The Bitter Battle Over Sweet Wine ROCHEFORT-SUR-LOIRE, FRANCE - The Loire Valley vineyard of Quarts-de-Chaume produces one of the most delectable sweet wines in the world, a nectar as mellifluous as the French that is spoken in this most linguistically correct region of France. But it has left a bitter taste on the tongues of some of the local producers. This is a dispute in which both very little and quite a lot is at stake. With only 50 hectares of vines, Quarts-de-Chaume is one of those postcard-size appellations that dot the French winemaking map. But the grapes it yields are special; the Layon River, which snakes its way toward the Loire in the valley below, sends humidity up the slope, fostering the development of botrytis, or noble rot, producing an unusually racy, complex, sweet wine. The quality of Quarts-de-Chaume, which lies just outside this town in the Anjou region, has been recognized since the Middle Ages. Its name, according to some tellings, refers to the fact that in pre-Revolutionary, feudal France, the tenant farmers were required to give one-quarter of their harvest to the landowner. Quarts-de-Chaume was also expected to lead the wines of the Loire into the future. After Bordeaux and the Rhône Valley, this is the third-largest quality wine- producing region in France, stretching from the hills of Auvergne to the mouth of the river near Nantes. While it has a trove of interesting varieties and unexpected finds, the wines have rarely fetched the consumer attention - or the prices - of their rivals from more prestigious French regions. One reason, some Loire producers say, is the lack of an official ranking system, like the classifications that govern the wines of Burgundy, Bordeaux and Champagne; there, the most aristocratic vineyards are labeled as grands crus or premier crus; in the Loire Valley, all the wines, in the best Republican tradition, are commoners. Some years ago, in an effort to raise the profile of the region's wines, Loire vignerons began agitating for the creation of their own hierarchy. Quarts-de-Chaume was nominated as the first candidate for grand cru status. A portion of the larger vineyard that surrounds Quarts-de-Chaume, called Coteaux-du-Layon, was nominated to become the first premier cru. Finally, late last year, the authority that oversees the complex system under which quality French wines are labeled, granted the vignerons their wish. There was just one final hurdle: approval from the Conseil d"État, a high administrative court, which is often just a rubber stamp in such matters. In January, however, one of the biggest and best Quarts-de-Chaume producers, Domaine des Baumard, filed a lawsuit with the council, seeking to block the project. A simmering feud between Baumard and the other vignerons flared up again. "Liberté, egalité, fraternité - these are no longer the three words of France," said Florent Baumard, who runs the family-owned estate. Dressed in a stylish suit, pouring samples of Quarts-de-Chaume at a recent wine fair in the city of Angers, Mr. Baumard hardly looked the part of the Jacobin. He said he had no objection to the creation of grands crus and premiers crus along the Loire - only to the way in which the plan had been drafted. Mr. Baumard said the authorities ought to have conducted a wholesale inventory of the Loire Valley's vineyards - a vast and jumbled landscape that includes well-known appellations like Sancerre, Vouvray and Saumur-Champigny, as well as more obscure regions like Muscadet-Côtes-de-Grandlieux, Touraine-Azay-le-Rideau and Côtes-du-Forez. Mr. Baumard has another objection, this one more personal. Under the fine print in the proposal, certain vine-growing and winemaking practices long employed by his estate would be banned. These include a technique called cryo-selection, which involves freezing the grapes before they are pressed. Some critics describe this as a way to artificially concentrate the wine, though Mr. Baumard said he used it merely as a way to sort out inferior grapes. Some of the most prominent producers of sweet wine in Sauternes, the great Bordeaux appellation, do the same, he added. Banning such processes "is Bolshevism, a return to the Middle Ages," he said.