Green and Black Tea are produced from the same plant, though the
botanists were long at issue about this matter. The idea of green tea
being dried upon copper is proved to be a popular fallacy, for the tea
would be flavoured and spoiled in the process; besides, the bloom can be
given by harmless means. Dr. Lettsom, by the way, thought it was given
by a vegetable process.
Mr. Ball, who has written a practical volume on "the Cultivation and
Manufacture of Tea," describes an experiment made by him, proving that
tea may be dried _black and green_, at once, in the same vessel and over
the same fire: he divided the pan, and the leaves on one side he kept in
motion, and the other quiet--when the latter became black, and the
former green; thus proving the difference of colour to be not derived
from any management of heat, but from manipulation, the heat being the
same in both cases.
At the same time, certain Chinese rogues glaze our hysons most
unscrupulously; and it has been proved by chemical analysis, that the
Chinese green teas are artificially coloured, though not with indigo, as
represented by the green tea merchants. We may add, that gunpowder tea
is dried at the highest temperature, and pekoe at the lowest; and the
chemical cause of black tea is its loss of tannin in its drying,
previous to roasting, an opinion that is supported by the testimony of
Liebig. Again, Mr. Ball thinks there may be one species of tea plant,
but several varieties, and that all botanical difference is destroyed in
the course of packing.
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