all about taste.”

The night before the weekend tastings, Mr. Bardet hosted me and a friend at his sprawling home near Tours, which doubles as a cozy hotel where he cooks for his guests. He explained that he’s not pro-pesticide — after all, his huge fruit and vegetable garden here is pesticide-free. He is just anti-bad-winemaking.

The use of pesticides has become a major issue among French vintners and drinkers. Many dismiss the sudden cascade of new wines that proclaim their environmental virtue as New Age gimmickry. Others condemn the resistance to pesticides as a potential threat to other wines — the equivalent, some say, of refusing a vaccine.

But the weekend salons I attended bore witness that these wines are more than just a splash in the glass; they attest to a movement that has been growing for years in France and elsewhere to produce quality wine that is as pure as it can be.

There is broad agreement that France, the European Union’s largest agricultural producer, uses too many pesticides on all kinds of produce. The nation is the third-largest consumer of pesticides in the world, after the United States and Japan. Apples grown in southern France, for example, are subjected to about three dozen pesticides.

The pesticide and big-agriculture lobbies are strong, resisting any initiative that could affect farm yields, so there is little political will to take risks. In late January, the French agriculture minister, Stéphane Le Foll, announced that a government pledge to cut pesticide use in half by 2018 would be delayed until 2025. “We set a goal that was too ambitious without giving the means to change the production model,” he said in a newspaper interview.

And the pesticide controversy is only part of a larger debate about the deployment of chemicals in vineyards. A 2013 report by a team of scientists near Bordeaux examined more than 300 French wines from the 2007 and 2008 vintages of the Rhône and the wider Aquitaine region. It found that 90 percent contained traces of chemicals commonly used to treat vines. Even some organic wines were tainted with pesticide residues, most likely a result of contamination from neighboring vines.

One challenge facing wine producers is that there is neither a definition nor regulation of what constitutes a “pure” or “natural” wine in France. Wines defined as organic by the European Union are produced from organically grown grapes that can be chemically manipulated, with limitations on the use of sulfites, in the winemaking process. Many producers call their wines natural, which connotes a further step: Nothing can be added or removed during winemaking. Some natural winemakers add a small quantity of sulfites at bottling; others do nothing more than bottle fermented grape juice, call it wine and hope that it’s fit to drink. Biodynamic methods involve a holistic, almost spiritual approach to the ecosystem that treats the soil as an organism in its own right.