Kombu has relatives round the world. In my opinion Kombucha is the king of all these. I tried some of these relatives, but always returned to my friend Kombu. Fermentation is the chemical breaking down of organic substances, such as the tea and sugar used in the production of Kombucha Tea by microscopic fungi called yeast. Other microorganisms can convert alcohol into acetic acid.
Yeast consumes the sugar and converts it to alcohol and carbon dioxide.
In order for fermentation to get a good start, oxygen is required for initial growth. If it doesn't have enough oxygen at the start of the fermentation process it will take longer to ferment. Nutrients Yeast requires certain nutrients such as soluble nitrogen, B vitamins and minerals. If you are adding a LOT of sugar, you may require additional nutrients. In the case of home fermentation, it is very important that everything be kept very clean to help stop your ferments from being contaminated by pathogenic bacteria.