Green tea processing technology

Abstract

The invention discloses a processing technology of green tea. The processing technology comprises the following steps: step 1, spreading fresh leaves for cooling; step 2, steam roller fixation; step 3, cooling; step 4, moisture regaining; step 5, rolling; step 6, drying; and step 7, cooling and bagging. The advantages of steam fixation and roller fixation are combined, the finished green tea is green in color and soup and high in fragrance, and the yield is increased by one third.

Description

Technical Field

[0001] The invention belongs to the field of tea processing, and in particular relates to a green tea processing technology. Background Art

[0002] Green tea is the tea with the largest production and consumption in my country. It is also the tea with the most tea polyphenols, and has the quality characteristics of clear soup and green leaves. In the process of green tea processing, killing green is a very critical step, and its success or failure directly affects the quality of the finished green tea. At present, the killing of green tea generally adopts two methods: steam killing and drum killing. The tea leaves killed by steam are green in color and soup, but the aroma is weak and not strong; the tea leaves killed by drums have a strong aroma, but the color is green and yellow, and if it is not well controlled, the tea leaves are prone to burnt smell. There is no process that combines the advantages of the two to achieve a better killing effect, so that the tea leaves can maintain the quality characteristics of clear soup and green leaves, and have a strong aroma. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a green tea processing technology that combines the advantages of steam and drum green tea, and the finished green tea has green color and green soup, strong aroma, and the output is increased by one third.

[0004] The technical solution adopted by the present invention is: a green tea processing technology, comprising the following steps:

[0005] Step 1: Cool the fresh leaves: Cool the picked and selected fresh leaves to remove excess water from the leaves until the water content is 70%-80%;

[0006] Step 2, steam drum fixing: placing the fresh leaves after cooling in step 1 in a steam drum fixing machine, and performing steam fixing and drum fixing on the fresh leaves to obtain fixed leaves;

[0007] Step 3, cooling: cooling the withered leaves obtained in step 2 to room temperature;

[0008] Step 4: Rehumidification: Spread the cooled and fixed leaves in step 3 to rehumidify, with a thickness of 50 cm and a drying time of 60 minutes;

[0009] Step 5, rolling: rolling the withered leaves that have been moistened in step 4 to obtain rolled leaves;

[0010] Step 6: Drying: Drying the rolled leaves obtained in step 5 to obtain finished green tea;

[0011] Step 7: Cooling and bagging: bag the dried finished green tea.

[0012] In one of the embodiments, the drum killing machine includes two frames and a drum arranged between the two frames, and both ends of the drum are respectively provided with a feed port and a discharge port connected to the interior of the drum, and one end of the drum provided with the feed port is provided with a steam inlet connected to the interior of the drum, and several natural gas burners are provided at the bottom of the drum.

[0013] In one embodiment, the drum is 7 meters long and is internally divided into a first drum section, a second drum section, a third drum section, a fourth drum section and a fifth drum section. The first drum section is 1 meter long, the second drum section is 1.5 meters long, the third drum section is 1.5 meters long, the fourth drum section is 1.5 meters long, and the fifth drum section is 1.5 meters long. The first drum section is used for simultaneous steam killing and drum killing, and the second drum section, the third drum section, the fourth drum section and the fifth drum section are used for drum killing.

[0014] In one embodiment, in step 2, the steam-dried and drum-dried fresh leaves are sequentially performed as follows:

[0015] The fresh leaves are fed into the steam drum greening machine through the entrance, and steam greening and first-stage greening are carried out simultaneously in the first drum section, the steam greening temperature is 530℃-550℃, and the steam greening time is 35 seconds-45 seconds;

[0016] The fresh leaves which have been steam-killed and drum-killed in the first drum section are subjected to two-stage drum-killing, three-stage drum-killing, four-stage drum-killing and five-stage drum-killing in the second drum section, the third drum section, the fourth drum section and the fifth drum section respectively.

[0017] In one of the embodiments, during the one-stage drum killing, the two-stage drum killing, the three-stage drum killing, the four-stage drum killing and the five-stage drum killing, the drum speed is 42 rpm, the killing temperature is 100°C-320°C, and the killing time is 4 minutes 15 seconds-4 minutes 30 seconds.

[0018] In one embodiment, the temperature of the first stage of the drum is 200°C;

[0019] The second-stage drum fixing temperature is 320°C;

[0020] The three-stage drum fixing temperature is 300°C;

[0021] The four-stage drum fixing temperature is 180°C;

[0022] The five-stage drum killing temperature is 100°C.

[0023] In one embodiment, in step 5, the kneading is specifically as follows:

[0024] Use a tea rolling machine to roll the withered leaves for 90 minutes. During the rolling process, no pressure is applied for the first 20 minutes, the speed of the tea rolling machine is 28 rpm, 100 mm pressure is applied from 20 minutes to 50 minutes, the speed of the rolling machine is 40 rpm, 200 mm pressure is applied from 50 minutes to 75 minutes, the speed of the tea rolling machine is 35 rpm, the pressure is reduced to no pressure from 75 minutes to 90 minutes, and the speed of the tea rolling machine is 30 rpm.

[0025] In one embodiment, in step six, the rolling and twisting of the fresh leaves is dried as follows:

[0026] The rolled tea leaves are initially baked at a temperature of 125°C to 135°C, with a leaf thickness of 2 cm and a baking time of 8 to 10 minutes until the water content is 20% to 25%;

[0027] The tea leaves are re-dried after the initial drying, the re-drying temperature is 90℃-100℃, the thickness of the leaves is 3.5cm-4cm, and the re-drying time is 12 minutes to 15 minutes, so that the tea leaves are fully dried and the moisture content is 6.5%-8%;

[0028] The fresh leaves after repeated drying are subjected to full fire to enhance the aroma, the temperature is 70℃-80℃, the aroma enhancement time is 15 minutes-20 minutes, until the tea aroma has a slight chestnut aroma and the water content is 6%.

[0029] The beneficial effects of the present invention are: combining the advantages of steam-curing and drum-curing, the finished green tea has green color and green soup, high aroma, and the output is increased by one third; the steam equipment is directly connected to the continuous drum-curing machine, and the fresh leaves are cured with 550°C steam when entering the continuous drum-curing, followed by curing with a drum temperature of 320°C, and the curing time is 4 to 5 minutes. The high-temperature steam in the new curing method can quickly and effectively passivate the activity of the enzyme. Since the steam-curing is completed in the drum, the leaf surface temperature will not drop rapidly. At this time, the color of the steam-cured leaves can be maintained by using a 320°C drum-curing, and the unique fragrance of the drum-cured leaves will not be produced; the new curing process retains the advantages of steam-curing and drum-curing at the same time (green color, bright yellow-green soup color, high aroma and no scorched leaves), the desktop output is increased by one third, the quality and output of tea leaves are improved, and the water content in the cured leaves is retained, which is convenient for the next step of rolling. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of the drum fixing machine of the present invention.

[0031] In the figure: 1. Feed inlet; 2. Steam inlet; 3. Drum; 4. Natural gas burner; 5. Discharge outlet; 6. Frame. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] As shown in the figure, the present invention discloses a green tea processing technology, comprising the following steps:

[0034] Step 1: Cool the fresh leaves: Cool the picked and selected fresh leaves to remove excess water from the leaves until the water content is 70%-80%;

[0035] Step 2, steam drum fixing: placing the fresh leaves after cooling in step 1 in a steam drum fixing machine, and performing steam fixing and drum fixing on the fresh leaves to obtain fixed leaves;

[0036] Step 3, cooling: cooling the withered leaves obtained in step 2 to room temperature;

[0037] Step 4: Rehumidification: Spread the cooled and fixed leaves in step 3 to rehumidify, with a thickness of 50 cm and a drying time of 60 minutes;

[0038] Step 5, rolling: rolling the withered leaves that have been moistened in step 4 to obtain rolled leaves;

[0039] Step 6: Drying: Drying the rolled leaves obtained in step 5 to obtain finished green tea;

[0040] Step 7: Cooling and bagging: bag the dried finished green tea.

[0041] In this embodiment, the drum fixing machine includes two frames 6 and a drum 3 arranged between the two frames 6, and the two ends of the drum 3 are respectively provided with a feed port 1 and a discharge port 5 connected to the interior thereof. The end of the drum 3 provided with the feed port 1 is provided with a steam inlet 2 connected to the interior of the drum, and several natural gas burners 4 are provided at the bottom of the drum 3.

[0042] In this embodiment, the drum 3 is 7 meters long, and the interior of the drum 3 is divided into a first drum section, a second drum section, a third drum section, a fourth drum section and a fifth drum section. The length of the first drum section is 1 meter, the length of the second drum section is 1.5 meters, the length of the third drum section is 1.5 meters, the length of the fourth drum section is 1.5 meters, and the length of the fifth drum section is 1.5 meters. The first drum section is used for simultaneous steam killing and drum killing, and the second drum section, the third drum section, the fourth drum section and the fifth drum section are used for drum killing.

[0043] In this embodiment, in step 2, the steam-curing and drum-curing of the fresh leaves are carried out in sequence as follows:

[0044] The fresh leaves are fed into the steam drum greening machine through the entrance, and steam greening and first-stage greening are carried out simultaneously in the first drum section, the steam greening temperature is 530℃-550℃, and the steam greening time is 35 seconds-45 seconds;

[0045] The fresh leaves which have been steam-killed and drum-killed in the first drum section are subjected to two-stage drum-killing, three-stage drum-killing, four-stage drum-killing and five-stage drum-killing in the second drum section, the third drum section, the fourth drum section and the fifth drum section respectively.

[0046] In this embodiment, during the one-stage drum killing, two-stage drum killing, three-stage drum killing, four-stage drum killing and five-stage drum killing, the drum speed is 42 rpm, the killing temperature is 100°C-320°C, and the killing time is 4 minutes 15 seconds-4 minutes 30 seconds.

[0047] In this embodiment, the temperature of the first stage of the drum is 200°C;

[0048] The second-stage drum fixing temperature is 320°C;

[0049] The three-stage drum fixing temperature is 300°C;

[0050] The four-stage drum fixing temperature is 180°C;

[0051] The five-stage drum killing temperature is 100°C.

[0052] In this embodiment, in step 5, the kneading is specifically as follows:

[0053] Use a tea rolling machine to roll the withered leaves for 90 minutes. During the rolling process, no pressure is applied for the first 20 minutes, the speed of the tea rolling machine is 28 rpm, 100 mm pressure is applied from 20 minutes to 50 minutes, the speed of the rolling machine is 40 rpm, 200 mm pressure is applied from 50 minutes to 75 minutes, the speed of the tea rolling machine is 35 rpm, the pressure is reduced to no pressure from 75 minutes to 90 minutes, and the speed of the tea rolling machine is 30 rpm.

[0054] In this embodiment, in step six, the rolling and twisting of the fresh leaves is dried as follows:

[0055] The rolled tea leaves are initially baked at a temperature of 125°C to 135°C, with a leaf thickness of 2 cm and a baking time of 8 to 10 minutes until the water content is 20% to 25%;

[0056] The tea leaves are re-dried after the initial drying, the re-drying temperature is 90℃-100℃, the thickness of the leaves is 3.5cm-4cm, and the re-drying time is 12 minutes to 15 minutes, so that the tea leaves are fully dried and the moisture content is 6.5%-8%;

[0057] The fresh leaves after repeated drying are subjected to full fire to enhance the aroma, the temperature is 70℃-80℃, the aroma enhancement time is 15 minutes-20 minutes, until the tea aroma has a slight chestnut aroma and the water content is 6%.

[0058] In the present invention, when the fresh leaves are spread out to cool, excess water in the fresh leaves is removed until the water content is 74% which is the best. When steaming, the best time for killing is 40 seconds. When drum killing, the best time for killing is 4 minutes and 20 seconds. The best temperature for initial drying is 130°C.

[0059] The purpose of cooling fresh leaves in this application is to dissipate part of the moisture in the fresh leaves, so as to facilitate the killing of green leaves. The steam drum killing machine directly connects the steam equipment to the continuous drum killing machine. When the fresh leaves enter the continuous drum killing machine, they are killed with steam at 530℃-550℃, followed by killing with a drum temperature of 320℃-100℃. The killing time is 4 minutes and 15 seconds to 4 minutes and 30 seconds. In this new withering method, high-temperature steam withering can quickly and timely inactivate the activity of enzymes. Since steam withering is completed in a drum, the leaf surface temperature will not drop rapidly. Low-temperature drum withering at 320℃-100℃ can maintain the color of the withered leaves, will not produce burnt leaves, and retains the unique fragrance of drum withering. The new withering process simultaneously maintains the advantages of steam withering and drum withering (green color, bright green-yellow soup color, strong aroma and no burnt leaves), and the desktop output is increased by one third, which improves the quality and output of tea, and retains the water content in the withered leaves, which is convenient for rolling. The withered leaves have a higher leaf surface temperature and are cooled in time to avoid yellowing and maintain the color of the tea. After withering, the water content on the leaf surface is uneven, and rehydration promotes the redistribution of water to avoid breaking due to rolling; rolling can break the cell walls, increase the flavor concentration of the tea, and roll the tea leaves into strips for easy brewing; drying can evaporate the water in the tea leaves, organize the shape, give full play to the tea aroma, and evaporate excess water for easy transportation and storage; drying is generally divided into three steps: initial baking, 125℃-135℃, to quickly dissipate water; re-baking, 90℃-100℃, to make the tea leaves dry enough; full fire to enhance the aroma: 70℃-80℃, to bring out the aroma of the tea leaves.

[0060] The above-mentioned embodiments only express the specific implementation of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A green tea processing process, characterized in that: The steps include: Step 1: Cool the fresh leaves: Cool the picked and selected fresh leaves to remove excess water from the leaves until the water content is 70%-80%; Step 2, steam drum fixing: placing the fresh leaves after cooling in step 1 in a steam drum fixing machine, and performing steam fixing and drum fixing on the fresh leaves to obtain fixed leaves; Step 3, cooling: cooling the withered leaves obtained in step 2 to room temperature; Step 4: Rehumidification: Spread the cooled and fixed leaves in step 3 to rehumidify, with a thickness of 50 cm and a drying time of 60 minutes; Step 5, rolling: rolling the withered leaves that have been moistened in step 4 to obtain rolled leaves; Step 6: Drying: Drying the rolled leaves obtained in step 5 to obtain finished green tea; Step 7: Cooling and bagging: bag the dried finished green tea.

2. A green tea processing technology according to claim 1, characterized in that: The drum fixing machine includes two frames and a drum arranged between the two frames. Both ends of the drum are respectively provided with a feed port and a discharge port connected to the interior thereof. One end of the drum provided with the feed port is provided with a steam inlet connected to the interior of the drum. Several natural gas burners are provided at the bottom of the drum.

3. A green tea processing technology according to claim 2, characterized in that: The drum is 7 meters long, and the interior of the drum is divided into the first drum section, the second drum section, the third drum section, the fourth drum section and the fifth drum section. The first drum section is 1 meter long, the second drum section is 1.5 meters long, the third drum section is 1.5 meters long, the fourth drum section is 1.5 meters long, and the fifth drum section is 1.5 meters long. The first drum section is used for steam killing and drum killing at the same time, and the second drum section, the third drum section, the fourth drum section and the fifth drum section are used for drum killing.

4. A green tea processing technology according to claim 3, characterized in that: In step 2, the steam-dried and drum-dried fresh leaves are sequentially performed as follows: The fresh leaves are fed into the steam drum greening machine through the entrance, and steam greening and first-stage greening are carried out simultaneously in the first drum section, the steam greening temperature is 530℃-550℃, and the steam greening time is 35 seconds-45 seconds; The fresh leaves which have been steam-killed and drum-killed in the first drum section are subjected to two-stage drum-killing, three-stage drum-killing, four-stage drum-killing and five-stage drum-killing in the second drum section, the third drum section, the fourth drum section and the fifth drum section respectively.

5. A green tea processing process according to claim 4, characterized in that: During the one-stage drum killing, the two-stage drum killing, the three-stage drum killing, the four-stage drum killing and the five-stage drum killing, the drum speed is 42 rpm, the killing temperature is 100° C.-320° C., and the killing time is 4 minutes 15 seconds-4 minutes 30 seconds.

6. A green tea processing process according to claim 5, characterized in that: The temperature of the first stage of the drum is 200°C; The second-stage drum fixing temperature is 320°C; The three-stage drum fixing temperature is 300°C; The four-stage drum fixing temperature is 180°C; The five-stage drum killing temperature is 100°C.

7. A green tea processing process according to claim 1, characterized in that: In step 5, the kneading is specifically as follows: Use a tea rolling machine to roll the withered leaves for 90 minutes. During the rolling process, no pressure is applied for the first 20 minutes, the speed of the tea rolling machine is 28 rpm, 100 mm pressure is applied from 20 minutes to 50 minutes, the speed of the rolling machine is 40 rpm, 200 mm pressure is applied from 50 minutes to 75 minutes, the speed of the tea rolling machine is 35 rpm, the pressure is reduced to no pressure from 75 minutes to 90 minutes, and the speed of the tea rolling machine is 30 rpm.

8. The green tea processing technology according to claim 1, characterized in that: In step six, the rolled fresh leaves are dried as follows: The rolled tea leaves are initially baked at a temperature of 125°C to 135°C, with a leaf thickness of 2 cm and a baking time of 8 to 10 minutes until the moisture content is 20% to 25%; The tea leaves are re-dried after the initial drying, the re-drying temperature is 90℃-100℃, the thickness of the leaves is 3.5cm-4cm, and the re-drying time is 12 minutes to 15 minutes, so that the tea leaves are fully dried and the moisture content is 6.5%-8%; The fresh leaves after repeated drying are subjected to full fire to enhance the aroma, the temperature is 70℃-80℃, the aroma enhancement time is 15 minutes-20 minutes, until the tea aroma has a slight chestnut aroma and the water content is 6%.

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