Different Types of Tea — Black, Oolong, Green, and White: Tea from the Camellia Sinensis Plant

Different Types of Tea — Black, Oolong, Green, and White: Tea from the Camellia Sinensis Plant
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Facts About Tea

The tea plant, camellia sinensis, is an evergreen shrub, native to parts of Asia. Its rich, glossy green leaves are used to make every variety of true tea. Left on its own, the tea shrub can grow to heights up to eight meters, although they are usually trimmed to one and one half meters for cultivation.

There are over three thousand varieties of camellia sinensis. Some, such as the chaicha bushes, characterized by fine white hairs on the young leaves and bud, are used specifically for white tea. Others can be used to make black, oolong, and green teas. Tea can also be named for the area it is grown in - such as darjeeling teas from India, and ceylon from Sri Lanka. Today tea is grown in China, India, Kenya, Japan, Sri Lanka, Nepal, Pakistan, and Argentina.

Different Methods of Tea Processing

Depending on how tea leaves are processed, they become either black, oolong, or green tea. Black tea leaves are oxidized; oolong tea has been partially-oxidized; and green tea leaves do not go through the oxidation process at all. With tea processing, oxidation is referred to as fermentation, although no live microbes are involved as is the case with true fermentation; it is simply a process of exposing the cells of the leaves to oxygen.

The processing of green tea begins as soon as the leaves are plucked. They are usually set out on a table and allowed to air-dry. This is called withering. The purpose of withering is to release some of the moisture so the leaves become more pliable. Green tea leaves are then immediately heated, either through steaming or frying. Heat is used to stop oxidation, or tea fermentation. The leaves are then rolled and dried until they reach the desired consistency to be packaged and sold. Bereft of oxidation, green tea is characterized by a fresh, grassy taste and a high level of polyphenols, catechins, and flavonoids.

Processing black tea is a much more involved process. The leaves are withered, but then they are rolled, usually by a machine, but sometimes by hand. Rolling begins the oxidation process as the cells are broken down, enzymes are released and exposed to oxygen, and juices come to the surface of the leaf which are later caramelized. Next, the leaves are fermented; in a heat and humidity controlled atmosphere they are set out until the desired color and moisture content is attained - this process usually takes from two to four hours. After fermentation, they are heated to stop oxidation. Oolong teas go through basically the same process as black teas, except they are exposed to oxygen for half the duration. They are much lighter than black tea in flavor, with a slightly smoky, yet still green taste.

White tea leaves are barely processed. They are picked when the leaves are still young and covered with a white, silvery fuzz. The young leaves and buds are steamed, and then dried. White tea has a slightly sweet, delicate flavor.

Benefits of Tea

All infusions of the camellia sinensis plant are beneficial, although white and green teas are the most potent sources of the benefits of tea. This is because most of the nourishing and protecting phytochemicals remain intact. Black teas, which are processed the most, have the least health benefits, while oolong teas have more than black tea, but less than green tea.

What are the benefits of drinking tea? The camellia sinensis plant is a rich source of several antioxidants, the most powerful of which is the catechin, epigallocatechin galate or EGCG. This is the main active component of green tea. It prevents free radical damage, protecting the body from cancer, heart disease, and aging. During fermentation, a significant portion of the catechins are lost - they become the darker colored molecules in black tea which give it its characteristic sweet and malty flavor and black color - theaflavins and thearubigens.

Tea also provides flavonoids, polyphenols, and tannins, all of which have antioxidant properties, gallic acid, which acts as an antibacterial and antifungal agent, and caffeine. Although there are negative effects of large amounts of caffeine, in moderation it stimulates the central nervous system and increases blood circulation. White tea has a minimal amount of caffeine, fifteen milligrams per cup, while black tea has anywhere from fifty to seventy milligrams. Both green and oolong teas have moderate amounts.

Tea has been a part of cultures across the world for thousands of years, often playing an important role in daily rituals. Aside from water, no other beverage is drunk more than tea, the humble yet extraordinary gift of the camellia sinensis plant.

Sources:

Page, Linda. " Healthy Healing: A Guide to Self-Healing for Everyone." (Traditional Wisdom, 2003).

Enjoying Tea