. More antioxidants
During the process of making tea, tea leaves are put into hot water and attract scented and nutritious compounds in the water. These nutritional compounds include flavonoids, which are natural compounds with antioxidant properties. The Green Tea website explains that these antioxidants are contained in fairly reactive tea, which means they oxidize and disappear quickly after exposure to oxygen in the air. Drinking hot fresh tea from the kettle allows for maximum antioxidant content. If you let the tea in the container open, the oxygen will slowly drain the supply of tea antioxidants.