Hi Anna, I’ve seen similar arguments, but at the same time there are several studies that show a reduction in caffeine during fermentation. Here is a study that measured how each property of the drink is affected by fermentation (Figure 2 shows a significant reduction in caffeine): http://www.researchgate.net/publication/23247500_Preservation_of_kombucha_tea-effect_of_temperature_on_tea_components_and_free_radical_scavenging_properties/file/d912f507e3b003a388.pdf. Also, average testing of kombucha shows a very low caffeine content, usually 14mg or less per 8oz, which is is much less than what most initial tea brews contain (again implying a reduction of caffeine). GT’s has also stated that caffeine is reduced as a part of their kombucha fermentation.