Major varieties include black tea, oolong tea, white tea and green tea. The taste, appearance, and nutritional components of these types of tea are the result of different processing methods. Note that the “red” tea, which is becoming popular does not come from Camellia sinensis. It is made from the needle-like leaves of a South African shrub. Also known as rooibus or red bush tea, it contains antioxidants and is said to help prevent cancer.
Black tea has a stronger flavour and darker colour than green tea. Black tea leaves have undergone considerable processing, including auto-oxidation. There is no vitamin C in black tea.
Fresh leaves are first “withered” by being dried in direct sunlight or by unheated air that is pumped through a layer of leaves. The leaves are then rolled to break up the cell surfaces to promote oxidization, which produces the dark colour and aroma. This process chemically alters the polyphenols originally present in the tea, decreasing their antioxidant power. Finally, the leaves are heated in iron pans and dried several times to prevent further oxidization.
Nearly 66% of all tea produced and consumed worldwide is black tea (International Tea Committee Annual Bulletin of Statistics, 2006).
Oolong tea takes the middle road between green and black tea. The method for processing it is the newest and was not developed until the mid-nineteenth century.
The tea leaves are “withered” in the sun and also indoors to reduce their moisture content. The leaves are then heated in an iron pan to prevent further oxidation. Oolong tea is partially auto-oxidized, so it is slightly stronger in taste than green tea but more delicate than the fully auto-oxidized black tea. Oolong tea has more nutrients, including vitamin C, than black tea, but less than green tea. Less than 2% of tea consumed worldwide is oolong tea.
White tea is made from the youngest leaves and buds, which are lightly steamed and then dried. White tea, like green tea, contains very little caffeine and very high levels of antioxidants – even slightly higher than those in green tea. Once brewed, white tea is very pale in colour. It is also rare.
Green tea is palest in colour, generally a subtle shade of light green or yellow. The green colour comes primarily from the chlorophyll that is extracted from the leaves by hot water.
After the leaves are picked, they are lightly steamed or gently heated to prevent oxidation, which preserves important natural antioxidants. Rolling and drying effectively seals in the nutritional components of the leaf and does not destroy the vitamin C.
Green tea comprises 28% percent of the tea produced and consumed worldwide.
Japanese Green Tea
There are about 20 different kinds of Japanese green tea. Some of the most popular are:
Sencha – Japan’s most popular tea, is distinguished by a delicate sweetness and a mild astringency. Sencha refers to the first picking of the tea leaves, which takes place from late February to the end of May, depending on location.
Fukamushicha – Ideal for delicate stomachs, this tea is processed the same as sencha, except that the leaves are steamed two or three times longer. The colour is darker than sencha, although the taste remains sweet and the fragrance is richer and deeper.
Kukicha – This tea consists of stems and stalks that are normally discarded in the production of sencha, gyokuro, and matcha teas. It has a clean taste and light fragrance.
Konacha – This is the tea served at sushi restaurants. It consists of the rejected buds and tea “dust” left over from the processing of sencha and gyokuro. Konacha is reasonably priced and has a strong colour, flavour, and aroma, making it an ideal cooking ingredient.
Bancha – This tea is made from the new shoots and leaf buds that grow after the first picking. They are picked in June, August and October, with the leaves becoming tougher with each subsequent picking. Bancha also includes the upper stems and some larger leaves discarded during the process of sencha production. This tea is more astringent and less fragrant than sencha, making it a good tea to sip after a heavy meal. It contains more fluoride than other teas and so is effective against tooth decay and halitosis.
Matcha – This is powdered tea that is used in the tea ceremony. In its unpowdered form, it is called “tencha”. Top grade matcha is a bright shade of green. In general, lighter green varieties are sweeter and darker ones more astringent. When the new shoots on the tea bush have two or three leaves, they are shaded from sunlight for two or three weeks. They are dried after being steamed, but are not rolled, producing tencha. During the drying process all the veins and stems are removed and the leaves are then ground into fine powder. Matcha completely dissolves in water and is entirely consumed, providing more nutrients than other types of green tea. Matcha is also a popular ingredient in food, including desserts.
Gyokuro – This top grade tea owes its sweet, mild flavour to high levels of theanine, an amino acid generated by covering the tea bushes with a reed screen two or three weeks prior to picking. The screen shields the leaves from sunlight and produces leaves that are dark green when dried. In this sense, it is similar to tencha, but it is also rolled and it contains veins and stems. Gyokuro contains a lot of caffeine (stimulates the brain and nervous system) and chlorophyll (stimulates tissue growth, resulting in healthy skin).
Hojicha – This tea is produced by roasting bancha or sencha over a high heat, resulting in brownish leaves imbued with a savoury fragrance. It contains relatively little caffeine and tannin, and is used in hospitals in Japan because it does not interfere with most medications. Hojicha, which is drunk by children, older people, and people with illness or with sensitive stomachs, can be served cold in the summer.
Genmaicha – To make this tea, bancha or medium grade sencha is combined with roasted and popped brown rice, which adds a slightly nutty taste. The mild flavour of genmaicha makes it a good tea to drink after a meal that includes oily or deep-fried foods, such as tempura, or after some Chinese dishes.