Manufacturing Process

All tea comes from the same plant. The different categories or types of tea are the result of different ways of processing the leaf once it is plucked. Any leaf plucked from any plant soon begins to wither, that is, to dehydrate. Once the plucked tea leaf has withered enough to be pliable, it is ready for processing. If the withered leaf is immediately subjected to heat, which arrests all further chemical change, the result is green tea. Black tea results when heat is applied only after withered leaf is subjected to bruising and allowed further time for its exposed juices to react with the air or oxidize. This is like taking a bite from an apple so that the exposed flesh begins to turn brown. Oolong tea is called semi-oxidized tea because the bruised leaf is subjected to heat before it has had time to oxidize fully, as black tea does. Besides green, black and oolong, white and other categories or types of tea exist also, but they are not very common outside of China.

Tea making, like wine making, is thus an entirely natural process and no matter how much equipment may be employed, it remains as much an art as a science as far as fine tea is concerned. Fine black tea is made by Orthodox Manufacture, a method in which machines duplicate work previously done by hand. After the leaf is hand-plucked and allowed to wither in the factory, it is rolled by machines that bruise and squish the leaf so that oxidation may begin.

When the tea-maker decides his rolled leaf has oxidized sufficiently, it is ready to be fired by passing through large drying ovens. In choosing exactly the right temperature to produce made tea which is neither under-fired nor over-fired, just as in deciding exactly when the wither is perfect or the oxidation is perfect, a tea-maker must consider numerous variables like the condition of the leaf he's using or the weather conditions during that day's manufacture. He is largely guided by smell.

A wondering resource to understanding the manufacturing process of tea is Coffee and Tea by Elin McCoy & John Frederick Walker.