Tea is made form the leaves of a plant known as the Camellia
sisensis. There are many varieties, sub-varieties, and
hybrids, but they are all of the Camellia sisensis family.
Tea plant varieties originally varied in size from a large bush
up to a 60 foot (20 meter) tree. Today they are all
trained to about 3 feet (1 meter) in height to facilitate plucking the
leaves.
The leaves of the different varieties range in size from 1 ½
inches to 10 inches. Tea can be
grown in many parts of the world with acidic soil and annual minimum rainfall of 45 to 50 inches spread fairly evenly
throughout the year. Although tea can be grown at elevations
ranging from sea level to
8,000 feet, it is generally accepted that the best tea is grown
at altitudes of 3,000 to 7,000 feet.
The quality and taste of tea is dependent on a number of
factors: the variety of tea plant, where it is grown,
weather during the growing season, the time of the year it is
harvested, how it is processed, and the care taken in processing.
The processing rather that the variety of Camellia
sinensis determines whether a tea is designated as black
(fermented), green (unfermented), or oolong (semi-fermented). It
is possible to make any of the three types from a given variety
of tea.
However, some varieties are particularly suited for one type
of tea and are seldom used to make the other types. For instance,
a particular tea plant grown in Southern China and
Taiwan makes a superior oolong. The Darjeeling district of
India is famous for black teas, and few green teas are produced
there.
The harvesting and manufacturing process differs somewhat by country
and manufacturer, but in general it involves similar
steps.
Leaves are harvested either by hand or mechanically. In
fine picking, only the top two leaves and buds are plucked.
For black tea, the freshly plucked leaves are brought to
the factory, where they are spread thinly on withering racks. As the moisture evaporates, the leaves become
soft and pliable.
From the withering rack the leaves are off to the
rolling machine, which breaks up the leaf cells and liberates the
oils that give tea its flavor. The leaves come out of the
rolling machine in twisted lumps. These are broken up by passing
them over course mesh sieves called roll breakers.
The next step
is fermentation, the leaves are spread in very thin
layers in a cool,
humid room . As the leaves absorb oxygen they turn a bright copper color.
This process, called oxidation, produces black tea.
The last stage is drying, or firing,
which stops further oxidation and dries the leaves evenly. Here
the leaves are spread on trays, and hot dry air is blown
through them. This firing turns the leaves black. The
tea maker's judgment as to time, temperature, and humidity is
critical to the quality of the final product.
Green tea is steamed immediately after picking. This softens
the leaves for rolling and keeps the juices from oxidizing. The
leaves are then rolled and dried. Since they do not go through
the oxidation stage, these leaves remain green after firing.
Oolong tea is prepared in a manner similar to that of
black
tea; however, oolong tea is only partially oxidized. The partial
oxidation and the particular variety of leaf used give Oolong
tea its special flavor.
Teas are divided into whole leaf and broken leaf grades.
Terms like Orange Pekoe, Pekoe, and Soughong refer to whole leaf
sizes, or grades. The terms do not indicate flavor or quality.
Broken grades are designated as Broken Orange Pekoe, Fannings, and Dust.
Only broken grades are used in tea bags.
