You unfortunately need to be fairly careful about the kombucha you select. Many of the big/common ones sold at grocery store chains oftentimes anywhere from 10-20mg sugar for a 12/14oz bottle (I've seen them with more than that too!). Better than soda but worse than many smaller brands or even local kombucha you might find at restaurants around town or a farmers market. My favorite kombuchas hover around 5mg per 12oz serving which is perfect.