The research results show that old wulong teas contain low levels of antioxidant catechins. During the process of becoming an old tea, catechins were broken down and gallic acid was also decomposed. In the process of making an old tea, the tea is repeatedly roasted and stored, and the tea leaves are conducting with Maillard reaction to produce a large amount of gallic acid. Gallic acid, a phenolic compound is commonly found in green plants and fruits. It is a substance that can antioxidize and with much helpfulness to health. Old oolong teas contain more antioxidant polyphenolic substances than common oolong teas and there's almost no caffeine content in the old oolong teas.
The cultivation, processing and storage conditions of tea itself will definitely affect the quality of old teas. Different years affirm the different degree of aging (chemical transformation). 10-year-old tea tastes smokey, burn wood, and subtle sweet aftertaste. 20-year-old tea has Meixiang (plum aroma). 30-year-old tea has the medicinal herbs hints. The old tea aged 40+ years has ginseng fragrance.
Translated and edited by Adm./Fong Mong Tea Corp, all rights reserved.