A brick tea production process capable of reducing fluoride content

Abstract

The invention relates to a brick tea production process capable of reducing fluorine content, comprising the following steps: picking old leaves, and placing the picked old leaves into a withering device to complete a withering operation; placing the withered tea leaves into a withering machine, adjusting the temperature of the withering machine to 380-400 DEG C, and withering for 3-5 minutes; rolling the withered tea leaves for 40-50 minutes, standing for 30 minutes, and rolling again for 70 minutes; performing a pile fermentation operation on the rolled tea leaves, the pile fermentation for 24 hours, and turning the tea leaves every 8 hours; drying the tea leaves after the pile fermentation with hot air, the temperature of the hot air being 100-120 DEG C; placing the dried tea leaves into a steamer with an upper opening for steaming, introducing an upward steam flow from the lower part of the steamer, and discharging the steam flow from the upper part of the steamer; placing the steamed tea leaves into a mold for pressing and forming to obtain brick tea, thereby ensuring the quality of the brick tea and reducing the fluorine content of the brick tea, so that the fluorine content in the brick tea is lower than 300 mg / kg.

Description

Technical Field

[0001] The invention relates to the field of tea making technology, in particular to a brick tea making technology capable of reducing fluorine content. Background Art

[0002] Brick tea is also called steamed and compressed tea. As the name suggests, it is tea leaves that look like bricks. It is also a more representative type of compressed tea. It is made of tea leaves, tea stems, and sometimes tea powder. The processing technology of brick tea generally includes picking, withering, killing green, rolling, piling, steaming, drying, steaming and pressing.

[0003] The tea leaves picked for brick tea are generally old tea leaves and tea stems, and the fluoride content in old tea leaves and tea stems is generally more than 1000mg / kg. The content in different tea planting bases will vary, but all are more than 800mg / kg. The national food safety standard for brick tea is to have a fluoride content of less than 300mg / kg. The detection method is GB19965-2005 "Fluoride Content in Brick Tea". Therefore, it is necessary to reduce the fluoride content in the tea leaves during the tea making process. During the withering, killing and rolling processes, some fluorine will naturally evaporate. However, after the production is completed, the fluoride content will still be above 500. There is no fluorine content standard. Summary of the invention

[0004] The purpose of the present invention is to provide a brick tea production process capable of reducing the fluorine content, by changing the sun-drying step to hot air drying, changing the traditional steaming of tea in a sealed steam box to steaming of tea with a steam flow from bottom to top, and allowing the steam to be discharged from the steam box with an opening on the top, thereby ensuring the quality of the brick tea and reducing the fluorine content of the brick tea, so that the fluorine content in the brick tea is less than 300 mg / kg.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is: a brick tea production process capable of reducing fluorine content, comprising the following steps:

[0006] Step 1: picking old leaves and placing the picked old leaves into a withering device to complete the withering operation;

[0007] Step 2: Place the withered tea leaves in a tea-fixing machine, adjust the temperature of the tea-fixing machine to 380-400°C, and fix for 3-5 minutes;

[0008] Step 3: Roll the withered tea leaves for 40-50 minutes, let them stand for 30 minutes, and roll them again for 70 minutes;

[0009] Step 4: pile the rolled tea leaves for 24 hours, turning them over every 8 hours.

[0010] Step 5: Dry the fermented tea leaves with hot air at a temperature of 100-120°C;

[0011] Step 6: Place the dried tea leaves into a steamer with an upper opening for steaming, introduce an upward steam flow from the lower part of the steamer, and discharge the steam flow from the upper part of the steamer;

[0012] Step 7: Place the steamed tea leaves into a mold and press them into shape to obtain brick tea.

[0013] According to the production process of the present application, compared with the traditional tender killing of old leaves (260-280°C), the present application adopts the old leaf killing, which can ensure thorough killing and evaporate part of the fluorine in the tea leaves. Compared with the traditional rolling for 40-50 minutes, the tea stems are rolled twice to damage the tea enzymes in the tea stems and volatilize part of the fluorine again. The pile is turned over during the fermentation process to discharge the volatilized fluorine and reduce the fluorine content again. Hot air drying is used instead of sun drying, and part of the volatilized fluorine can be blown away while hot air drying. During the steaming process, an upward steam flow is formed to soften the tea leaves, and the fluorine volatilized during the steaming process can be carried out from the upper opening of the steamer. Through the synergistic effect of multiple steps, the fluorine content in the brick tea after production can be greatly reduced, so that the fluorine content of the produced brick tea is less than 300mg / kg.

[0014] Preferably, the withering device comprises a ventilation box, the top plate of which is a withering mesh plate, the side of which is provided with a withering trough plate, one end of the ventilation box is provided with a blower connected to its inner cavity, the air outlet end of the blower is equipped with a heating structure, the side of the ventilation box is provided with a withering opening and closing door through an opening and closing structure, and a temperature measuring device is installed at intervals below the withering mesh plate; the blower is an axial flow fan with a flow rate of 1100m 3 / h, power is 1.5Kw, speed is 2900r / min.

[0015] The hot air blown out by the blower is introduced into the ventilation box, so that the inside of the ventilation box can guide the diffused hot air upward, which can ensure that the tea leaves on the withering mesh plate are completely withered, and an openable and closable withering opening and closing door is set in the ventilation box. According to the measurement results of temperature measuring devices in different parts, the corresponding withering opening and closing door is selectively opened to avoid excessive upward diffusion of hot air and the occurrence of excessive withering temperature. Since the hot air is introduced into the ventilation box, it can only be diffused sideways after the withering opening and closing door is opened, so the power of the blower can be reduced, thereby saving energy.

[0016] Preferably, a control box with a display function is provided on the outside of the ventilation box, and the control box is used to control the operation of the blower and the temperature measuring device, and display the measured temperature of the temperature measuring device in real time. A withering opening and closing door is installed on the outside of the ventilation box through a hinge, and an opening and closing lock is installed on the withering opening and closing door for realizing the unlocking function by rotation. A withering walking wheel with a self-locking function is provided at the bottom of the ventilation box, and a discharge port is provided on the side of the withering trough plate away from the blower, and the discharge port is matched with a conical discharge chute.

[0017] The operation of the blower and the temperature measuring device is controlled by the control box, so as to facilitate the intermittent hot air withering in coordination with the withering process, and the withering opening and closing door corresponding to the part with excessively high temperature can be opened according to the displayed temperature.

[0018] Preferably, in the withering step, the withering temperature is 30-35°C, the picked tea leaves are placed on the withering mesh plate and left to stand for 10-50 minutes, then blown with hot air for 30 minutes, and then blown again for 30 minutes after an interval of 60 minutes. A total of three hot air blowings are performed to complete the withering.

[0019] The withering mode of three hot air blows can blow away the fluorine volatilized in the tea leaves during the withering process.

[0020] Preferably, the steamer comprises a box body, which is a coverless structure, and a tea steaming mesh plate is provided at a position 2-10 cm away from the bottom surface of the box body, and circular hole-shaped meshes are evenly arranged on the tea steaming mesh plate, and the diameter of the mesh is 0.2-0.4 mm, and the center distance between two adjacent meshes is twice the mesh diameter. A steam transmission hole connected to the cavity below the tea steaming mesh plate is provided on the side of the box body, and the steam transmission hole is connected to the steam generating device through a pipeline.

[0021] A tea steaming screen is set at the bottom of the box, and steam is introduced from the bottom of the screen, so that it can be sprayed into the box from the mesh of the screen. Since the diameter of the mesh is small, an upward airflow with a certain pressure can be formed, and the fluorine discharged from the tea leaves during the steaming process can be taken away from the upper part of the opening, so that the tea leaves can be steamed and softened while reducing the fluorine.

[0022] Preferably, at least three parallel steam pipes are arranged at the bottom of the box body, the steam pipes are provided with steam holes, and one end of all the steam pipes close to the steam transmission holes is connected to the steam transmission pipes arranged in the box body, and the steam transmission pipes are connected to the steam transmission holes.

[0023] A steam pipe with a steam hole is arranged at the bottom of the box body, so that the steam transmitted from the steam transmission hole can be sprayed out from the steam hole, so that the sprayed steam can be more dispersed and the steam portion sprayed into the box body can be more uniform.

[0024] Preferably, the outer end of the steam transmission hole is threadedly sleeved with a steam transmission joint, the other end of the steam transmission joint is connected to the joint sleeve of the steam hose, and the steam hose is connected to the steam generating device.

[0025] The steam transmission hole is connected to the steam generating device by means of a steam transmission structure and a joint sleeve, so that it can be easily disassembled from the steam generating device.

[0026] Preferably, steam holes are provided on the upper part and the side part of the steam pipe, the steam holes on the upper part are vertically upward, and the steam holes on the side part are inclined upward.

[0027] The distribution of the steam holes can increase the steam ejection efficiency and the ejection range of the steam pipe.

[0028] Preferably, the steam pressure introduced by the steam generating device is 5-10 MPa, and 5-10 kg of water vapor is introduced for every 1000 kg of tea leaves.

[0029] The design of the amount and pressure of water vapor can ensure that the tea leaves are steamed soft while removing the fluorine.

[0030] Preferably, one side panel of the box body is a steamer opening and closing door, and reinforcing ribs are arranged on the inner side of the side panel of the box body, an opening and closing handle is installed on the steamer opening and closing door, and self-locking tea steaming walking wheels are arranged at the lower part of the box body.

[0031] The steam box door can be opened and closed to facilitate loading and unloading of materials. The reinforcing ribs can improve the strength of the side panels. The walking wheels can change the position of the box. The box and the mesh plate are both made of 304 stainless steel, which can prevent the wooden box from absorbing the discharged fluorine and allowing the fluorine to enter the tea again. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The figure is a schematic diagram of a process for producing brick tea with reduced fluoride content.

[0033] Figure 2 It is a top view of the withering device.

[0034] Figure 3 It is the front view of the withering device.

[0035] Figure 4 It is a structural schematic diagram of a steam box.

[0036] Figure 5 for Figure 4 A partial enlarged view of middle A.

[0037] Figure 6 A top view of the mesh.

[0038] Figure 7 This is a top view of the box bottom after removing the mesh.

[0039] The text labels shown in the figure are: 1. ventilation box; 2. withering mesh plate; 3. withering trough plate; 4. discharging chute; 5. blower; 6. control box; 7. withering walking wheel; 8. withering opening and closing door; 9. hinge; 10. opening and closing lock; 21. box body; 22. reinforcement rib; 23. steam box opening and closing door; 24. opening and closing handle; 25. steaming tea mesh plate; 26. steam pipe; 27. steam hole; 28. steam transmission hole; 29. ​​steam transmission pipe; 30. steam transmission joint; 31. joint sleeve; 32. steaming tea walking wheel. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings. The description in this part is only exemplary and explanatory and should not have any limiting effect on the protection scope of the present invention.

[0041] like Figure 2-Figure 3 As shown, the withering device used in the present application comprises a ventilation box 1, the top plate of the ventilation box 1 is a withering mesh plate 2, the side of the withering mesh plate 2 is provided with a withering trough plate 3, one end of the ventilation box 1 is provided with a blower 5 connected to its inner cavity, the air outlet end of the blower 5 is equipped with a heating structure, the side of the ventilation box 1 is provided with a withering opening and closing door 8 through an opening and closing structure, and a temperature measuring device is installed at intervals below the withering mesh plate 2; the blower 5 is an axial flow fan with a flow rate of 1100m 3 / h, the power is 1.5Kw, the speed is 2900r / min, and a control box 6 with a display function is arranged on the outside of the ventilation box 1. The control box 6 is used to control the operation of the blower and the temperature measuring device, and to display the measured temperature of the temperature measuring device in real time. A withering opening and closing door 8 is installed on the outside of the ventilation box 1 through a hinge 9, and an opening and closing lock for rotating to realize the unlocking function is installed on the withering opening and closing door 8. A withering walking wheel 7 with a self-locking function is arranged at the bottom of the ventilation box 1, and a discharge port is opened on the side of the withering trough plate 3 away from the blower 5, and the discharge port is matched with a conical discharge chute 4.

[0042] When the withering device of the present application is used for withering, the tea leaves to be withered are first placed on the withering mesh plate 2. After standing for 50 minutes, the blower 5 and the temperature measuring device are controlled by the control box 6. The heating structure works together with the blower 5. The blower draws in the outside air, which forms a flow of air after passing through the heating structure and enters the ventilation box 1. As the air flow moves, it will diffuse to the surroundings. Since it is in the ventilation box 1, the air flow diffused to the side will be guided upward, which can increase the upward diffusion, that is, the air flow acting on the tea leaves on the withering mesh plate 2 will increase, avoiding the tea leaves at one end of the blower 5. The withering is incomplete, and the temperature measured by the temperature measuring device exceeds the set value due to the increased air diffusion in the rear part. Therefore, the withering opening and closing door 8 at the corresponding position needs to be opened to allow the air diffused from the side to dissipate directly from the side. In this way, the tea leaves on the entire withering mesh plate 2 can be withered more evenly. The blower 5 works for 30 minutes at a time. After completing a hot air withering, it is generally necessary to stand for 60 minutes before hot air withering is carried out again. The number of hot air withering is generally 3 times. In this way, a good withering effect can be achieved while taking away some of the fluorine in the tea leaves.

[0043] like Figure 4-Figure 7 As shown, the steam box used in the present application includes a box body 21, the box body 21 is a coverless structure, and a tea steaming mesh plate 25 is arranged at a position 2-10 cm away from the bottom surface of the box body 21, and circular hole-shaped meshes are evenly opened on the tea steaming mesh plate 25, the diameter of the mesh is 0.2-0.4 mm, and the center distance between two adjacent meshes is twice the mesh diameter. The side of the box body 21 is provided with a steam transmission hole 28 connected to the cavity below the tea steaming mesh plate 25, and the steam transmission hole 28 is connected to the steam generating device through a pipeline. At least three parallel steam pipes 26 are arranged at the bottom of the box body 21, and the steam pipes 26 are provided with steam holes 27, and all steam pipes 26 are close to the steam transmission holes 28. One end of each of the steam pipes 26 is connected to a steam transmission pipe 29 arranged in the box body 21, and the steam transmission pipe 29 is connected to the steam transmission hole 28. The outer end of the steam transmission hole 28 is threadedly sleeved with a steam transmission joint 30, and the other end of the steam transmission joint 30 is connected to a joint sleeve 31 of a steam hose, and the steam hose is connected to a steam generating device. Steam holes 27 are provided on the upper and side parts of the steam pipe 26, the steam holes on the upper part are vertically upward, and the steam holes on the side parts are inclined upward. One side panel of the box body 21 is a steam box opening and closing door 23, and a reinforcing rib 22 is provided on the inner side of the side panel of the box body 21. An opening and closing handle 24 is installed on the steam box opening and closing door 23, and a self-locking steaming tea walking wheel 22 is provided at the lower part of the box body 21.

[0044] When using the steamer of the present application to steam tea, first put the tea leaves to be steamed and softened on the tea steaming mesh plate 25 of the box body 21. After the tea leaves are put in, close the tea steaming opening and closing door 23, and then connect the steam hose of the steam generating device with the steam transmission joint 31 through the joint sleeve 31. Then, steam with a pressure of 5-10MPa is input through the steam generating device. The steam will pass through the steam hose, the steam transmission hole 28 and the steam transmission pipe 29 and enter the steam pipe 26, and then be ejected from the steam hole 27. The ejected high-pressure steam will enter the cavity of the box body 21 containing tea leaves through the mesh of the mesh plate 25. Due to the high pressure of the steam, a steam flow with a certain pressure will be formed after passing through the mesh. The steam flow will steam the tea leaves and soften them. Most of the steam will be absorbed by the tea leaves, and some steam will still be discharged from the uncovered upper part of the box body 21. The discharged steam will carry the fluorine discharged during the steaming process of the tea leaves. Therefore, it can not only steam the tea leaves but also reduce the fluorine.

[0045] The specific example of brick tea production using the withering device and steamer is as follows: Example 1

[0046] A brick tea production process capable of reducing fluorine content comprises the following steps:

[0047] Step 1, pick old leaves in Tea Garden No. 1, and put the picked old leaves into the withering device to complete the withering operation; the withering temperature is 30-35°C, the picked tea leaves are placed on the withering mesh plate and left to stand for 10 minutes, then blown with hot air for 30 minutes, and then blown again for 30 minutes after an interval of 60 minutes, and the withering is completed after a total of three hot air blowings.

[0048] Step 2: Place the withered tea leaves in a tea-fixing machine, adjust the temperature of the machine to 380-400°C, and fix for 5 minutes;

[0049] Step 3: Roll the withered tea leaves for 40 minutes, let them stand for 30 minutes, and roll them again for 70 minutes;

[0050] Step 4: pile the rolled tea leaves for 24 hours, turning them over every 8 hours.

[0051] Step 5: Dry the fermented tea leaves with hot air at a temperature of 100°C;

[0052] Step 6: Place the dried tea leaves on the tea steaming screen, and then introduce steam into the steam transmission hole through the steam generating device, the steam pressure is 10MPa, and 5kg of water vapor is introduced for every 1000kg of tea leaves; the water vapor passes through the mesh of the tea steaming screen from the lower part of the steam box to form an upward steam flow, and the steam flow is discharged from the upper part of the steam box;

[0053] Step seven, put the steamed tea leaves into a mold for pressing and forming to obtain brick tea, and name it Baotian No. 1 according to the tea base and tea batch. The above embodiment was completed in June 2020.

[0054] Samples of brick tea prepared in the above embodiment were selected and sent to a professional testing agency for fluoride content testing. The testing agency was China Testing & Certification Group Beijing Co., Ltd. The testing time was July 31, 2020, and the testing time was July 31, 2020-August 6, 2020. The sample was 500g*1 bag, and the sample state was solid. The content of the test was fluorine content. The standard for the test was GB19965-2005 "Fluoride Content in Brick Tea", and the test result was a fluorine content of 292 mg / kg. Example 2

[0055] A brick tea production process capable of reducing fluorine content comprises the following steps:

[0056] Step 1, pick old leaves in Tea Garden No. 1, and put the picked old leaves into the withering device to complete the withering operation; the withering temperature is 30-35°C, the picked tea leaves are placed on the withering mesh plate and left to stand for 50 minutes, then blown with hot air for 30 minutes, and then blown again for 30 minutes after an interval of 60 minutes, and the withering is completed after a total of three hot air blowings.

[0057] Step 2: Place the withered tea leaves in a tea-fixing machine, adjust the temperature of the tea-fixing machine to 380-400°C, and fix for 3 minutes;

[0058] Step 3: Roll the withered tea leaves for 40 minutes, let them stand for 30 minutes, and roll them again for 70 minutes;

[0059] Step 4: pile the rolled tea leaves for 24 hours, turning them over every 8 hours.

[0060] Step 5: Dry the fermented tea leaves with hot air at a temperature of 120°C.

[0061] Step 6: Place the dried tea leaves on the tea steaming screen, and then introduce steam into the steam transmission hole through the steam generating device, the steam pressure is 5MPa, and 10kg of water vapor is introduced for every 1000kg of tea leaves; the water vapor passes through the mesh of the tea steaming screen from the lower part of the steam box to form an upward steam flow, and the steam flow is discharged from the upper part of the steam box;

[0062] Step seven, put the steamed tea leaves into a mold for pressing and molding to obtain brick tea, and name it Baotian No. 2 according to the tea base and tea batch. The above embodiment was completed in June 2020.

[0063] A sample of brick tea prepared in the above embodiment was selected and sent to a professional testing agency for fluoride content testing. The testing agency was China Testing & Certification Group Beijing Co., Ltd. The testing time was July 31, 2020, and the testing time was July 31, 2020-August 6, 2020. The sample was 500g*1 bag, and the sample state was solid. The content of the test was fluorine content. The standard for the test was GB19965-2005 "Fluoride Content in Brick Tea", and the test result was a fluorine content of 294 mg / kg. Example 3

[0064] A brick tea production process capable of reducing fluorine content comprises the following steps:

[0065] Step 1, pick old leaves in Tea Garden No. 2, and put the picked old leaves into the withering device to complete the withering operation; the withering temperature is 30-35°C, the picked tea leaves are placed on the withering mesh plate and left to stand for 30 minutes, then blown with hot air for 30 minutes, and then blown again for 30 minutes after an interval of 60 minutes, and the withering is completed after a total of three hot air blowings.

[0066] Step 2: Place the withered tea leaves in a tea-fixing machine, adjust the temperature of the tea-fixing machine to 380-400°C, and fix for 4 minutes;

[0067] Step 3: Roll the withered tea leaves for 42 minutes, let them stand for 30 minutes, and roll them again for 70 minutes;

[0068] Step 4: pile the rolled tea leaves for 24 hours, turning them over every 8 hours.

[0069] Step 5: Dry the fermented tea leaves with hot air at a temperature of 110°C.

[0070] Step 6: Place the dried tea leaves on the tea steaming screen, and then introduce steam into the steam transmission hole through the steam generating device, the steam pressure is 8MPa, and 8kg of water vapor is introduced for every 1000kg of tea leaves; the water vapor passes through the mesh of the tea steaming screen from the lower part of the steam box to form an upward steam flow, and the steam flow is discharged from the upper part of the steam box;

[0071] Step seven, put the steamed tea leaves into a mold for pressing and forming to obtain brick tea. It is named dark tea according to the tea base and tea batch. The above embodiment is completed in October 2020.

[0072] A sample of brick tea prepared in the above embodiment was selected and sent to a professional testing agency for fluoride content testing. The testing agency is China Testing & Certification Group Beijing Co., Ltd. The testing time was November 20, 2020, and the testing time was November 201, 2020-November 26, 2020. The sample was 200g and the sample state was solid. The content of the test was fluorine content. The standard for the test was GB19965-2005 "Fluoride Content in Brick Tea". The test result was a fluorine content of 286 mg / kg. Example 4

[0073] A brick tea production process capable of reducing fluorine content comprises the following steps:

[0074] Step 1, pick old leaves in Tea Garden No. 3, and put the picked old leaves into the withering device to complete the withering operation; the withering temperature is 30-35°C, the picked tea leaves are placed on the withering mesh plate and left to stand for 40 minutes, then blown with hot air for 30 minutes, and then blown again for 30 minutes after an interval of 60 minutes, and the withering is completed after a total of three hot air blowings.

[0075] Step 2: Place the withered tea leaves in a tea-fixing machine, adjust the temperature of the tea-fixing machine to 380-400°C, and fix for 3.5 minutes;

[0076] Step 3: Roll the withered tea leaves for 48 minutes, let them stand for 30 minutes, and roll them again for 70 minutes;

[0077] Step 4: pile the rolled tea leaves for 24 hours, turning them over every 8 hours.

[0078] Step 5: Dry the fermented tea leaves with hot air at a temperature of 105°C.

[0079] Step 6: Place the dried tea leaves on the tea steaming screen, and then introduce steam into the steam transmission hole through the steam generating device, the steam pressure is 7MPa, and 7kg of water vapor is introduced for every 1000kg of tea leaves; the water vapor passes through the mesh of the tea steaming screen from the lower part of the steam box to form an upward steam flow, and the steam flow is discharged from the upper part of the steam box;

[0080] Step seven, put the steamed tea leaves into a mold for pressing and forming to obtain brick tea. According to the tea base and tea batch, it is named Ruichun Tea No. 1. The completion time of the above embodiment is September 2021.

[0081] A sample of brick tea prepared in the above embodiment was selected and sent to a professional testing agency for fluorine content testing. The testing agency was Shanghai Huace Pinbiao Testing Technology Co., Ltd. The testing time was October 25, 2021, and the testing time was October 25, 2021-October 29, 2021. The sample was 200g and the sample state was solid. The content of the test was fluorine content. The standard for the test was GB19965-2005 "Fluoride Content in Brick Tea". The test result was a fluorine content of 294.2 mg / kg. Example 5

[0082] A brick tea production process capable of reducing fluorine content comprises the following steps:

[0083] Step 1, pick old leaves in the No. 5 tea garden, and put the picked old leaves into the withering device to complete the withering operation; the withering temperature is 30-35°C, the picked tea leaves are placed on the withering mesh plate and left to stand for 25 minutes, then blown with hot air for 30 minutes, and then blown again for 30 minutes after an interval of 60 minutes. A total of three hot air blows are performed to complete the withering.

[0084] Step 2: Place the withered tea leaves in a tea-fixing machine, adjust the temperature of the tea-fixing machine to 380-400°C, and fix for 4 minutes;

[0085] Step 3: Roll the withered tea leaves for 47 minutes, let them stand for 30 minutes, and roll them again for 70 minutes;

[0086] Step 4: pile the rolled tea leaves for 24 hours, turning them over every 8 hours.

[0087] Step 5: Dry the fermented tea leaves with hot air at a temperature of 100-120°C;

[0088] Step 6: Place the dried tea leaves on the tea steaming screen, and then introduce steam into the steam transmission holes through the steam generating device, with a steam pressure of 6 MPa, and 6 kg of water vapor is introduced for every 1000 kg of tea leaves; the water vapor passes through the mesh of the tea steaming screen from the lower part of the steam box to form an upward steam flow, and the steam flow is discharged from the upper part of the steam box;

[0089] Step seven, put the steamed tea leaves into a mold for pressing and forming to obtain brick tea. According to the tea base and tea batch, it is named Ruichun Tea No. 2. The completion time of the above embodiment is September 2021.

[0090] A sample of brick tea prepared in the above embodiment was selected and sent to a professional testing agency for fluoride content testing. The testing agency was Shanghai Huace Pinbiao Testing Technology Co., Ltd. The testing time was October 25, 2021, and the testing time was October 25, 2021-October 29, 2021. The sample was 200g and the sample state was solid. The content of the test was fluorine content. The standard for the test was GB19965-2005 "Fluoride Content in Brick Tea". The test result was a fluorine content of 258.5 mg / kg.

[0091] The above five embodiments picked old leaves from three different tea gardens and completed the production in different years. The fluorine content was tested by a professional testing agency and was lower than 300 mg / kg. This proves that the brick tea production process of the present application does reduce the fluorine content in old tea leaves.

[0092] It should be noted that, in this article, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0093] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above examples is only used to help understand the method of the present invention and its core idea; the above is only a preferred implementation method of the present invention. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the protection scope of the present invention.

Claims

1. A brick tea production process capable of reducing fluorine content, characterized in that: The steps include: Step 1: picking old leaves and placing the picked old leaves into a withering device to complete the withering operation; Step 2: Place the withered tea leaves in a tea-fixing machine, adjust the temperature of the tea-fixing machine to 380-400°C, and fix for 3-5 minutes; Step 3: Roll the withered tea leaves for 40-50 minutes, let them stand for 30 minutes, and roll them again for 70 minutes; Step 4: pile the rolled tea leaves for 24 hours, turning them over every 8 hours. Step 5: Dry the fermented tea leaves with hot air at a temperature of 100-120°C; Step 6: Place the dried tea leaves into a steamer with an upper opening for steaming, introduce an upward steam flow from the lower part of the steamer, and discharge the steam flow from the upper part of the steamer; Step 7: Put the steamed tea leaves into a mold and press them into shape to obtain brick tea; The withering device comprises a ventilation box (1), the top plate of the ventilation box (1) is a withering mesh plate (2), the side of the withering mesh plate (2) is provided with a withering trough plate (3), one end of the ventilation box (1) is provided with a blower (5) connected to its inner cavity, the air outlet end of the blower (5) is equipped with a heating structure, the side of the ventilation box (1) is provided with a withering opening and closing door (8) through an opening and closing structure, and a temperature measuring device is installed at intervals below the withering mesh plate (2); the blower (5) is an axial flow fan with a flow rate of 1100m 3 / h, power is 1.5kW, speed is 2900r / min; the box body and mesh plate of the steamer are made of 304 stainless steel; The withering temperature is 30-35℃. The picked tea leaves are placed on the withering screen and left to stand for 10-50 minutes. Then, hot air is blown for 30 minutes. After an interval of 60 minutes, hot air is blown again for 30 minutes. A total of three hot air blows are performed to complete the withering. The steam pressure introduced into the steam generating device is 5-10MPa, and 5-10kg of water vapor is introduced for every 1000kg of tea leaves.

2. A brick tea production process capable of reducing fluorine content according to claim 1, characterized in that: A control box (6) with a display function is arranged on the outside of the ventilation box (1), and the control box (6) is used to control the operation of the blower and the temperature measuring device, and to display the measured temperature of the temperature measuring device in real time. A withering opening and closing door (8) is installed on the outside of the ventilation box (1) through a hinge (9), and an opening and closing lock that can be rotated to realize the unlocking function is installed on the withering opening and closing door (8). A withering walking wheel (7) with a self-locking function is arranged below the ventilation box (1), and a discharge port is opened on the side of the withering trough plate (3) away from the blower (5), and the discharge port is matched with a conical discharge chute (4).

3. A brick tea production process capable of reducing fluorine content according to claim 1, characterized in that: The steam box comprises a box body (21), the box body (21) is a coverless structure, and a tea steaming mesh plate (25) is arranged at a position 2-10 cm away from the bottom surface of the box body (21), and circular meshes are evenly arranged on the tea steaming mesh plate (25), the diameter of the meshes is 0.2-0.4 mm, and the center distance between two adjacent meshes is twice the mesh diameter. A steam transmission hole (28) connected to a cavity below the tea steaming mesh plate (25) is arranged on the side of the box body (21), and the steam transmission hole (28) is connected to a steam generating device through a pipeline.

4. A brick tea production process capable of reducing fluorine content according to claim 3, characterized in that: The bottom of the box body (21) is provided with no less than three steam pipes (26) extending in parallel, each of the steam pipes (26) being provided with a steam hole (27), and one end of each of the steam pipes (26) close to the steam transmission hole (28) is connected to a steam transmission pipe (29) provided in the box body (21), and the steam transmission pipe (29) is connected to the steam transmission hole (28).

5. A brick tea production process capable of reducing fluorine content according to claim 4, characterized in that: The outer end of the steam transmission hole (28) is threadedly sleeved with a steam transmission joint (30), the other end of the steam transmission joint (30) is connected to a joint sleeve (31) of a steam hose, and the steam hose is connected to a steam generating device.

6. A brick tea production process capable of reducing fluorine content according to claim 5, characterized in that: Steam holes (27) are provided on the upper part and the side part of the steam pipe (26), the steam holes on the upper part are vertically upward, and the steam holes on the side part are inclined upward.

7. A brick tea production process capable of reducing fluorine content according to claim 3, characterized in that: A side panel of the box body (21) is a steamer opening and closing door (23), and a reinforcing rib (22) is provided on the inner side of the side panel of the box body (21). An opening and closing handle (24) is installed on the steamer opening and closing door (23), and a self-locking tea steaming running wheel (32) is provided at the lower part of the box body (21).

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