Oolong tea represents only 2% of the world's tea. It combines the qualities of dark and green teas, giving it several interesting health benefits.
It's made from the leaves of the Camellia sinensis plant, the same plant used to make green tea and black tea. The difference is in how the tea is processed. Oolong is partially oxidized and fermented where green tea is not and black tea is fully oxidized and fermented.
All tea leaves contain certain enzymes, which produce a chemical reaction called oxidation. Oxidation is what turns the green tea leaves into a deep black color.
Through this semi oxidation process Oolong tea uncovers the chemical reactions that eventually give Oolong tea is great health benefits.