The tea is a product of a plant known as C. sinensis , a native of Southeast Asia. Leaf buds and young leaves are used in making tea, the age of the leaves determining the taste and name of the particular commercial variety. After picking, the leaves either are dried immediately and completely to produce green teas, or are partially dried and then allowed to ferment to produce various kinds of black teas. After being sorted, all grades of tea are packed in foil-lined chests to prevent the absorption of unpleasant odors or the loss of aroma during shipment. In China, tea is sometimes allowed to absorb the scent from various flowers particularly Jasmine.
Tea is an aromatic stimulant, containing various polyphenols, essential oils, and caffeine .
The concentration of caffeine in tea ranges from 2.5 to 4.5 percent, in contrast to an average concentration of about 1.5 percent in coffee. Green Tea, is abundantly grown in the foothills of the mighty Himalayas. This belt grows the best teas in the world. Scientists from Japan Cancer Institute have been successful in identifying a substance in Green Tea called Catechins or Polyphenols, which act as strong antioxidants. Catechins remain unchanged in Green Tea as leaves are merely steamed, rolled and dried as opposed to black tea which is fermented.