DARJEELING, India — Among connoisseurs, few teas surpass a good Darjeeling. The smooth and mellow taste commands a premium price, and the name itself evokes a bygone era when the British first introduced Chinese tea plants here in the Indian foothills of the Himalayas.

To Anil K. Jha, the superintendent of the Sungma Tea Estate, all this would be extremely good for business, except that much of the tea sold globally as Darjeeling is not actually grown here. Foreign wholesalers often put the name on a blend of the real stuff and lesser teas. And in some cases, growers elsewhere simply slap a Darjeeling label on their tea.

So Mr. Jha and other Darjeeling growers have followed the example of Scottish whisky distillers and French wineries, winning legal protection for the Darjeeling label under laws that limit the use of certain geographic names to products that come from those places.

In a decision this year, the European Union agreed to phase out the use of “Darjeeling” on blended teas. Now, just as a bottle of Cognac must come from the region around the French town of Cognac, a cup of Darjeeling tea will have to be made only from tea grown around Darjeeling.