Types of Tea
All tea comes from the leaves of the Camellia Sinensis plant. The styles of tea are produced by altering the shape and chemistry of the leaf. Once this alteration is complete, all teas are finished by drying the leaves. This lesson will focus on the step between picking and drying... a tea is defined by the way it is processed.
The primary impact of the way a leaf is processed, and the main indicator of how the tea will be classified, is oxidation. Oxidation is the natural process by which enzymes in the tea leaf are exposed to, and interact with, the oxygen in the area after the cellular structure of the leaf has been broken. This can happen quickly, through rolling, cutting or crushing, or more slowly through the natural decomposition of the leaf. You see the same process in a piece of fruit. Left to sit, the fruit will slowly turn brown. Cut or bruise the fruit and it will brown much more quickly. The oxidation process is stopped by drying the leaf down to 5-6% moisture content (or less) which prevents the remaining enzymes from interacting with the oxygen in the air.
NOTE: Oxidation is commonly, but incorrectly, referred to by some in the tea industry as fermentation. This is likely a mistaken comparison to the more familiar fermentation process involved in converting grapes into wine.
The four basic styles of tea, in order from least oxidized to most oxidized, are White, Green, Oolong and Black.
The primary impact of the way a leaf is processed, and the main indicator of how the tea will be classified, is oxidation. Oxidation is the natural process by which enzymes in the tea leaf are exposed to, and interact with, the oxygen in the area after the cellular structure of the leaf has been broken. This can happen quickly, through rolling, cutting or crushing, or more slowly through the natural decomposition of the leaf. You see the same process in a piece of fruit. Left to sit, the fruit will slowly turn brown. Cut or bruise the fruit and it will brown much more quickly. The oxidation process is stopped by drying the leaf down to 5-6% moisture content (or less) which prevents the remaining enzymes from interacting with the oxygen in the air.
NOTE: Oxidation is commonly, but incorrectly, referred to by some in the tea industry as fermentation. This is likely a mistaken comparison to the more familiar fermentation process involved in converting grapes into wine.
The four basic styles of tea, in order from least oxidized to most oxidized, are White, Green, Oolong and Black.
