Stargazer Kombucha's Assam Kombucha is an alcohol-free kombucha from this US producer, built on Assam black tea rather than the more common green tea. Kombucha is made by fermenting sweetened tea with a live culture, which gradually converts most of the sugar. Here that base is loose leaf Assam, brewed with raw cane sugar before the culture goes to work. It is an award-winning drink.