WASHINGTON — It took Jamba Dunn about four years to realize life on the outer edge of the nation’s capital wasn’t for him.

So in 2012, the one-time employee of Rosetta Stone ditched his Virginia home for the foothills of Boulder and in a matter of months started making kombucha, a kind of fermented tea brewed with yeast and bacteria.

But escaping the orbit of Washington, D.C., didn’t mean the federal government was done with Dunn.

As head of Rowdy Mermaid Kombucha, the 49-year-old father of two said he has to contend constantly with a potent blend of chemistry and bureaucracy that threatens to sink his business.

Because fermentation is required to make kombucha, the drink generally includes a trace of alcohol. And because federal law has strict rules governing any drink with more than 0.5 percent alcohol by volume — a Bud Light, for example, is 4.2 percent — Dunn said he worries about running afoul of the feds.

“I stress about it every single day,” Dunn said. “It’s the No. 1 topic of conversation. It’s overshadowing everything else. And for what?”

He has a reason to be concerned. For years, agents with the U.S. Alcohol and Tobacco Tax and Trade Bureau have monitored kombucha makers nationwide for violations of federal alcohol rules.

Just last month, the agency sent letters to several producers with warnings that they had exceeded the limit — sometimes by just a few tenths of a percentage point, according to industry officials.

One such letter provided to The Denver Post made mention of a fine that could cost as much as $11,000. Perhaps more worrisome is that offenders could be subject to the substantial taxes and regulations that come with brewing booze.

“We live in fear that we will get one of those letters,” Dunn said.

That concern is shared across the kombucha industry. Long a novelty drink among U.S. consumers, it recently has grown in popularity. One report cited by supporters predicted the global market would increase from $600 million in 2015 to $1.8 billion by 2020.

With the rise, however, has come more scrutiny.

Asked about the alcohol violations, Tom Hogue, a spokesman with the Alcohol and Tobacco Tax and Trade Bureau, said he couldn’t discuss specific cases. But he said the intent of enforcement letters is to help protect unknowing consumers and kombucha manufacturers who follow the law.

A product with more than 0.5 percent alcohol by volume must be labeled as such, and Hogue said it’s critical that customers have that information — whether it’s for health, religious or some other reason, such as fears of childhood consumption.

“It gives the consumer a heads-up they are consuming an alcoholic beverage,” Hogue said.

And he noted that testing has proved that many kombucha makers do, in fact, adhere to government standards. “Those industry members who are following the rules deserve a level playing field,” Hogue said. “That’s where we are coming from.”

(One alternative: Some kombucha makers have opted to get a brewing license, either to avoid the hassle or to simply sell a new product.)

Still, U.S. Rep. Jared Polis has sought to temper the oversight. The Boulder Democrat last week sent a letter to John Manfreda, head of the Alcohol and Tobacco Tax and Trade Bureau, with the request that his agency back off.

His argument is that bottles of kombucha consistently test below the 0.5 percent mark when cold and that they usually exceed that limit when they are improperly stored at higher temperatures.

“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.

He wants the agency to exempt kombucha companies from fines and punishments while Kombucha Brewers International, a booster group for the industry, develops a new testing method with AOAC International, a nonprofit scientific group that focuses on developing microbiological and chemical standards.

Polis and the industry have argued that a new testing method is needed for the unique chemistry of kombucha, which they say differs substantially from beer or wine.

“(The) current testing method often confuses organic acids and naturally occurring sedimentation for ethanol, which increases the reading of the alcohol content to a higher percentage than is actually contained in the product,” Polis noted.

One major draw for many kombucha consumers is the drink’s supposed health benefits, which some say can help with a range of afflictions, from poor digestion to even cancer — although there is significant skepticism in medical circles.

A spokeswoman with the U.S. Food and Drug Administration compared kombucha to dietary supplements and noted the tea did not need to “go through FDA review in order to reach the market.”

But Lauren Kotwicki of the FDA added in an e-mail that the agency had taken “enforcement action against manufacturers of kombucha that made drug claims (treats, prevents, cures, mitigates, diagnoses disease).”

Still, one kombucha maker credits the drink with helping him recover from a catastrophic injury.

Ed Rothbauer of High Country Kombucha said he fell from a roof in the 1990s during a construction job and was paralyzed from the ribs down.

He said a year and a half later that he had his first drink of kombucha. “I kept drinking it and I kept getting better and better,” said Rothbauer, who added he now walks with a cane.

Awed by his recovery, Rothbauer started brewing and selling kombucha and now runs a business in Eagle County.

He said he didn’t hear much from the federal government until 2011, when he got a threatening letter from the Alcohol and Tobacco Tax and Trade Bureau.

Rothbauer said he contacted Polis, who helped get the agency off his back, and he hasn’t heard from them since.

“We’re arguing over decimal points,” Rothbauer said.

He added that concerns about the drink’s alcohol content are overblown.

“You wouldn’t be able to drink enough (kombucha) to get intoxicated,” he said. “You would have a complete cleansing effect before you got intoxicated.”

Mark K. Matthews: 202-662-8907, mmatthews@ denverpost.com or twitter.com/mkmatthews