Black Tea
Black Tea is a type of tea that is more oxidized than other types, resulting in a generally stronger flavor than other teas. While there are several different types of tea, black tea is the most widely consumed, containing more antioxidants and caffeine than most other types of tea. Black tea is also known to contain a unique type of amino acid called L-theanine, which increases the formation of alpha brain waves, which are associated with alert relaxation, and a milder effect than many other forms of caffeine.
Fun Fact: In China, where black tea was developed, the beverage is called "red tea", due to the color of the oxidized leaves when processed appropriately.