As with any fermentation process, sugar is necessary to feed the yeast. Think about yogurt, the yogurt cultures consume the milk sugar (lactose) to produce a sweet-tart milk product teaming with probiotics. The process is similar for kombucha. The sugar feeds the yeast, which creates CO2 & ethanol, then the bacteria consume the ethanol and convert it into healthy acids. Very little sugar remains when it is bottled depending on how long the fermentation process lasts. Moreover, the fermentation process cleaves sucrose (polysaccharide) into fructose and glucose – both of which are utilized by the fermentation process thereby reducing the glycemic load.