The sugar added to kombucha should ferment out. That means, sugar is there for the bacteria and yeast culture to consume – that’s how fermentation happens.
But the sugar content is in the hands of the brewers. Some companies add more sugar than needed, knowing that the culture will not consume all of the sugar, but hoping that the brew will taste sweeter and more appealing. That’s why it’s best if you do your own brew and keep it to the minimum.
RE: Homemade Kombucha Tea