The level of fermentation is THE element used to categorise teas. For example, green teas are unfermented, Oolong teas are semi-fermented and black teas are fully fermented. The level of fermentation of teas is high associated with its appearance and taste: Green teas are light in colour, more ‘grassy green’ and refreshing in aroma and taste; Black teas are more smooth in texture and often dark yellow and red in tea brew colour.
A way of illustrating this is through Oolong tea, classified as semi-fermented. Different Oolong teas have various fermentation levels, which is carefully controlled and crucial to the nature of the final product. During Oolong tea’s processing, one of the important steps is to ‘bruise’ the edges of the tea leaves by putting the leaves in a bamboo cylinder and toss around (Yao Qing - 摇青). This process triggers the enzymes to be released from the cells and start a chain of chemical reactions within the tea leaves to facilitate the later fermentation. Once the tea leaves are fermented to the desired level, a process called Chao Qing (炒青) is applied, where the tea leaves are heated (NOT dired!), often in a wok, with highly skilful temperature control to stop the fermentation to progress further.
The image below is from a semi-fermented Oolong (Zhang Ping Shui Xian). As seen on image, the edges of the tea leaves are red in comparison to the rest of the green ( called ‘green leaf of golden edge’ - 金边绿叶 in Chinese). The red part is where the leaves are fermented and border between the red and the green is where the fermentation stopped.
All teas are categorised around their levels of fermentChinese Oolong teaation, and maybe some additional elements if relevant.
The founder and owner of Valley Green Tea
I grew up in the Fu-Jian Province – the tea country of China. Tea drinking has been part of our daily life for as long as I can remember.
While I was working as a public health researcher a few years ago, I read many research reports conducted over the last 30 years about the health benefits of green tea in fighting certain life style related challenges such as cancer, obesity, cardio-vascular and inflammatory diseases etc.
From my research, I realised there is a significant gap between what people consume (i.e. commercial tea bags) for assumed health benefits and the actual benefits that have been enjoyed by the Chinese for a long history from the premium loose leaf teas.
As well as being potentially beneficial to health, the premium loose teas (green tea being the biggest group) are most enjoyable beverages with a fascinating history, colourful culture and holistically dynamic in every aspect.
It is my passion to share, not only the products, but also the whole culture dynamics around the premium teas with the tea enthusiasts, here in Australia and around the world.
Valley Green Tea currently supplis a diverse range of premium loose teas to the tea drinking community that suit all tastes and all cultures and to pass on a deep understanding of the history and benefits of this wonder beverage.Website: https://www.valleygreentea.com.au