Coffee bean roasting apparatus and coffee bean roasting method

Abstract

To provide a method for roasting and producing coffee beans by which coffee beans are roasted at a roasted bean temperature equal to a roasted bean temperature by a conventional hydrocarbon-based fuel burner to make different tastes.SOLUTION: The coffee bean roasting method for roasting coffee beans with hot air generated by a hydrogen-mixed combustion burner includes a control step of controlling the heating power of the hydrogen-mixed combustion burner so that the hot air temperature at the start of roasting is higher than the hot air temperature in other roasting periods.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a coffee bean roasting device and a method for roasting and producing coffee beans. [Background technology]

[0002] Typical heat sources for generating hot air in coffee bean roasting devices include burners that burn natural gas, liquefied petroleum gas, wood, etc., as well as heat sources such as electric heaters, halogen heaters, infrared rays, and microwaves (see, for example, Patent Documents 1 and 2).

[0003] Burners include, for example, burners equipped with nozzles that supply one type of fuel and one type of oxidizer, and multi-fuel burners equipped with nozzles that supply multiple types of fuel (hydrogen, city gas) and one type of oxidizer (air) (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2022-537262 [Patent Document 2] Patent No. 6173395 [Patent Document 3] Patent No. 7064474 Summary of the Invention [Problem to be solved by the invention]

[0005] Burners that use hydrocarbon fuels such as city gas as a heat source for generating hot air inevitably generate carbon dioxide. Therefore, as a measure against global warming, it is expected that coffee bean roasters will also suppress the generation of carbon dioxide. Furthermore, although the use of hydrogen in the above-mentioned dual-fuel burner is disclosed, its use in coffee bean roasters is not disclosed.

[0006] While there is a demand for creating a taste equivalent to that of coffee beans roasted using a hydrocarbon fuel burner, there is also a demand for creating the unique taste of coffee roasted using a hydrogen co-fuel burner.

[0007] The present disclosure provides a coffee bean roasting device and a coffee bean roasting method that can roast coffee beans at a hot air temperature equivalent to that of a conventional hydrocarbon fuel burner, thereby creating a different taste. [Means for solving the problem]

[0008] The coffee bean roasting device (1) an adjustable hydrogen-mixed combustion burner (10) using hydrogen and hydrocarbon fuel with a turndown ratio of 1:10 or more; a roaster (20) that uses the hot air generated by the hydrogen-mixed combustion burner as a heat source for roasting; The apparatus is provided with a control device (30) that controls the heat power of the hydrogen-mixed combustion burner so that the hot air temperature at the start of roasting is higher than the hot air temperatures during the rest of the roasting period (in a roasted bean temperature curve that is downwardly convex throughout the roasting period). The "roasted bean temperature" is the temperature of the coffee beans roasted with the hot air from the hydrogen-mixed combustion burner (10) (or the temperature of the surrounding atmosphere). Examples of "hydrocarbon fuels" include city gas, propane gas, and ethane gas. A "hydrogen-mixed combustion burner" may use only hydrogen fuel. The "roaster" may be a hot air roaster or a semi-hot air roaster. The "controller" may control the roaster and / or the hydrogen-mixed combustion burner. Roasting may begin when the coffee beans start to be added or when the entire amount has been added. The hot air temperature may be the temperature of the hot air inside the roaster or the temperature of the hot air sent to the roaster. The hot air temperature at the start of roasting may be 1% or more, 4% or more, or 6% or more higher than the hot air temperature during the rest of the roasting period. The hot air temperature is preferably above 400° C. at the start of roasting, such as 420° C. or higher, 430° C. or higher, 440° C. or higher, or 450° C. or higher. By increasing the hot air temperature at the start of roasting, the roasting period can be made shorter than that of normal roasting or low-temperature roasting.

[0009] The coffee bean roasting device (1) may be equipped with a bean temperature measuring device (45) that measures the temperature of the roasted beans (or the temperature of the surrounding atmosphere) during roasting. The control device (30) may control the heating power of the hydrogen-mixed combustion burner (10) so that the roasted bean temperature (CPV_t) measured by the bean temperature measuring device (45) corresponds to a preset roasted bean temperature profile (roasted bean temperature set value data (CSV_t)). The roasted bean temperature is preferably, for example, above 180°C at the start of roasting and below 240°C. The bean temperature measuring device (45) may be a thermometer that measures the temperature by contacting the coffee beans, or a non-contact thermometer.

[0010] The coffee bean roasting device (1) may include a hot air temperature measuring device (40) for measuring the temperature of the hot air generated by the hydrogen-mixed combustion burner (10). The control device (30) may control the heating power of the hydrogen-mixed combustion burner (10) so that the hot air temperature (HPV_t) measured by the hot air temperature measuring device (40) corresponds to a preset hot air roasting profile (hot air temperature set value data (HSV_t) for roasting). One or more hot air temperature measuring devices (40) may be provided on any hot air supply pipe before roasting, pipe inside the roaster, or hot air discharge pipe after roasting.

[0011] When either the roasted bean temperature profile or the hot air roasting profile is set, the other may be set in association with it. The roasted bean temperature profile and the hot air roasting profile may be set in a plurality of types depending on the desired type of roasting, bean type (including place of production, year of production, etc.), roast amount, etc. The roasted bean temperature profile and the hot air roasting profile may be stored in the memory of the device 1 or the control device 30. The profiles may be sent from an external device. The device 1 may have a profile setting unit that sets the roasting profile.

[0012] The roasted bean temperature profile and the hot air roasting profile are set to produce a roasted bean temperature curve during roasting that will achieve the desired taste. The present invention can produce a roasted bean temperature curve that is the same as or cannot be achieved with conventional 100% natural gas burners. The roasted bean temperature curve is a downward convex curve, and when divided into three parts, namely, the early stage, the middle stage, and the late stage of roasting, the hot air temperature at the start of roasting in the early stage of roasting is higher than those in the other roasting periods. The temperature at the start of roasting in the early stage of roasting may be the maximum temperature. For example, at the start of roasting, the roasted bean temperature is set to a maximum value between 180°C and 240°C, and the temperature is gradually decreased from the start of roasting to a minimum value in the middle of roasting, with a downward convex shape, and the temperature is gradually increased from the middle to the latter stages of roasting. In the downward convex approximation curve of the roasted bean temperature between the start point and the end point of roasting, the period from the start point (maximum value) to the first midpoint (midpoint in roasting time or midpoint in temperature), which is the midpoint between the start point and the lowest point (minimum value), can be defined as the early stage of roasting, the period from the first midpoint to the second midpoint (midpoint in roasting time or midpoint in temperature), which is the midpoint between the lowest point (minimum value) and the end point of roasting, can be defined as the middle stage of roasting, and the period from the second midpoint to the end point of roasting can be defined as the late stage of roasting. The high-temperature roasting period using the hydrogen burner of the present invention is the same as that using a conventional hydrocarbon-fuel burner, but it can achieve a different taste.

[0013] The hydrogen-mixed combustion burner (10) may include a burner body (11), a burner tip (12), a hydrogen supply nozzle (13) disposed inside the burner body (11) and having a nozzle tip with a circular cross section for supplying hydrogen, an oxidizer supply nozzle (14) disposed inside the burner body (11) and provided outside the hydrogen supply nozzle and having a ring cross section for supplying an oxidizer (e.g., air or oxygen), and a fuel supply nozzle (15) disposed inside the burner body and provided outside the oxidizer supply nozzle and having a ring cross section for supplying a hydrocarbon fuel. The hydrogen-mixed combustion burner (10) may include a hydrogen source (S2) (e.g., a main pipe, a cylinder, or a cylinder) of a predetermined pressure, a hydrogen pipe (L2), a valve (V2) (e.g., a control valve, a gate valve) provided on the hydrogen pipe (L2), an optional gas flow meter, an optional gas pressure gauge, an oxidizer source (S1) (e.g., a main pipe, a cylinder, a pressure pump, or a compressor) of a predetermined pressure, an oxidizer pipe (L1), a valve (V1) (e.g., a control valve, a gate valve) provided on the oxidizer pipe (L1), an optional gas flow meter, an optional gas pressure gauge, a hydrocarbon fuel source (S3) (e.g., a main pipe, a cylinder, or a cylinder) of a predetermined pressure, a hydrocarbon fuel pipe (L3), a valve (V3) (e.g., a control valve, a gate valve) provided on the hydrocarbon fuel pipe (L3), an optional gas flow meter, and an optional gas pressure gauge. The control device (30) may control the combustion power (thermal power) (control the mixed-fuel ratio) by adjusting the valve openings of one or more valves among a valve provided in the hydrogen pipe (L2), a valve provided in the oxidizer pipe (L1), and a valve provided in the hydrocarbon fuel pipe (L3). The control device (30) may proportionally control the valve openings in response to an increase or decrease in the combustion power (thermal power).

[0014] The hydrogen-mixed combustion burner (10) may include a circulation pipe (L10) for circulating hot air (waste gas) from the burner tip to the oxidizer pipe (L1), a suction pump (P10) provided in the circulation pipe (L10), a valve (e.g., a control valve, a gate valve) provided in the circulation pipe (L10), an optional gas flow meter, and an optional gas pressure gauge. The control device (30) may control the amount of circulation of hot air (waste gas) by adjusting the drive of a suction pump (P10) provided in the circulation pipe (L10) and the opening of a valve (V10) (e.g., a control valve, a gate valve) provided in the circulation pipe (L10).

[0015] The coffee bean roasting device (1) may include a storage device (31) for storing the roasting profile.

[0016] Coffee bean roasting method A coffee bean roasting and manufacturing method in which coffee beans are roasted using hot air generated by an adjustable hydrogen-mixed combustion burner with a turndown ratio of 1:10 or more, includes a control step of controlling the heat power of the hydrogen-mixed combustion burner so that the hot air temperature at the start of roasting is higher than the hot air temperatures during the remaining roasting periods (in a downward-convex roast bean temperature curve over the entire roasting period). The control step may control the thermal power of the hydrogen-mixed combustion burner (10) so that the roasted bean temperature (CPV_t) measured by the bean temperature measuring device (45) corresponds to a preset roasted bean temperature profile (roasted bean temperature set value data (CSV_t)). The control step may control the heat power of the hydrogen-mixed combustion burner (10) so that the hot air temperature (HPV_t) measured by the hot air temperature measuring device (40) corresponds to a preset hot air roasting profile (hot air temperature set value data (HSV_t) for roasting). The control step may control the combustion power (thermal power) (control the mixed-fuel ratio) by adjusting the valve opening of one or more valves selected from a valve provided in a hydrogen pipe, a valve provided in an oxidizer pipe, and a valve provided in a hydrocarbon fuel. The control step may control the amount of circulated waste gas by adjusting the driving of a suction pump provided in the circulation pipe and the opening of a valve provided in the circulation pipe.

[0017] "Coffee beans" includes all coffee beans, regardless of origin (brand) or type.

[0018] The control device (30) may be configured as an information processing device (e.g., a computer, a server) having a memory, a processor, a software program, a dedicated circuit, firmware, etc. The information processing device may be either on-premise or cloud-based, or a combination of both.

[0019] (effect) (1) The hydrogen-mixed combustion burner reproduces the same hot air temperature as that of roasting equipment using hydrocarbon fuels such as natural gas, making it possible to create a taste that is different from conventional ones. (2) By using 100% hydrogen fuel, carbon dioxide-free hot air can be generated. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a diagram showing an example of a coffee bean roasting device according to a first embodiment. [Figure 2] FIG. 2 is a diagram showing an example of the structure of a multi-fuel burner. [Figure 3] FIG. 2 is a diagram showing an example of a piping configuration of a multi-fuel burner. [Figure 4] FIG. 1 is a diagram showing an example of a roasted bean temperature curve. DETAILED DESCRIPTION OF THE INVENTION

[0021] (Embodiment 1) Figure 1 shows an example of the function of the coffee bean roaster 1 of embodiment 1. Figure 2 shows an example of the structure of a multi-fuel burner. Figure 3 shows an example of the piping configuration of a multi-fuel burner. Figures 1 to 3 show examples of the configuration and function, and are not intended to be limiting, and various configuration changes are possible.

[0022] Coffee bean roasting apparatus 1 includes hydrogen-mixed combustion burner 10, roaster 20, control device 30, storage device 31, hot air temperature measuring device 40, and bean temperature measuring device 45.

[0023] The hydrogen-mixed combustion burner 10 uses hydrogen and hydrocarbon fuel and has an adjustable burner function with a turndown ratio of 1:10 or more. It is also possible to stop the supply of hydrocarbon fuel and supply only hydrogen fuel. The turndown ratio is 1:10 or more, but 1:15 or 1:20 is preferable. In this embodiment, the hydrocarbon fuel is compressed natural gas, but is not limited to this. The hydrogen fuel is compressed hydrogen at 0.1 MPa. The oxidizer is air.

[0024] The structure of the hydrogen-mixed combustion burner 10 will be described with reference to Figure 2. The hydrogen-mixed combustion burner 10 comprises a burner body 11 and a burner tip 12. The opening area of ​​the burner tip 12 increases toward the tip. Inside the burner body 11, there are a hydrogen supply nozzle 13 with a circular cross-section at the nozzle tip for supplying hydrogen, an oxidizer supply nozzle 14 with a ring cross-section located outside the hydrogen supply nozzle 13 for supplying air, and a fuel supply nozzle 15 with a ring cross-section located outside the oxidizer supply nozzle 14 for supplying compressed natural gas. Rather than directly contacting the hydrogen fuel and natural gas, the hydrogen fuel and natural gas are mixed in an area suitable for each fuel by injecting an oxidizer between them.

[0025] Roaster 20 uses the hot air generated by hydrogen-mixed combustion burner 10 as a heat source for roasting. Roaster 20 of this embodiment is a drum-type hot air roaster or a fluidized-bed hot air roaster.

[0026] The controller 30 controls the heating power of the hydrogen-mixed combustion burner 10 so that the hot air temperature at the start of roasting is higher than the hot air temperature at other times in the roasting period, based on the downward-convex roasted bean temperature curve for the entire roasting period. In this embodiment, the controller 30 controls the heating power of the hydrogen-mixed combustion burner 10 so that the roasted bean temperature (CPV_t) measured by the bean temperature measuring device 45 corresponds to a preset roasted bean temperature profile (roasted bean temperature set value data (CSV_t)). The control device 30 controls the heat power of the hydrogen-mixed combustion burner 10 so that the hot air temperature (HPV_t) measured by the hot air temperature measuring device 40 corresponds to a preset hot air roasting profile (hot air temperature setting value data (HSV_t) for roasting).

[0027] The storage device 31 stores a roasting profile 311. The roasted bean temperature and hot air roasting profile 311 includes roasted bean temperature set value data (CSV_t) and hot air temperature set value data (HSV_t) according to the roasting time linked to the bean type and roasting conditions.

[0028] The piping configuration of the hydrogen-mixed combustion burner 10 will be described with reference to Figure 3. The hydrogen-mixed combustion burner 10 includes a 0.1 MPa compressed hydrogen cylinder S2, a hydrogen pipe L2, a flow meter-equipped flow control valve V2 provided on the hydrogen pipe L2, an air pump P, an air pipe L1, a flow meter-equipped flow control valve V1 provided on the air pipe L1, a compressed natural gas cylinder S3, a natural gas pipe L3, and a flow meter-equipped flow control valve V3 provided on the natural gas pipe L3.

[0029] The hydrogen-mixed combustion burner 10 is equipped with a circulation pipe L10 for circulating hot air (waste gas) from the burner tip 12 to the air pipe L1, a suction pump P10 installed in the circulation pipe L10, and a flow rate control valve with a flow meter installed in the circulation pipe L10. A temperature measuring device 40 is installed in the hot air supply pipe before roasting. The temperature measuring device 40 measures the temperature of the hot air generated by the hydrogen-mixed combustion burner 10. The hot air from the hydrogen-mixed combustion burner 10 is sent to the fluidized bed 21 of the roaster 20. A bean temperature measuring device 45 installed in the fluidized bed 21 is a contact thermometer that measures the temperature of the coffee beans in the fluidized bed 21 during roasting.

[0030] The burner control unit 101 of the hydrogen-mixed combustion burner 10 can control combustion (proportional control of the fuel supply amount and air supply amount) in response to the roasted bean temperature, the hot air roasting profile 311, and commands from the control device 30. The control device 30 may issue commands to the burner control unit 101 of the hydrogen-mixed combustion burner 10 so that the measured temperature (HPV_t) measured by the hot air temperature measuring device 40 corresponds to the roasted bean temperature and the hot air roasting profile 311. The control device 30 may issue commands to the burner control unit 101 of the hydrogen-mixed combustion burner 10 so that the measured temperature (CPV_t) measured by the roasted bean temperature measuring device 45 corresponds to the roasted bean temperature and the hot air roasting profile 311.

[0031] The control device 30 controls the combustion power (thermal power) by adjusting the valve opening of one or more of the flow control valves: the flow control valve V2 installed in the hydrogen pipe L2, the flow control valve V1 installed in the air pipe L1, and the flow control valve V3 installed in the natural gas pipe L3, either directly or by issuing a command to the burner control unit 101. The control device 30 can control the ratio of the supply amounts of hydrogen and natural gas, and the air amount. The valve opening can be proportionally controlled according to the increase or decrease in the combustion power (thermal power).

[0032] The control device 30 can control the start / stop and circulation amount of hot air (waste gas) by controlling the operation of the suction pump P10 provided in the circulation pipe L10 and the valve opening of the flow control valve V10 provided in the circulation pipe L10, either directly or by issuing commands to the burner control unit 101. When the combustion power (heating power) is reduced, the control can start the circulation or increase the circulation amount to reduce the oxygen concentration supplied to the burner. This also reduces the amount of NOx generated.

[0033] According to this embodiment, the mixture ratio of hydrogen and hydrocarbon fuel can be freely set in the multi-fuel burner. A high turndown ratio can be used in the hydrogen burner, and new profiles (roasted bean temperature curve, hot air temperature curve) equivalent to those of conventional hydrocarbon fuel burners can be designed. Even with the same roasted bean temperature profile or hot air roasting profile, a different taste can be created than with a natural gas burner. Examples of "taste" include sourness, richness, bitterness, aroma (fragrance), etc. Since aroma stimulates the sense of smell, this can also be described as an improvement in the sense of smell.

[0034] (Example 1: Medium roast) We will explain Example 1 and Comparative Example 1, which are high-temperature roasting using the hydrogen-mixed combustion burner in embodiment 1, Comparative Examples 2 and 3, which are normal roasting, and Comparative Examples 4 and 5, which are low-temperature roasting. Coffee beans: 5kg Roast level: Medium roast High-temperature roasting time: 9 minutes (Example 1, Comparative Example 1) Normal roasting time: 14 minutes (Comparative Examples 2 and 3) Low-temperature roasting time: 20 minutes (Comparative Examples 4 and 5) Hot air temperature at the start of high-temperature roasting: 450°C (Example 1, Comparative Example 1) Hot air temperature at the start of normal roasting: 400°C (Comparative Examples 2 and 3) Hot air temperature at the start of low-temperature roasting: 280°C (Comparative Examples 4 and 5) Heat source used: Hydrogen 0.1MPa : Natural gas 10kPa (0.01MPa) Hydrogen only (Example 1, Comparative Examples 2 and 4): 100% hydrogen Natural gas (Comparative Examples 1, 3, and 5): 100% natural gas Supply pressure: 10kPa

[0035] Figure 4 shows examples of roasted bean temperature curves for high-temperature, normal, and low-temperature roasting. The same roasting temperature curve was used for Example 1 and Comparative Example 1, which were high-temperature roasted (450°C). The same roasting temperature curve was also used for Comparative Examples 2 and 3, which were normal roasted (400°C), and Comparative Examples 4 and 5, which were low-temperature roasted (280°C). The roasted bean temperature was measured by directly contacting the beans during roasting.

[0036] (Taste evaluation) Example 1 and Comparative Examples 1 to 5 were each subjected to a taste evaluation. The method for obtaining the extract is as follows. Extraction method: Paper drip method Extraction conditions: 20g of coffee powder, 320g of hot water, 20 seconds of steeping time Sensory evaluation The extracted samples were blinded and absolute evaluation was carried out according to the following sensory evaluation criteria: the intensity of the taste in five categories (sourness, bitterness, astringency, richness, and aftertaste) was rated on a nine-level scale (ranging from -4 (very weak) to +4 (very strong), with the median value of 0 being considered normal). Subjects: 16 people in Example 1 and Comparative Examples 1, 4, and 5 : Comparative Examples 2 and 3 are 14 people The roast level (L value) of the roasted coffee beans was evaluated using a colorimeter (ZE-6000, manufactured by Nippon Denshoku Industries Co., Ltd.). The evaluation results are shown in Table 1.

[0037] [Table 1]

[0038] For the evaluation results in Table 1, a significance test (t-test: significance level 5%) was conducted for Example 1 using the roasted product of Comparative Example 1 (natural gas) as the standard. The results showed that Example 1 had a stronger sour taste than Comparative Example 1. No significant difference was confirmed between Comparative Examples 2 and 3, which were normally roasted (400°C), and Comparative Examples 4 and 5, which were low-temperature roasted (280°C).

[0039] (Example 2: Light roast) Example 2 was carried out under light roasting conditions. Coffee beans: 5kg Roast level: Light roast High-temperature roasting time: 8 minutes (Example 2, Comparative Example 6) Normal roasting time: 11 minutes (Comparative Examples 7 and 8) Hot air temperature at the start of high-temperature roasting: 450°C (Example 2, Comparative Example 6) Hot air temperature at the start of normal roasting: 400°C (Comparative Examples 7 and 8) Heat source used: Hydrogen 0.1MPa : Natural gas 10kPa (0.01MPa) Hydrogen only (Example 2, Comparative Example 7): 100% hydrogen Natural gas (Comparative Examples 6 and 8): 100% natural gas

[0040] The taste evaluation and roast level evaluation were carried out in the same manner as in Example 1. Table 2 shows the evaluation results. Subjects: 14 people in Example 2 and Comparative Example 6 : Comparative Examples 7 and 8 are 16 people

[0041] [Table 2]

[0042] For the evaluation results in Table 2, a significance test (t-test: significance level 5%) was conducted for Example 2 using the roasted product of Comparative Example 6 (natural gas) as the standard. Example 2 had a weaker aftertaste than Comparative Example 6. No significant difference was confirmed between Comparative Examples 7 and 8, which were roasted using normal roasting (400°C).

[0043] (Example 3: Deep-fried) Example 3 was carried out under dark roasting conditions. Coffee beans: 5kg Roast level: dark roast High-temperature roasting time: 9 minutes (Example 3, Comparative Example 9) Normal roasting time: 13 minutes (Comparative Examples 10 and 11) Hot air temperature at the start of high-temperature roasting: 450°C (Example 3, Comparative Example 9) Hot air temperature at the start of normal roasting: 400°C (Comparative Examples 10 and 11) Heat source used: Hydrogen 0.1MPa : Natural gas 10kPa (0.01MPa) Hydrogen only (Example 3, Comparative Example 10): 100% hydrogen Natural gas (Comparative Examples 9 and 11): 100% natural gas

[0044] The taste evaluation and roast level evaluation were carried out in the same manner as in Example 1. Table 3 shows the evaluation results. Subjects: 14 people in Example 3 and Comparative Example 9 : Comparative Examples 10 and 11 are 16 people

[0045] [Table 3]

[0046] For the evaluation results in Table 3, a significance test (t-test: significance level 5%) was performed for Example 3 using the roasted product of Comparative Example 9 (natural gas) as the standard. Example 3 was found to have a weaker bitterness than Comparative Example 9. No significant difference was confirmed between Comparative Examples 10 and 11, which were normally roasted (400°C).

[0047] Even with the same roasted bean temperature curve, a different taste was produced using a hydrogen burner. We believe this is due to the high energy of superheated steam. When superheated steam is cooled by the temperature difference with the heated object and attempts to return to water, the "heat of condensation" that is generated carries a large amount of energy, and we believe it also has excellent thermal conductivity (energy transfer to the heated object is approximately 1.2 times). The hot air produced by a hydrogen burner contains approximately twice as much superheated steam compared to hot air produced by a natural gas burner with the same heat capacity, and is therefore thought to be more strongly influenced by the superheated steam. In other words, in the Examples, the draining (drying) process at the beginning of roasting was able to proceed more quickly than in the Comparative Examples, which is thought to have contributed to the longer time for flavor development and the creation of a different flavor.

[0048] (method) The coffee bean roasting production method involves roasting coffee beans with hot air generated by an adjustable hydrogen-mixed combustion burner with a turndown ratio of 1:10 or more, and includes a control step of controlling the heat power of the hydrogen-mixed combustion burner so that the hot air temperature at the start of roasting is higher than the hot air temperatures at other times in a downwardly convex curve of roasted bean temperatures over the entire roasting period. The control step may control the thermal power of the hydrogen-mixed combustion burner 10 so that the roasted bean temperature (CPV_t) measured by the bean temperature measuring device 45 corresponds to a predetermined roasted bean temperature profile (roasted bean temperature set value data (CSV_t)). The control step may control the combustion power (thermal power) (control the mixed-fuel ratio) by adjusting the valve opening of one or more valves selected from a valve provided in a hydrogen pipe, a valve provided in an oxidizer pipe, and a valve provided in a hydrocarbon fuel. The control step may control the amount of circulated waste gas by adjusting the driving of a suction pump provided in the circulation pipe and the opening of a valve provided in the circulation pipe. The control step may control the combustion power (thermal power) (control the mixed combustion ratio) by adjusting the valve opening of one or more valves among a valve provided in the hydrogen pipe, a valve provided in the oxidizer pipe, and a valve provided in the hydrocarbon fuel. The control step may control the amount of circulated waste gas by adjusting the driving of a suction pump provided in the circulation pipe and the opening of a valve provided in the circulation pipe. [Explanation of symbols]

[0049] 1. Coffee bean roasting equipment 10 Hydrogen mixed combustion burner 20 roaster 30 Control device 31 Storage device 40 Hot air temperature measuring device 45 Bean temperature measuring device

Claims

1. A coffee bean roasting and manufacturing method in which coffee beans are roasted using hot air generated by a hydrogen-mixed combustion burner, a control step of controlling the heat power of the hydrogen-mixed combustion burner so that the hot air temperature at the start of roasting is higher than the hot air temperature during other roasting periods; Coffee bean roasting production method.

2. 2. The coffee bean roasting and producing method according to claim 1, wherein the hot air temperature at the start of roasting exceeds 400°C.

3. The coffee bean roasting method according to claim 1, wherein the hot roasted bean temperature at the start of roasting is greater than 180°C and less than 240°C.

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