Cigar tobacco five-section type step air-curing method suitable for tropical monsoon climate

Abstract

The invention discloses a cigar tobacco leaf five-section stepped air-curing method suitable for tropical monsoon climate, which comprises the following steps of: dividing an air-curing period into five stages, namely a withering stage, a yellowing stage, a browning stage, a color fixing stage and a stem drying stage, and taking'temperature + humidity 'regulation and control management of each stage as a core; in the cigar tobacco leaf airing period, temperature and humidity values of airing racks with different heights from bottom to top in an airing room are monitored in real time according to the actual condition of the airing room, and the different temperature and humidity values from bottom to top are compared with temperature and humidity data of cigar tobacco leaves in different airing stages to serve as the basis of stepped rising of tobacco stems in different airing stages. Adjusting the tobacco stems in the transition period of each stage to the layer height of suitable temperature and humidity of a tobacco air-curing rack until the tobacco leaves reach the top of the air-curing rack and tobacco ribs are completely dried, naturally regaining moisture until the tobacco leaves are soft and then taking the tobacco leaves out of the rack, and entering a tobacco leaf fermentation stage; according to the method, natural environment conditions are fully utilized, the airing cost of the cigar tobacco leaves is obviously reduced, and the internal component coordination and the appearance quality of the aired cigars are improved.

Description

Technical Field

[0001] The invention relates to a five-stage step-drying method for cigar tobacco leaves suitable for tropical monsoon climates, belonging to the technical field of cigar tobacco leaf drying. Background Art

[0002] Cigars are a special tobacco product made entirely of rolled tobacco leaves, and are widely popular among consumers for their special cigar-like aroma. The overall preparation methods of tobacco are generally divided into baking, sun-drying, and air-drying. Cigars and cigar tobacco leaves are generally air-dried tobacco, and their preparation methods are generally air-dried, that is, they are air-dried in a cool place after harvesting. The air-drying process is an important key link in the formation of cigar tobacco leaf quality, but the air-drying mechanism has not yet been clearly revealed. Most of the domestic cigar tobacco leaf preparation technologies rely on traditional experience and customary summaries. In some areas, tobacco leaf air-drying mainly depends on the weather, while in some areas, high costs of temperature and humidity control air-drying rooms and related facilities are required to ensure that the air-drying quality meets the standards, resulting in large economic losses in each production area every year due to a large proportion of "moldy tobacco" and "quickly dried tobacco".

[0003] The drying of cigar tobacco leaves is not just a simple drying process of fresh tobacco leaves, but a complex physiological and biochemical metabolic process. During this process, the tobacco leaves need to maintain different temperatures and humidity at different stages of the drying environment. The climate type of foreign high-quality cigar tobacco production areas mainly belongs to the tropical marine monsoon climate. Cigar tobacco leaves are planted in the dry season and the drying period is close to the rainy season. The temperature and humidity of the atmosphere provide better environmental conditions for the drying of cigar tobacco leaves. Hainan and some inland cigar tobacco producing areas in China have a tropical monsoon climate, with an average annual temperature above 22°C and an average temperature above 18°C ​​in the coldest month. The average monthly rainfall in spring, autumn and winter is below 100 mm, while the rainfall is heavier from June to September. The annual precipitation in most areas is 1500-2500 mm, and even more in some areas. Due to the small specific heat capacity of land and the large specific heat capacity of the ocean, the land warms up quickly in summer and the ocean warms up slowly, forming hot low pressure and cold high pressure, causing air flow from the ocean to blow to the land, forming a warm and humid summer monsoon; the opposite is true in winter, forming a cold and dry winter monsoon. These producing areas are more suitable for the production of cigar tobacco and naturally have better climate advantages for drying.

[0004] However, due to the lack of systematic research, the current mechanism of cigar tobacco drying is not fully understood. The phenomenon of cigar tobacco "growing well" but "drying poorly" often occurs. In order to solve the problem of "drying poorly", production areas with better conditions must build intelligent drying rooms, or invest a lot of money in drying room construction and temperature and humidity control facilities. Although it can effectively improve the quality of cigar tobacco drying, it also makes the current cigar tobacco production cost and facility investment huge, and the production area is burdened. In cigar tobacco producing areas with general or simple production conditions, the drying room does not have temperature and humidity control facilities. Under conventional drying conditions, the position of the tobacco rod does not change during the drying process after the cigar tobacco is loaded in the drying room, and it is basically completely "dependent on the weather". Although some labor costs are saved, every year the tobacco area will suffer great economic losses to tobacco farmers due to the large proportion of variegated tobacco, moldy tobacco, and quick-dried tobacco in the drying of cigar tobacco leaves. Therefore, in cigar tobacco producing areas with simple drying conditions, it is necessary to study and improve the existing drying methods without additional investment in drying and control facilities, in order to make full use of the climatic conditions during the drying of cigar tobacco leaves, and through scientific and simple adjustment methods, achieve the goal of improving the quality and efficiency of cigar tobacco drying, saving labor and reducing costs, so that the proportion of high-quality tobacco leaves dried by tobacco farmers in the producing areas can be increased and their income can be increased. Summary of the invention

[0005] Based on the above, the present invention provides a five-stage stepped drying method for cigar tobacco leaves suitable for tropical monsoon climate, which closely combines the drying states of tobacco leaves at different stages with the different natural vertical temperature differences and humidity differences in the drying room during the tropical monsoon climate drying period to overcome the shortcomings of the prior art.

[0006] The technical solution of the present invention is: a five-stage ladder drying method for cigar tobacco leaves suitable for tropical monsoon climate, comprising the following steps:

[0007] The air-conditioning period of tobacco leaves is divided into five stages: withering period, yellowing period, browning period, color fixing period and dry tendon period. The withering period is the air-conditioning period from when the fresh tobacco leaves turn yellow at the tip and edge of the leaves, the yellowing period is the air-conditioning period from when the withering period ends to when the tobacco leaves turn eight layers of yellow, and the tip and edge of the leaves turn brown, the browning period is the air-conditioning period from when the yellowing period ends to when the tobacco leaves turn eight layers of brown, and the tip and edge of the leaves become dry, the color fixing period is the air-conditioning period from when the browning period ends to when the tobacco leaves turn all brown, the leaves become dry, and the main veins turn green, and the dry tendon period is the air-conditioning period from when the color fixing period ends to when the tobacco tendons of the tobacco leaves are completely dry.

[0008] Detect the temperature and humidity values ​​of the drying racks of different heights from top to bottom in the drying room, and divide the drying racks into a first low temperature and high humidity area, a second low temperature and high humidity area, a medium temperature and medium humidity area, a first high temperature and low humidity area, and a second high temperature and low humidity area from bottom to top, wherein the temperature of the first low temperature and high humidity area is 25-30°C, and the humidity is 80±5%, the temperature of the second low temperature and high humidity area is 24-28°C, and the humidity is 85±5%, the temperature of the medium temperature and medium humidity area is 28-32°C, and the humidity is 70-80%, the temperature of the first high temperature and low humidity area is 32-35°C, and the humidity is 65-75%, and the temperature of the second high temperature and low humidity area is 35-40°C, and the humidity is 45-55%;

[0009] Hang the tobacco leaves in the withering stage in the first low temperature and high humidity area, hang the tobacco leaves in the yellowing stage in the second low temperature and high humidity area, hang the tobacco leaves in the browning stage in the medium temperature and medium humidity area, hang the tobacco leaves in the color fixing stage in the first high temperature and low humidity area, hang the tobacco leaves in the dry tendon stage in the second high temperature and low humidity area, and gradually move the tobacco leaves upwards according to the achievement of the goals of each air-drying stage until they are taken off the shelves after the dry tendon stage and become soft through natural rehumidification.

[0010] Preferably, the method specifically comprises the following steps:

[0011] S1 Withering period: Place the cigar tobacco leaves in the first low temperature and high humidity area (middle and lower layer) on the drying rack in the drying room for 2-3 days, until the leaves wither, the leaf tips and leaf edges turn yellow, and the overall change of the air-dried tobacco leaves is more than 80% up to standard; under natural drying conditions, the ventilation and dehumidification devices are generally turned on during the day and off at night, and the switching time is flexibly controlled according to the changes in temperature and humidity in the drying room;

[0012] S2 Yellowing Stage: Place the cigar tobacco leaves in the second low temperature and high humidity area (middle and lower layer) on the drying rack in the drying room for 5-7 days, until the leaves turn yellow in eight layers, the leaf tips and leaf edges turn brown, and the overall change of the dried tobacco leaves is more than 80% up to standard; under natural drying conditions, the general operation is to ventilate and convection for about 1 hour in the morning and evening, and the opening and closing time is flexibly controlled according to weather changes;

[0013] S3 Browning Stage: Place the cigar tobacco leaves in the drying room on the drying rack in the medium temperature and medium humidity area (middle position) for 6-8 days, until the leaves are eight layers brown, the leaf tips and leaf edges become dry, and the overall change of the dried tobacco leaves is more than 80% up to standard; under natural drying conditions, the general operation is to properly ventilate and dehumidify during the day and close it at night, and the opening and closing time is flexibly controlled according to weather changes;

[0014] S4 Color Fixation Period: Place the cigar tobacco leaves in the first high temperature and low humidity area (middle and upper position) on the drying rack in the drying room for 7-9 days, until the leaves are completely brown, dry, the main veins turn green, and the overall change of the air-dried tobacco leaves is more than 90% up to standard; under natural drying conditions, the ventilation and dehumidification device is generally half-open or slightly open during the day and closed at night, and the opening and closing time and degree are flexibly controlled according to weather changes;

[0015] S5 Drying period: Place the cigar tobacco leaves in the second high temperature and low humidity area (upper to top layer) on the drying rack in the drying room, or transfer them to a separate drying area for drying for 5-10 days, until the tobacco ribs of the leaves are completely dry and the overall change of the dried tobacco leaves is 100% up to standard; under natural drying conditions, the general operation is to fully open the ventilation and dehumidification device during the day and close it at night, and the switching time and degree are flexibly controlled according to weather changes.

[0016] The technical principle of the present invention is as follows: The tropical monsoon climate area presents the climate characteristics of "high temperature all year round, obvious dry and rainy seasons, and tobacco planting in the dry season". The applicant divides the drying period into five stages: withering period, yellowing period, browning period, color fixing period and dry tendon period according to the changes in the appearance, color, moisture, identity and other comprehensive states of cigar tobacco leaves. It is found that the temperature and humidity required for cigar tobacco leaves at each drying stage are highly integrated with the bottom-up temperature and humidity field generated by the tropical monsoon climate in the drying room. Therefore, the technical concept of "making full use of the vertical temperature and humidity difference from bottom to top in the drying room during the drying period of cigar tobacco leaves under the temperature and humidity of the natural environment of the tropical monsoon climate, and according to the appearance change characteristics of tobacco leaves at different drying stages, the cigar tobacco leaves that are mature, harvested and put on the shelves are gradually transferred from the bottom of the drying room to the top like climbing a ladder, until the tobacco leaves reach the dry tendon period and are taken off the shelves" is produced. Through the operation of this air-drying technology, the cigar tobacco leaf air-drying is generally divided into five air-drying stages, namely the withering stage, the yellowing stage, the browning stage, the color fixing stage and the dry tendon stage. The air-drying status of the tobacco leaves at different stages is closely combined with the different natural vertical temperature differences and humidity differences in the air-drying room during the tropical monsoon climate air-drying period, which provides the temperature and humidity guarantee under suitable natural conditions for the pigment degradation and stable carbon and nitrogen metabolism of cigar tobacco leaves at different stages, significantly reduces the air-drying cost of cigar tobacco leaves, and improves the internal composition coordination and appearance quality of the cigar tobacco after air-drying.

[0017] The beneficial effects of the present invention are as follows: the present invention divides the air-drying period into five stages: withering stage, yellowing stage, browning stage, color fixing stage and dry tendon stage according to the changes in the comprehensive states of cigar tobacco leaves such as appearance changes, color, moisture, and identity, and takes the "temperature + humidity" control management of each stage as the core. During the air-drying period of cigar tobacco leaves, the temperature and humidity values ​​of the air-drying racks at different heights from bottom to top in the air-drying room are monitored in real time according to the actual situation of the air-drying room, and the different temperature and humidity values ​​from bottom to top are compared with the temperature and humidity data of cigar tobacco leaves at different air-drying stages, which serve as the basis for the step-by-step increase of tobacco rods at different air-drying stages, and the tobacco rods in the transition period of each stage are adjusted to the layer height of the air-drying rack suitable for temperature and humidity, until the tobacco leaves reach the top of the air-drying rack and the tobacco tendons are completely dry, and then the tobacco leaves are naturally rehydrated until they are soft before being taken off the rack to enter the tobacco leaf fermentation stage.

[0018] The present invention carries out tobacco leaf airing based on the good natural temperature and humidity conditions during the tobacco leaf airing period in the tropical monsoon climate, wherein steps S1 and S2 generally place tobacco leaves in a relatively "low temperature and high humidity" area in the middle and lower layers of the airing room, ensuring that tobacco leaves lose water moderately, chlorophyll degrades and balanced material transformation in the "low temperature and high humidity" environment, promoting the tobacco leaves to turn yellow steadily and fully, and avoiding rapid water loss in a high temperature and low humidity environment to form "overall floating green" and "partial dead green" of tobacco leaves. Step S3 places tobacco leaves in the "medium temperature and medium humidity" area in the middle layer of the airing room, ensuring that tobacco leaves carry out carbon and nitrogen metabolism and material transformation more evenly in a milder temperature and humidity environment, and ensuring that tobacco leaves turn from yellow to brown steadily and evenly. Step S4 places tobacco leaves in the "high temperature and low humidity" area in the middle and upper layers of the airing room, further accelerating the browning of the leaf surface and the drying of the veins, and promoting the rapid color fixation of tobacco leaves. Step S5 places the tobacco leaves in a "high temperature and low humidity" area on the upper or top floor of the drying room, or transfers them to a separate tobacco "drying area" for rapid drying, aiming to quickly remove moisture from the tobacco leaves, especially the tobacco tendons, through a high temperature and low humidity environment, thereby avoiding mildew caused by a long tobacco tendon drying period and changes in environmental temperature and humidity.

[0019] Compared with the prior art, the advantages of the present invention are:

[0020] 1. This cigar tobacco leaf drying method organically combines the drying state of cigar tobacco leaves at each stage, the temperature and humidity conditions required for drying, and the temperature and humidity conditions at different vertical heights in the tobacco leaf drying room during the tropical monsoon climate drying period. It is a perfect fusion of cigar tobacco leaf drying technology, science and natural environment.

[0021] 2. This cigar tobacco leaf drying method fully utilizes the natural drying conditions in tropical monsoon climate areas. The entire cigar tobacco leaf drying process can be completed only by adjusting the tobacco leaf rods in a step-by-step manner and properly switching the ventilation and dehumidification devices. This method not only makes the most of the natural environment, but also facilitates practical operations, making the cigar tobacco leaf drying process in tropical monsoon climate areas more scientific, economical and reasonable.

[0022] 3. The method of the present invention uses five stages of air-drying, and formulates clear adjustment standards and operation details for the air-drying changes of tobacco leaves in each stage. The color of the air-dried tobacco leaves obtained is more uniform, which can significantly improve the uniformity of cigar tobacco leaves in air-drying, and effectively reduce the loss of dead green tobacco leaves, floating green tobacco leaves, and other colored tobacco leaves and moldy tobacco leaves.

[0023] In summary, the present invention is suitable for the five-stage stepped drying method of cigar tobacco leaves in tropical monsoon climates. The key technology is to measure and determine the temperature and humidity conditions of drying racks of different heights according to the actual situation of the drying room, clearly judge the drying status of cigar tobacco leaves in five stages, and step-by-step adjust the temperature and humidity to a drying layer with suitable temperature and humidity during the transition stage of different stages. This method makes better use of natural environmental conditions than the prior art, avoids the instability of tobacco leaf drying quality caused by drastic artificial regulation of temperature and humidity, and has very important practical significance for improving the quality and uniformity of tobacco leaf drying, reducing capital investment in production facilities, reducing tobacco leaf drying losses, and saving labor and reducing costs for farmers. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a process diagram for the five-stage stepped drying method of cigar tobacco leaves suitable for tropical monsoon climates. DETAILED DESCRIPTION

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific implementation disclosed below.

[0026] Embodiment 1:

[0027] In 2023, in Nanda Town, Danzhou City, Hainan Province, the variety Haiyan 101 was planted in shade planting, and the field management and harvesting were carried out using conventional production methods of local high-quality cigar tobacco leaves. The tobacco leaves began to be harvested on March 22, 2023, and the cigar tobacco leaves were dried using the method of the present invention and the conventional drying method.

[0028] The five-stage step-drying method of the present invention comprises: (1) wilting period, temperature 25-30°C, humidity 80-85%, time 3 days, tobacco leaves are placed in the middle and lower layers of the drying rack at the bottom of the drying room, ventilation and dehumidification devices are turned on during the day and turned off at night, and the leaves are dried until the leaves wilt, the leaf tips and leaf edges turn yellow, and the overall change of the dried tobacco leaves is more than 80% and enters the yellowing period. (2) yellowing period: temperature 26-28°C, humidity 80-85%, time 5 days, tobacco leaves are placed in the middle and lower layers of the drying rack, ventilation convection is about 1-2 hours in the morning and evening, and the leaves are dried until the eighth layer of the leaves turns yellow, the leaf tips and leaf edges turn brown, and the overall change of the dried tobacco leaves is more than 80% and enters the browning period. (3) Browning period: temperature 30-32℃, humidity 70-80%, time 6 days, tobacco leaves are placed in the middle layer of the drying rack, ventilation and dehumidification are properly carried out during the day and closed at night, and the leaves are dried until the eighth layer of the leaves are brown, the leaf tips and leaf edges are dry, and the overall change of the air-dried tobacco leaves is more than 80% and enters the color fixing period. (4) Color fixing period: temperature 33-35℃, humidity 65-75%, time 7 days, tobacco leaves are placed in the middle and upper layers of the drying rack, ventilation and dehumidification devices are half-open or slightly open during the day and closed at night, and the leaves are dried until the leaves are completely brown, the leaves are dry, and the main veins turn green. The overall change of the air-dried tobacco leaves is more than 90% and enters the dry rib period. (5) Dry rib period: temperature 37-40℃, humidity 45-55%, time 10 days, tobacco leaves are placed in the top layer of the drying rack, ventilation and dehumidification devices are fully opened during the day and closed at night, and the leaves are dried until the tobacco ribs of the leaves are completely dry, and the overall change of the air-dried tobacco leaves is 100% and the leaves are removed from the rack.

[0029] Table 1 is a statistical table of tobacco leaf quality after air-drying in Example 1

[0030]

[0031] As shown in Table 1, the five-stage step-drying method of the present invention can effectively increase the proportion of the first and second level cigar wrappers and the first and second level cigar cores compared to the conventional drying method. In addition, the present invention makes full use of the natural drying conditions in the tropical monsoon climate area, and can complete the entire cigar tobacco drying process by only adjusting the tobacco rods in a step-by-step manner and properly switching the ventilation and dehumidification device, without the need to modify the facilities of the drying room, which greatly reduces the cost compared to the existing intelligent drying room.

[0032] Embodiment 2:

[0033] In 2024, in Nada Town, Danzhou City, Hainan Province, Poxin Town, Tunchang County, and Datian Town, Dongfang City, the variety is Haiyan 101. Except for the sunny planting in Poxin Town, Tunchang County, the other two production areas are shade-planted. Each production area adopts a unified fertilization method, and uses the conventional production method of local high-quality cigar tobacco leaves for field management and harvesting. The method of the present invention is used for drying cigar tobacco leaves. The cigar tobacco leaves in the Danzhou production area were harvested on March 25, 2024, the cigar tobacco leaves in Tunchang County were harvested on March 22, 2024, and the cigar tobacco leaves in the Dongfang production area were harvested on March 28, 2024. The air-drying is divided into five stages: (1) the withering stage, the temperature in the Danzhou production area is 26-30°C, the humidity is 80-85%, and the time is 3 days; the temperature in the Tunchang production area is 25-29°C, the humidity is 83-85%, and the time is 3 days; the temperature in the Dongfang production area is 27-30°C, the humidity is 76-80%, and the time is 2.5 days; the tobacco leaves are placed in the middle and lower layers of the drying rack at the bottom of the air-drying room, and the ventilation and dehumidification devices are turned on during the day and turned off at night. The leaves are air-dried until they wither and the leaf tips and leaf edges turn yellow. The overall change of the air-dried tobacco leaves is more than 80% and enters the yellowing stage. (2) Yellowing stage: The temperature in Danzhou production area is 26-28℃, the humidity is 78-82%, and the time is 4.5 days; the temperature in Tunchang production area is 25-27℃, the humidity is 82-85%, and the time is 5 days; the temperature in Dongfang production area is 27-29℃, the humidity is 80-85%, and the time is 4.5 days. The tobacco leaves are placed in the middle and lower layers of the drying rack, and ventilation and convection are carried out for about 1-2 hours in the morning and evening. The leaves are dried until the eighth layer of the leaves turns yellow, and the leaf tips and leaf edges turn brown. The overall change of the dried tobacco leaves is more than 80%, entering the browning stage. (3) Browning period: The temperature in Danzhou production area is 30.5-32℃, the humidity is 72-80%, and the time is 5.5 days; the temperature in Tunchang production area is 28-31℃, the humidity is 75-80%, and the time is 6 days; the temperature in Dongfang production area is 30.5-33℃, the humidity is 70-80%, and the time is 5 days; the tobacco leaves are placed in the middle layer of the drying rack, which is properly ventilated and dehumidified during the day and closed at night. The leaves are dried until the leaves turn eight layers brown, the leaf tips and leaf edges become dry, and the overall change of the dried tobacco leaves is more than 80%, entering the color fixing period. (4) Color fixing period: The temperature in Danzhou production area is 33.5-35.5℃, the humidity is 67-75%, and the time is 7 days; the temperature in Tunchang production area is 32-34℃, the humidity is 70-75%, and the time is 8 days; the temperature in Dongfang production area is 34-36℃, the humidity is 65-70%, and the time is 6 days. The tobacco leaves are placed in the middle and upper layers of the drying rack, and the ventilation and dehumidification devices are half-open or slightly open during the day and closed at night. The leaves are dried until they are completely brown, the leaves become dry, and the main veins turn green. The overall change of the dried tobacco leaves is that more than 90% enters the dry tendon stage. (5) Drying period: The temperature in Danzhou production area is 38-40℃, the humidity is 43-53%, and the time is 9 days; the temperature in Tunchang production area is 36-40℃, the humidity is 50-55%, and the time is 10 days; the temperature in Dongfang production area is 38-40℃, the humidity is 42-52%, and the time is 8 days. The tobacco leaves are placed on the top layer of the drying rack, and the ventilation and dehumidification devices are fully opened during the day and closed at night. The tobacco leaves are dried until the tobacco veins are completely dry. The overall change of the dried tobacco leaves is 100% and then they are taken off the shelves.

[0034] Table 2 is a statistical table of tobacco leaf quality in the air-cured production area of ​​Example 2

[0035]

[0036] It can be seen from Table 2 that the five-stage step-drying method of the present invention has similar effects in various test areas and is universal.

[0037] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent 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. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A five-stage step-drying method for cigar tobacco leaves suitable for tropical monsoon climate, characterized in that: include: The air-conditioning period of tobacco leaves is divided into five stages: withering period, yellowing period, browning period, color fixing period and dry tendon period. The withering period is the air-conditioning period from when the fresh tobacco leaves turn yellow at the tip and edge of the leaves, the yellowing period is the air-conditioning period from when the withering period ends to when the tobacco leaves turn eight layers of yellow, and the tip and edge of the leaves turn brown, the browning period is the air-conditioning period from when the yellowing period ends to when the tobacco leaves turn eight layers of brown, and the tip and edge of the leaves become dry, the color fixing period is the air-conditioning period from when the browning period ends to when the tobacco leaves turn all brown, the leaves become dry, and the main veins turn green, and the dry tendon period is the air-conditioning period from when the color fixing period ends to when the tobacco tendons of the tobacco leaves are completely dry. Detect the temperature and humidity values ​​of the drying racks of different heights from top to bottom in the drying room, and divide the drying racks into the first low temperature and high humidity area, the second low temperature and high humidity area, the medium temperature and medium humidity area, the first high temperature and low humidity area, and the second high temperature and low humidity area from bottom to top. The temperature of the first low temperature and high humidity area is 25-30°C, and the humidity is 80±5%. The temperature of the second low temperature and high humidity area is 24-28°C, and the humidity is 85±5%. The temperature of the medium temperature and medium humidity area is 28-32°C, and the humidity is 70-80%. The temperature of the first high temperature and low humidity area is 32-35°C, and the humidity is 65-75%. The temperature of the second high temperature and low humidity area is 35-40°C, and the humidity is 45-55%; Hang the tobacco leaves in the withering stage in the first low temperature and high humidity area, hang the tobacco leaves in the yellowing stage in the second low temperature and high humidity area, hang the tobacco leaves in the browning stage in the medium temperature and medium humidity area, hang the tobacco leaves in the color fixing stage in the first high temperature and low humidity area, hang the tobacco leaves in the dry tendon stage in the second high temperature and low humidity area, and gradually move the tobacco leaves upwards according to the achievement of the goals of each air-drying stage until they are taken off the shelves after the dry tendon stage and become soft through natural rehumidification.

2. The five-stage step-drying method for cigar tobacco leaves according to claim 1, characterized in that: The following steps are involved: S1 Withering stage: Place the cigar tobacco leaves in the first low temperature and high humidity area on the drying rack in the drying room for 2-3 days, until the leaves wither, the leaf tips and leaf edges turn yellow, and the overall change of the air-cured tobacco leaves reaches more than 80% of the standard; S2 Yellowing Stage: Place the cigar tobacco leaves in the second low temperature and high humidity area on the drying rack in the drying room for 5-7 days until the leaves turn eight layers yellow, the leaf tips and leaf edges turn brown, and the overall change of the dried tobacco leaves is more than 80% up to standard S3 Browning Stage: Place the cigar tobacco leaves in the drying room on the drying racks in the medium temperature and medium humidity area for 6-8 days, until the leaves turn eight layers of brown, the leaf tips and leaf edges become dry, and the overall change of the air-dried tobacco leaves reaches more than 80% of the standard; S4 Color Fixation Period: Place the cigar tobacco leaves in the first high temperature and low humidity area on the drying rack in the drying room for 7-9 days, until the leaves are completely brown, dry, the main veins turn green, and the overall change of the air-cured tobacco leaves is more than 90% up to standard; S5 Drying period: Place the cigar tobacco leaves in the second high temperature and low humidity area on the drying rack in the drying room, or transfer them to a separate drying area for drying for 5-10 days until the tobacco ribs of the leaves are completely dry and the overall change of the dried tobacco leaves is 100% up to standard.

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