Oxidation vs. Fermentation

I have been puzzling this one for some time!  Oxidation v Fermentation.

Why do some tea texts refer to Oxidation and others to Fermentation?

I found an exceptional description of this process on Wikipedia. The link for this tea lover’s article is here. The processing chart for the different teas is brilliant.

Here you go…

OXIDATION is the process of chlorophyll in tea leaves enzymatically breaking down.  Tannins are released or transformed.  Referred to as FERMENTATION in the tea industry, however, no true fermentation happens.  No energy is generated in this process, and micro-organisms do not drive it.  In other tea processing steps, for example, aging, microorganisms are used actually to carry out fermentation.

Each tea producer picks when to stop oxidation.  This may be anywhere from 5-40% oxidation for light oolong teas, in darker oolong teas 60-70%, and in black teas 100% oxidation.

FERMENTATION (tea). The term used for the aerobic treatment of tea leaves to break down certain unwanted chemicals and modify others to develop the tea’s flavor.

Oxidation v Fermentation?  In conclusion, I am not sure if this clarified anything. I guess it all boils down to the same thing…Keep Sipping.


the Tea Lady

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