i’ve read the store bought is sugary, and also they changed the formula a few years ago and you can no longer grow a SCOBY from a bottle. I think that means there isn’t enough good bacteria in the bottle. I finished my first batch of homemade kombucha yesterday and it is really tasty. even more than water kefir. it was quite easy to make too. you can order the scobys online. i got a goldfinch scoby on Amazon for i think $20.