VANCOUVER – Some kombucha drinkers believe the fermented tea beverage helps with everything from digestion to liver health – but people don't generally buy it to get tipsy.

Under the wrong storage conditions, however, researchers say even kombucha that's labelled "non-alcoholic" can become as boozy as beer or cider.

And with the fermented tea becoming more popular than ever, the B.C. Center for Disease Control is working to determine whether it could potentially pose a public health risk. The centre is having hundreds of kombucha samples tested for ethanol levels using drinks found at grocery stores, farmers markets and other retailers.

All kombucha is slightly alcoholic because of the fermentation process, but in Canada the drink has to stay below 1.1 per cent alcohol by volume to be sold as a non-alcoholic beverage. In the U.S. it's even lower, at 0.5 per cent.

Dr. Paula Brown from the B.C. Institute of Technology is part of the research team conducting the tests, and told CTV News they have already processed more than 700 samples. While she couldn't disclose any of the results, Brown said previous testing found some kombucha drinks sold south of the border were found to be above the allowable limit.

Separate from the BCCDC's study, Brown and her team are researching kombucha production methods to help determine the best ways for makers to avoid accidentally selling what drinkers might call "hard tea."

"We as researchers decided we should investigate the fermentation process so we could come up with best practices to make sure people weren't inadvertently making alcoholic beverages," said Brown, the director of BCIT's natural health and food products research group.

Some of the factors that could contribute to higher alcohol levels include how long kombucha is stored, whether or not it's refrigerated, and how much sugar and yeast are in the bottles, she said.

Brown said her team still has about 50 samples left to test. The BCCDC is expected to report the findings of the ethanol study later this month.