What is Black/Green/Oolong/XXXX Tea Anyhow?
The first thing that you need to know about tea is that all tea comes from the
same plant. The difference between the different types of tea have to do with how the
leaves are processed.
So why the different varieties? Well, it has to do with the amount of oxygen the leaves
absorb during the processing. A lot of oxygen produces dark-leaved black teas, while
less oxygen is what gives green tea leaves their color. Tea leaves that are not processed
at all are what white tea is made of.
Black Tea | Green Tea | Oolong Tea | White Tea | Rooibos Tea | Herbal Tea
Black tea is the most "processed" of all teas. This involves four basic steps - withering
the leaves, rolling, fermenting and finally drying. This process actually ferments the leaves,
which is what gives this type of tea its recognizable scent and flavor. Black tea has the highest
level of caffeine content between Black, Green, White, Oolong and Rooibos teas.
Some of the best known Black teas of the world hail from the Darjeeling and Assam regions of India. Black
tea characteristics vary from region to region, but generally black teas are strong with a
flavour of tannins that the fermentation process creates. If you steep black tea for too long
you can get a bitter flavour, which are the tannins in the leaf being released.
- After the harvest, the leaves are first withered by blowing air on them.
- Then black teas are processed in either of two ways, CTC (Crush, Tear, Curl) or orthodox. The CTC method is used for lower quality leaves that end up in tea bags and are processed by machines. This method is efficient and effective for producing a better quality product from medium and lower quality leaves. Orthodox processing is done either by machines or by hand. Hand processing is used for high quality teas. While the methods employed in orthodox processing differ by tea type, this style of processing results in the high quality loose tea sought by many connoisseurs.
- Next, the leaves are oxidized under controlled temperature and humidity. (This process is also called "fermentation", which is a misnomer since no actual fermentation takes place.) The level of oxidation determines the quality of the tea. Since oxidation begins at the rolling stage itself, the time between these stages is also a crucial factor in the quality of the tea.
- Then the leaves are dried to arrest the oxidation process.
- Finally, the leaves are sorted into grades according their sizes (whole leaf, brokens, fannings and dust), usually with the use of sieves. The tea could be further sub-graded according to other criteria.
Indian and Ceylon tea is usually named after the region of origin: Darjeeling, Assam, Ceylon, etc. and further by estates and grades for quality leaf: e.g., "Darjeeling Lingia FTGFOP1".
In Ceylon tea from Sri Lanka the grade names are an indication of the size and/or appearance of the tea but not the quality. There can be a lack of uniformity in the market grades which makes it difficult to describe them with accuracy. Ceylon teas can be divided into two groups:
List of Ceylon tea leaf grades:
- The leaf grades originally made by the Ceylon tea pioneers.
- The smaller broken grades which are used today.
A small quantity of Tippy or Flowery grades (including Flowery Orange Pekoe (F.O.P) and Flowery Broken Orange Pekoe (F.B.O.P) are made. They are much more expensive to produce than run-of-the-mill grades, as this involves sorting out the tip by hand.
- Orange Pekoe (O.P.) - Long, thin, wiry leaves which sometimes contain the tip. The liquors are light or pale in colour.
- Pekoe (Pek.) - The leaves are shorter and not so wiry as O.P., but the liquors generally have more colour.
- Souchong (Sou.) - A bold and round leaf, with pale liquors.
- Broken Orange Pekoe (B.O.P. or BOP) - This grade is one of the most sought after. It is much smaller than any of the other leaf grades and contains the tip. The liquors have good colour and strength.
- Broken Pekoe (B.P.) - Slightly larger than B.O.P., with rather less colour in the cup; useful primarily as a filler in blends.
- Broken Pekoe Souchong (B.P.S) - A little larger that B.P. and in consequence lighter in the cup, but also used as a filler in blends.
- Broken Orange Pekoe Fannings (B.O.P.F.) - This grade is much sought after, especially in the UK. It is much smaller than B.O.P. and its main virtues are quick brewing, with good colour in the cup.
In Assam, the main leafy tea grades produced are flowery pekoe (FP), orange pekoe (OP), pekoe (P), pekoe souchong (PS), and souchong (S), with broken tea grades BOP = Broken Orange pekoe; FOP = Flowery Orange Pekoe; TGFOP = Tippy Golden Flowery Orange Pekoe; FTGFOP = Finest Tippy Golden Flowery Orange Pekoe.
All types are sold as either "single" teas, meaning just one variety, or as blends. Blend names are usually more general e.g. "Assam Tea".
Plain black tea without sweeteners or additives contains negligible quantities of calories, protein, sodium, and fat. Some flavored tea with different herbs added may have less than 1gram of carbohydrates. (top)
Green tea is often called an unfermented tea. Fresh leaves are allowed to dry, then are
heated to stop the oxidation/fermentation process. Methods of rolling green tea vary, but
generally, in China, many plantations still hand-roll the leaves.
Proponents of green tea note that its medicinal benefits have been described for over 1000
years. The Kissa Yojoki, or Book of Tea written by Zen priest Eisai in 1191, describes how drinking
green tea can have a positive effect on the five vital organs, especially the heart. The book
discusses tea's medicinal qualities which include easing the effects of alcohol, acting as
a stimulant, curing blotchiness, quenching thirst, eliminating indigestion, curing
beriberi disease, preventing fatigue, and improving urinary and brain function.
In more recent times, many studies have investigated a link between the consumption of
green tea and a lower incidence of a range of cancers in populations, with mixed results.
Green tea has been claimed to be useful for:
Avoid drinking green tea or at least talk to your doctor before taking green tea if you have:
- Stopping certain neurodegenerative illnesses such as Alzheimers
- Preventing/ treating cancer
- Treating Arthritis
- Treating MS
- Preventing the degradation of cell membranes by neutralizing the spread of free radicals (which occurs during the process of oxidation)
- Increases fat oxidation (helps the body use fat as an energy source) and raises metabolism.
- Lowering LDL cholesterol (in high doses in lab tests)
- Preventing lowered T-Cells due to HIV - In lab tests, EGCG, found in green tea, was found to prevent HIV from attacking T-Cells. However, it is not known if this has any effect on humans yet.
Green tea contains a compound - epigallocatechin gallate - that blocks the enzyme
necessary for folic acid to be utilized in the cells. Folic acid is needed for cells to
divide, which is especially important during the critical periods of growth and development
during the first trimester of pregnancy. Without folic acid, cell division is slowed down.
In fact, inadequate intakes of folic acid have been linked to an increased risk of giving birth
to an infant with neural tube defects. While green tea can be beneficial at other times,
to be safe, pregnant women should avoid green tea throughout their pregnancy. (top)
- heart problems
- kidney disease
- nervous disorder
- If you are pregnant, think you may be pregnant, or are planning to become pregnant.
Oolong is a traditional Chinese type of tea somewhere in between green and black in oxidation.
Although it has a taste more akin to green tea than to black tea, it does not have the
stridently grassy vegetal notes that typify green tea. The best Oolong has a nuanced
flavor profile. It should be brewed strong and bitter, yet leave one's mouth with a
faintly sweet aftertaste.
Oolong tea undergoes a few delicate processes in order to produce the unique aroma and
taste. Typical Oolong tea is processed according to the following steps:
- Wilting. Sun dry or air dry to remove some moisture.
- Yaoqing. To bruise the edge of the tea leaf to create more contacting surface for oxidization.
- Rouqing. The tea leaves are tumbled for the next stage.
- Shaqing. Process to stop further oxidization. Depending on the quality of the leaves, they will be dried in a large pan over heat and stirred by hand (for premium tea) or by machinery.
- Drying. To remove excessive moisture.
White tea is tea made from new growth buds and young leaves of the tea plant.
The leaves are steamed or fried to inactivate polyphenol oxidation, and then dried.
White tea therefore retains the high concentrations of catechins which are present in
fresh tea leaves. The buds may also be shielded from sunlight during growth to reduce
formation of chlorophyll. White tea is a specialty of the Chinese province Fujian.
Green tea is made from more mature tea leaves than white tea, and may be withered prior
to steaming or firing. Although green tea is also rich in catechins, it may have different
catechin profiles than white tea. For white tea, the little buds that form on the plant are
covered with silver hairs that give the young leaves a white appearance. The leaves come
from a number of varieties of tea cultivars, the most popular are Da Bai (Large White),
Xiao Bai (Small White), Narcissus and Chaicha bushes. According to the different standards
of picking and selecting, White teas can be classified into a number of grades.
White tea is steamed and dried almost immediately after harvesting (sometimes before even
leaving the fields). This method of minimal processing may account for white tea's higher
than normal medical benefits. Roderick H. Dashwood, an Oregon State University biochemist,
has stated that the polyphenols, called catechins, are altered through subsequent processing
to other teas (green, oolong, and finally black). (top)
Rooibos (Afrikaans for 'red bush') is a member of the legume family of plants and is used
to make a tisane (herbal tea). The product has been popular in South Africa for generations
and is now consumed in many countries.
Rooibos is only grown in a small area in the Cedarberg region of the Western Cape province.
Generally, the leaves are oxidized or fermented to produce the distinctive reddish-brown color,
but unfermented "green" rooibos is also produced.
In South Africa it is more usual to drink rooibos with milk and sugar, but elsewhere it
is usually served without. The flavor of rooibos tea is often described as being sweet
(without sugar added) and slightly nutty. Preparation of rooibos tea is essentially the
same as black tea though some brew it slightly longer. The resulting brew is a reddish
brown color, perhaps explaining why rooibos is sometimes referred to as "red tea."
Rooibos is becoming more popular in Western countries particularly amongst health-conscious
consumers, who appreciate it for its high level of antioxidants and lack of caffeine.
While technically not a tea (because it is not from a variety of the "tea" bush), it is
gaining a foothold in the tea market because of its health benefits, as well as its ability
to be mixed and flavored similar to black teas. (top)
A tisane, ptisan or herbal "tea" is any herbal infusion not made from the leaves of the
tea bush (Camellia sinensis). Tisanes can be made with fresh or dried flowers, leaves,
seeds or roots, generally by pouring boiling water over the plant parts and letting them
steep for a few minutes. Seeds and roots can also be boiled on a stove. The tisane is then
strained, sweetened if so desired, and served.
Many blends of real tea are prepared by adding other plants to an actual tea (black,
oolong, green, yellow or white tea), for example, the popular Earl Grey tea is black tea
with bergamot. Such preparations are varieties of tea, not tisanes. (top)