Green, black, oolong … what’s the difference?
All tea varieties are obtained from the leaves and leaf buds of the evergreen plan called Camellia sinensis.
Tea can be broadly categorised into three basic types: green tea, black tea and oolong tea.
During the manufacturing process, the leaves are heated at different stages of oxidation (commonly known as fermentation).
The is produces chemical reactions that result in different flavours and colours as well as the different health benefits of tea.
Green tea is the “least processed”. To produce it, freshly harvested leaves are rapidly steamed or pan-fried to deactivate the enzymes, thereby preventing fermentation and producing a dry, stable product,
To produce black tea, the fresh leaves are allowed to wither until their moisture content is less than 55 per cent of the original leaf weight.
The withered leaves are then rolled and crushed.
Black tea can then be further processed into oolong tea.
Shortly after the leaves are rolled, they are further fired or friend in a drying chamber to terminate the oxidation.
Indian and Ceylon tea, such as Darjeeling and Earl Grey, are all blends of black tea.
Unlike other types of tea, herbal tea is not derived from the tea plant but rather, is made from a blend of herbs, flowers, fruits and spices. So far no studies have shown that they yield the same benefits as tea varieties obtained from Camellia sinensis.
Source: Ms Wong Yuefan, a senior dietician at the National Healthcare Group Polyclinics