DENVER (AP) -- A tangy fermented tea called kombucha has moved from the natural foods aisle to the mainstream. But it's also moved into the hot seat amid renewed concerns that it can contain low levels of alcohol.
Five years after alcohol levels detected in kombucha prompted nationwide recalls, federal authorities again are warning producers to relabel their products to indicate alcohol content or face fines. But this time around dozens of producers are resisting, and have asked for new federal tests to help them avoid running afoul of alcohol laws.
Kombucha is a tea that has been fermented with bacteria and yeast, giving it a tart, vinegar-like zip and high levels of bacteria that some consider to impart health benefits. And its hugely popular. Sales of kombucha jumped nearly five times between 2013 and 2015, to about $600 million a year, according to retail analysts at Markets and Markets.
The tea's fermentation process dates back centuries, but its popularity in recent years has landed kombucha in the sights of the U.S. Alcohol and Tobacco Tax and Trade Bureau. That's because the fermentation process can give the drink too much alcohol for it to be legally sold as a non-alcoholic beverage.
Kombucha makers complain that the alcohol threshold that triggers the law - 0.5 percent - is too low to intoxicate people, pointing out that many fruits naturally ferment on shelves to about the same level. But federal authorities over the years have sent kombucha makers letters threatening fines when tests indicate that kombucha on store shelves is too alcoholic.
Kombucha tea naturally walks the line of what federal authorities consider an alcoholic beverage. Yeast and sugars in the tea create both the desired bacteria and alcohol. A kombucha tea can edge toward 1 percent alcohol if it is aged and not refrigerated. That's about a quarter as strong as a Bud Light, which is 4.2 percent alcohol, but still is too alcoholic to be sold to minors.
The latest federal intervention in the kombucha market came late this summer, when fine letters went to an undisclosed number of kombucha makers nationwide, said bureau spokesman Tom Hogue. He declined to specify how many brewers' products failed alcohol tests, or how many producers have been fined. "What we're concerned about here is that when a consumer picks up a product, they know the product is alcoholic," Hogue said.
The letters have kombucha brewers on edge.
"It's almost like a witch hunt," said Tom Nieder, founder of Companion Kombucha in St Louis. He hasn't received an enforcement letter, but said brewers are fighting comparisons to alcohol or other drinks.
Kombucha is one of many fermented foods enjoying a renaissance. From kimchi (a Korean pickled cabbage dish) to kefir (fermented milk with a yogurt-like tang), fermented foods deliver "good bacteria" to the digestive system. Some fermented drinks - such as pulque, a milky agave drink native to Mexico that often is about 3 percent alcohol - have always been sold as alcoholic beverages.
Kombucha brewers say the agency needs a new alcohol test specific to fermented drinks. They say the commonly used test to determine alcohol by volume (often listed as ABV on alcoholic beverages) doesn't account for naturally occurring sediment in kombucha, from bits of tea leaves to strands of yeast.
"We're working on a more accurate test that will show people that kombucha is not an alcoholic beverage," said Hannah Crum, head of the Los Angeles-based Kombucha Brewers International group, an industry advocate.
The federal agency says it is interested in an alcohol test specific to fermented beverages. But in the meantime, it says it won't stop issuing fines when it gets reports of products that exceed alcohol limits using existing tests.
The kombucha testing dilemma caught the interest of a Colorado congressman who wrote to the bureau seeking a reprieve for some fined kombucha makers. In his Sept. 14 letter, Democratic Rep. Jared Polis argued that kombucha stays below the alcohol threshold when refrigerated. "Eight spoiled kombuchas are roughly the equivalent of one beer, but that doesn't mean we should regulate it like we do alcohol - it makes absolutely no sense," Polis wrote.
The agency politely declined the reprieve request, saying it won't hold off fining kombucha makers until there's a new test. Instead the agency re-released an industry bulletin about the testing policy.
"Punishing kombucha producers for a grocery store's or consumer's error is like punishing a farmer when a supermarket sells spoiled milk," Polis wrote back via an email.
Kristen Wyatt can be reached at http://www.twitter.com/APkristenwyatt