How the flavor and aroma of tea were composited is pretty similar to wine and coffee, all of them are influenced by variety, processes, and production regions, the combination of the three main factors cause these diversifications.
Tea from oriental was classified by processes, and there are six different types — green tea, white tea, yellow tea, oolong tea, black tea, and dark tea.
Black tea is the most popular all over the world, green tea is popular from Japan, oolong tea is known from Taiwan, while white tea, yellow tea, and dark tea are specialties of China.
The key point of the process of tea is about controlling the level of oxidation, different level comes with different flavors and aromas. In addition to the oxidation level, different roasting levels also create distinct features of the tea.
Fermentation of tea or Oxidation of tea
When it comes to fermentation of tea, it's has been a misunderstanding for such long period. In fact, what should be discussed is the oxidation of tea, more precisely, the oxidation of catechins in the tea leaves. During the production of tea, the level of catechin oxidation is controlled through withering and rolling of tea to regulate the flavor of the tea.
Among the six types of tea, the three most common ones, green tea, oolong tea, and black tea, can be easily distinguished by the level of oxidation. Green tea undergoes no oxidation during its processing and is therefore defined as non-oxidized tea (non-fermented tea). In the process of black tea, there is no step of "fixation" which aims to stop oxidation, hence black tea is defined as fully oxidized tea (fully fermentation tea). And every level of oxidation between green tea and black tea can be defined as oolong tea.
Among the six types of tea, the only one that truly undergoes fermentation is dark tea, most of dark tea originates from China. If someone talking about black tea and fermentation, readers of Kochill Tea understand that is not entirely correct.
Decaffeination of tea
Being a heat-soluble substance and due to its large molecular structure, Caffeine requires prolonged heating for caffeine to degrade. During the tea roasting process, the Caffeine is sured to be degrafed.
Catechins in tea
In general, green tea is considered to have the highest content of catechins, making it the most beneficial type of tea for the human body, however, this is not entirely accurate. During the oxidation process of tea, catechins can transform into theaflavins and thearubigins. Green tea, being a non-oxidized tea, tends to have a relatively high catechin content.
In fact, catechins, theaflavins, and thearubigins are all types of polyphenols. Polyphenols are often referred to as antioxidants, and the content of polyphenol in all types of tea is quite similar. Therefore, the impact of each type of tea on the body is also similar.