Processing method of sichuan congou black tea

Abstract

The application relates to the technical field of tea processing, in particular to a Sichuan Congou black tea processing method. Fresh leaves are picked in a limited time, low-temperature and low-humidity withering is carried out for multiple times, low-temperature and low-humidity shaking is carried out for multiple times, sunlight withering is carried out, then low-temperature and low-humidity variable-speed rolling is carried out, light fermentation, microwave low-temperature rough firing, high-temperature full firing and static aroma extraction are carried out, and finally, the finished tea leaves are obtained. The finished tea leaves have higher aroma purity, less impurities, fruit and honey aroma, long-lasting, fresh and sweet taste, greatly reduced bitterness, slowed down water extract rate, improved tea resistance, and the tea is thick and not greasy, fresh and sweet.

Description

Technical Field

[0001] This application relates to the field of tea processing technology, and in particular to a method for processing Sichuan Gongfu black tea. Background Technology

[0002] Tea, the world's second most consumed beverage after water, is widely loved by consumers for its excellent taste and its rich content of phenols, caffeine, and amino acids.

[0003] Based on different processing methods, tea can be divided into different categories such as black tea, green tea, oolong tea, dark tea, white tea, and yellow tea. Among them, black tea is the most consumed type of tea in the world, accounting for more than 60% of the total tea production.

[0004] In my country, black tea, as the second largest tea category after green tea, has experienced rapid development. With the revival of traditional black tea and the rapid growth of emerging black tea varieties, the black tea industry has seen rapid growth, with a surge in production and increasingly diversified flavors. Significant progress has also been made in the research of processing technology for Chinese black tea products. Taste is a crucial attribute for evaluating the sensory quality and market value of black tea. Excellent taste is characterized by sweetness, mellowness, and refreshing sweetness, while poor taste is characterized by a grassy, ​​astringent, overly roasted, or bitter flavor. Unlike the "strong, intense, and fresh" standard for large-leaf black teas abroad, Chinese black tea is characterized by its "sweet, mellow, and fresh" characteristics, as exemplified by Jiuqu Hongmei, Hunan black tea, Ninghong Gongfu, and Yihong Gongfu. The production of sweet and mellow taste is significantly related to the variety and quality of the fresh leaves, as well as the processing techniques. Fresh leaves are the foundation of quality formation, while the accompanying processing technology is the condition for quality development. Traditional black tea processing involves withering, rolling, fermentation, and drying. The rolling and fermentation processes are heavily emphasized, leading to a tendency for the finished black tea to develop bitter and astringent flavors. Drying often uses oven-drying, which, due to poor equipment stability and improper parameter settings, can easily result in a musty, burnt, or scorched taste. Furthermore, my country's black tea production still suffers from inconsistent fresh leaf raw materials, low levels of standardized processing, and outdated processing facilities. These issues contribute to unstable quality, poor taste, and excessive bitterness in Chinese black tea products, negatively impacting the economic benefits of my country's black tea industry. Summary of the Invention

[0005] This application provides a method for processing Sichuan Gongfu black tea to solve the technical problems of black tea prepared in the prior art having a cloying aroma and a heavy bitter taste.

[0006] This application provides a method for processing Sichuan Gongfu black tea, including the following steps:

[0007] S1. Fresh leaf picking;

[0008] S2, Low-temperature and low-humidity wilting I:

[0009] Spread the fresh leaves evenly on the withering equipment, with 1 kg of fresh leaves per square meter. Blow air for 20 minutes and let stand for 1 hour until the tea leaves lose 3%-5% of their weight to obtain withered product I. The withering temperature is 10℃-16℃ and the humidity is 40%-50%.

[0010] S3, Low Temperature and Low Humidity Shaking withering I:

[0011] The withered product I is placed in a shaking machine, the shaking machine frequency is set to 15 times / min, and the shaking is carried out for 4-5 minutes to obtain the shaken product I; the shaking temperature is 10℃-16℃ and the relative humidity is 40%-50%;

[0012] S4, Low Temperature and Low Humidity Wilting II:

[0013] The shaken product I is evenly spread on the withering equipment, with 1 kg of fresh leaves per square meter. After blowing for 20 minutes, it is left to stand for 1 hour until the tea leaves lose 12%-15% of their weight, thus obtaining withered product II. The withering temperature is 10℃-16℃ and the relative humidity is 40%-50%.

[0014] S5, Low Temperature and Low Humidity Shaking II:

[0015] The withered product II is placed in a shaking machine with a shaking frequency of 30 times / min. The shaking is stopped after 5-6 minutes to obtain the shaken product II. The shaking temperature is 10℃-16℃ and the relative humidity is 40%-50%.

[0016] S6, Low Temperature and Low Humidity Wilting III:

[0017] The shaken product II is evenly spread on the withering equipment, with 1 kg of fresh leaves per square meter. After blowing for 20 minutes, it is left to stand for 1 hour until the tea leaves lose 28%-32% of their weight, thus obtaining withered product III. The withering temperature is 10℃-16℃ and the relative humidity is 40%-50%.

[0018] S7, Sunlight withering:

[0019] The withered product III was subjected to sun withering for 20 minutes, and was turned over every 10 minutes to obtain withered leaves;

[0020] S8, Natural stacking:

[0021] The withered leaves are piled up for 20 minutes to obtain piled leaves;

[0022] S9, Low-temperature and low-humidity variable-speed kneading:

[0023] The stacked leaves are kneaded in a variable speed kneading machine to obtain kneaded leaves;

[0024] S10, Light Fermentation:

[0025] The kneaded leaves are evenly spread in a bamboo fermentation tray, with a thickness of 4-6 cm. During the fermentation process, when the temperature of the core of the fermentation leaf pile reaches 30℃, the fermentation leaves are turned over. Fermentation lasts for 3.5-4.5 hours to obtain fermented leaves.

[0026] S11, Microwave Low-Temperature Burning:

[0027] The fermented leaves are spread out to a thickness of 1-2 cm and then subjected to micro-firing to obtain the raw-fired leaves.

[0028] S12, High Temperature and Thorough Cooking:

[0029] The raw tea leaves are spread out to a thickness of 1-2 cm and then subjected to high-temperature firing until the moisture content of the tea leaves is 7%-9%, thus obtaining fully fired tea leaves.

[0030] S13, Static Fragrance Enhancement:

[0031] The fully roasted tea leaves are placed in an electric tea roasting cage, with the leaf thickness spread to 5-8cm. They are then roasted at a temperature of 50℃-70℃ for 24-36 hours until the moisture content of the tea leaves is below 5%, thus obtaining the finished tea product.

[0032] Optionally, the kneading includes the following steps:

[0033] The first kneading process involved air-pressure kneading for 20 minutes at 20 rpm; the second kneading involved light-pressure kneading for 20 minutes at 25 rpm; the third kneading involved medium-pressure kneading for 20 minutes at 30 rpm; the fourth kneading involved medium-pressure kneading for 10 minutes at 35 rpm; the fifth kneading involved air-pressure kneading for 10 minutes at 35 rpm; and the sixth kneading involved heavy-pressure kneading for 10 minutes at 40 rpm, yielding the kneaded leaves. The kneading temperature was 10℃-20℃, and the relative humidity was 60%-70%.

[0034] Optionally, the rate of curling the twisted leaves into strips is higher than 90%, and the rate of leaf cell breakage is higher than 80%.

[0035] Optionally, the fermentation temperature is 24℃-26℃, the relative humidity is 90%-95%, and the oxygen concentration is 21-23%.

[0036] Optionally, low-temperature initial firing involves microwave treatment at an intensity of 800W for 2-5 minutes, with the tea temperature at the microwave outlet at 80℃-90℃ and the tea moisture content at 10%-20%.

[0037] Optionally, the high-temperature drying machine temperature is set to 110℃-115℃. When the temperature reaches the set temperature, the burrs are placed in the machine, and the dryer door is not closed tightly.

[0038] Optionally, before static aroma enhancement, the fully roasted tea leaves can be left to stand for 10-15 days to remove stems and leaves.

[0039] Optionally, the fresh leaves are fresh leaves from a highly aromatic oolong tea tree variety.

[0040] Optionally, the fresh leaves are picked during sunny days in spring and autumn, from 09:00 to 16:00.

[0041] Alternatively, the best time to pick is between 11:00 and 15:00 on a sunny day.

[0042] Compared with the prior art, the above-mentioned technical solutions provided in this application have the following advantages: the black tea prepared by this application has higher aroma purity and fewer off-flavors, with floral and fruity aromas with honey fragrance, rich and lasting, and a fresh, sweet and mellow taste. It greatly reduces the bitterness of black tea, slows down the leaching rate of tea water extracts, improves the tea's brewing endurance, and makes the tea flavor strong but not greasy, fresh and sweet. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] In one embodiment of this application, a method for processing Sichuan Gongfu black tea includes the following steps:

[0045] S1. Fresh leaf picking;

[0046] S2, Low-temperature and low-humidity wilting I:

[0047] Spread the fresh leaves evenly on the withering equipment, with 1 kg of fresh leaves per square meter. Blow air for 20 minutes and let stand for 1 hour until the tea leaves lose 3%-5% of their weight and emit a pleasant aroma. This will give you withered product I. The withering temperature is 10℃-16℃ and the humidity is 40%-50%.

[0048] S3, Low Temperature and Low Humidity Shaking withering I:

[0049] The withered product I is placed in a shaking machine with a shaking frequency of 15 times / min for 4-5 minutes to reduce the pleasant aroma and release a strong grassy smell, thus obtaining the shaken product I; the shaking temperature is 10℃-16℃ and the relative humidity is 40%-50%.

[0050] S4, Low Temperature and Low Humidity Wilting II:

[0051] The shaken product I is evenly spread on the withering equipment, with 1 kg of fresh leaves per square meter. After blowing air for 20 minutes, it is left to stand for 1 hour until the tea leaves lose 12%-15% of their weight and emit a pleasant aroma, thus obtaining withered product II. The withering temperature is 10℃-16℃ and the relative humidity is 40%-50%.

[0052] S5, Low Temperature and Low Humidity Shaking II:

[0053] The withered product II is placed in a shaking machine. The shaking machine frequency is set to 30 times / min. The shaking is stopped after 5-6 minutes to reduce the pleasant aroma and release a strong grassy smell, thus obtaining the shaken product II. The shaking temperature is 10℃-16℃ and the relative humidity is 40%-50%.

[0054] S6, Low Temperature and Low Humidity Wilting III:

[0055] The shaken tea product II is evenly spread on the withering equipment, with 1 kg of fresh leaves per square meter. After blowing for 20 minutes, it is left to stand for 1 hour until the tea leaves lose 28%-32% of their weight. The tea leaves then emit a pleasant aroma again, the leaf surface becomes soft, the tender stems are pliable but do not break when squeezed, and the tea leaves can be formed into a ball by hand without making a noticeable breaking sound. When released, they can slowly disperse, thus obtaining withered product III. The withering temperature is 10℃-16℃ and the relative humidity is 40%-50%.

[0056] S7, Sunlight withering:

[0057] The withered product III was subjected to sun withering for 20 minutes, and was turned over every 10 minutes to obtain withered leaves;

[0058] S8, Natural stacking:

[0059] The withered leaves are piled up for 20 minutes until the center of the pile is slightly heated to obtain the piled leaves.

[0060] S9, Low-temperature and low-humidity variable-speed kneading:

[0061] The stacked leaves are kneaded in a variable speed kneading machine to obtain kneaded leaves;

[0062] S10, Light Fermentation:

[0063] The kneaded leaves are evenly spread in a bamboo fermentation tray, with a thickness of 4-6 cm. During the fermentation process, when the temperature of the center of the fermentation leaf pile reaches 30℃, the fermentation leaves are turned over. Fermentation lasts for 3.5-4.5 hours. When the leaf color turns red, the green smell fades significantly, and a fresh floral and fruity fragrance is emitted, the fermented leaves are obtained.

[0064] S11, Microwave Low-Temperature Burning:

[0065] The fermented leaves are spread out to a thickness of 1-2 cm and then heated in a microwave until they do not clump together when squeezed in the hand.

[0066] S12, High Temperature and Thorough Cooking:

[0067] Spread the raw tea leaves out to a thickness of 1-2 cm, and then heat them at a high temperature until the moisture content of the tea leaves is 7%-9%. Quickly remove the tea leaves and spread them out thinly to obtain fully heated tea leaves.

[0068] S13, Static Fragrance Enhancement:

[0069] The fully roasted tea leaves are placed in an electric tea roasting cage, with the leaf thickness spread to 5-8cm. They are then roasted at a temperature of 50℃-70℃ for 24-36 hours until the moisture content of the tea leaves is below 5%, thus obtaining the finished tea product.

[0070] This application provides a novel preparation process for Sichuan Gongfu black tea, comprehensively optimizing each process step to produce a rich and lasting floral, fruity, and honey-scented aroma. The finished tea boasts a higher purity of aroma and fewer off-flavors, with a fresh, sweet, and mellow taste. It significantly reduces bitterness, slows the extraction rate of water-soluble components, and improves the tea's brewing endurance, resulting in a strong yet not cloying, refreshing, and sweet flavor. This application incorporates a shaking process during the fresh leaf withering stage to accelerate the volatilization of grassy components. Lowering the withering (shaking) temperature to 10℃-16℃ avoids excessively rapid enzymatic reactions within the leaves, especially at the leaf edges, caused by high temperatures during withering or shaking. This prevents excessive oxidation of polyphenols at the leaf edges and a darker leaf color, ensuring that the polyphenol oxidation process is largely preserved within the fermentation process. Relative humidity is reduced to 40%-50%, allowing fresh leaves to lose moisture quickly due to humidity differences, increasing their softness and plasticity, which is beneficial for rolling. Short-term sun withering and natural stacking are introduced, giving the fresh leaves a brief period to warm to room temperature or slightly above, effectively blending the withered leaves and preventing uneven rolling quality due to varying degrees of withering. In the withering, rolling, and fermentation processes, the rate of moisture loss from the leaves is gradually reduced by progressively increasing the relative humidity. Withering accelerates moisture loss to reach the optimal withering stage as quickly as possible; rolling slows moisture loss, preserving the tea's elasticity and facilitating shaping; and fermentation prevents moisture loss, ensuring the necessary moisture for fermentation and guaranteeing uniform fermentation.

[0071] As an optional implementation, the kneading includes the following steps:

[0072] The rolling process involved: a first kneading under air pressure for 20 minutes at 20 rpm; a second kneading under light pressure for 20 minutes at 25 rpm; a third kneading under medium pressure for 20 minutes at 30 rpm; a fourth kneading under medium pressure for 10 minutes at 35 rpm; a fifth kneading under air pressure for 10 minutes at 35 rpm; and a sixth kneading under heavy pressure for 10 minutes at 40 rpm, yielding rolled leaves. The kneading temperature was 10℃-20℃, and the relative humidity was 60%-70%. The rolled leaves exhibited a curling rate exceeding 90% and a leaf cell breakage rate exceeding 80%.

[0073] In this application, the rolling process involves a series of stages: air pressure – light pressure – medium pressure – medium pressure – air pressure – heavy pressure. The rolling time is strictly controlled, and the rolling speed is gradually increased from slow to fast. This promotes the gradual formation and tightening of tea leaves into strips, and ensures that cell breakdown occurs from the leaf surface inwards. Simultaneously, the hydrolysis of polysaccharides, proteins, and polyphenols all proceed from the leaf surface inwards, thereby increasing the tea's brewing endurance and the consistency of flavor across multiple infusions. Furthermore, the temperature is controlled between 10℃ and 20℃, further slowing down the oxidation rate of polyphenols in the tea leaves.

[0074] As an optional implementation method, the fermentation temperature is 24℃-26℃, the relative humidity is 90%-95%, and the oxygen concentration is 21-23%.

[0075] In this application, a light fermentation process is adopted to reduce the excessive oxidation of polyphenols in tea.

[0076] As an optional implementation method, the low-temperature initial firing uses a microwave treatment with an intensity of 800W for 2-5 minutes, with the temperature of the tea leaves at the microwave outlet being 80℃-90℃ and the moisture content of the tea leaves being 10%-20%.

[0077] In this application, the microwave low-temperature flame causes the temperature inside the leaf to rise sequentially from the inside out, and the inactivation of enzymes inside the leaf also proceeds sequentially from the inside out. By using a moderate low temperature, the aroma loss caused by traditional high-temperature hot air is avoided, as well as the problems of low aroma, musty taste, and lack of freshness caused by the rise in leaf temperature from the outside in.

[0078] As an optional implementation, the high-temperature firing setting involves setting the dryer temperature to 110℃-115℃. When the temperature reaches the set temperature, the burrs are placed inside, and the dryer door is not closed tightly.

[0079] In this application, high temperature and sufficient heat cause the tea leaves to tighten quickly and lose moisture as quickly as possible, so that the moisture content of the tea leaves reaches 7%-9%.

[0080] As an optional implementation, the fresh leaves are those of a highly aromatic oolong tea tree variety, specifically Jin Xuan or Jin Guan Yin. The fresh leaves are harvested on sunny days in spring and autumn, from 09:00 to 16:00, with the optimal time being from 11:00 to 15:00 on sunny days.

[0081] In this application, based on the geographical environment and climate conditions of Sichuan, fresh leaves were selected for harvesting in spring and autumn (the period when the content of aroma components in fresh leaves is high). At this time, the fresh leaves have low water content and are easy to "dissipate water and develop fragrance". Furthermore, the tenderness of the fresh leaves was specified as one bud and two or three leaves, and medium to small openings of the same tenderness, to ensure that the content of aroma components is high while retaining the appropriate tenderness of the fresh leaves.

[0082] Example 1

[0083] A method for processing Sichuan Gongfu black tea includes the following steps:

[0084] S1. Fresh leaf picking:

[0085] Fresh leaves of the Jin Xuan tea variety are picked on sunny days in spring and autumn, between 09:00 and 11:00.

[0086] S2, Low-temperature and low-humidity wilting I:

[0087] The freshly picked leaves are evenly spread on the withering equipment, with 1 kg of fresh leaves per square meter. The leaves are blown for 20 minutes and left to stand for 1 hour until the weight of the tea leaves decreases by 3%, thus obtaining withered product I. The withering temperature is 10℃ and the humidity is 40%.

[0088] S3, Low Temperature and Low Humidity Shaking withering I:

[0089] The withered product I was placed in a shaking machine, the shaking machine frequency was set to 15 times / min, and the shaking was carried out for 4 minutes to obtain the shaken product I; the shaking temperature was 10℃ and the relative humidity was 40%;

[0090] S4, Low Temperature and Low Humidity Wilting II:

[0091] The shaken product I is evenly spread on the withering equipment, with 1 kg of fresh leaves per square meter. After blowing for 20 minutes, it is left to stand for 1 hour until the tea leaves lose 12% of their weight, thus obtaining withered product II. The withering temperature is 10℃ and the relative humidity is 40%.

[0092] S5, Low Temperature and Low Humidity Shaking II:

[0093] The withered product II was placed in a shaking machine with a shaking frequency of 30 times / min. The shaking was stopped after 5 minutes to obtain the shaken product II. The shaking temperature was 10℃ and the relative humidity was 40%.

[0094] S6, Low Temperature and Low Humidity Wilting III:

[0095] The shaken product II is evenly spread on the withering equipment, with 1 kg of fresh leaves per square meter. After blowing for 20 minutes, it is left to stand for 1 hour until the tea leaves lose 28% of their weight, thus obtaining withered product III. The withering temperature is 10℃ and the relative humidity is 40%.

[0096] S7, Sunlight withering:

[0097] The withered product III was subjected to sun withering for 20 minutes, and was turned over every 10 minutes to obtain withered leaves;

[0098] S8, Natural stacking:

[0099] The withered leaves are piled up for 20 minutes to obtain piled leaves;

[0100] S9, Low-temperature and low-humidity variable-speed kneading:

[0101] The stacked leaves were rolled in a variable-speed rolling machine; the first rolling was performed under air pressure for 20 minutes at 20 rpm; the second rolling was performed under light pressure for 20 minutes at 25 rpm; the third rolling was performed under medium pressure for 20 minutes at 30 rpm; the fourth rolling was performed under medium pressure for 10 minutes at 35 rpm; the fifth rolling was performed under air pressure for 10 minutes at 35 rpm; and the sixth rolling was performed under heavy pressure for 10 minutes at 40 rpm, resulting in rolled leaves; the rolling temperature was 10℃ and the relative humidity was 60% to obtain rolled leaves; the rolled leaves had a curling rate of over 90% and a leaf cell breakage rate of over 80%.

[0102] S10, Light Fermentation:

[0103] The kneaded leaves are evenly spread in a bamboo fermentation tray, with a thickness of 4 cm. During the fermentation process, when the temperature of the core of the fermentation leaf pile reaches 30°C, the fermentation leaves are turned over. Fermentation lasts for 3.5 hours to obtain fermented leaves. The fermentation temperature is 24°C, the relative humidity is 90%, and the oxygen concentration is 21%.

[0104] S11, Microwave Low-Temperature Burning:

[0105] The fermented leaves were spread out to a thickness of 1 cm and then treated in a microwave oven at 800W for 2 minutes to obtain the initial roasted leaves. The temperature of the tea leaves at the microwave outlet was 80℃, and the moisture content of the tea leaves was 10%.

[0106] S12, High Temperature and Thorough Cooking:

[0107] The raw tea leaves are spread out to a thickness of 1 cm and then subjected to full-fire treatment at 110°C until the moisture content of the tea leaves is 7%, thus obtaining fully-fired tea leaves.

[0108] S13, Static Fragrance Enhancement:

[0109] The fully roasted tea leaves are left to stand for 10 days. After removing the stems and leaves, they are placed in an electric tea roasting cage and spread out to a thickness of 5 cm. The leaves are then roasted at 50°C for 24 hours until the moisture content of the tea leaves is less than 5%, thus obtaining the finished tea product.

[0110] Example 2

[0111] A method for processing Sichuan Gongfu black tea includes the following steps:

[0112] S1. Fresh leaf picking:

[0113] Fresh leaves of the Golden Guanyin tea variety are picked on sunny days in spring and autumn, between 11:00 and 15:00.

[0114] S2, Low-temperature and low-humidity wilting I:

[0115] The freshly picked leaves are evenly spread on the withering equipment, with 1 kg of fresh leaves per square meter. After blowing air for 20 minutes, the leaves are left to stand for 1 hour until the weight of the tea leaves decreases by 4%, thus obtaining withering product I. The withering temperature is 13℃ and the humidity is 46%.

[0116] S3, Low Temperature and Low Humidity Shaking withering I:

[0117] The withered product I was placed in a shaking machine, the shaking machine frequency was set to 15 times / min, and the shaking was carried out for 4 minutes to obtain the shaken product I; the shaking temperature was 13℃ and the relative humidity was 46%;

[0118] S4, Low Temperature and Low Humidity Wilting II:

[0119] The shaken product I is evenly spread on the withering equipment, with 1 kg of fresh leaves per square meter. After blowing for 20 minutes, it is left to stand for 1 hour until the tea leaves lose 13% of their weight, thus obtaining withered product II. The withering temperature is 13℃ and the relative humidity is 46%.

[0120] S5, Low Temperature and Low Humidity Shaking II:

[0121] The withered product II was placed in a shaking machine with a shaking frequency of 30 times / min. The shaking was stopped after 6 minutes to obtain the shaken product II. The shaking temperature was 13℃ and the relative humidity was 46%.

[0122] S6, Low Temperature and Low Humidity Wilting III:

[0123] The shaken product II is evenly spread on the withering equipment, with 1 kg of fresh leaves per square meter. After blowing for 20 minutes, it is left to stand for 1 hour until the tea leaves lose 30% of their weight, thus obtaining the withered product III. The shaking temperature is 13℃ and the relative humidity is 46%.

[0124] S7, Sunlight withering:

[0125] The withered product III was subjected to sun withering for 20 minutes, and was turned over every 10 minutes to obtain withered leaves;

[0126] S8, Natural stacking:

[0127] The withered leaves are piled up for 20 minutes to obtain piled leaves;

[0128] S9, Low-temperature and low-humidity variable-speed kneading:

[0129] The stacked leaves are rolled in a variable speed rolling machine; the first rolling is performed under air pressure for 20 minutes at 20 rpm; the second rolling is performed under light pressure for 20 minutes at 25 rpm; the third rolling is performed under medium pressure for 20 minutes at 30 rpm; the fourth rolling is performed under medium pressure for 10 minutes at 35 rpm; the fifth rolling is performed under air pressure for 10 minutes at 35 rpm; and the sixth rolling is performed under heavy pressure for 10 minutes at 40 rpm, to obtain rolled leaves; the rolling temperature is 10℃-20℃ and the relative humidity is 60%-70% to obtain rolled leaves; the rolled leaves have a curling rate of over 90% and a leaf cell breakage rate of over 80%.

[0130] S10, Light Fermentation:

[0131] The kneaded leaves were evenly spread in a bamboo fermentation tray, with a thickness of 5 cm. During fermentation, when the temperature at the center of the leaf pile reached 30°C, the leaves were turned over. Fermentation lasted for 4.0 hours to obtain fermented leaves. The fermentation temperature was 25°C, the relative humidity was 93%, and the oxygen concentration was 22%.

[0132] S11, Microwave Low-Temperature Burning:

[0133] The fermented leaves were spread out to a thickness of 2 cm and treated in a microwave oven at 800W for 4 minutes to obtain the initial roasted leaves. The temperature of the tea leaves at the microwave outlet was 87℃, and the moisture content of the tea leaves was 16%.

[0134] S12, High Temperature and Thorough Cooking:

[0135] The raw tea leaves are spread out to a thickness of 1 cm and then subjected to full-fire treatment at 114°C until the moisture content of the tea leaves is 8%, thus obtaining fully-fired tea leaves.

[0136] S13, Static Fragrance Enhancement:

[0137] The fully roasted tea leaves are left to stand for 13 days. After removing the stems and leaves, they are placed in an electric tea roasting cage and spread out to a thickness of 7 cm. The tea is then roasted at a temperature of 66°C for 30 hours until the moisture content of the tea leaves is less than 5%, thus obtaining the finished tea product.

[0138] Example 3

[0139] A method for processing Sichuan Gongfu black tea includes the following steps:

[0140] S1. Fresh leaf picking:

[0141] Fresh leaves of the Jin Xuan tea variety are picked on sunny days in spring and autumn, between 3:00 PM and 4:00 PM.

[0142] S2, Low-temperature and low-humidity wilting I:

[0143] The freshly picked leaves are evenly spread on the withering equipment, with 1 kg of fresh leaves per square meter. The leaves are blown for 20 minutes and left to stand for 1 hour until the weight of the tea leaves decreases by 5%, thus obtaining withered product I. The withering temperature is 16℃ and the humidity is 50%.

[0144] S3, Low Temperature and Low Humidity Shaking withering I:

[0145] The withered product I was placed in a shaking machine, the shaking machine frequency was set to 15 times / min, and the shaking was carried out for 5 minutes to obtain the shaken product I; the shaking temperature was 16℃ and the relative humidity was 50%;

[0146] S4, Low Temperature and Low Humidity Wilting II:

[0147] The shaken product I is evenly spread on the withering equipment, with 1 kg of fresh leaves per square meter. After blowing for 20 minutes, it is left to stand for 1 hour until the tea leaves lose 15% of their weight, thus obtaining withered product II. The withering temperature is 16℃ and the relative humidity is 50%.

[0148] S5, Low Temperature and Low Humidity Shaking II:

[0149] The withered product II was placed in a shaking machine with a shaking frequency of 30 times / min. The shaking was stopped after 6 minutes to obtain the shaken product II. The shaking temperature was 16℃ and the relative humidity was 50%.

[0150] S6, Low Temperature and Low Humidity Wilting III:

[0151] The shaken tea product II is evenly spread on the withering equipment, with 1 kg of fresh leaves per square meter. After blowing air for 20 minutes, it is left to stand for 1 hour until the tea leaves lose 32% of their weight, thus obtaining withered tea product III. The withering temperature is 16℃ and the relative humidity is 50%.

[0152] S7, Sunlight withering:

[0153] The withered product III was subjected to sun withering for 20 minutes, and was turned over every 10 minutes to obtain withered leaves;

[0154] S8, Natural stacking:

[0155] The withered leaves are piled up for 20 minutes to obtain piled leaves;

[0156] S9, Low-temperature and low-humidity variable-speed kneading:

[0157] The stacked leaves were rolled in a variable-speed rolling machine; the first rolling was performed under air pressure for 20 minutes at 20 rpm; the second rolling was performed under light pressure for 20 minutes at 25 rpm; the third rolling was performed under medium pressure for 20 minutes at 30 rpm; the fourth rolling was performed under medium pressure for 10 minutes at 35 rpm; the fifth rolling was performed under air pressure for 10 minutes at 35 rpm; and the sixth rolling was performed under heavy pressure for 10 minutes at 40 rpm, to obtain rolled leaves; the rolling temperature was 20℃ and the relative humidity was 70% to obtain rolled leaves; the rolled leaves had a curling rate of over 90% and a leaf cell breakage rate of over 80%.

[0158] S10, Light Fermentation:

[0159] The kneaded leaves were evenly spread in a bamboo fermentation tray, with a thickness of 6 cm. During fermentation, when the temperature at the center of the leaf pile reached 30°C, the leaves were turned over. Fermentation lasted 4.5 hours to obtain fermented leaves. The fermentation temperature was 26°C, the relative humidity was 95%, and the oxygen concentration was 23%.

[0160] S11, Microwave Low-Temperature Burning:

[0161] The fermented leaves are spread out to a thickness of 1-2 cm and treated in a microwave oven at 800W for 5 minutes to obtain the initial roasted leaves. The temperature of the tea leaves at the microwave outlet is 90℃, and the moisture content of the tea leaves is 20%.

[0162] S12, High Temperature and Thorough Cooking:

[0163] The raw tea leaves are spread out to a thickness of 2cm and then subjected to full-fire treatment at 115℃ until the moisture content of the tea leaves is 9%, thus obtaining fully-fired tea leaves.

[0164] S13, Static Fragrance Enhancement:

[0165] The fully roasted tea leaves are left to stand for 15 days. After removing the stems and leaves, they are placed in an electric tea roasting cage and spread out to a thickness of 8 cm. The tea is then roasted at 70°C for 36 hours until the moisture content of the tea leaves is less than 5%, thus obtaining the finished tea product.

[0166] Comparative Example 1

[0167] Comparing Comparative Example 1 and Example 1, the difference between Comparative Example 1 and Example 1 is that the fresh leaves of the Jin Guan Yin tea tree variety were picked on a sunny summer day from 11:00 to 15:00.

[0168] Comparative Example 2

[0169] Comparing Comparative Example 2 with Example 1, the difference between Comparative Example 2 and Example 1 is that the withering and shaking temperature is 25°C.

[0170] Comparative Example 3

[0171] Comparing Comparative Example 3 with Example 1, the difference between Comparative Example 2 and Example 1 is that the relative humidity during withering and shaking was 60%.

[0172] Comparative Example 4

[0173] Comparing Comparative Example 4 with Example 1, the difference between Comparative Example 2 and Example 1 is that the kneading method adopts the traditional light-heavy-light pressure method.

[0174] Comparative Example 5

[0175] Comparing Comparative Example 5 with Example 1, the difference between Comparative Example 2 and Example 1 is that the fermentation time is 5.5 h.

[0176] Comparative Example 6

[0177] Comparing Comparative Example 6 with Example 1, the difference between Comparative Example 2 and Example 1 is that the microwave intensity of the initial firing is 850W and the tea outlet temperature is 100℃.

[0178] Comparative Example 7

[0179] Comparing Comparative Example 7 with Example 1, the difference between Comparative Example 2 and Example 1 is that the foot firing temperature is 90°C.

[0180] Comparative Example 8

[0181] Comparing Comparative Example 8 with Example 1, the difference between Comparative Example 2 and Example 1 is that the fully roasted tea leaves were statically enhanced without being left to stand.

[0182] Related experiments:

[0183] A five-person evaluation panel composed of senior tea tasters conducted a coded evaluation of the black teas prepared in Examples 1-3 and Comparative Examples 1-8, referring to the tea evaluation method in GB / T23776—2018. The results are shown in Table 1.

[0184] Table 1 Sensory Evaluation Form

[0185]

[0186] As can be seen from the table above, the sensory evaluation results show that the products processed by the process of the present invention in Examples 1-3 are better than the comparative examples in terms of appearance, soup color, aroma and taste.

[0187] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0188] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for processing Sichuan Gongfu black tea, characterized in that, Includes the following steps: S1. Fresh leaf picking; the fresh leaves are those of high-aroma oolong tea tree varieties. S2, Low-temperature and low-humidity wilting I: Spread the fresh leaves evenly on the withering equipment, with 1 kg of fresh leaves per square meter. Blow air for 20 minutes and let stand for 1 hour until the tea leaves lose 3%-5% of their weight to obtain withered product I. The withering temperature is 10℃-16℃ and the humidity is 40%-50%. S3, Low Temperature and Low Humidity Shaking withering I: Place withered product I into a shaking machine. Set the shaking machine frequency to 15 times / min and shake for 4-5 minutes to obtain shaken product I. The shaking temperature is 10℃-16℃ and the relative humidity is 40%-50%. S4, Low Temperature and Low Humidity Wilting II: Spread the shaken leaves I evenly on the withering equipment, with 1 kg of fresh leaves per square meter. Blow air for 20 minutes and let stand for 1 hour until the tea leaves lose 12%-15% of their weight to obtain withered leaves II. The withering temperature is 10℃-16℃ and the relative humidity is 40%-50%. S5, Low Temperature and Low Humidity Shaking II: Place withered product II into a shaking machine. Set the shaking machine frequency to 30 times / min and stop shaking for 5-6 minutes to obtain shaken product II. The shaking temperature is 10℃-16℃ and the relative humidity is 40%-50%. S6, Low Temperature and Low Humidity Wilting III: The shaken product II is evenly spread on the withering equipment, with 1 kg of fresh leaves per square meter. It is blown for 20 minutes and left to stand for 1 hour until the tea leaves lose 28%-32% of their weight, thus obtaining withered product III. The withering temperature is 10℃-16℃ and the relative humidity is 40%-50%. S7, Sunlight withering: The withered product III was subjected to sun withering for 20 minutes, and was turned over every 10 minutes to obtain withered leaves; S8, Natural stacking: The withered leaves are piled up for 20 minutes to obtain piled leaves; S9, Low-temperature and low-humidity variable-speed kneading: The stacked leaves are kneaded in a variable speed kneading machine to obtain kneaded leaves; S10, Light Fermentation: Spread the kneaded leaves evenly in a bamboo fermentation tray, with a thickness of 4-6 cm. During the fermentation process, when the temperature of the core of the fermentation leaf pile reaches 30℃, turn the fermentation leaves over. Ferment for 3.5-4.5 hours to obtain fermented leaves. S11, Microwave Low-Temperature Burning: Spread the fermented leaves out to a thickness of 1-2 cm, and microwave them for initial heating to obtain initial heated leaves; S12, high-temperature final heating: Spread the raw tea leaves out to a thickness of 1-2cm, and then fire them at a high temperature until the moisture content of the tea leaves is 7%-9%, thus obtaining fully fired tea. S13, Static Fragrance Enhancement: Place the fully roasted tea leaves into an electric tea roasting cage, spreading them out to a thickness of 5-8cm. Roast them at a temperature of 50℃-70℃ for 24-36 hours, until the moisture content of the tea leaves is below 5%, thus obtaining the finished tea product.

2. The processing method for Sichuan Gongfu black tea according to claim 1, characterized in that, The kneading process includes the following steps: The first kneading process involved air-pressure kneading for 20 minutes at 20 rpm; the second kneading involved light-pressure kneading for 20 minutes at 25 rpm; the third kneading involved medium-pressure kneading for 20 minutes at 30 rpm; the fourth kneading involved medium-pressure kneading for 10 minutes at 35 rpm; the fifth kneading involved air-pressure kneading for 10 minutes at 35 rpm; and the sixth kneading involved heavy-pressure kneading for 10 minutes at 40 rpm, yielding the kneaded leaves. The kneading temperature was 10℃-20℃, and the relative humidity was 60%-70%.

3. The processing method for Sichuan Gongfu black tea according to claim 2, characterized in that, The rate of the twisted leaves curling into strips is higher than 90%, and the rate of leaf cell breakage is higher than 80%.

4. The processing method for Sichuan Gongfu black tea according to claim 1, characterized in that, The fermentation temperature is 24℃-26℃, the relative humidity is 90%-95%, and the oxygen concentration is 21-23%.

5. A method for processing Sichuan Gongfu black tea according to claim 1, characterized in that, The initial firing process involves microwave treatment at 800W for 2-5 minutes, with the tea leaves exiting the microwave at a temperature of 80℃-90℃ and a moisture content of 10%-20%.

6. The processing method for Sichuan Gongfu black tea according to claim 1, characterized in that, The high-temperature drying machine is set to 110℃-115℃. When the temperature reaches the set temperature, the burrs are placed in the machine, and the dryer door is not closed tightly.

7. The processing method for Sichuan Gongfu black tea according to claim 1, characterized in that, Before static aroma enhancement, the fully roasted tea leaves are left to stand for 10-15 days to remove stems and leaves.

8. A method for processing Sichuan Gongfu black tea according to claim 1, characterized in that, The fresh leaves are to be picked on sunny days in spring and autumn, from 09:00 to 16:

00.

9. A method for processing Sichuan Gongfu black tea according to claim 8, characterized in that, The best time to pick them is between 11:00 and 15:00 on a sunny day.

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