Ever noticed that drinking a green tea at night is more likely to lead to a sleepless night than drinking a strong black tea? We have. At first we thought we were crazy. Then we encountered many other people with the same observation.

Since there is no universal reason for green tea to contain more caffeine than black tea, we went looking for an answer. We came across one reasonable explanation for the effect. As black tea goes through the oxidation process( that’s what makes it black.) tannins are created, and caffeine gets bound to the tannins. When the tannins are released during infusion, the caffeine remains attached. Tannins tend to hold the caffeine until they are broken down through digestion in the intestines- effectively creating a time released form of caffeine. In green tea however, the caffeine is released in a “ready to absorb” form that is easily absorbed in the stomach and leads to a more rapid rise in the caffeine level in the body, and a much stronger effect.