Processing technology for improving aroma and taste of black tea of ancient tea tree

Abstract

The invention relates to the technical field of tea production, and discloses a processing technology for improving aroma and taste of ancient tea tree black tea. Performing rolling; deblocking is performed; performing fermentation; gross firing; kneading again; performing complete firing; spreading for cooling; and improving fragrance. The technical scheme of step-by-step temperature raising is adopted in the aroma raising step, the temperature and the temperature raising rate are accurately regulated and controlled, volatile aroma substances in the tea leaves are gradually released in different temperature intervals, the flower fragrance, the fruit fragrance and the caramel fragrance are displayed layer by layer, the overall aroma is coordinated and rich in layering sense, and compared with a single constant-temperature or high-temperature aroma raising process in the prior art, the aroma raising method has the advantages that the cost is low; according to the method, rapid loss of low-boiling-point aroma substances is effectively avoided, meanwhile, the stability and durability of the aroma are remarkably improved, the defects that the aroma is single and is prone to loss in the traditional process are overcome, and therefore the aroma and taste of the tea leaves are improved.

Description

Technical Field

[0001] The invention relates to the technical field of tea production, and in particular to a processing technology for improving the aroma and flavor of ancient tea tree black tea. Background Art

[0002] Ancient tea tree black tea has a unique aroma and flavor due to its long tree age and rich internal substances. However, in traditional processing technology, although the internal quality of ancient tea tree raw materials is relatively good, the finished black tea has a lack of aroma layering and poor taste coordination. This is mainly due to the fact that the existing technology is relatively rough in the key links of aroma, fermentation, rolling, etc., and cannot fully tap the potential quality of ancient tea tree raw materials.

[0003] In the prior art, the aroma of black tea mainly comes from the complex decomposition and transformation process of aromatic substances in fresh leaves, including low-boiling-point floral aroma substances, medium-boiling-point fruity aroma substances, and high-boiling-point caramel aroma substances. Under constant temperature or high-temperature aroma extraction processes, the release rates of these different volatile substances are not matched, which often causes some aromas to volatilize too early, other aromas to be insufficiently released, and the aroma layering is significantly insufficient, which cannot reflect the high-end characteristics of ancient tea tree black tea.

[0004] Moreover, the aroma extraction temperature and time have not been gradually optimized according to the characteristics of aromatic substances, which makes the release process of different aroma components interfere with each other. After a large amount of low-boiling point substances are released, it is difficult for medium and high-boiling point substances to follow up in time, and the overall performance of the aroma lacks coordination, which easily appears too single or unbalanced. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a processing technology for improving the aroma and flavor of ancient tea tree black tea, which solves the problems of insufficient aroma layering, uneven aroma release, poor coordination and insufficient mellow taste of the existing ancient tea tree black tea.

[0006] To achieve the above objectives, the present invention is implemented through the following technical scheme: A processing technology for improving the aroma and taste of ancient tea tree black tea, comprising the following steps: Spread green and wither; Kneading; Unblock; Fermentation; Hair fire; Repeat kneading; Foot fire; Let cool; Titian.

[0007] Preferably, the green withering comprises: Indoor natural withering: Spread the fresh tea leaves in the withering trough with a thickness of 10-15cm, and cool for 5-6 hours; at the same time, adopt heated air withering, the temperature is 25℃, the duration is 85-95 minutes, stop the air and let the water flow for 55-60 minutes, stir evenly, and then continue the next round of air blowing operation, in which the air blowing time is shortened round by round, and the air blowing time is reduced by 10-15 minutes each time; the water flow time is extended round by round, and the static time is increased by 10-15 minutes each time, so as to ensure that the moisture distribution of the tea leaves and stems is even; During the natural withering process indoors, the combination of temperature control and air blowing promotes the uniform distribution of moisture on the tea leaves and stems, avoiding damage caused by excessive evaporation of moisture on the leaves. At the same time, natural enzymatic reactions begin to release floral and fruity aroma precursors, laying the foundation for subsequent fermentation.

[0008] Sunlight withering: It is carried out under sunny conditions. The withering time is 45 to 50 minutes. Turn it over every 11 to 12 minutes. After the flower and fruit fragrance begins to appear, move it indoors to continue with natural withering. The total withering time is 14 to 15 hours. After the sunlight withering is completed, move it outdoors for sunlight withering for 90 to 100 minutes, turning it over every 14 to 15 minutes. After the sunlight withering is completed, move it indoors for natural withering indoors until the leaves lose their luster, the leaves become dark green, and brown appears on the leaf edges.

[0009] Among them, sunlight withering accelerates the transformation of the precursors of aromatic substances in the leaves through the appropriate ultraviolet rays and heat energy, promoting the appearance of the "floral and fruity aroma" of tea. At the same time, repeated indoor and outdoor combined operations help to achieve a slow and uniform loss of moisture, avoiding the damage of the texture and aroma of the leaves due to excessive dehydration.

[0010] Preferably, the kneading uses a 6CR-65 kneading machine, with 45-50 kg of leaves thrown in each time, and variable speed kneading, which sequentially includes: Initial kneading, time 28-30min, speed 25r / min; Medium kneading, time 28-30min, speed 35r / min; Knead again for 30 minutes at a speed of 45 rpm until the tea leaves turn from green to light red.

[0011] Rolling is a key step in destroying the cell structure of tea leaves. Mechanical rolling gradually destroys the cell walls of tea leaves through different stages of pressure and rotation speed, promoting the precipitation of contained substances (such as tea polyphenols, caffeine, etc.) on the surface of the leaves, forming a tight tea leaf structure. At the same time, the friction heat generated by rolling further activates the enzyme activity in the leaves, providing rich substrates for the fermentation stage.

[0012] Preferably, the deblocking is performed using a 6CJ-50 tea deblocking machine, and after deblocking, the tea is spread flat in a wet dustpan or bamboo basket with a thickness of 20 to 25 cm, and finally covered with wet cotton gauze.

[0013] The block step disperses the tea strands to avoid uneven fermentation caused by excessive aggregation of tea leaves during the rolling process. At the same time, proper moisture retention provides the required humidity conditions for subsequent fermentation and maintains the activity of tea surface cells.

[0014] Preferably, the fermentation comprises one of fermentation in a fermentation chamber and fermentation in a fermentation machine: Fermentation in the fermentation room At room temperature of 27-28℃ and humidity of 92-95%, place the tea leaves in a dustpan covered with white cloth with a thickness of 8-10cm. Fermentation time: 4 hours. During fermentation, shake once every 2 hours. Fermentation is moderate when the grass smell disappears, the tea leaves have a floral aroma, and the leaves are evenly red and yellow. Fermentation machine fermentation Use 6CFJ intelligent black tea fermentation machine, spread the leaves in a stainless steel fermentation box, cover the box with white cloth or gauze with a thickness of 10-15 cm, ferment for 4 hours at a temperature of 28-30°C and a humidity of 94-96%, automatically ventilate and dehumidify every 10 minutes, and shake once every 2 hours. Fermentation should be carried out in the same fermentation room as in the fermentation room.

[0015] Fermentation is the core link in the formation of tea quality. Under suitable temperature and humidity conditions, tea polyphenols are converted into color and aroma substances such as theaflavins and thearubigins through the catalytic action of oxidase, which makes the tea produce the unique black tea soup color and floral and fruity aroma. At the same time, the shaking operation avoids excessive local fermentation and ensures uniform fermentation.

[0016] Preferably, the rough fire is carried out using an 8CST drum fixing machine, and the specific steps include: The preheating time is 19 to 21 minutes, and the air inlet temperature is 115°C to 125°C; When the air temperature in the tube reaches 140-160℃, the leaves are cast; The duration of withering is 6 to 8 minutes, the rotation speed is 30 to 35 r / min, and it is turned every 15 to 20 seconds to ensure that the tea leaves are heated evenly.

[0017] The raw fire inactivates the activity of oxidase in tea leaves through high temperature, stops fermentation, and removes the residual grass smell in the leaves, making the tea aroma pure. The turning operation ensures uniform heating to prevent local scorching or insufficient heating.

[0018] Preferably, the re-kneading step comprises: Use a rolling machine to operate, with an initial speed of 30-40r / min; The amount of leaves added each time is 40-50kg; Hot kneading time 12 to 18 minutes; When the tea leaves are tightly rolled, evenly stripped, and have a rosy and lustrous color, they are taken off the machine and spread out to cool naturally.

[0019] Repeated kneading further optimizes the shape and appearance of the tea leaves, while enhancing the surface gloss and aroma of the tea leaves through frictional heat.

[0020] Preferably, the step of sufficient tempering is carried out using a 6CDY-80-12 stripping machine, comprising: After re-kneading, the tea leaves are spread out to cool for 30-32 minutes to redistribute the moisture in the leaves evenly. When operating with full fire, the temperature is 144-155℃, and the amount of leaves added each time is 1.3-1.5kg; During the full-fire process, when the moisture content of the tea drops to 5-6%, the tea leaves are taken off the machine and spread out evenly to cool to room temperature.

[0021] Full firing further reduces the moisture content of tea, ensuring the storage stability of tea. At the same time, it strengthens the production of tea aroma substances under high temperature conditions and improves the quality.

[0022] Preferably, during the cooling process, the thickness of the cooling process is 3 to 5 cm; The cooling time is 30 to 60 minutes, allowing the tea leaves to gradually cool to room temperature.

[0023] Cooling stabilizes the chemical composition and aroma of the tea leaves, making their aroma lasting and their taste stable.

[0024] Preferably, the aromatization is carried out in a 6CHS-100 / 16 aromatization machine, comprising: Spread the tea leaves in the bamboo sieve to a thickness of 2 to 3 cm; Preheat the aroma machine to 80℃ and put the bamboo sieve into the aroma machine; Fragrance extraction was carried out at 80°C for 90 minutes; Gradually increase the temperature: when the temperature rises to 88-90℃, the aroma is increased for 30-31 minutes; when the temperature rises to 98-100℃, the aroma is increased for 30-31 minutes; when the temperature rises to 181-120℃, the aroma is increased for 30-31 minutes; After the aroma is extracted, the tea leaves are removed from the machine, spread out and allowed to cool naturally to room temperature.

[0025] The aroma enhancement process stimulates the volatile aroma substances in the tea leaves by gradually increasing the temperature, so that their concentration and persistence reach the optimal level while maintaining the layering of the tea aroma.

[0026] The present invention provides a processing technology for improving the aroma and flavor of ancient tea tree black tea. It has the following beneficial effects: 1. The present invention adopts a technical scheme of gradually increasing the temperature in the aroma-enhancing step, accurately controls the temperature and the heating rate, so that the volatile aroma substances in the tea leaves are gradually released in different temperature ranges, and the floral, fruity and caramel aromas are gradually revealed. The overall aroma is coordinated and rich in layers. Compared with the single constant temperature or high temperature aroma-enhancing process in the prior art, the present invention effectively avoids the rapid loss of low-boiling point aroma substances, and at the same time significantly improves the stability and durability of the aroma, making up for the shortcomings of the traditional process that the aroma is single and easy to dissipate, thereby improving the aroma and taste of the tea leaves.

[0027] 2. The present invention effectively promotes the enzymatic oxidation reaction of polyphenols in tea leaves by adopting a process scheme of precisely controlling temperature, humidity and stirring frequency in the fermentation process, optimizes the production ratio of theaflavins and thearubigins, and makes the tea soup bright red and mellow in taste. Compared with the problem of difficult precise control of fermentation time and conditions in traditional technology, the present invention solves the defects of dark tea soup color and less full taste in the existing process while achieving fermentation uniformity, greatly improving the overall quality of black tea.

[0028] 3. The present invention adopts multi-stage variable speed kneading technology and introduces a re-kneading process to make the tea strips tighter and more uniform, and significantly improve the overall appearance quality. The surface of the strips is smooth and dark, and has great commercial value. Compared with the problem of loose or fragile strips due to a single operating parameter in the traditional kneading process, the present invention overcomes this shortcoming, solves the bottleneck of unstable tea appearance quality, and provides strong support for the marketization of high-end tea products. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention are described clearly and completely below. 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.

[0030] In order to better understand the present invention, the above contents are described in detail below in conjunction with specific embodiments.

[0031] Embodiment 1 Withering Spread the fresh leaves in the withering trough with a thickness of 12 cm, and carry out natural withering indoors for 6 hours, with the room temperature maintained at 22℃~24℃. Then carry out heated air withering, with the temperature set to 25℃, the first round of air blowing time is 90 minutes, and the leaves are left to stand for 60 minutes. After stirring, the second round of air blowing operation is carried out, with the time shortened by 10 minutes for each round, and the standing time extended by 10 minutes for each round. After withering, move to the sun for solar withering for 50 minutes, and turn over every 12 minutes. After completion, move to the room for natural withering for 14 hours, until the gloss of the leaves disappears and the leaf edges appear brown.

[0032] Rolling The 6CR-65 rolling machine is used, with 45kg of leaves thrown in each time, and variable speed rolling is performed. The initial rolling speed is 25r / min, which lasts for 30 minutes, the leaves become soft, and the tea strips begin to appear; in the middle rolling stage, the speed is adjusted to 35r / min, the time is 30 minutes, and the tea strips gradually become tight; in the heavy rolling stage, the speed is 45r / min, which lasts for 30 minutes, the tea strips are tight, and the color changes from green to light red, and the machine is removed after completion.

[0033] Unblock The rolled tea leaves were put into a 6CJ-50 deblocking machine for deblocking. After deblocking, the tea leaves were spread flat in a bamboo basket with a thickness of 20 cm and the surface was covered with wet cotton gauze to keep it moist.

[0034] Fermentation The deblocked tea leaves are moved into the 6CFJ intelligent fermentation machine, the temperature is set to 28℃, the humidity is 94% to 96%, and the thickness of the tea leaves is controlled to be 10cm. During the fermentation process, the tea leaves are automatically ventilated and dehumidified every 10 minutes, and shaken every 2 hours. The total fermentation time is 4 hours. After fermentation, the tea leaves have completely lost their grassy smell, exuding a floral fragrance, and the leaves are evenly red and yellow in color.

[0035] Mao Huo The fermented tea leaves are directly put into the 8CST drum tea-fixing machine for rough burning. The air inlet temperature is 120℃, the temperature inside the drum is maintained at 145℃, and the amount of leaves is 50kg. The rough burning time is 7 minutes, the speed is set to 30r / min, and the tea leaves are turned every 15 seconds to ensure that the tea leaves are evenly heated. After the rough burning is completed, the tea leaves are taken off the machine for cooling.

[0036] Repeat kneading The tea leaves after being roasted are put into the rolling machine for re-rolling. The initial speed is set to 35r / min, the amount of leaves put in each time is 40kg, and the re-rolling time is 15 minutes. When the tea leaves are tightly rolled, uniform in shape, and have a ruddy and shiny surface, the re-rolling is finished and the tea leaves are spread out to cool naturally.

[0037] Foot Fire The 6CDY-80-12 tea straightener is used for full-cooking, with a leaf weight of 1.3 kg, a temperature of 150°C, and a full-cooking time of 8 minutes. During the operation, the moisture content of the tea leaves gradually decreases to 5% to 6%. After full-cooking, the tea leaves are spread out to cool naturally to room temperature.

[0038] Let cool Spread the fully roasted tea leaves evenly in a bamboo basket with a thickness of 3 cm. Allow the tea leaves to cool naturally to room temperature for 45 minutes and allow the aroma to gradually stabilize.

[0039] Titian After the tea leaves have been cooled, they are spread on a bamboo sieve with a thickness of 2.5 cm and placed in a fragrance machine. The initial temperature of the fragrance machine is set at 80°C and the fragrance is added for 90 minutes. Then the temperature is gradually raised to 95°C for 30 minutes; to 105°C for 30 minutes; and then to 115°C for 30 minutes. After the fragrance is added, the tea leaves are taken out and spread to cool. After cooling to room temperature, the finished product is obtained. The finished tea has a rich floral and fruity aroma and caramel aroma, with rich and lasting aroma.

[0040] Embodiment 2 Withering Spread the fresh leaves in the withering trough with a thickness of 15 cm, and naturally wither indoors for 5 hours at a temperature of 22°C. Then move them outdoors for sunlight withering for 45 minutes, turning them over every 15 minutes. After completion, move them indoors for air withering at a temperature of 24°C, with each round of air withering for 80 minutes and static water flow for 50 minutes. Repeat the operation until the moisture distribution of the leaves is even. The total withering time is 13 hours.

[0041] Rolling The 6CR-65 rolling machine is used in the rolling stage, with the initial rolling speed of 25r / min and the time of 25 minutes; the middle rolling speed of 35r / min and the time of 30 minutes; the heavy rolling speed of 45r / min and the time of 30 minutes. After the rolling is completed, the tea leaves are tight and shiny, and are taken off the machine for use.

[0042] Unblock The rolled tea leaves are delumped with a delumping machine and then spread in a bamboo basket with a thickness of 22 cm and covered with wet gauze to keep it moist for subsequent processing.

[0043] Fermentation Fermentation is carried out in a fermentation room at a temperature of 27°C and a humidity of 92%. The tea leaves are spread out at a thickness of 8cm. The tea leaves are shaken every 2 hours, and the total fermentation time is 4 hours. After fermentation, the grassy smell of the tea leaves disappears, and the floral and fruity aroma emerges.

[0044] Mao Huo The raw fire uses a drum tea-killing machine with a temperature controlled at 140°C, a speed set at 35r / min, and a killing time of 7 minutes to ensure that the tea leaves are evenly heated. After the killing is completed, the tea leaves are spread out to cool for later use.

[0045] Repeated kneading The re-kneading is carried out using a rolling machine, with an initial speed of 40r / min and a hot kneading time of 18 minutes. The tea leaves are tight and even, with a bright red color. After completion, they are cooled naturally.

[0046] Foot Fire The full fire is carried out using a stripping machine, the temperature is 155℃, the leaf amount is 1.5kg, the duration is 8 minutes, and the moisture content of the leaves gradually decreases to 5% during the operation. After completion, cool and spread.

[0047] Let cool The tea leaves are spread evenly in a bamboo basket with a thickness of 3 cm. The cooling time is 50 minutes, and the tea leaves are gradually cooled to room temperature.

[0048] Titian The initial temperature of the aroma machine is 80℃, and the tea leaves are spread in a bamboo sieve with a thickness of 2cm. The aroma enhancement lasts for 90 minutes, and then the temperature is gradually raised to 95℃, 105℃ and 115℃, each lasting for 30 minutes. After the aroma enhancement is completed, the tea leaves are taken out and cooled naturally, and the aroma is richer and the taste is fuller.

[0049] Embodiment 3 This embodiment significantly improves the aroma layering and soup color uniformity of ancient tea tree black tea by more sophisticated process parameter control. The specific steps are as follows: Withering The fresh leaves are evenly spread in the withering trough with a thickness of 10 cm, and withered indoors for 5.5 hours. The room temperature is kept at about 23°C, and the leaves are turned over every 2 hours. After completion, they are moved to the sun for solar withering for 45 minutes, turning over every 13 minutes, until the tea leaves begin to show floral and fruity aroma. Then they are returned to the room and continue to use heated air withering. The temperature is set to 26°C, and the duration of air withering is shortened from 85 minutes to 70 minutes per round. The static water flow time is gradually extended from 50 minutes to 65 minutes, and the total withering time is 14 hours.

[0050] Rolling The withered tea leaves are put into the 6CR-65 rolling machine for rolling operation, with 48kg of leaves put in each time. In the initial rolling stage, the speed is 30r / min, the time is 28 minutes, making the tea leaves soft and beginning to show strands; in the middle rolling stage, the speed is increased to 40r / min, the time is 30 minutes, and the strands are gradually tightened; in the heavy rolling stage, the speed is 45r / min, the time is 30 minutes, the tea strands are tight, and the surface is ruddy and shiny. After completion, the tea leaves are taken off the machine for use.

[0051] Unblock The rolled tea leaves are put into the 6CJ-50 deblocking machine for deblocking. After deblocking, they are evenly spread in bamboo baskets with a thickness of 20 cm. Cover with wet gauze and let stand for 1 hour to make the moisture content of the tea leaves moderate and prepare for fermentation.

[0052] Fermentation Put the deblocked tea leaves into the 6CFJ intelligent black tea fermentation machine for fermentation. The leaf thickness is controlled at 12cm, the temperature is set to 28℃, and the humidity is maintained at 96%. The fermentation time is 4 hours, with automatic ventilation and dehumidification every 10 minutes, and shaking every 2 hours. The moderate fermentation is manifested by the complete disappearance of the tea's grassy smell, the rich tea aroma, and the uniform red and yellow leaf color. After completion, proceed to the next step.

[0053] Mao Huo The fermented tea leaves are put into the 8CST drum withering machine for rough burning. The temperature in the drum is maintained at 150℃, the amount of leaves is 50kg, the speed is 35r / min, it is turned every 20 seconds, and the rough burning time is 6.5 minutes. After the rough burning, the tea leaves emit a distinct aroma and enter the next step.

[0054] Repeated kneading The tea leaves after rough roasting are put into the rolling machine for re-rolling. The initial speed of re-rolling is 35r / min, the amount of leaves put in each time is 40kg, and the rolling time is 15 minutes. After the re-rolling is completed, the tea leaves are tight and uniform, with a ruddy and shiny surface. After cooling, they are spread out for use.

[0055] Foot Fire After repeated kneading, the tea leaves enter the 6CDY-80-12 stripping machine for full-cooking operation. The amount of leaves is 1.4kg, the temperature is controlled at 150℃, the full-cooking time is 9 minutes, and the moisture content of the tea leaves is reduced to 5%. After full-cooking, the tea leaves are quickly cooled to make the aroma of the tea leaves stable and not easy to dissipate.

[0056] Let cool After being fully roasted, the tea leaves are evenly spread in a bamboo basket with a thickness of 3 cm. The cooling time is 50 minutes. The tea leaves gradually cool to room temperature, the aroma becomes more stable, and the appearance quality is also improved.

[0057] Titian After cooling, spread the tea leaves on a bamboo sieve with a thickness of cm and place them in an aroma machine for aroma treatment. The initial temperature of the aroma machine is set to 80℃, and the aroma time is 90 minutes. Then gradually increase the temperature to 92℃, and the aroma lasts for 30 minutes; then increase to 98℃ for 30 minutes; and finally increase to 110℃ for 30 minutes. After the aroma is completed, take out the tea leaves and spread them to cool to room temperature. The finished tea leaves have a strong aroma, distinct layers of floral and fruity aromas and caramel aromas, a mellow taste, and a bright red soup color, and the quality of the finished tea is significantly improved.

[0058] Comparative Example 1 Withering Spread the fresh leaves in the withering trough with a thickness of 10 cm, and carry out natural withering indoors for 5.5 hours, with the room temperature maintained at 23°C. Then move them to the sun for sunlight withering for 45 minutes, turning them every 12 minutes. Then return them to the room for blast withering, with the blast temperature at 26°C, the first round of blast time of 85 minutes, and the static water flow for 50 minutes. The blast time is shortened round by round, with each round reduced by 10 minutes, and the static time is extended by 10 minutes each round. The total withering time is 14 hours, until the leaf surface loses its luster and the leaf edge is slightly brown.

[0059] Rolling The 6CR-65 rolling machine is used in the rolling stage, with a leaf feeding amount of 45kg. The initial rolling speed is 30r / min, the time is 28 minutes, and the strips begin to appear; the middle rolling speed is 40r / min, the time is 30 minutes, the strips are tight; the heavy rolling speed is 50r / min, the time is 30 minutes, the strips are tighter, and the surface is ruddy and smooth. After the rolling is completed, the machine is removed.

[0060] Unblock The rolled tea leaves are sent to a 6CJ-50 deblocking machine for deblocking. The deblocked tea leaves are spread flat in a bamboo basket with a thickness of 22 cm, covered with wet gauze to keep it moist, and left to stand for 45 minutes.

[0061] Fermentation The fermentation is carried out using a 6CFJ intelligent black tea fermentation machine. The tea leaves are evenly spread in a stainless steel fermentation box with a thickness of 10 cm. The fermentation temperature is controlled at 28°C, the humidity is 94%, the fermentation time is 4 hours, and the air is automatically ventilated and dehumidified every 10 minutes. The leaves are manually turned over every 2 hours until the tea leaves have lost their grassy smell, emit a floral fragrance, and have a uniform red and yellow color.

[0062] Mao Huo Put the fermented tea leaves into the 8CST drum withering machine, set the air inlet temperature to 120℃, and keep the temperature inside the drum at 145℃. The amount of leaves is 50kg, and the leaves are turned every 20 seconds. The rough burning time is 7 minutes to ensure that the tea leaves are evenly heated.

[0063] Repeated kneading The tea leaves after rough roasting are sent to the rolling machine for re-rolling operation, with a speed of 40r / min and a hot rolling time of 15 minutes. After re-rolling, the tea leaves are tight and even, with a ruddy color, and are spread out to cool for later use.

[0064] Foot Fire After re-kneading, the tea leaves are fully roasted using a 6CDY-80-12 stripper, with a leaf weight of 1.4 kg, an operating temperature of 150°C, and a full roasting time of 9 minutes. After the full roasting, the moisture content of the tea leaves drops to 6%, and they are immediately spread out to cool.

[0065] Let cool After being fully roasted, the tea leaves are evenly spread in a bamboo basket with a thickness of 3 cm. The cooling time is 50 minutes. After the tea leaves cool to room temperature, they enter the aroma enhancement stage.

[0066] Titian During the aroma stage, the tea leaves are spread in a bamboo sieve with a thickness of 2.5 cm. The temperature of the aroma machine is set to a constant 95°C, and the aroma time is 90 minutes. No staged heating operation is performed. After completion, the tea leaves are taken out and cooled naturally to room temperature.

[0067] Comparative Example 2 Withering The fresh leaves are evenly spread in the withering trough with a thickness of 12 cm. Wither naturally indoors for 5 hours, and the room temperature is kept at about 22°C. Move to the outdoors for sunlight withering for 45 minutes, turning every 13 minutes. After the initial floral and fruity fragrance appears, move indoors to continue with natural withering. The total withering time is 14 hours.

[0068] Rolling During the kneading stage, the initial kneading speed is 25r / min, the time is 30 minutes; the medium kneading speed is 35r / min, the time is 30 minutes; the heavy kneading speed is 45r / min, the time is 30 minutes. After completion, the ropes are tight and the surface is dark and moist, and they are taken off the machine for use.

[0069] Unblock The rolled tea leaves are sent to the 6CJ-50 deblocking machine. After deblocking, the tea leaves are evenly spread in a bamboo basket with a thickness of 20 cm, covered with wet gauze, and left to stand to keep moisture.

[0070] Fermentation During the fermentation process, the temperature, humidity and shaking frequency were not precisely controlled. The temperature was set at 30°C, the humidity was 90%, the thickness of the tea leaves was 12cm, and the fermentation time was 4 hours. The ventilation and dehumidification function was not set, and no manual shaking was performed. After completion, the grass smell partially disappeared, and the fermentation uniformity was poor.

[0071] Rough fire, repeated kneading, full fire, cooling, fragrance enhancement The parameters are the same as those in Example 2, without any other changes.

[0072] Comparative Example 3 Withering The fresh leaves were spread to a thickness of 10 cm and withered naturally for 5.5 hours. The leaves were withered in the sun for 45 minutes, and turned over every 12 minutes. Then they were transferred to the room for air withering. The air withering time was shortened by 10 minutes each time, and the total withering time was 14 hours.

[0073] Rolling The kneading process did not use variable speed operation, and only used a fixed speed to complete the entire kneading. Specifically, the speed was set at 30r / min, the kneading time was 90 minutes, and the initial kneading, intermediate kneading and heavy kneading stages were not distinguished.

[0074] Deblocking, fermentation, rough fire, re-kneading, full fire, cooling, aroma enhancement The parameters are the same as those in Example 3, with no other changes.

[0075] Comparative Example 4: Withering The spreading and withering operation is consistent with that of Example 1.

[0076] Rolling The kneading parameters are completely consistent with those in Example 1.

[0077] De-blocking, fermentation, rough cooking, re-kneading The parameters are the same as those in Example 1, without any other changes.

[0078] Foot Fire The full-fire temperature was set at 130°C, which is lower than 150°C in Example 1, the amount of leaves was 1.4 kg, and the full-fire time was 8 minutes. The moisture content of the tea leaves did not reach the standard of 5% and was still damp.

[0079] Cooling and fragrance The parameters are the same as those in Example 1, without any other changes.

[0080] Experiment 1: The influence of aroma enhancement techniques on aroma levels and persistence Experimental Description Experimental objective: To compare the effects of gradually increasing the temperature and constant temperature on the aroma layering and persistence of black tea, and to verify the technical advantages of the aroma enhancement process of the present invention.

[0081] Experimental steps: Sample preparation: Example 1: Tea leaves were prepared according to the process of Example 1. A gradual heating method was adopted in the aroma enhancement stage. The initial temperature was 80°C, and the temperature was gradually increased to 95°C, 105°C, and 115°C every 30 minutes. The total aroma enhancement time was 90 minutes.

[0082] Comparative Example 1: Tea leaves were prepared according to the process of Comparative Example 1, with the temperature of the aroma enhancement stage being kept constant at 95°C, the aroma enhancement time being 90 minutes, and no staged temperature increase operation.

[0083] Aroma level test: Ten professional tea tasters were organized to conduct sensory analysis of the tea samples in a closed environment, and the intensity of the floral, fruity and caramel aromas was recorded on a 5-point scale.

[0084] Each tea taster independently evaluates the aroma performance of the sample using a dedicated scoring form.

[0085] Fragrance persistence test: Using a closed aroma release analyzer, 20 g of the sample was stored in a sealed container for 72 hours, and the release intensity (integrated area) of its volatile aroma components was measured.

[0086] Repeat the test: The two groups of samples were prepared three times respectively, randomly sampled and tested, and the data were averaged.

[0087] Experimental data Table 1: Experimental data of aroma enhancement technology on the aroma level and persistence of black tea Experimental Summary The process effect of gradually increasing the temperature to enhance the aroma is significantly better than that of constant temperature, which is mainly due to the precise release and regulation of different volatile aroma substances by staged temperature control. In the initial stage of aroma enhancement, the low temperature environment of 80°C effectively avoids the rapid loss of low-boiling point floral aroma substances, allowing the floral aroma to be released evenly. As the temperature gradually increases, the fruity aroma components begin to volatilize at 95°C, and the caramel aroma further emerges at 105°C and 115°C. This layered release process gives the aroma a distinct sense of hierarchy and coordination.

[0088] The persistence of aroma is closely related to the release mode of aroma substances in tea. Although constant temperature aroma extraction can release a certain amount of volatile components, the release rate lacks change because it is always maintained at a single temperature, resulting in insufficient release of some aroma substances and premature volatilization of others, making it impossible to form a stable aroma structure. The gradual heating technology achieves the slow release and accumulation of volatile components by gradually increasing the temperature, significantly enhancing the persistence of aroma. This release process is also closely related to the transformation and combination of polyphenols in different temperature ranges.

[0089] In addition, due to the single heating conditions of constant temperature aroma treatment, some high-boiling point aroma substances are difficult to fully volatilize, and the caramel aroma is weak. Gradually increasing the temperature can provide more optimized transformation and release conditions for the complex aromatic substances in tea, making the overall aroma of the finished tea fuller and more layered. This method overcomes the shortcomings of the traditional aroma treatment process, which is monotonous and easy to dissipate, and significantly improves the quality and market competitiveness of the finished product.

[0090] Experiment 2: Effect of fermentation control on soup color and taste Experimental Description Experimental objective: To verify the importance of controlling temperature, humidity and stirring frequency during the fermentation process by comparing the effects of precise and imprecise fermentation conditions on the color and taste of black tea.

[0091] Experimental steps: Sample preparation Example 2: Tea leaves were prepared according to the process of Example 2, with a temperature of 28°C and a humidity of 94% during the fermentation stage, and a fermentation time of 4 hours. The tea leaves were spread to a thickness of 10 cm, and a 6CFJ intelligent black tea fermentation machine was used, with automatic ventilation and dehumidification every 10 minutes, and manual shaking every 2 hours.

[0092] Comparative Example 2: Tea leaves were prepared according to the process of Comparative Example 2, with a temperature of 30°C, a humidity of 90%, a fermentation time of 4 hours, and a tea leaf thickness of 12 cm. During the fermentation process, no ventilation, dehumidification, or manual shaking was performed.

[0093] Soup color determination Randomly sample 5 g of the prepared tea leaves, brew with 200 mL of boiling water, and filter the tea soup after soaking for 5 minutes.

[0094] Use a spectrophotometer to measure the transmittance of the tea soup at a wavelength of 460nm, and record the changes in the brightness of the tea soup.

[0095] Taste sensory evaluation Ten professional tea tasters were organized to randomly distribute tea samples and evaluate the mellowness and harmony of the tea flavor using a 5-point scoring system (1 = bland taste, 5 = rich and harmonious taste).

[0096] Repeat the experiment Each group of samples was prepared three times, and the spectrophotometer was used to measure three times to get the average value, and the sensory score was the average value of each tea taster.

[0097] Experimental data Table 2: Experimental data of fermentation control on the color and taste of black tea Experimental Summary The brightness of tea soup is closely related to the oxidation reaction during the fermentation stage. Accurately controlling the temperature and humidity of the fermentation can significantly promote the moderate oxidation of polyphenols, thereby generating the right amount of theaflavins and thearubigins. These two substances are the key to the bright red color of black tea soup. In contrast, under inaccurate fermentation conditions, excessively high temperatures and low humidity will lead to unbalanced oxidation reactions, affecting the decomposition of polyphenols, and causing the soup to appear dark red or yellowish, with insufficient luster.

[0098] The richness of the flavor mainly depends on the transformation process of aromatic substances and tea polyphenols during the fermentation process. In Example 2, the frequency control of ventilation and dehumidification and the shaking operation ensure the uniformity of fermentation, avoid the phenomenon of local over-fermentation or under-fermentation, and make the flavor fuller. In Comparative Example 2, because the water content in the tea leaves was not evenly distributed due to the lack of shaking, the flavor was bland and uncoordinated. The balance of the flavor was therefore affected.

[0099] In addition, precise control of fermentation plays a key role in the connection between aroma and flavor. The moderately oxidized tea not only has a bright red soup color, but also has a significantly improved floral and fruity aroma. In comparative example 2, the degree of oxidation is unbalanced, which not only reduces the mellowness of the flavor and weakens the bright red soup color, but also increases the bitterness in the tea soup. The precisely controlled fermentation process overcomes the problem of fermentation uniformity that is difficult to achieve in traditional technologies, forming a more coordinated overall quality.

[0100] Experiment 3: Effect of rolling process on the appearance and aroma of tea leaves Experimental Description Experimental objective: To verify the advantages of the multi-stage rolling process of the present invention by comparing the effects of multi-stage variable speed rolling and single speed rolling on the compactness and aroma release of tea leaves.

[0101] Experimental steps: Sample preparation Example 3: Tea leaves were prepared according to the process of Example 3, and a multi-stage variable speed operation was adopted in the rolling stage. The initial rolling speed was 30 r / min, and the time was 28 minutes; the intermediate rolling speed was 40 r / min, and the time was 30 minutes; the heavy rolling speed was 50 r / min, and the time was 30 minutes. After rolling, the tea leaves were tight and even.

[0102] Comparative Example 3: Tea leaves were prepared according to the process of Comparative Example 3, with a single speed of 30 r / min and a rolling time of 90 minutes, without staged speed change operation.

[0103] Rope tightness test 100g of tea leaves were randomly sampled and evaluated by 10 professional tea tasters using the tea strand tightness scoring method. The score range is 1 to 5 (1 = loose tea strands, 5 = tight tea strands).

[0104] Aroma release test Static headspace gas chromatography was used to test the release of the main volatile components of tea (such as linalool and geraniol).

[0105] 3g of tea leaves were randomly sampled from each group and sealed in a sample bottle to test the content of volatile components in mg / kg.

[0106] Repeat the experiment Each group of samples was prepared three times, and the strip tightness score and volatile component test were repeated three times each, and the average value was taken as the final result.

[0107] Experimental data Table 3: Experimental data of the rolling process on the compactness and aroma release of tea leaves Experimental Summary The tightness of the tea leaves directly reflects the impact of the rolling process on the appearance quality of tea leaves. Multi-stage variable speed rolling can give the tea leaves precise rolling intensity at different stages, making the leaves fully soft during the initial rolling and gradually forming a tight and uniform tea leaf structure during the middle and heavy rolling. In contrast, the rolling process with a single speed cannot adapt to the gradual changes in the texture of the leaves due to its consistent intensity, resulting in loose and uneven tea leaves.

[0108] The improvement of aroma release is inseparable from the cell wall breaking effect during the strip forming process. Multi-stage variable speed rolling not only optimizes the appearance of the strips through progressive pressure, but also more effectively destroys the tea cell walls, allowing the internal aromatic substances to be fully released. In particular, the content of ingredients such as linalool and geraniol is significantly higher than that of the single speed rolling sample, indicating that variable speed rolling can better stimulate the aroma potential of black tea.

[0109] Although rolling at a single speed can also form tea strips, the lack of force variation can easily lead to partial over-rolling or under-rolling of tea leaves. This unevenness not only affects the appearance, but also reduces the release efficiency of aromatic substances, which ultimately manifests as a weak aroma and loose tea strips. The present invention scientifically sets the speed and time of the rolling stage, making the tea strips tighter and more fragrant, and significantly improving both the appearance and internal quality.

[0110] Experiment 4: Effects of Full-Fire Temperature on Moisture Content and Aroma Persistence of Tea Leaves Experimental Description Experimental objective: By comparing different full-fire temperature treatments, verify the effect of full-fire temperature on the moisture content and aroma persistence of tea, and illustrate the importance of optimizing full-fire temperature.

[0111] Experimental steps: Sample preparation Example 1: Tea leaves were prepared according to the process of Example 1, the temperature of the full-fire stage was set to 150° C., the duration was 9 minutes, and the moisture content of the tea leaves was controlled at 5% to 6%.

[0112] Comparative Example 4: Tea was prepared according to the process of Comparative Example 4, the temperature of the full-fire stage was set to 130°C and lasted for 8 minutes, the moisture content of the tea did not reach 5% to 6%, and the finished product was slightly moist.

[0113] Moisture content determination Randomly sample 10g of tea leaves and determine their final moisture content using a 105°C constant temperature drying method. Each measurement is continued until the sample mass is constant, and the final moisture content is recorded.

[0114] Fragrance persistence test Using a closed aroma release analyzer, take 20 g of the sample and place it in a sealed container. After storing it for 72 hours, test its aroma release intensity (integrated area, mg / s).

[0115] Repeat the experiment Each group of samples was prepared three times, and the moisture content determination and aroma release intensity test were repeated three times each, and the average value was taken as the final result.

[0116] Experimental data Table 4: Experimental data of the effect of full fire temperature on tea water content and aroma persistence Experimental Summary The temperature in the full-fire stage directly determines the degree of moisture removal in the tea leaves and the final physical stability. Under 150°C conditions, the moisture content of the tea leaves can be precisely controlled within the range of 5% to 6%. This moisture level is a key indicator for maintaining tea quality. Higher temperatures not only effectively reduce the moisture content, but also further promote the release of volatile aroma substances in the tea leaves. In the comparative example, due to the low full-fire temperature, the moisture removal of the tea leaves was not thorough, resulting in the finished product being slightly damp, the structure being unstable, and even affecting the aroma performance during the storage period.

[0117] The persistence of aroma is significantly affected by the moisture content. Tea with too much moisture is prone to secondary chemical reactions during storage, which will accelerate the volatilization of some low-boiling point aroma substances, thereby causing the aroma intensity to decrease. Example 1 uses high-temperature full-fire treatment to make the chemical reaction inside the tea more stable, the volatile components are released more evenly in the later stage, and the aroma persistence is significantly enhanced. In contrast, the aroma release curve of the comparative example is steeper, showing the rapid disappearance of the aroma.

[0118] In addition, the temperature of the full fire also affects the taste and internal quality of the tea. The appropriate high temperature and full fire help the further transformation of esters and aldehydes in the tea, making the aroma more layered and stable. In the case of insufficient temperature, this transformation process is inhibited, and the final result is that the aroma is not full and the taste lacks the mellowness it should have. This difference emphasizes the importance of accurately controlling the temperature of the full fire, and provides a reliable process basis for the production of high-quality black tea.

[0119] Experiment 5: Effects of withering methods on tea aroma and flavor Experimental Description Experimental objectives: To verify the optimization effect of introducing sunlight withering on the aroma and flavor of tea, and to illustrate the necessity of combining natural withering with sunlight withering.

[0120] Experimental steps: Sample preparation Example 2: Tea leaves were prepared according to the process of Example 2. The withering stage used a combination of natural withering (room temperature 22°C-24°C, for 5 hours) and sunlight withering (45 minutes, with tea leaves turned over every 12 minutes), with a total withering time of 14 hours.

[0121] Comparative Example 5: Tea leaves were prepared according to the process of Comparative Example 5. During the withering stage, only natural withering (room temperature 22°C to 24°C, for 14 hours) was used, and no sunlight withering was introduced.

[0122] Aroma evaluation Ten professional tea tasters were organized to record the concentration of floral and fruity aromas of the samples through sensory analysis, with a score range of 1 to 5 (1 = weak aroma, 5 = strong aroma).

[0123] Taste measurement High performance liquid chromatography (HPLC) was used to determine the content of major flavor substances (such as theaflavins and thearubigins) in tea soup, and the results were expressed in mg / L.

[0124] Take 5 g of the sample, add 200 mL of boiling water and soak for 5 minutes, then filter the tea soup for analysis.

[0125] Repeat the experiment Each group of samples was prepared three times, and the aroma and taste were measured three times respectively, and the results were averaged.

[0126] Experimental data Table 5: Experimental data of the effect of withering method on tea aroma and flavor Experimental Summary The introduction of sunlight withering plays an important role in improving the aroma of tea. Compared with simple natural withering, sunlight withering accelerates the generation and release of aromatic substances in tea through photothermal effects, especially the accumulation of floral and fruity aroma components. This unique heat treatment method promotes the earlier volatilization of low-boiling point aroma substances, while stimulating the activity of secondary metabolic pathways, making the overall aroma more rich and distinct.

[0127] Not only that, sunlight withering can also improve the flavor of tea. Short-term exposure to sunlight helps to quickly and evenly distribute water inside tea cells, promotes the conversion and oxidation of polyphenols, and thus increases the content of theaflavins and thearubigins. In contrast, samples that rely solely on natural withering have a slower internal enzymatic reaction due to the slow loss of water, significantly reducing the production of flavor substances, and the overall taste is slightly bland.

[0128] More interestingly, sunlight withering also seems to play a subtle role in the coordination of aroma and flavor. The floral and fruity aromas of the naturally withered samples are weak, while the contents of theaflavins and thearubigins are low, showing a disconnect between aroma and flavor. The process combined with sunlight withering makes up for this defect, making the finished tea reach a higher level of matching in aroma and flavor. This unique flavor characteristic makes it more attractive in the market.

[0129] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A processing technology for improving the aroma and flavor of ancient tea tree black tea, characterized in that: The following steps are involved: Spread green and wither; Kneading; Unblock; Fermentation; Hair fire; Repeat kneading; Foot fire; Let cool; Titian.

2. A processing technology for improving the aroma and flavor of ancient tea tree black tea according to claim 1, characterized in that: The green withering comprises: Indoor natural withering: Spread the fresh tea leaves in the withering trough with a thickness of 10-15cm, and cool for 5-6 hours; at the same time, adopt heated air withering, the temperature is 25℃, the duration is 85-95 minutes, stop the air and let the water flow for 55-60 minutes, stir evenly, and then continue the next round of air blowing operation, in which the air blowing time is shortened round by round, and the air blowing time is reduced by 10-15 minutes each time; the water flow time is extended round by round, and the static time is increased by 10-15 minutes each time, so as to ensure that the moisture distribution of the tea leaves and stems is even; Sunlight withering: It is carried out under sunny conditions. The withering time is 45 to 50 minutes. Turn it over every 11 to 12 minutes. After the flower and fruit fragrance begins to appear, move it indoors to continue with natural withering. The total withering time is 14 to 15 hours. After the sunlight withering is completed, move it outdoors for sunlight withering for 90 to 100 minutes, turning it over every 14 to 15 minutes. After the sunlight withering is completed, move it indoors for natural withering indoors until the leaves lose their luster, the leaves become dark green, and brown appears on the leaf edges.

3. The processing technology for improving the aroma and flavor of ancient tea tree black tea according to claim 1, characterized in that: The kneading is carried out using a 6CR-65 kneading machine, with 45-50 kg of leaves thrown in each time, and variable speed kneading is adopted, which includes: Initial kneading, time 28-30min, speed 25r / min; Medium kneading, time 28-30min, speed 35r / min; Knead again for 30 minutes at a speed of 45 rpm until the tea leaves turn from green to light red.

4. The processing technology for improving the aroma and flavor of ancient tea tree black tea according to claim 1, characterized in that: The tea deblocking machine of 6CJ-50 type is used for deblocking. After deblocking, the tea blocks are spread flat in a wet dustpan or bamboo basket with a thickness of 20 to 25 cm, and finally covered with wet cotton gauze.

5. The processing technology for improving the aroma and flavor of ancient tea tree black tea according to claim 1, characterized in that: The fermentation includes one of fermentation in a fermentation chamber and fermentation in a fermentation machine: Fermentation in the fermentation room At room temperature of 27-28℃ and humidity of 92-95%, place the tea leaves in a dustpan covered with white cloth with a thickness of 8-10cm. Fermentation time: 4 hours. During fermentation, shake once every 2 hours. Fermentation is moderate when the grass smell disappears, the tea leaves have a floral aroma, and the leaves are evenly red and yellow. Fermentation machine fermentation Use 6CFJ intelligent black tea fermentation machine, spread the leaves in a stainless steel fermentation box, cover the box with white cloth or gauze with a thickness of 10-15 cm, ferment for 4 hours at a temperature of 28-30°C and a humidity of 94-96%, automatically ventilate and dehumidify every 10 minutes, and shake once every 2 hours. Fermentation should be carried out in the same fermentation room as in the fermentation room.

6. The processing technology for improving the aroma and flavor of ancient tea tree black tea according to claim 1, characterized in that: The rough fire is carried out using an 8CST drum fixing machine, and the specific steps include: The preheating time is 19 to 21 minutes, and the air inlet temperature is 115°C to 125°C; When the air temperature in the tube reaches 140-160℃, the leaves are cast; The duration of withering is 6 to 8 minutes, the rotation speed is 30 to 35 r / min, and it is turned every 15 to 20 seconds to ensure that the tea leaves are heated evenly.

7. The processing technology for improving the aroma and flavor of ancient tea tree black tea according to claim 1, characterized in that: The re-kneading step comprises: Use a rolling machine to operate, with an initial speed of 30-40r / min; The amount of leaves added each time is 40-50kg; Hot kneading time 12 to 18 minutes; When the tea leaves are tightly rolled, evenly stripped, and have a rosy and lustrous color, they are taken off the machine and spread out to cool naturally.

8. The processing technology for improving the aroma and flavor of ancient tea tree black tea according to claim 1, characterized in that: The step of heating is carried out using a 6CDY-80-12 stripping machine, comprising: After re-kneading, the tea leaves are spread out to cool for 30-32 minutes to redistribute the moisture in the leaves evenly. When operating with full fire, the temperature is 144-155℃, and the amount of leaves added each time is 1.3-1.5kg; During the full-fire process, when the moisture content of the tea drops to 5-6%, the tea leaves are taken off the machine and spread out evenly to cool to room temperature.

9. The processing technology for improving the aroma and flavor of ancient tea tree black tea according to claim 1, characterized in that: During the cooling process, the thickness of the cooling process is 3 to 5 cm; The cooling time is 30 to 60 minutes, allowing the tea leaves to gradually cool to room temperature.

10. The processing technology for improving the aroma and flavor of ancient tea tree black tea according to claim 1, characterized in that: The aromatization is carried out in a 6CHS-100 / 16 aromatization machine, including: Spread the tea leaves in the bamboo sieve to a thickness of 2 to 3 cm; Preheat the aroma machine to 80℃ and put the bamboo sieve into the aroma machine; Fragrance extraction was carried out at 80°C for 90 minutes; Gradually increase the temperature: when the temperature rises to 88-90℃, the aroma is increased for 30-31 minutes; when the temperature rises to 98-100℃, the aroma is increased for 30-31 minutes; when the temperature rises to 181-120℃, the aroma is increased for 30-31 minutes; After the aroma is extracted, the tea leaves are removed from the machine, spread out and allowed to cool naturally to room temperature.

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