Processing method of highly sweet and mellow yellow tea

Abstract

The invention relates to a processing method of sweet and mellow yellow tea. The processing method comprises the following steps: 1, providing negative oxygen heaping yellowing equipment; 2, raw material selection; 3, tedding; 4, performing fixation; 5, cooling; 6, moisture regaining; 7, rolling; 8, heaping for yellowing; 9, primary drying; according to the method, the yellow tea yellowing environment is subjected to effective'three-control '(temperature control, humidity control and gas control) regulation through the yellowing equipment, the influence of environmental factors on the yellowing effect is eliminated, the repeated work of multiple times of wrapping of traditional yellowing wet cloth is relieved, and the yellow tea production efficiency is greatly improved; through precise control of heaping yellowing equipment, establishment of an oxygen-enriched micro-domain environment and manual control of heaping yellowing reaction degree, the characteristic quality sweet and mellow feeling of yellow tea is promoted, high-quality yellow tea products can be stably produced in batches, an advanced control system is adopted, control parameters of a whole set of yellow tea processing technology are integrated, produced high-sweet and mellow type yellow tea raw materials are adopted, and the production cost is reduced. And a production technology guarantee is provided for popularization of application of the yellow tea raw materials in other food industries.

Description

Technical Field

[0001] The invention relates to the field of tea processing, in particular to a method for processing high-sweetness and high-mellow yellow tea. Background Art

[0002] The use of tea as a beverage began in the Pre-Qin period. It has now become one of the world's three major health beverages and is loved by people all over the world. During the Qing Dynasty, yellow tea developed rapidly. With the expansion of production and marketing structure, processing technology was constantly improved, and various unique products appeared. The style characteristics of yellow tea were basically formed, becoming one of the six major tea categories in my country. The basic processing technology of yellow tea is: spreading green tea - killing green tea - rolling - steaming yellow - drying. Due to its unique "steaming yellow" process, it has formed the unique "three yellows" quality characteristics of yellow tea, namely "yellow dry tea, yellow soup color, and yellow leaf bottom". Through the steaming yellow process, the bitterness of the tea soup gradually weakens, the taste intensity decreases, and the sweetness and mellowness of the taste gradually increase. The overall flavor changes from the freshness of green tea to the sweetness and mellowness with the characteristics of yellow tea.

[0003] The steaming process is mainly affected by temperature, humidity, ventilation volume, duration, pile thickness (air permeability) and other factors. Any of these factors will cause differences in the flavor quality of yellow tea. There are many different steaming techniques. According to the water content of the tea leaves, it can be divided into wet steaming and dry steaming. According to the steaming method, it can be divided into steaming pile steaming and baking steaming. According to the number of steaming times, it can be divided into 1 time, 2 times and multiple times. Different steaming techniques determine the sensory quality style characteristics of yellow tea, and also affect the appropriate degree of sweetness and mellowness of yellow tea soup.

[0004] The process of yellowing is difficult to control accurately. If the control is not in place, the sweet and mellow taste of yellow tea quality is also difficult to reflect. If the yellowing is not thorough, the tea soup has the freshness of green tea, and has a certain bitterness and astringency, mixed taste, and the appearance color is yellow and green; if the yellowing is excessive, it will also produce an unpleasant watery taste, the appearance color is dark brown and yellow, sweet and greasy, accompanied by bitterness and astringency. At present, high-quality yellow tea (famous tea) mainly depends on the tea making experience and tea making logic algorithm of the tea maker, and it is difficult to form a standardized production of local yellow tea with stable quality. Therefore, according to the tea making theory and experience of traditional yellow tea, using advanced industrial control systems, the tea base can be stably mass-produced with high-quality yellow tea with sweet and mellow flavor characteristics under oxygen-rich conditions, which has very important application value. Summary of the invention

[0005] The purpose of the present invention is to provide a method for processing high-sweetness and mellow yellow tea, so that during the process of yellowing, the tea leaves are yellowed in a micro-environment with artificial temperature, humidity and air control, so as to stably improve the sweet and mellow flavor quality of the yellow tea, so as to solve the core control technology defects of the existing yellowing process of high-quality yellow tea and the production technology requirements that the characteristic quality stability of sweet and mellow yellow tea cannot be achieved. To achieve the above purpose, the present invention provides the following technical solutions: A method for processing high-sweetness and mellow yellow tea, comprising the following steps:

[0006] 1. Provide an oxygen-enriched yellowing equipment: comprising: a main body, wherein a multi-layer leaf storage frame is arranged inside the main body, and the surrounding and bottom surfaces of the leaf storage frame are spliced ​​(welded) by mesh stainless steel plates, the main purpose of which is to ensure sufficient ventilation during the yellowing process.

[0007] A fluid transport component, which is arranged on the inner wall of the main body and is used for transporting fluid inside and outside the main body. The fluid transport component includes a fluid channel and a power drive member, and the power drive member is arranged in each fluid channel. The fluid channel includes an air inlet, an air outlet, an oxygen inlet and a humidification port;

[0008] An intelligent control device, the intelligent control device comprising a controller and a detection component, the controller being electrically connected to the detection component and the power drive component respectively, and being used to control the power drive component according to the data detected by the sensor, so as to complete the intelligent control of the internal environment of the main body, wherein the detection component comprises an ambient temperature sensor, an ambient humidity sensor, an ambient oxygen concentration sensor and an ambient CO2 concentration sensor for measuring the environmental parameters inside the main body, and also comprises a tea temperature sensor, a tea moisture meter and a tea humidity sensor, and the probes thereof are all buried in the tea leaves, and are used to measure the parameters of the tea leaves;

[0009] Among them, the space inside the main body is divided into different layers by a multi-layer support frame, and the leaf storage frame is arranged on the support frame. Each layer of the leaf storage frame is correspondingly provided with a group of tea temperature sensors, tea moisture meters and tea humidity sensors, which are arranged on the side walls of the main body. An ambient temperature sensor, an ambient humidity sensor, an ambient oxygen concentration sensor and an ambient CO2 concentration sensor are arranged at the middle layer of the whole. The air inlet and the air outlet are respectively arranged at the highest layer and the lowest layer of the inner wall of the main body. The oxygen inlet and the humidification port are also located on the inner wall of the main body. The controller is arranged on the outside of the main body for receiving data information of the detection component and controlling the working state of the electric drive component.

[0010] In addition, in this application, the ambient temperature sensor, ambient humidity sensor, tea temperature sensor and tea humidity sensor are all temperature sensors and humidity sensors (existing equipment) commonly used in the art. The name prefixes are only to distinguish the test objects. Similarly, the ambient oxygen concentration sensor and ambient CO2 concentration sensor are also common oxygen sensors and carbon dioxide sensors in the prior art. The noun prefixes also only indicate the detection object, that is, the environment refers to the part of the internal space of the main body, and the equipment prefixed with tea is used to detect the parameters of the tea itself. The tea humidity sensor detects the humidity in the tea pile, that is, the humidity between tea leaves, and the tea moisture meter detects the moisture content inside the tea. In this application, the grain moisture meter is mainly used to measure the moisture content of tea leaves or the Sartorius infrared moisture meter is used to detect the moisture content of tea leaves.

[0011] 2. Raw material selection: fresh tea leaves are used as raw materials;

[0012] 3. Spreading: placing fresh tea leaves in a spreading room (equipment in the prior art) for spreading;

[0013] Fourth, fixation: put the green leaves into the electromagnetic induction drum fixation machine (i.e., the induction heating drum fixation machine, such as the equipment in the existing patent CN108669248B) for segmented fixation;

[0014] 5. Cooling: Cool the withered leaves to room temperature;

[0015] 6. First rehydration: rehydrate the cooled withered leaves until they are soft and can be folded by hand;

[0016] 7. Rolling: Place the moistened leaves into a rolling barrel (equipment in the prior art) and roll them with air pressure;

[0017] 8. Oxygen-enriched yellowing: Place the rolled leaves into the yellowing equipment in step 1 for oxygen-enriched yellowing;

[0018] 9. Raw fire: Dry the yellow tea leaves by hot air dehydration;

[0019] 10. Secondary moisture recovery: After the tea leaves have cooled down after being roasted, they are piled up thickly until they are fully moistened.

[0020] 10. Sufficient fire: Place the secondary moistened leaves into a box dryer (equipment in the prior art) or an electric baking cage (equipment in the prior art) for drying.

[0021] Preferably, in step 2, the specific content of the raw material selection is: selecting fresh tea leaves with one bud and two or three leaves as raw materials.

[0022] Preferably, in step three, the specific content of spreading the tea leaves is: spreading the fresh tea leaves flatly on a spreading rack (equipment in the prior art), and then placing the spreading rack in a spreading room of the facility, controlling the relative humidity in the spreading environment to be 70% to 75%, and the ambient temperature to be 18°C ​​to 23°C, and stopping spreading the tea leaves when the moisture content of the leaves is 65% to 68%.

[0023] In the present application, relative humidity is represented by RH, so in the above description, relative humidity is expressed in percentage.

[0024] Preferably, in step 4, the drum is composed of multiple groups of induction heating sections and low-temperature buffer sections, a low-temperature buffer section is provided between two adjacent groups of induction heating sections, the width of each group of induction heating sections is equal, the width of each group of low-temperature buffer zones is equal, and the ratio of the width of the induction heating section to the width of the low-temperature buffer zone is 7:1;

[0025] The specific content of step 4 is: first start the drum-type tea-fixing equipment, when the drum wall temperature of the first drum reaches 240℃~280℃, evenly put the green tea leaves into the drum equipment, so that the tea leaf surface temperature reaches 85℃~87℃, the leaf temperature drops to 65℃~70℃ through the low-temperature buffer section, so that the drum wall temperature of the second section reaches 200℃~220℃, the tea leaf surface temperature reaches 70℃~75℃, the leaf temperature drops to 50℃~55℃ through the low-temperature buffer section, so that the drum wall temperature of the third section reaches 140℃~160℃, and the leaf surface temperature reaches 55℃~60℃;

[0026] The total time for withering is 330s to 420s, and the moisture content of the tea leaves is 38%-42%.

[0027] Preferably, in step five, the specific content of the cooling is: spreading the withered leaves thinly on an air cooler (equipment in the prior art) or a bamboo mat (equipment in the prior art) and blowing air to quickly cool the tea leaves to room temperature.

[0028] Preferably, in step six, the specific content of the one moisture regaining is: stacking the cooled withered leaves with a stacking height of 15cm-20cm, allowing the tea leaves to regain moisture until they are soft and cannot be broken by hand, and then stopping the moisture regaining.

[0029] Preferably, in step seven, the specific content of the kneading is: placing the rehydrated leaves into a kneading barrel (equipment in the prior art), and performing air-pressure kneading on the tea leaves (pressurized kneading is to make the strips thin and tight; the yellow tea is made into relatively strips, which does not need to be too tight, which is conducive to uniform yellowing. The air-pressure kneading described in the present application means that during the whole kneading process, the kneading top cover is located at the upper edge of the kneading barrel, and no downward pressure is applied throughout the whole process; the air kneading pressure comes from the weight of the tea leaves themselves and the thrust of the barrel wall), the kneading time is 15min to 20min, and the kneading strip rate is greater than 85%.

[0030] Preferably, in step eight, the specific content of the yellowing is:

[0031] 8.1. Tea placement: Place the rolled leaves evenly in the leaf storage frame, and stack the tea leaves naturally to a thickness of 15 cm to 20 cm. The distance between the top of the tea leaves in each layer of the leaf storage frame and the bottom of the tea leaves in the previous layer of the leaf storage frame is 15 cm to 20 cm.

[0032] 8.2. Yellowing processing of tea leaves: controlled by a controller, oxygen is passed through every 5 minutes for 30 seconds, and the oxygen concentration in the yellowing machine is maintained between 22% and 23%. The internal ambient temperature of the main body is set to 50°C, the temperature of the tea leaves is maintained at 45±1°C, the internal humidity of the main body is maintained at 65±3%, and the relative humidity of the tea leaves is maintained at 55±0.5%. After 2 hours of yellowing, the CO2 concentration in the main body is detected every 10 seconds. When the concentration exceeds 600ppm, the air outlet is opened by the controller. When the CO2 concentration in the main body is lower than 500ppm, the air outlet is closed by the controller. The total yellowing time is 12h to 16h. After the yellowing is completed, the moisture content of the tea leaves is controlled at 30% to 35%.

[0033] Preferably, in step nine, the specific content of the raw fire is: the yellowed tea leaves are dried by hot air drying, the hot air temperature is controlled at 95°C, the drying time is 15min to 20min, and the moisture content of the tea leaves is 10% to 12%.

[0034] Preferably, in the step ten, the specific content of the secondary moisture regain is: after cooling the tea leaves after rough firing, the tea leaves are fully moisturized by natural secondary moisture regain or heating moisture regain. If natural moisture regain is adopted, the pile thickness is 40±5cm, and the moisture regain time is 12h~16h. If low-temperature heating moisture regain is adopted, the heating temperature needs to be controlled at 28℃~30℃ in a closed container, and the moisture regain time is 2~4h.

[0035] Preferably, in the step eleven, the specific content of the sufficient roasting is: placing the tea leaves after rough roasting into a box-type dryer or an electric roasting cage for processing, setting the temperature to 70°C to 75°C, and heat treatment time for 30min to 35min, so that the moisture content of the dried tea leaves is less than 6%.

[0036] In the above text, some of the equipment are commonly used in tea processing in this field, so they will not be described one by one here.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. Through the yellowing equipment, the yellow tea yellowing environment is effectively regulated by the "three controls" (temperature control, humidity control, and air control), which reduces the impact of environmental factors on the yellowing effect, reduces the repetitive labor of multiple wrapping with wet cloth for yellowing, and greatly improves the production efficiency of yellow tea;

[0039] 2. Through the precise control of the yellowing equipment and the establishment of an oxygen-rich micro-environment, the degree of the yellowing reaction is artificially controlled to promote the sweet and mellow quality of yellow tea. It can be widely used in the key processes of yellow tea production and can stably produce high-quality yellow tea products in batches;

[0040] 3. The advanced control system integrates a complete set of yellow tea processing control parameters to produce high-sweetness and mellow yellow tea raw materials, providing production technology guarantee for promoting the application of yellow tea raw materials in other food industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is the overall processing flow chart of the present invention;

[0042] Figure 2 This is a system control logic diagram when the device is yellowing in the present invention;

[0043] Figure 3 It is a schematic diagram of the overall structure of the oxygen-enriched yellowing equipment in the present invention;

[0044] Figure 4 It is a schematic diagram of the overall structure of the oxygen-enriched yellowing device in the present invention from other angles;

[0045] Figure 5 It is a schematic diagram of the overall structure of the main body in the present invention;

[0046] Figure 6 It is a partial enlarged schematic diagram shown at A in the figure of the present invention;

[0047] In the figure: main body 1, leaf storage frame 2, air inlet 3, air outlet 4, oxygen inlet 5, humidification port 6, controller 7, ambient temperature sensor 8, ambient humidity sensor 9, ambient oxygen concentration sensor 10, ambient CO2 concentration sensor 11, tea temperature sensor 12, tea moisture meter 13, tea humidity sensor 14, support frame 15, slide rail 16. DETAILED DESCRIPTION

[0048] The following will be combined with the attached embodiment of the present invention Figure 1-6 , the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] See also Figure 1-6 , embodiments of the present invention:

[0050] Embodiment 1:

[0051] like Figure 1-6 A method for processing high sweetness and mellow yellow tea, comprising the following steps:

[0052] 1. Provide an oxygen-enriched yellowing device: comprising: a main body 1, wherein a multi-layer leaf storage frame 2 is arranged inside the main body 1, and the surroundings and bottom surface of the leaf storage frame 2 are spliced ​​by mesh stainless steel plates;

[0053] A fluid transport component, which is arranged on the inner wall of the main body 1 and is used for transporting fluid inside and outside the main body 1. The fluid transport component includes a fluid channel and a power drive member, and the power drive member is arranged in each fluid channel. The fluid channel includes an air inlet 3, an air outlet 4, an oxygen inlet 5 and a humidification port 6;

[0054] An intelligent control device, the intelligent control device includes a controller 7 and a detection component, the controller 7 is electrically connected to the detection component and the power drive component respectively, and is used to control the electric drive component according to the data detected by the sensor to complete the intelligent control of the internal environment of the main body 1, wherein the detection component includes an ambient temperature sensor 8, an ambient humidity sensor 9, an ambient oxygen concentration sensor 10 and an ambient CO2 concentration sensor 11 for measuring the environmental parameters inside the main body 1, and also includes a tea temperature sensor 12, a tea moisture meter 13 and a tea humidity sensor 14, whose probes are all buried in the tea leaves for measuring the parameters of the tea leaves;

[0055] Specific as Figure 3-6As shown, on the basis of the above, only a layer of support frame 15 is provided in the main body 1. The reason why it is called a frame is that there is a space inside this supporting part for fluid to circulate, and a number of parallel slide rails 16 are also provided on the support frame 15, and the leaf storage frame 2 is installed on the support frame 15 through the slide rails 16, that is, each layer of the leaf storage frame 2 is supported by the support frame 15, that is, it can be understood that the internal space of the main body 1 is divided by multiple layers of support frames 15, and the number of guide rails on each support frame 15 is two groups, that is, two parallel leaf storage frames 2 are arranged on each support frame 15, and the side walls and bottom walls of the leaf storage frames 2 are set by mesh plates, and the whole is made of stainless steel. At the same time, there is a spacing space between each leaf storage frame 2, and the leaf storage frame 2 is connected to the main body 1. There is also space between the inner walls of the body 1 (including the door. In this embodiment, a double-door setting is adopted) to ensure better flow of the fluid in the main body 1. Specifically, the height of the leaf storage frame 2 is 25 cm, the distance between the leaf storage frame 2 and the inner wall of the main body 1 is 35 cm, the distance between the uppermost leaf storage frame 2 and the top inner wall of the main body 1 is 40 cm, the distance between the lowermost leaf storage frame 2 and the bottom inner wall of the main body 1 is 40 cm, the distance between the leaf storage frame 2 and the door on the main body 1 is 30 cm, and the distance between the leaf storage frame 2 and the rear wall of the main body 1 is 40 cm. The ambient temperature sensor 8, the ambient humidity sensor 9, the ambient oxygen sensor and the ambient CO2 concentration sensor 11 are arranged on the side wall of the main body 1, and the horizontal position is arranged at a relatively middle layer. The tea temperature sensor 12, tea moisture meter 13 and tea humidity sensor 14 are sensors corresponding to each layer of the leaf storage frame 2, that is, in each layer, each leaf storage frame 2 is correspondingly provided with a group of tea temperature sensors 12, tea moisture meters 13 and tea humidity sensors 14, and one end of each sensor is arranged on the corresponding inner wall of the main body 1, and the probe can be extended into the leaf storage frame 2. It should be noted that the extension direction of the tea temperature sensor 12, tea moisture meter 13 and tea humidity sensor 14 is adjustable, so there is no need to affect the sliding installation of the leaf storage frame 2 on the guide rail, and the air outlet 4 is arranged at the upper part of the main body 1, located at the topmost layer, and the air inlet 3 is located at the lower part of the main body 1, located At the top layer, the humidification port 6 and the oxygen inlet port 5 are both arranged at the bottom of the inner wall of the subject. In the horizontal direction, both are located between two adjacent leaf storage frames 2, wherein the air inlet 3 takes in hot air. The corresponding electric drive components of the corresponding fluid channels include an air inlet motor connected to the air inlet 3, an exhaust motor in the air outlet 4, an atomizer generator in the humidification port 6 and an oxygen pump at the oxygen inlet port 5. The arrangement of the above fluid pipelines can make the fluid inside the main body 1 more uniform, and the above sensors and electric drive components are electrically connected to a controller 7 arranged outside the main body 1. The controller 7 adjusts or presets the opening and closing of the fluid channel and the size of the fluid flow rate according to the data fed back by the detection component to adjust the environment inside the main body 1. A display screen is arranged on the controller 7.It also has the functions of preset and manual parameter adjustment.

[0056] 2. Raw material selection: Choose fresh tea leaves with one bud and two leaves as raw materials;

[0057] 3. Spreading: Spread the fresh tea leaves flat on the spreading rack, and then place the spreading rack in the spreading room. Control the relative humidity in the spreading environment to 73% and the ambient temperature to 20°C. Stop spreading when the water content of the leaves reaches 67%.

[0058] 4. Fixing: Place the green leaves in an electromagnetic induction drum fixing machine (induction heating drum fixing machine, CN108669248A) for segmented fixing;

[0059] Specifically, the roller is composed of multiple groups of induction heating sections and low-temperature buffer sections, and a low-temperature buffer section is provided between two adjacent groups of induction heating sections. The width of each group of induction heating sections is equal, the width of each group of low-temperature buffer zones is equal, and the ratio of the width of the induction heating section to the width of the low-temperature buffer zone is 7:1; (Induction heating roller fixing machine, CN108669248A)

[0060] The specific content of step 4 is: first start the drum-type tea-fixing equipment, when the drum wall temperature of the first drum reaches 260°C, evenly put the green tea leaves into the drum equipment, so that the tea leaf surface temperature reaches 87°C, the leaf temperature drops to 65°C in the low-temperature buffer section, the drum wall temperature of the second section reaches 210°C, the tea leaf surface temperature reaches 73°C, the leaf temperature drops to 55°C in the low-temperature buffer section, the drum wall temperature of the third section reaches 150°C, and the leaf surface temperature reaches 57°C;

[0061] The total withering time is 370s, and the moisture content of the tea leaves is 40%.

[0062] 5. Cooling: Spread the withered leaves thinly on a bamboo mat and blow air to quickly cool the tea leaves to room temperature;

[0063] 6. One-time rehydration: stack the cooled withered leaves to a height of 17 cm, and allow the leaves to rehydrate until they are soft and cannot be folded by hand, then stop rehydration;

[0064] 7. Rolling: Place the rehydrated leaves in the rolling barrel and roll the tea leaves with air pressure for 15 minutes, with the rolling rate of the tea leaves greater than 85%;

[0065] 8. Oxygen-enriched yellowing: Place the rolled leaves into the yellowing equipment in step 1 for oxygen-enriched yellowing;

[0066] like Figure 2 Shown: The specific content is:

[0067] 8.1. Tea placement: Place the rolled leaves evenly in the leaf storage frame 2, and stack the tea leaves to a thickness of 17 cm. The distance between the top of the tea leaves in each layer of the leaf storage frame 2 and the bottom of the tea leaves in the previous layer of the leaf storage frame 2 is 17 cm.

[0068] 8.2. Processing of tea leaves turning yellow:

[0069] By controlling the ambient temperature, humidity, oxygen supply and ventilation in the main body 1, an oxygen-rich micro-environment is formed. Through the control of the controller 7, oxygen is supplied once every 5 minutes for 30 seconds to maintain the oxygen concentration in the yellowing machine at 22.5%;

[0070] Set the internal ambient temperature of the main body 1 to 50°C and maintain the temperature of the tea leaves at 45°C;

[0071] The humidity inside the main body 1 is maintained at 68% (the humidity inside the main body 1 is maintained at 66±2%), so that the relative humidity inside the tea leaves is 55%, so that after 2 hours of yellowing, the relative humidity inside the tea leaves is 45%, and the CO2 concentration in the main body 1 is detected every 10 seconds. When the concentration exceeds 600ppm, the air outlet 4 is opened by the controller 7. When the CO2 concentration in the main body 1 is lower than 500ppm, the air outlet 4 is closed by the controller 7. The total yellowing time is 14 hours.

[0072] After the yellowing process is completed, the moisture content of the tea leaves is controlled at 33%.

[0073] 9. Raw fire: The yellow tea leaves are dried by hot air dehydration. The hot air temperature is controlled at 95℃ for 15 minutes until the moisture content of the tea leaves reaches 12%.

[0074] 10. Secondary moisture recovery: After the tea leaves have cooled down after being roughly fired, use natural moisture recovery or heated moisture recovery to fully recover the tea leaves. If natural moisture recovery is used, the recovery time is 13 hours.

[0075] 11. Sufficient roasting: Place the tea leaves after rough roasting in a box dryer or electric roasting cage, set the temperature to 73°C, and heat treatment time for 33 minutes, so that the moisture content of the dried tea leaves is 5%.

[0076] Comparative Example 1:

[0077] The difference between this embodiment and embodiment 1 is that:

[0078] Step 8, yellowing: placing the rolled leaves into the yellowing equipment in step 1 for air ventilation and yellowing;

[0079] The specific contents are:

[0080] 8.1. Tea placement: Place the rolled leaves evenly in the leaf storage frame 2, and stack the tea leaves naturally to form a fluffy shape, with a thickness of 17 cm. The distance between the top of the tea leaves in each layer of the leaf storage frame 2 and the bottom of the tea leaves in the previous layer of the leaf storage frame 2 is 17 cm.

[0081] 8.2. Processing of tea leaves turning yellow:

[0082] By controlling the ambient temperature, humidity and ventilation in the main body 1, a normal oxygen concentration micro-environment is formed. Through the control of the controller 7, air is ventilated once every 5 minutes for 30 seconds to maintain the oxygen concentration in the suffocating machine at 20%;

[0083] Set the internal ambient temperature of the main body 1 to 50°C and maintain the temperature of the tea leaves at 45°C;

[0084] The relative humidity of the environment is 68%, and the humidity inside the main body 1 is maintained at 66±2%, so that the relative humidity inside the tea leaves is 55%, so that after 2 hours of yellowing, the relative humidity inside the tea leaves is 45%, and the concentration of CO2 in the main body 1 is detected every 10 seconds. When the concentration exceeds 600ppm, the air outlet 4 is opened through the controller 7. When the CO2 concentration in the main body 1 is lower than 500ppm, the air outlet 4 is closed through the controller 7. The total yellowing time is 14 hours;

[0085] After the yellowing process is completed, the moisture content of the tea leaves is controlled at 33%.

[0086] Comparative Example 2

[0087] The difference between this embodiment and embodiment 1 is that:

[0088] Step 8, yellowing: placing the rolled leaves into traditional yellowing equipment for yellowing;

[0089] Wrap the first moistened leaves with wet cloth, 1 catties / bag, 10 tea bags are evenly placed in a stainless steel bucket, and electrically heated. The temperature of the leaves is controlled between 45°C, and the relative humidity of the stainless steel bucket is 55% to 60%. During the yellowing process, unpack, pile and wrap every 1 hour, and the yellowing time is 14 hours;

[0090] After the yellowing process is completed, the moisture content of the tea leaves is controlled at 32%.

[0091] Professionals in the field brewed and tasted the tea leaves obtained in Example 1, Comparative Example 1 and Comparative Example 2, and the specific results are as follows:

[0092]

[0093]

[0094] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0095] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that those skilled in the art can understand.

Claims

1. A method for processing high sweetness and mellow yellow tea, characterized in that: The following steps are involved:

1. Provide an oxygen-enriched yellowing device, comprising: a main body (1), wherein a multi-layer leaf storage frame (2) is arranged inside the main body (1), and the periphery and bottom surface of the leaf storage frame (2) are spliced ​​by mesh stainless steel plates; a fluid transport component, the fluid transport component being arranged on the inner wall of the main body (1) and being used for transporting fluid inside the main body (1) and outside the main body (1), the fluid transport component comprising a fluid channel and a power drive member, the power drive member being arranged in each fluid channel, the fluid channel comprising an air inlet (3), an air outlet (4), an oxygen inlet (5) and a humidification port (6); An intelligent control device, the intelligent control device comprising a controller (7) and a detection component, the controller (7) being electrically connected to the detection component and the power drive component respectively, and being used to control the power drive component according to data detected by the detection component, so as to complete intelligent control of the internal environment of a main body (1), wherein the detection component comprises an ambient temperature sensor (8), an ambient humidity sensor (9), an ambient oxygen concentration sensor (10) and an ambient CO2 concentration sensor (11) for measuring the environmental parameters inside the main body (1), and also comprises a tea temperature sensor (12), a tea moisture meter (13) and a tea humidity sensor (14), wherein the probes thereof are all embedded in the tea leaves and are used to measure the parameters of the tea leaves; 2. Raw material selection: Select fresh tea leaves with one bud and two or three leaves as raw materials; 3. Spreading the tea leaves: Place the fresh tea leaves in the spreading room for spreading; 4. Fixing: Place the green leaves into the electromagnetic induction drum fixing machine for segmented fixing; 5. Cooling: Cool the withered leaves to room temperature; 6. First rehydration: rehydrate the cooled withered leaves until they are soft and can be folded by hand; 7. Rolling: Place the moistened leaves into the rolling barrel and roll them with air pressure; 8. Oxygen-enriched yellowing: Place the rolled leaves into the yellowing equipment in step 1 for oxygen-enriched yellowing; 9. Raw fire: Dry the yellow tea leaves by hot air dehydration; 10. Secondary moisture recovery: After the tea leaves have cooled down after being roughly roasted, they are piled up thickly to fully recover moisture.

11. Sufficient fire: Place the leaves that have been moistened for the second time into a box dryer or electric baking cage for drying.

2. A method for processing high sweetness and mellow yellow tea according to claim 1, characterized in that: In the step three, the specific content of spreading the tea leaves is: spreading the fresh tea leaves flat on the spreading rack, and then placing the spreading rack in the spreading room, controlling the relative humidity in the spreading environment to 70%-75%, the ambient temperature to 18°C-23°C, and stopping spreading when the moisture content of the leaves is 65%-68%.

3. A method for processing high sweetness and mellow yellow tea according to claim 2, characterized in that: In the step 4, the drum in the electromagnetic induction drum fixing machine is composed of multiple groups of induction heating sections and low-temperature buffer sections, and a low-temperature buffer section is provided between two adjacent groups of induction heating sections. The width of each group of induction heating sections is equal, and the width of each group of low-temperature buffer zones is equal. The ratio of the width of the induction heating section to the width of the low-temperature buffer zone is 7:1; The specific content of step 4 is: first start the drum-type tea-fixing equipment, when the drum wall temperature of the first drum reaches 240℃~280℃, evenly put the green tea leaves into the drum equipment, so that the tea leaf surface temperature reaches 85℃~87℃, the leaf temperature drops to 65℃~70℃ through the low-temperature buffer section, so that the drum wall temperature of the second section reaches 200℃~220℃, the tea leaf surface temperature reaches 70℃~75℃, the leaf temperature drops to 50℃~55℃ through the low-temperature buffer section, so that the drum wall temperature of the third section reaches 140℃~160℃, and the leaf surface temperature reaches 55℃~60℃; The total time for withering is 330s to 420s, and the moisture content of the tea leaves is 38%-42%.

4. A method for processing high sweetness and mellow yellow tea according to claim 3, characterized in that: In the step 5, the specific content of the cooling is: spreading the withered leaves thinly on an air cooler or a bamboo mat and blowing air to quickly cool the tea leaves to room temperature.

5. A method for processing high sweetness and mellow yellow tea according to claim 4, characterized in that: In step six, the specific content of the one moisture regaining is: stacking the cooled withered leaves with a stacking height of 15cm-20cm, allowing the tea leaves to regain moisture until they are soft and cannot be broken by hand, and then stopping the moisture regaining.

6. A method for processing high sweetness and mellow yellow tea according to claim 5, characterized in that: In the step seven, the specific content of the rolling is: placing the rehydrated leaves into a rolling barrel, and performing air pressure rolling on the tea leaves, the rolling time is 15 minutes to 20 minutes, and the rolling rate is greater than 85%.

7. A method for processing high sweetness and mellow yellow tea according to claim 6, characterized in that: In the step eight, the specific content of the yellowing is: 8.

1. Tea placement: The rolled leaves are evenly placed in the leaf storage frame (2), and the tea leaves are naturally stacked and spread out in a fluffy state, with a spreading thickness of 15 cm to 20 cm, and the distance between the top of the tea leaves in each layer of the leaf storage frame (2) and the bottom of the tea leaves in the upper layer of the leaf storage frame (2) is 15 cm to 20 cm; 8.

2. Yellowing processing of tea leaves: controlled by controller (7), oxygen is passed through once every 5 minutes for 30 seconds, and the oxygen concentration in the yellowing machine is maintained between 22% and 23%. The internal ambient temperature of the main body (1) is set to 50°C, the temperature of the tea leaves is maintained at 45±1°C, the internal humidity of the main body (1) is maintained at 65±3%, and the relative humidity inside the tea leaves is maintained at 55±0.5%°C. After 2 hours of yellowing, the CO2 concentration in the main body (1) is detected every 10 seconds. When the concentration exceeds 600ppm, the air outlet (4) is opened by controller (7). When the CO2 concentration in the main body (1) is lower than 500ppm, the air outlet (4) is closed by controller (7). The total yellowing time is 12h to 16h. After the yellowing is completed, the moisture content of the tea leaves is controlled at 30% to 35%.

8. The method for processing high sweetness and mellow yellow tea according to claim 7, characterized in that: In the step nine, the specific content of the rough fire is: the yellowed tea leaves are dried by hot air, the hot air temperature is controlled at 95°C, the drying time is 15min to 20min, and the moisture content of the tea leaves is 10% to 12%.

9. A method for processing high sweetness and mellow yellow tea according to claim 8, characterized in that: In the step ten, the specific content of the secondary moisture recovery is: after cooling the tea leaves after rough firing, the tea leaves are fully moisture recovered by natural moisture recovery or heated moisture recovery. If natural moisture recovery is adopted, the pile height is 40±5cm, and the moisture recovery time is 12h~16h. If low-temperature heating moisture recovery is adopted, the heating temperature in the closed container needs to be controlled at 28℃~30℃, and the moisture recovery time is 2~4h.

10. A method for processing high sweetness and mellow yellow tea according to claim 9, characterized in that: In the step eleven, the specific content of the sufficient roasting is: placing the tea leaves after rough roasting into a box-type dryer or an electric roasting cage for processing, setting the temperature to 70°C to 75°C, and the heat treatment time to 30min to 35min, so that the moisture content of the dried tea leaves is less than 6%.

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