Red Tea

Red Tea: An Oxidized Tea

Although known in the West as black tea because of the dark-brown color of its dried leaves, the Chinese call this red tea as, once wet, the leaves take a on a tawny color. It is one of the world's most widely produced tea types.
Unlike green tea, the aim is to produce leaves that are fully oxidized. This affects the taste of the tea, which usually has a more developed structure and less bitterness as a result of the polymerization of the polyphenols, as well as "heavier" core and background aromas.
Two initial stages are required to activate the oxidation process: withering and rolling. In the withering process, the tea is spread out on large mesh-bottomed trays placed in a ventilated room for a few hours. The leaves are heated to accelerate water evaporation. When they have lost more than 50 % of their humidity, they are sufficiently pliable for rolling. This process is carried out using a roller, a piece of equipment with two disks that turn in opposite directions. The leaf cells are broken, freeing up the enzymes and stimulating a uniform, enzymatic oxidation to take place over the entire surface of the disks. With Darjeeling spring teas, rolling is very light and very short, whereas with Darjeeling monsoon teas, which have tougher leaves, more pressure is used for a longer time.
The tea is then ready for oxidation (often known as fermentation), which brings out its particular aromatic qualities. The grower's skill is knowing when to halt the oxidation: if insufficiently oxidized, the tea will be bitter with unpleasant green notes; if over oxidized, it will be flat. The shoots are arranged in layers a few centimeters thick on large white ceramic tables in a room at around 68° F (20° C). They oxidize on contact with the air. The leaves then take on a brown-red or golden-green color and the buds a beautiful golden or silvery sheen, depending on their origin. The tea is then dried in an oven at approximately 248° F (120° C). This stage is followed by the grading (separation of grades): the tea is passed through vibrating sieves to separate the broken leaves from the whole leaves. In China this tea is made into compressed cakes, which are much used among the nomadic peoples of Central Asia. The tea is molded before drying.

- p. 99, Alchemy of Tea in Tea: Aromas and Flavors Around the World by Lydia Gautier (2005)

Red Tea
Darjeeling Tea