I had my first black tea yesterday. I usually drink green or white. It was an organic strawberry black tea.....very good I must say! I drank alot of it...32oz, and I had alot of trouble sleeping...in fact I don't think I did ever sleep more than 2 hours.....I am wondering how much caffeine was in that tea, I drank over the whole day....I finished it about 6:30PM went to bed @ 10:30 and no sleeping for me, I was wide awake @3AM!!!!!! I guess I better stick to black only during the day.