2 questions

How do I get my homemade kombucha to be fizzy like the kind I purchase in the store? I was told that if I let it set out for a few days after bottling it with a tight fitting cap, before I put it in the refrigerator, it would be come fizzy. Mine is totally flat. I use plain white sugar and caffeinated black tea.

After 10 days, sometimes my kombucha grows a mushroom about a 1/4 inch thick, my friend's mushroom (scrooby) is thicker. Sometimes it's as thins a paper. Warmth is not a problem as it is warm, fairly drak, and fairly quit where it brews. Does the amount of previous kombucha added to the new sugar-tea sol'n have an effect on "mushroom- scrooby" growth?

The carbonation in the finished kombucha has alot to do with the residual sugar available when bottling. It sounds like your kombucha is pretty dry when you bottle it. Consider adding 1/4-1/2 tsp sugar per 16oz bottle, that should do it.

There are so many variables which impact scoby growth. Are you adding a scoby to each new batch along with starter tea, or just starter tea? Try a blend of black and green tea, I bet you get better scoby growth and will like the tea much better.