Green Tea
The production of the green tea is different than the production of black tea in terms of the processes and properties. The green tea leaves sent to the factory are directly subjected to shock-withering at high temperatures within a short period to ensure all oxidation enzymes are deactivated so that the green color of the leaves can be preserved.
There are basically two types of green tea production in the world, which are the Japanese and Chinese methods. But each production method has many different versions. The Chinese method was adopted by our country for green tea production before 1990s.
The Stages of Production
Aeration: When the harvested fresh tea that is sent to the factories for green tea production becomes delayed, the aeration process is carried out to prevent oxidation by transferring the tea to vessels to which cold air is provided. This process can be regarded as continuous storage of factory production for 24 hours.
Shocking: It is carried out to remove the enzymes within the tea to prevent oxidation in the next stages and to ensure better curling of the leaves. This process can be carried out in two ways.
First one is carried out by supplying dry air (120-150 C) for 15-20 seconds to the shock-withering device that rotates on its own axis. The shocking process by providing dry warm air is recommended to minimize the negative factors that may occur during the next stages.
In the second approach the fresh tea is provided for 3-5 minutes, preferably in a closed tunnel, with steam, of which temperature can be adjusted between 90-110 C temperatures depending on the freshness of the tea as obtained from the steam boilers. Polyfenol-oxidase enzyme is deactivated in both cases.
Cooling - Accumulating: If the steaming is especially carried out by shocking, the cooling becomes more important; the water sticking on the fresh leave walls needs to be removed. Dry air (around 30 C) is supplied to the shocked leaves.
The fresh tea must be curled simultaneously; it cannot be expected from the tea that directly emerges from the shocking process to complete curling process within 2-3 minutes of time. If the tea cannot be sent for curling in a short time, some of them will turn into Oolong tea; in order to prevent this, there must be a cooling-accumulating stage where there will be no heating and the fresh tea can accumulate for a single curling process. I. Curling: The shocked tea is subjected to the first curling process for 15-20 minutes of time. The first form occurs at this stage. Small curling is preferred.
I. Drying: The tea leaves that are taken from the curling process which are selected for aeration are dried within classical fresh tea furnaces, of which entrance temperature is 55 C. In case of rotary furnaces, this can reach 80-90 C. The purpose is to prevent the beginning of the oxidation process by reducing the humidity rate of tea to 20-25%.
II. Curling: The tea taken from the furnaces is subjected to the second curling process for 20 minutes of time. This period can be extended depending on the desire of formation. Pressure application exists but it is not recommended.
II. Drying: Tea that passed the curling process is dried within 70-75 kg of rotary furnaces at 110-120 C temperature for 50-60 minutes of time. The purpose is to reduce the humidity rate of the tea to 3-5%. Sorting: At first, the tea is passed through fiber holders to eliminate the fibers and other unwanted pieces. They are sorted afterwards. The sorting process is based on particle weight rather than the particle size.
There are basically two types of green tea production in the world, which are the Japanese and Chinese methods. But each production method has many different versions. The Chinese method was adopted by our country for green tea production before 1990s.
The Stages of Production
Aeration: When the harvested fresh tea that is sent to the factories for green tea production becomes delayed, the aeration process is carried out to prevent oxidation by transferring the tea to vessels to which cold air is provided. This process can be regarded as continuous storage of factory production for 24 hours.
Shocking: It is carried out to remove the enzymes within the tea to prevent oxidation in the next stages and to ensure better curling of the leaves. This process can be carried out in two ways.
First one is carried out by supplying dry air (120-150 C) for 15-20 seconds to the shock-withering device that rotates on its own axis. The shocking process by providing dry warm air is recommended to minimize the negative factors that may occur during the next stages.
In the second approach the fresh tea is provided for 3-5 minutes, preferably in a closed tunnel, with steam, of which temperature can be adjusted between 90-110 C temperatures depending on the freshness of the tea as obtained from the steam boilers. Polyfenol-oxidase enzyme is deactivated in both cases.
Cooling - Accumulating: If the steaming is especially carried out by shocking, the cooling becomes more important; the water sticking on the fresh leave walls needs to be removed. Dry air (around 30 C) is supplied to the shocked leaves.
The fresh tea must be curled simultaneously; it cannot be expected from the tea that directly emerges from the shocking process to complete curling process within 2-3 minutes of time. If the tea cannot be sent for curling in a short time, some of them will turn into Oolong tea; in order to prevent this, there must be a cooling-accumulating stage where there will be no heating and the fresh tea can accumulate for a single curling process. I. Curling: The shocked tea is subjected to the first curling process for 15-20 minutes of time. The first form occurs at this stage. Small curling is preferred.
I. Drying: The tea leaves that are taken from the curling process which are selected for aeration are dried within classical fresh tea furnaces, of which entrance temperature is 55 C. In case of rotary furnaces, this can reach 80-90 C. The purpose is to prevent the beginning of the oxidation process by reducing the humidity rate of tea to 20-25%.
II. Curling: The tea taken from the furnaces is subjected to the second curling process for 20 minutes of time. This period can be extended depending on the desire of formation. Pressure application exists but it is not recommended.
II. Drying: Tea that passed the curling process is dried within 70-75 kg of rotary furnaces at 110-120 C temperature for 50-60 minutes of time. The purpose is to reduce the humidity rate of the tea to 3-5%. Sorting: At first, the tea is passed through fiber holders to eliminate the fibers and other unwanted pieces. They are sorted afterwards. The sorting process is based on particle weight rather than the particle size.
