Tannins are found in many different types of food such as cheese, nuts and even wine. Of course, different types of teas comprise of different levels of tannins.
Tannins are widely known as being effective antioxidants that can help to counter stomach upsets and even tackle cavities issues. According to some studies, tannins are even capable of fighting cancer and certain respiratory diseases as it is able to stimulate the immune system.
Upon steeping of the tea leaves, caffeine and tannin elements are gradually brought out. Especially during the first two minutes of steeping, most of the caffeine will be drawn out. Subsequently, the tannins will be brought out which acts as a neutralizer to cancel out the caffeine and turn it into a more calming tea.
Therefore, if you are one who seeks for just the calming effects of the tea, you may want to discard the liquid from the first two minutes of steeping. As a result, what is left would be the liquid with lesser caffeine content and more tannins.
Cheers to Tannins!