Processing technology of white tea

Abstract

The application discloses a white tea processing technology and belongs to the technical field of tea processing. The white tea processing technology comprises picking, withering, drying and cake pressing. Multiple withering racks can be placed in a withering room during withering. Multiple liftable air curtain machines are arranged on the inner walls of the opposite sides of the withering room. During withering, the air outlet directions of the air curtain machines on the opposite sides are oppositely arranged, one side moves downwards from the top, and the other side moves upwards from the bottom. The air curtain machines reciprocate during operation, each operation lasts for 20-30 minutes, and each operation is followed by a pause of 10-15 minutes. After the air direction of the air curtain machine is adjusted, the air curtain machine is operated again, and the operation is repeated. After the overall application, the single withering amount of tea leaves is much larger than that of a withering groove, and the tea leaf production rate is improved. The air in the whole withering room is circulated during the whole withering process, the withering of tea leaves is more uniform, and the withering effect of tea leaves is better.

Description

Technical Field

[0001] This invention relates to the field of tea processing technology, specifically a white tea processing technique. Background Technology

[0002] White tea, a lightly fermented tea, is a prized variety of Chinese tea. It gets its name from the fact that the finished tea consists mostly of buds covered in white down, resembling silver and snow. It is one of the six major tea categories in China.

[0003] White tea is a type of tea that is processed without being killed or rolled, but only dried by air or gentle heat. It has the following quality characteristics: intact buds and hairs covering the whole body, fresh and delicate aroma, clear yellow-green liquor, and light and sweet taste.

[0004] White tea is made through processes such as withering, baking (or air drying), sorting, and re-firing. It can also be made by air-drying. The advantage of air-dried tea is that it retains the original fresh aroma of the tea leaves. Withering is a key process in forming the quality of white tea.

[0005] The most common withering equipment is the withering trough. When the amount of tea to be withered is large, the maximum amount of tea that can be withered in the withering trough is fixed, and the daily withering volume is easily limited. Moreover, most withering troughs use a hot air blower at one end to ventilate the trough for withering. During withering, tea leaves closer to the air outlet may be over-withered, while tea leaves farther away from the air outlet may be under-withered. Furthermore, the tea leaves in the middle layer of the withering trough do not come into contact with the hot air, resulting in a poorer withering effect. The overall taste of the tea produced is not good, which also reduces the commercial value of the tea.

[0006] Chinese Patent No. CN116584556A discloses a tea withering and cooling trough, including a trough frame and a mesh surface. An air supply device is installed inside the trough frame, and heating mechanisms are located on both sides of the air supply device. The air outlet of the air supply device faces the mesh surface. The air supply device is connected to a moving device, which can drive the air supply device to reciprocate within the trough frame. The air supply device is positioned below the mesh surface, with its air outlet perpendicular to the mesh surface. The moving device enables the air supply device to reciprocate within the trough frame. Through localized air supply and moving coverage, the airflow and heat distribution on the tea leaves on the mesh surface are uniform. The device also allows for control of the air supply frequency and speed, and precise control of the air supply temperature at different times, enabling precise withering or cooling of the tea leaves under different weather conditions or climates. However, during use, this equipment may result in over-withering of the tea leaves at the bottom and under-withering of the tea leaves in the middle and upper layers. Summary of the Invention

[0007] In order to solve the problems mentioned in the background art, the applicant, together with the factory's technical personnel, conducted a number of experiments to increase the total amount of tea leaves withered each day and the quality of withering. Finally, the white tea processing technology proposed in this application was invented. After the application of this technology, the daily withering amount of tea leaves in the factory was greatly increased, and the quality of the tea leaves was also better guaranteed.

[0008] The purpose of this invention is to overcome the aforementioned technical difficulties and provide a processing technology for white tea with a larger withering volume and a better withering effect.

[0009] To achieve the above objectives, the technical solution adopted is: a white tea processing technique, comprising the following steps:

[0010] A. Picking: Pick tender tea leaves in spring or semi-ripe tea leaves in autumn for later use;

[0011] B. Withering: After picking, the tea leaves are laid flat on withering racks and pushed into the withering room. Multiple layers are placed, and hot air or fans are used to wither the tea leaves layer by layer until the moisture content of the tea leaves reaches 25%-50%.

[0012] C. Drying: After withering, the tea leaves are bagged and placed in a drying chamber. The time of entry into the drying chamber for each bag of tea is recorded. The ambient temperature of the drying chamber is controlled at 20-25℃. Each bag of tea leaves is naturally dried for more than one year. The moisture content of the dried tea leaves is 3-5%.

[0013] D. Pressing: The dried tea leaves are pressed into cakes using a tea cake forming machine, and then the tea cakes are dried in a dryer for 30-40 minutes at a temperature of 40-50℃ before being packaged and shipped.

[0014] Furthermore, the inner walls of the two opposite sides of the withering chamber are equipped with multiple air curtain machines. The left and right ends of the air curtain machines are equipped with vertically arranged sliding tracks, allowing the air curtain machines to move up and down along the sliding tracks. The air curtain machines are equipped with heating components. The top of the withering chamber is equipped with an exhaust fan, and the bottom of the withering chamber is equipped with an air inlet. The outside of the withering chamber is equipped with a central control panel for controlling the exhaust fan and the air curtain machines.

[0015] Furthermore, the withering process includes: controlling the temperature inside the withering chamber at 30-35℃, withering the tea leaves in the withering chamber for 10-24 hours, and controlling the moisture content of the withered tea leaves at 30-40%.

[0016] Furthermore, during the withering process, the airflow directions of the air curtain machines on both sides are set in opposite directions. One side moves downwards from the top at a 30-45° angle upwards, while the other side moves upwards from the bottom at a 30-45° angle downwards. The end point of the air curtain machine's operation is the midpoint of the sliding track. During operation, it reciprocates for 20-30 minutes each time, and pauses for 10-15 minutes after each operation. During the pause, the airflow direction of the air curtain machines is adjusted to match the airflow direction of the opposing air curtain machine. When the operation resumes, the air curtain machines reciprocate on the other half of the sliding track.

[0017] Furthermore, the air curtain machine operates for 20 minutes each time, and needs to be paused for 10 minutes after each operation.

[0018] Furthermore, the withering chamber is divided into multiple separate withering spaces by multiple partition plates.

[0019] The beneficial effects of adopting the above scheme are as follows: This white tea processing technology is carried out in a withering room, where multiple withering racks can be placed. Multiple air curtain machines are installed on the inner walls of the two sides of the withering room. After application, the amount of tea leaves withered in the withering room each time is much greater than that using withering troughs, which improves the tea production rate.

[0020] The air curtain machines on both sides are set with opposite airflow directions, and the running end point of the air curtain machine is the midpoint of the sliding track. During operation, they reciprocate. The airflow direction of the air curtain machine is adjusted after a period of use. During the withering process of tea, after the air curtain machine is started, the indoor temperature rises and the pressure increases. The exhaust fan at the top of the withering chamber starts to exhaust. At this time, because there is an air inlet at the bottom of the withering chamber to replenish air upwards, the exhaust fan, the airflow direction of the air curtain machine and the air inlet of the withering chamber present an overall air circulation process, resulting in better air circulation and better withering effect of tea.

[0021] When the air curtain is on, the edges of the tea leaves begin to evaporate moisture first. During the pause of the air curtain, the moisture in the middle of each tea leaf is greater and seeps into the edges. At the same time, after adjusting the air direction of the symmetrically set air curtain before turning it on again, the tea leaves stacked in multiple layers on the withering rack can also be slightly misaligned with the change in air direction. This allows the tea leaves in the middle of the tray to also be blown by the air for withering, resulting in very uniform withering of each layer of tea leaves. The moisture loss process of each tea leaf during withering is also more uniform, which improves the overall withering effect. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the white tea processing technology of the present invention.

[0023] Figure 2 This is a schematic diagram of the internal structure of the withering chamber.

[0024] Figure 3 for Figure 2 The diagram shows the structure after the partition plates were installed.

[0025] Figure 4 for Figure 3 A schematic diagram of the structure after the withering rack is placed inside.

[0026] Figure 5 for Figure 4 A schematic diagram of the wind direction around the central withering frame.

[0027] Figure 6 for Figure 5 A schematic diagram of the four-axis wind direction of the withering frame after it has been paused and then restarted.

[0028] In the diagram, 1 is the wilting chamber; 2 is the exhaust fan; 3 is the central control panel; 4 is the wilting rack; 5 is the air curtain machine; 6 is the air inlet; and 7 is the partition plate. Detailed Implementation

[0029] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. The described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0030] Example 1

[0031] like Figure 1-2 A white tea processing technique includes the following steps:

[0032] A. Picking: Pick tender tea leaves in spring or semi-ripe tea leaves in autumn for later use;

[0033] B. Withering: After laying the picked tea leaves flat on a plate, place them on the withering rack 4 and push the withering rack 4 into the withering chamber 1. The withering chamber 1 is equipped with symmetrically arranged air curtain machines 5 on both sides. During withering, the air curtain machines 5 on opposite sides are set with opposite airflow directions. The left side moves horizontally upward at 30-45° and downward from the top; the right side moves horizontally downward at 30-45° and upward from the bottom. The end point of the air curtain machine 5 is the midpoint of the sliding track. It moves back and forth during operation, each run lasting 20-30 minutes. After each run, it is paused for 10-15 minutes. During the pause, the airflow direction of the air curtain machine 5 is adjusted to the opposite air curtain machine 5. When it starts running again, the air curtain machine 5 moves back and forth on the other half of the sliding track. The ambient temperature of the withering chamber 1 is controlled at 30-35℃. The tea leaves are withered in the withering chamber 1 for 10-24 hours. The moisture content of the withered tea leaves is controlled at 30-40%.

[0034] C. Drying: After withering, the tea leaves are bagged and placed in a drying chamber. The time of entry into the drying chamber for each bag of tea is recorded. The drying chamber is equipped with temperature and humidity detectors and ventilation fans. The ambient temperature of the drying chamber is controlled at 20-25℃. Each bag of tea leaves is naturally dried for more than one year. The moisture content of the dried tea leaves is 3-5%.

[0035] D. Pressing: The dried tea leaves are pressed into cakes using a tea cake forming machine, and then the tea cakes are dried in a dryer for 30-40 minutes at a temperature of 40-50℃ before being packaged and shipped.

[0036] like Figure 1-2 The top of the withering chamber 1 is connected to an exhaust fan 2, and the bottom of the withering chamber 1 is connected to an air inlet 6.

[0037] like Figure 1 A central control panel 3 is located outside the withering chamber 1. In practice, tea leaves are spread evenly on multiple trays, which are then placed sequentially onto withering racks 4. The withering racks 4 are then pushed sequentially into the withering chamber 1. Figure 2 Multiple air curtain machines 5 are installed on the inner walls of both sides of the withering chamber 1. Vertical sliding rails are installed at the left and right ends of the air curtain machine 5. Sliding seats are slidably connected to the sliding rails at the left and right ends of the air curtain machine 5. Chains are installed in the rails. Gears are meshed at the upper end of the chains. The gears are connected to motors. Heating components are installed on the air curtain machine 5.

[0038] The air curtain machine 5 and the exhaust fan 2 are electronically connected to the central control panel 3. The tea leaves are withered in the withering chamber 1 for 10-24 hours. The ambient temperature of the withering chamber 1 is controlled at 30-35℃. The moisture content of the dried tea leaves is controlled at 30-40%.

[0039] In practice, the operation of the air curtain machine 5 and the exhaust fan 2 controlled by the central control console 3 is existing technology. The surface of the central control console 3 is equipped with a temperature control screen and an air distribution control screen. The temperature in the withering chamber 1 is controlled by the temperature of the air curtain machine 5 and the exhaust fan 2 in a coordinated manner. The central control console 3 is equipped with a button to control the automatic up and down operation of each air curtain machine 5, and also has a button to control the operation of the exhaust fan 2.

[0040] In practice, the air curtain machines 5 are set up facing each other on the left and right sides of the withering rack 4. After the air direction and running trajectory of the air curtain machine 5 on the left and right sides are set as described above, the blown air will not blow against each other, and the indoor air can be kept circulating. After each pause and reversal, the tea leaves in the middle layer of each plate in the withering rack 4 can be staggered, which helps to wither evenly.

[0041] Example 2

[0042] Based on Example 1, the applicant discovered that the withering effect of tea leaves on the trays of withering racks 4 in withering chamber 1 is directly determined by the blowing effect of air curtain machine 5 and the airflow effect of the entire withering chamber 1. Therefore, the applicant conducted the following experiment to investigate the influence of the blowing condition of air curtain machine 5 on the withering effect of tea leaves, wherein:

[0043] Control group 1: The air curtain machine 5, which is symmetrically set up, blows horizontally and moves up and down repeatedly;

[0044] Control group 2: Withering was carried out in withering troughs, with air curtain machine 5 set at the bottom of the withering troughs and the air curtain machine 5 moving back and forth at the bottom of the withering troughs;

[0045] Control group 3: Fixed hot air blowers were installed at both ends of the withering rack 4;

[0046] Control group 4: Example 1.

[0047] In control groups 1-4, the weight and maturity of the tea leaves were consistent in each control group. The tea leaves from all four groups were placed on trays and withered in withering chamber 1 for 24 hours. The ambient temperature in withering chamber 1 was controlled at 30-35℃. Symmetrically arranged air curtain machines 5 were controlled by a central control unit 3 for vertical movement. After withering, the tea leaves were analyzed, and the results are as follows:

[0048] Control group 1: The middle layer of tea leaves showed clumping, a lot of green color, and hard leaf texture, and the overall tea aroma was weak.

[0049] Control group 2: The bottom layer of tea leaves appeared grayish, dry, and crumbly when squeezed, while the top layer of tea leaves showed wrinkled leaves, dark green color, and a lot of green.

[0050] Control group 3: The tea leaves near the two ends of the hot air blower were dry and hard, while the tea leaves in the middle layer were squeezed into clumps.

[0051] Control group 4: The leaves are soft, the tender stems are wilted and soft, the leaves are soft and fluffy when squeezed, the wilted leaves can be clumped together when tightly squeezed, and can slowly fall apart when released, and the tea has a strong aroma.

[0052] Based on the above table, the applicant concluded that only the tea leaves withered in control group 4 had better quality in all aspects, and that only when the air curtain machines 5 were symmetrically arranged with one airflow direction upwards and the other downwards did the withering effect on the tea leaves on the withering rack 4 be the best.

[0053] Based on Example 2, the applicant found that in Control Group 1, the air curtain machine 5's direct blowing easily caused air convection, failing to achieve air circulation, and the middle layer of tea leaves could not be evenly withered; in Control Group 2, the airflow of the air curtain machine 5 could only blow from bottom to top, resulting in a very uniform effect and uneven withering; in Control Group 3, air could not circulate, and tea leaves near the heat source were easily over-withered, while those far from the heat source were under-withered, and the middle layer of tea leaves were not withered at all; in Control Group 4, the applicant operated the air curtain machine 5 for 20-30 minutes each time, and the air curtain machine 5 needed to be paused for 10-15 minutes after each operation. The optimal operating time is 20 minutes, with a 10-minute pause. This is because when the air curtain 5 is running, the edges of the tea leaves begin to evaporate moisture first. During the pause of the air curtain 5, the moisture in the center of each tea leaf is higher and then seeps towards the edges. Additionally, after adjusting the symmetrical air curtain 5 before restarting, the tea leaves stacked on the withering rack 4 can be slightly misaligned with the changing airflow, allowing even the tea leaves in the middle layers of the tray to be exposed to the airflow for withering. This ensures even withering of each layer of tea leaves and more uniform moisture loss during the withering process, thus improving the overall withering effect.

[0054] After overall application, the air curtain machine 5, the air supply vents and the exhaust fans 2, which are symmetrically arranged in the entire withering chamber 1, form a... Figure 5 and Figure 6 Air circulation, ( Figure 5 This is a schematic diagram showing the airflow direction inside the withering chamber 1 after the air curtain machine 5 is turned on. Figure 6 for Figure 5 (Schematic diagram of air direction in withering chamber 1 after a pause) After air circulation, the heat flow in the plate can be accelerated. After adjusting the corresponding setting of the air curtain machine 5, the withering of the tea leaves in the middle layer of the plate can be promoted. The overall temperature and humidity conditions in the plate are kept consistent, and the withering effect is optimal.

[0055] Example 3

[0056] Based on Example 2, such as Figure 3-4 The applicant divides the withering chamber 1 into a left withering chamber 1 and a right withering chamber 1. A sliding partition 7 separates the left withering chamber 1 and the right withering chamber 1. The partition 7 can be in the form of a windproof blanket commonly found at the entrance of a shopping mall.

[0057] After this application, when the demand for tea withering is not too large, operators can turn on only some of the air curtain machines 5 to wither the tea on the withering racks 4, and then pull up the partition plates 7. Alternatively, when the withering times for the tea in the left withering chamber 1 and the right withering chamber 1 are different, the air curtain machines 5 on both sides can be turned on and off separately for withering. The overall application is more scientific and effective.

[0058] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0059] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A tea processing technique, characterized by: Includes the following steps: A. Picking: Pick tender tea leaves in spring or semi-ripe tea leaves in autumn for later use; B. Withering: After the picked tea leaves are laid flat on the withering rack (4), they are pushed into the withering room (1) and placed in multiple layers; the inner walls of the withering room (1) on both sides are equipped with multiple air curtain machines (5), and the left and right ends of the air curtain machine (5) are equipped with vertically arranged sliding tracks, so that the air curtain machine (5) can move up and down along the sliding tracks. The air curtain machine (5) is equipped with a heating component. During withering, the air curtain machines (5) on both sides are set to opposite air directions. One side is set to move downwards from the top at a 30-45° angle upwards; the other side is set to move upwards from the bottom at a 30-45° angle downwards. The running end point of the air curtain machine (5) is the midpoint of the sliding track. During operation, it makes reciprocating motion for 20-30 minutes each time. After each operation, it is paused for 10-15 minutes. During the pause, the air direction of the air curtain machine (5) is adjusted to the air direction setting of the opposite air curtain machine (5). When it runs again, the air curtain machine (5) makes reciprocating motion on the other half of the sliding track. Through the above process, the moisture content of the tea leaves reaches 25%-50%; C. Drying: After withering, the tea leaves are bagged and placed in a drying chamber. The time of entry into the drying chamber for each bag of tea is recorded. The ambient temperature of the drying chamber is controlled at 20-25℃. Each bag of tea leaves is naturally dried for more than one year. The moisture content of the dried tea leaves is 3-5%. D. Pressing: The dried tea leaves are pressed into cakes using a tea cake forming machine, and then the tea cakes are dried in a dryer for 30-40 minutes at a temperature of 40-50℃ before being packaged and shipped.

2. The tea processing technology according to claim 1, characterized in that: The top of the withering chamber (1) is equipped with an exhaust fan (2), the bottom of the withering chamber (1) is equipped with an air inlet (6), and the outside of the withering chamber (1) is equipped with a central control panel (3) for controlling the exhaust fan (2) and the air curtain machine (5).

3. The tea processing technology according to claim 1, characterized in that: The withering process includes: the temperature inside the withering chamber (1) is controlled at 30-35℃, the tea leaves are withered in the withering chamber (1) for 10-24 hours, and the moisture content of the withered tea leaves is controlled at 30-40%.

4. The tea processing technology according to claim 1, characterized in that: The air curtain machine (5) is opened for 20 minutes each time, and the air curtain machine (5) needs to be paused for 10 minutes after it is opened once.

5. The tea processing technology according to claim 1, characterized in that: The withering chamber (1) is provided with multiple partitions (7) to divide the withering chamber (1) into multiple separate withering spaces.

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