Commercial Kombucha Tea is typically sold and labeled as “non-alcoholic”. However, this does not mean that it doesn’t contain alcohol. It means that it contains less than 0.5% alcohol to be sold as a non-alcoholic beverage. Home brewed Kombucha teas can have up to as much as 3% alcohol content. For comparison, a regular beer, on average, is 5% alcohol. Left unrefrigerated for an extended period of time, the alcohol content of some Kombucha teas can increase.
If you want to steer completely clear of a DOT violation or a zero-tolerance violation of many European countries, treat Kombucha Tea as an alcoholic beverage. If you have a medical or religious reason to abstain from all sources of alcohol, you would also want to avoid Kombucha Tea.