Will Savitri, owner of Katalyst Kombucha fermented tea, drinks some tea from inside his refrigerated storage unit in this July 1 photo at the Katalyst Kombucha company in Greenfield, Mass. Regulators are concerned that the tea may need to be regulated as an alcoholic drink. Some bottles have more than 0.5 percent alcohol, the legal limit for a drink not to be considered alcoholic.

The product line of Katalyst Kombucha fermented tea is shown at the company in Greenfield, Mass.

New York ? It’s a fermented, pungent tea, but it’s the alcohol that can lurk inside kombucha that’s causing a stink.

Regulators and retailers are concerned that the ancient and trendy tea may need to be regulated as an alcoholic drink. That’s because some bottles have more than 0.5 percent alcohol — the legal limit for a drink not to be considered alcoholic.

The drink dates back thousands of years and across cultures, though its actual country of origin is unclear. But it has gained popularity in the past few years in the U.S., partly because of claimed health benefits, though there’s little science behind them. And it doesn’t hurt when stars like Lindsay Lohan are photographed drinking kombucha.

Since last month, the government has been testing kombucha to determine whether it should be labeled like beer or wine. Distributors and retailers like Whole Foods Inc. have removed raw kombucha from stores, saying they won’t restock until they know more.

That’s upsetting fans, who enjoy the sweet-but-sour taste and shell out more than $3 for a bottle. They’re scouring stores and starting Facebook groups such as “Dude, where’s my kombucha?”

Anne Sommer misses drinking kombucha each day at 5 p.m., while her husband had wine. She can’t find any at home on Bainbridge Island, Wash., about 30 minutes outside Seattle and misses her “Booch.”

“I’ve considered taking up wine. I just don’t like how that feels,” she said. “I just drink water and count the days.”

Kombucha contains live bacteria and yeast, similar to yogurt. Many fans make it at home by acquiring a kombucha “mother,” a cloudy mass of bacteria and yeast. But most prefer to buy it for convenience. Pasteurized versions — where the yeast and bacteria are heated, much like milk — are still for sale because the process kills the yeast, which make the alcohol. But fans tend to prefer the raw version.

Kombucha makers say it leaves production with almost no alcohol. But alcohol can develop over time in unpasteurized versions because the yeast converts sugars to alcohol. The more sugar a drink has, the more alcohol can ferment. So each recipe might be different.

Gerry Khermouch, editor of Beverage Business Insights, estimates some kombucha brands might have 2 to 3 percent alcohol, based on reports from producers doing independent testing. Regular beer has about 4 to 5 percent alcohol.

Sales have been doubling each year for at least the past four years and are worth more than $150 million a year at retail, according to Beverage Business Insights. That’s barely a drop compared to the $100 billion-a-year U.S. drinks market. Big brands like Celestial Seasonings and Honest Tea have launched their own raw kombucha brands. Both have taken their products off shelves and are working on new versions.

G.T. Dave, CEO of the company that makes category leaders GT’s Kombucha and Synergy, said the products should return in weeks. His company plans to resume production with a new version that will keep alcohol levels under the limit, though he declined to say how the company would do that.

“We’re hoping this month, but nothing is definitive,” he said.

Neither Austin, Texas-based Whole Foods or United Natural Foods, kombucha’s largest distributor, returned calls seeking comment.