The method by which the tea leaves from the tea plant Camellia Sinensis are transformed into the dried tea leaves is known as tea processing. The dried tea leaves are used for brewing tea. The tea processing techniques utilized in the manufacturing and processing of tea leaves determine the varieties of tea.
Classification of Teas
In all, there are four varieties of tea- green tea, white tea, black tea and oolong tea which are made from the leaves as well as young buds of the Camellia sinensis plant. In the tea processing techniques, there are different manners and degree of oxidation of the leaves involved as well as stopping the oxidation, forming the tea and drying it.
The flavor of the final dried tea leaves is determined by the type of cultivar of the tea bush which is used for cultivation of the tea plant and also the quality of the tea leaves along with the manner as well as the quality of the production processing which they undergo.
Sometimes, in order to alter the flavor of the final tea, a tea might even be blended with some other teas or mixed with different flavors to achieve a particular blend and taste.
The different types of tea each have a different taste, flavor, smell as well as visual appearance. The tea processing techniques for all kinds of teas consists of very similar methods and steps with only slight variations. It is important to note that if proper care is not taken during the tea processing in regards to the moisture control as well as the temperature control, there is a significant chance that fungi will grow on the tea. This may lead the tea to be unfit for consumption since this form of the fungus causes real fermentation which contaminates the tea.
Tea Processing Techniques
Now, let us have a look at the general tea processing techniques
Plucking- Generally, twice a year, the tea leaves and flushes that includes a terminal bud and two young leaves, are picked from the Camellia sinensis plant. This plucking usually takes place during early spring or late spring. This flush is much more common. The other less common flush is the autumn or winter pickings of tea flushes. The generals tend to happen in areas and regions where the climate permits plucking. For a higher quality tea, the picking of the tea leaves and young buds is generally done by hand. Picking by hand is also done when the labor costs are not prohibitive. A great importance is given to the skill of the picker since that determines the final product. In the case of hand picking, it is performed by pulling the flush with a snap of the forearm, arm, and sometimes even the shoulders. The picker grass the tea shoot using the thumb and forefinger and sometimes might also use the middle finger in combination. When the picking is not done by hand, then machines are used. However, these do result in broken leaves as well as partial flushes which can reduce the quality of the tea. But, if harvesting is one by machines at correctly timed harvesting period, then it may even result in good leaves which can be utilized for producing high-quality teas.
Withering or Wilting- Once the tea leaves are picked, they soon begin to wilt. In other words, there is a gradual onset of enzymatic oxidation soon after picking of the tea leaves. To avoid this, the technique of withering is used to remove excess water from the leaves and only allow a very slight amount of oxidation. To remove moisture from the leaves, the leaves are put either under the sun or are left in a cool and reel room. During this stage, the leaves tend to lose more than a quarter of their weight due to moisture loss. This process of watering or wilting of the tea leaves is also essential since it promotes the breakdown of leaf proteins into free amino acids.
Disruption- Disruption is also known as leaf maceration. In this step, the teas are bruised or torn to promote as well as quicken the oxidation of the tea leaves. To do this, the tea leaves are lightly bruised on their edges. This is done by either shaking and tossing the tea leaves in a bamboo tray or tumbling them in baskets. For a more extensive leaf disruption, it may be achieved by kneading, rolling, tearing, and crushing. This is usually done by machinery. This step helps to break down the structures inside as well as outside the leaf cells thereby leading to the beginning of oxidation. The leaf juices are also released which changes the taste profile of the tea.
Oxidation of Fermentation- In case of tea varieties which require oxidation, the tea leaves are left in a climate controlled room where oxidation takes place turning the leaves progressively darker. This may be accompanied by agitation for different results. In this step, the chlorophyll of the leaves breaks down, and the tennis is released. This process of oxidation is sometimes also referred as fermentation.
Fixation- Also known as kill-green, this step is done to stop the process of leaf oxidation at the desired level according to the variety of tea being produced. To achieve that, the tea leaves are moderately heated which deactivates their oxidative enzymes. This process also helps to remove the unwanted scents in the tea leaves without inducing any damage in the final flavor of the tea.
Sweltering- This technique is also known as yellowing and is unique to yellow teas. After the previous stage, the warm and damp tea leaves are lightly heated in a closed container so that the green leaves can turn yellow. This technique produces tea leaves which produce a beverage that has yellowish-green hue as the leaf chlorophyll is transformed.
Rolling- The damp tea leaves are rolled into wrinkled strips either by manually by hands or by using machines that wrap the tea leaves around itself. This process further enhances the flavor profile of the tea leaves since it causes some of the sap as well as the essential oils and juices of the leaves to ooze out.
Drying- This is done to finish the tea for selling. There are many ways in which drying is done. The tea leaves are dried using techniques such as panning, sunning, air drying, or baking. Out of these, baking is most commonly used for drying. This step is particularly important for producing green tea varieties.
Aging- This step is not always required for producing all types of tea.This is an additional aging step which is merely a secondary formation baking of the leaves to reach their drinking potential.
