Coffee bean baking method based on heating degree control

Abstract

The invention relates to the technical field of coffee baking, in particular to a coffee bean baking method based on heating degree control, which comprises the following steps: step 1, selecting green coffee beans; step 2, storing and analyzing raw coffee beans; step 3, preheating the green coffee beans; step 4, baking the coffee beans; and step 5, cultivating the beans. According to analysis and judgment under different freshness and storage states of the green coffee beans, a corresponding baking plan can be adopted for accurate design and fixed adjustment, the purpose that the green coffee beans can be changed and upgraded due to differences of varieties, planting environments, altitudes, processing methods and the like of the green coffee beans is achieved, and a baker can bake the green coffee beans with the method to create unique flavor.

Description

Technical Field

[0001] The present invention relates to the technical field of coffee roasting, and in particular to a coffee bean roasting method based on temperature control. Background Art

[0002] Coffee is a beverage made from roasted and ground coffee beans. The coffee tree is a perennial evergreen shrub or small tree in the Rubiaceae family. Everyday coffee is made from coffee beans, the kernel inside the coffee berry, using various cooking utensils. Coffee beans refer to the kernel inside the coffee plant, which is then roasted using appropriate methods. A standard cup of coffee should taste more than just bitter. A qualified barista meticulously prepares each step, resulting in a cup that exhibits varying degrees of sweetness, acidity, body, and cleanliness. Coffee roasting involves heating the raw beans, initiating a series of physical and chemical reactions within and outside the beans. This process develops the coffee's various flavors, including sourness, bitterness, and sweetness, and creates its body and color, transforming the raw beans into dark brown roasted beans.

[0003] From procurement, storage, preheating, roasting and other processes, the color, aroma, taste and appearance of coffee beans are changing at each stage. If the sensory changes of coffee beans at each stage are very different, the taste and flavor of the coffee will be more significantly affected.

[0004] Currently, coffee roasting generally relies on techniques based on roast curves, rather than methods. The difference between a method and a roast curve is that a method is the process of creating a curve, while a curve is the result of a method, whereas a curve is a line connecting points formed by time and temperature during the roasting process. Therefore, the desired flavor of a coffee bean can be determined by analyzing the green beans, preheating, roasting process, and the color, aroma, and flavor of the roasted beans. The roasting temperature is the time and temperature during the roasting process that achieves the optimal roasting degree through thermal and chemical reactions. Summary of the Invention

[0005] The present invention provides a coffee bean roasting method based on temperature control. By analyzing and judging the different freshness and storage conditions of green coffee beans, corresponding roasting plans can be accurately designed and set. The roasting plan can be changed and upgraded according to differences in green bean variety, planting environment, altitude, processing method, etc., and roasters can use this method to create unique flavors.

[0006] In order to achieve the above object, the present invention provides the following technical solution: a coffee bean roasting method based on temperature control, which comprises the following steps:

[0007] Step 1: Select green coffee beans;

[0008] Step 2: Green coffee bean storage and analysis;

[0009] Step 3: Preheat the green coffee beans;

[0010] Step 4: Roasting coffee beans;

[0011] Step 5: Growing beans.

[0012] Preferably, in step 1, Arabica coffee beans produced in Yunnan are selected, and the green beans are required to be neat in shape, uniform in size, blue-green or light green in color and shiny, have a floral or fruity aroma, and be hard and free from moisture and mold; and the coffee beans must have a growth cycle of at least 5 years.

[0013] Preferably, in step 2, the green beans are stored in a dark and ventilated environment at 20° C. to 25° C. and a humidity of 50% to 60%, maintaining a moisture content of 10% to 12%; and the green beans are tested for their content of 34% to 45% polysaccharides, 12% protein, 1% to 2% amino acids, 20% lipids, 5% to 8% chlorogenic acid, 2% other acids, and 0.9% to 1.4% caffeine.

[0014] Preferably, the step three includes:

[0015] Calculate the bean input temperature and re-temperature point, observe the changes in bean color, aroma, taste, and appearance during the heating process, and calibrate the preheating time and temperature to set the target roasting degree;

[0016] Adjust the fire pressure and wait for the furnace to heat up to the set temperature. After the green beans are preheated to the set temperature and put into the furnace, the point where the temperature in the furnace drops and then rises again is the re-temperature point.

[0017] Observe the beans from the re-warming point. The color changes from green to light yellow-green, and the aroma changes from light to strong. The overall performance is the change in size, consistency and color. This is the standard for cooling the beans out.

[0018] Determine the aroma, color, and appearance of the beans during thermal reactions to determine the appropriate preheating point for the desired roasting degree.

[0019] Smell the green beans after the return to temperature point to release the odor supplementary items in the classification attribute;

[0020] Grade A. Blue-green in color, with a green grass and green pepper flavor, and a dull, matte surface.

[0021] Grade B. Green color, grass aroma, smooth surface.

[0022] Grade C. Green with light yellow, sweet flowers and fruits, smooth surface.

[0023] Grade D. Light yellow-green, fruity and sour aroma, matte and dull surface.

[0024] Grade E. Yellowish white, with a grain peanut shell smell and a bland surface.

[0025] Grade F. Light brown, slightly sour smell of sack, with gray surface.

[0026] Grade G. Brown, spicy smell, dry surface.

[0027] Grade H. Dark grayish white, sour and musty smell, dark gray and mixed surface condition.

[0028] The green beans are preheated according to their freshness: Grade A and B green beans are preheated at 135°C to 145°C until they are light yellow-green and have a sweet sucrose aroma; Grade C and D green beans are preheated at 110°C to 120°C until they have a sweet floral and fruity aroma; Grade E and F green beans are preheated at 125°C until they have a slight sweet sucrose aroma. The caramelization of carbohydrates and the decomposition of chlorogenic acid are also monitored during the preheating process.

[0029] Preferably, in step 4, the SCAA color value standard is used to control the degree of baking, including:

[0030] Light baking: 180℃ to 205℃ / 8 to 10 minutes, color value 85 to 95;

[0031] Medium baking: 210℃ to 220℃ / 11 to 15 minutes, color value 65 to 75;

[0032] Dark baking: 225℃ to 240℃ / 15 to 20 minutes, color value below 55;

[0033] During the baking process, the fire pressure is adjusted in stages to complete dehydration at 170℃ to 190℃.

[0034] Preferably, the step five includes performing index detection on the coffee beans at time points of 1 hour, 12 hours, 24 hours, 48 ​​hours and 72 hours.

[0035] The beneficial effects of the present invention are as follows: there are significant differences in concepts, flavor performance and technical processing between authentic CAFA roasted coffee and traditional roasting. Traditional roasting focuses on stability and standardization, pursues popular taste and consistency, and usually serves commercial needs. Its acidity is weak and tends to be soft or converted into a burnt bitter taste through dark roasting to reduce the sharpness of the acidity. The taste of traditional roasting is thick and full, with a distinct oily feel, which is often seen in the rich and mellow style brought by dark roasting. Dark roasting can cover up some defects of raw beans, and has a relatively high fault tolerance rate. It is a "flavor shaper" and achieves balance and universality through roasting technology. The authentic CAFA roasted coffee emphasizes the expression of the origin and terroir of the coffee beans, highlighting the uniqueness of the variety, processing method and planting environment. The light-medium roasting retains the bright acidity, giving the coffee a lively fruity aroma and layering. Its taste is light and delicate, with a silky smoothness, highlighting the cleanliness and complexity of the coffee. The authentic CAFA roasted coffee has extremely high requirements for the quality of the raw beans and the roasting precision. Any flaws will be magnified. It is an "interpreter of terroir" and focuses on native flavor and transparency. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 It is a schematic diagram of the main process of the present invention. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0039] according to Figure 1 As shown, a coffee bean roasting method based on temperature control includes the following steps:

[0040] Step 1: Select green coffee beans, primarily from Yunnan. The growing cycle for green coffee beans is relatively long. For example, Arabica coffee typically takes five years to produce a harvest, going through the seedling, sapling, production, peak production, and aging stages. The peak production stage, which can last for approximately 30 years, is the most valuable and economically profitable stage in cultivation, when yields reach their peak. Furthermore, environmental factors such as temperature, rainfall, sunlight, soil, wind, and altitude are crucial for coffee cultivation. During the planting process, seed selection, seedling cultivation, and transplanting all require optimal temperature and humidity, based on high-quality seeds, to ensure proper grafting and growth. Suitable soil and fertilizer are also crucial, as is maintaining adequate humidity and ventilation. As coffee trees develop into full-grown plants, farmers must regularly prune them. This includes applying fertilizer at appropriate times, removing weeds, and controlling pests. These practices aim to maintain a healthy tree shape, promote growth and branching, and ensure nutrient distribution, ultimately maximizing yield and quality.

[0041] In addition, there are the following requirements for the appearance of green coffee beans:

[0042] (1) Size and shape: High-quality coffee beans are neatly shaped and uniform in size. Beans with different shapes usually mean rough grading, which requires a high level of control over roasting techniques and is prone to uneven heating, affecting the flavor of the coffee.

[0043] (2) Color: Fresh coffee beans are usually blue-green or light green, that is, beans that are four months old, with a uniform and shiny color. If the beans appear yellow-green or whitish, they are relatively old.

[0044] (3) Aroma: Fresh coffee beans have a light floral or fruity aroma. If the beans have a hay, grain, or sack smell, they are losing their freshness and need to be roasted to a higher degree. If the beans have no flavor, or have a pungent chemical or moldy smell, they are not fresh at all.

[0045] (4) Texture: Good coffee beans have a firm texture, a crisp bite, and no signs of moisture or mold.

[0046] Step 2: Green Coffee Bean Storage and Analysis. Green coffee beans are best stored at room temperature (20°C to 25°C) and humidity (50% to 60%). This maintains a constant moisture content, preventing excessive surface moisture loss or gain. Maintaining a moisture content between 10% and 12% is ideal. If the moisture content is too low, the beans will overheat quickly during roasting, resulting in a lack of flavor. If the moisture content exceeds 15%, the beans will easily become moldy and smelly, hindering the quality of roasted coffee. Furthermore, green beans in sacks should be placed on wooden racks to prevent direct contact with the ground and provide moisture-proof storage. Storage rooms should be protected from direct sunlight and designed to be cool, dry, and well-ventilated for optimal storage.

[0047] The mineral content of green coffee beans mainly includes polysaccharides, proteins, lipids, oligosaccharides, chlorogenic acids, acids and caffeine.

[0048] Taking Arabica as an example, the specific content is as follows:

[0049] (1) Polysaccharides: refers to the fibers that make up the skeleton of plant cells. They account for the largest content in the entire raw bean, about 34% to 45%. However, due to their extremely large molecules, reduced solubility and increased degree of polymerization, their perception is reduced and they have little sweetness.

[0050] (2) Protein: Like polysaccharides, it is also an important component of the plant cell skeleton. The protein content in raw beans is 12%.

[0051] (3) Amino acids: They are the basic units of protein. The amino acid content in green coffee beans is 1% to 2%. Amino acids include aspartic acid, glutamic acid, etc.

[0052] (4) Lipids: Mainly composed of linoleic acid, palmitic acid and other oils, accounting for about 20% of the raw beans.

[0053] (5) Chlorogenic acids: 5% to 8% in Arabica green beans.

[0054] (6) Acids: In addition to chlorogenic acids, coffee green beans also contain citric acid, malic acid, quinic acid, phosphoric acid, etc., which account for only 2%.

[0055] (7) Caffeine: 0.9% to 1.4% in Arabica.

[0056] Of course, the density and moisture of coffee green beans also have a subtle feature in the specifications and burlap packaging of coffee beans for import and export transportation. The density of different coffee green beans will change due to different regions, such as the density of beans at high altitudes will be higher, and the density of beans at low altitudes will be lower. Obviously, beans with high density will occupy less space during burlap packing, however, beans with low density will require more beans to achieve the same space. This greatly increases the cost of manual collection and bean processing of low-altitude beans, making the overall profit lower. If the plantation owners in low-altitude areas want to avoid this situation, the moisture content of the beans will be higher during the processing of green beans. In summary, the above situation makes the storage environment of green beans more demanding.

[0057] Step three: coffee green beans preheating

[0058] The specific process of coffee preheating includes the following steps:

[0059] (1) Calculate the bean temperature and reheat point, observe the changes in color, aroma and taste of the beans during the heating process, and set the preheating time and temperature for the target roasting degree.

[0060] (2) Adjust the fire pressure to the set degree, after the green beans are put into the furnace after the preheating temperature is set, the point of the furnace temperature drop and then rise is the reheat point.

[0061] (3) From the reheat point, observe the beans, the color changes from green to light yellow green, the aroma changes from light to strong, and the overall color change is consistent, which is the standard for locking the temperature drop when the beans are taken out.

[0062] (4) Determine the smell released by the thermal reaction of the beans, the color presented, and the appearance, and set the preheating point for the desired roasting degree.

[0063] (5) Smell the smell released by the green beans after the reheat point and classify the attributes in the supplement.

[0064] (6) The reaction of A and B is that the green beans mature in a short time, and the preheating time and temperature are longer and higher, the preheating temperature is around 135 to 145 degrees Celsius, to achieve light yellow green and sucrose sweet aroma.

[0065] (7) Reactions belonging to C and D are when the raw beans reach maturity. The preheating temperature is around 110 to 120 degrees Celsius, and the beans have a sweet and fruity aroma.

[0066] (8) Reactions E and F indicate that the beans have begun to age and have basically lost their freshness. The preheating temperature should be around 125 degrees Celsius, and a slight sweet aroma of sucrose is sufficient.

[0067] (9) Reactions G and H indicate that the green beans are already aged and are not suitable for roasting. Forcing them to be used may affect the overall flavor of the coffee. This is an exception for some coffee varieties that have been properly stored and are aged.

[0068] (10) After preheating, the beans are taken out for natural cooling to determine the desired bean temperature for formal roasting.

[0069] Step 4: Roasting process is divided into 8 levels according to the coffee bean roasting color chart developed by SCAA, from light to dark:

[0070] Very light roast (Agtron color value 95): light yellow-brown, baked at the end of the intense first crack, the flavor is mainly bright acidity.

[0071] Cinnamon Roast (Agtron color value 85): Cinnamon color, baked around the end of first crack, the flavor is mainly sour with a sweet taste.

[0072] Medium roast (Agtron color value 75): chestnut color, baked after the first crack is completely over, the flavor is mainly sweet with a little fruit acidity.

[0073] Highly roasted (Agtron color value 65): light brown, baked in the quiet period before the start of the second crack, the flavor is mainly nutty and caramel, balanced and not sour.

[0074] City Roast (Agtron color value 55): Brown, baked at the beginning of the second crack, the flavor is more bitter and the caramel aroma is stronger.

[0075] City-wide roast (Agtron color value 45): dark brown, baked before the second crack, with a more bitter and fragrant flavor.

[0076] French roast (Agtron color value 35): black, with a mainly bitter flavor and a rich burnt aroma.

[0077] Italian Roast (Agtron Color 25): Very black, the darkest roast, and has a very bitter flavor.

[0078] These roasting degrees not only affect the flavor of the coffee, but also determine the color changes of the coffee beans. Lightly roasted coffee beans are lighter in color, and as the roasting degree deepens, the color of the coffee beans gradually darkens.

[0079] In non-competition applications, roasts are generally divided into three categories from light to dark: light roast, medium roast, and dark roast.

[0080] Lightly roasted coffee beans have a color value between 85 and 95, and are roasted at temperatures between 180°C and 205°C for 8 to 10 minutes. They range in color from light yellow-brown to cinnamon-colored, with a rough surface and a few black threads. They are dry and lack any oiliness. Their flavor profile is characterized by a strong acidity, often with notes of fruit, floral, and herbal enzymes. They have distinct layers but a low body.

[0081] Medium roasted coffee beans have a color value between 65 and 75, and are roasted at temperatures between 210°C and 220°C for 11 to 15 minutes. They range in color from ochre red to dark brown, with moderate bean expansion and a rough to smooth surface. A small amount of oil is matte. While the floral and fruity aromas are less pronounced, and notes of Maillard reaction, such as caramel and nuts, are more common, the acidity and sweetness are balanced, resulting in a mellower overall taste. The beans have a balanced acidity and bitterness, with prominent caramel and chocolate flavors.

[0082] The color value of dark roasted coffee beans is below 55, the temperature range is: 225℃ to 240℃, the time is: 15 to 20 minutes, the color is very dark brown sugar color or even close to black, the bean body is large and the bean surface is shiny, its flavor: rich bitterness, with smoky and caramel flavors, and the lowest acidity.

[0083] The starting pressure of roasting, the temperature of the beans, the preheating temperature, the setting of the pressure after the first stage of temperature recovery, the time to 100℃, pay attention to the heating rate from 100℃ to 130℃, observe the changes in the beans, determine the pressure of the next stage, adjust the pressure and heating rate at 150℃, observe the condition of the beans and calculate the pressure for catalytic explosion, the dehydration stage before the start of the first explosion: 170 to 185 (190)℃, and sample and test the effect of the preheating effect of the green beans on the flavor and taste of the coffee.

[0084] Step 5: Bean conditioning, which involves testing the coffee beans at 1 hour, 12 hours, 24 hours, 48 ​​hours, and 72 hours after roasting.

[0085] Through the above examples, there are significant differences in concepts, flavor performance and technical processing between authentic CAFA roasted coffee and traditional roasting. Traditional roasting focuses on stability and standardization, pursues popular taste and consistency, and usually serves commercial needs. Its acidity is weaker and tends to be softer or converted into a burnt bitterness through dark roasting to reduce the sharpness of the acidity. The taste of traditional roasting is thick and full, with a distinct oily feel, which is often seen in the rich and mellow style brought by dark roasting. Dark roasting can cover up some defects of raw beans, and has a relatively high fault tolerance rate. It is a "flavor shaper" and achieves balance and universality through roasting technology.

[0086] The authentic CAFA coffee roasting method emphasizes the expression of the origin and terroir of the coffee beans, highlighting the uniqueness of the variety, processing method and planting environment. It retains bright acidity through light-medium roasting, giving the coffee a lively fruity aroma and layered feeling. Its taste is light and delicate, with a silky smoothness, highlighting the cleanliness and complexity of the coffee. The authentic CAFA coffee roasting method has extremely high requirements for the quality of raw beans and roasting precision. Any defects will be magnified. It is an "interpreter of terroir" and focuses on native flavor and transparency.

[0087] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A coffee bean roasting method based on temperature control, characterized in that: The following steps are involved: Step 1: Select green coffee beans; Step 2: Green coffee bean storage and analysis; Step 3: Preheat the green coffee beans; Step 4: Roasting coffee beans; Step 5: Growing beans.

2. The coffee bean roasting method based on temperature control according to claim 1, characterized in that: In step 1, Arabica coffee beans produced in Yunnan are selected, and the beans are required to be neat in shape, uniform in size, blue-green or light green in color and shiny, have a floral or fruity aroma, and be hard and free from moisture and mold. The coffee beans must have been grown for at least five years.

3. The coffee bean roasting method based on temperature control according to claim 2, characterized in that: In step 2, the green beans are stored in a light-proof and ventilated environment at a room temperature of 20° C. to 25° C. and a humidity of 50% to 60%, maintaining a moisture content of 10% to 12%. The green beans are tested for polysaccharides (34% to 45%), proteins (12%), amino acids (1% to 2%), lipids (20%), chlorogenic acid (5% to 8%), other acids (2%), and caffeine (0.9% to 1.4%).

4. The coffee bean roasting method based on temperature control according to claim 3, characterized in that: The step three includes: Calculate the bean input temperature and re-temperature point, observe the changes in bean color, aroma, taste, and appearance during the heating process, and calibrate the preheating time and temperature to set the target roasting degree; Adjust the fire pressure and wait for the furnace to heat up to the set temperature. After the green beans are preheated to the set temperature and put into the furnace, the point where the temperature in the furnace drops and then rises again is the re-temperature point. Observe the beans from the re-warming point. The color changes from green to light yellow-green, and the aroma changes from light to strong. The overall performance is the change in size, consistency and color. This is the standard for cooling the beans out. Determine the aroma, color, and appearance of the beans during thermal reactions to determine the appropriate preheating point for the desired roasting degree. Smell the green beans after the return to temperature point to release the odor supplementary items in the classification attribute; Grade A. Blue-green, with a green grass and green pepper flavor, and a dull surface. Grade B. Green, grassy aroma, smooth surface; Grade C: Green with light yellow, sweet flowers and fruits, smooth surface; Grade D. Light yellow-green, fruity and sour, with a matte and dull surface; Grade E. Yellowish white, with a grain peanut shell smell and a bland surface; Grade F: Light brown, slightly sour smell, gray surface; The green beans are preheated according to their freshness: Grade A and B green beans are preheated at 135°C to 145°C until they are light yellow-green and have a sweet sucrose aroma; Grade C and D green beans are preheated at 110°C to 120°C until they have a sweet floral and fruity aroma; Grade E and F green beans are preheated at 125°C until they have a slight sweet sucrose aroma. The caramelization of carbohydrates and the decomposition of chlorogenic acid are also monitored during the preheating process.

5. The coffee bean roasting method based on temperature control according to claim 1, characterized in that: In step 4, the SCAA color value standard is used to control the baking degree, including: Light baking: 180℃ to 205℃ / 8 to 10 minutes, color value 85 to 95; Medium baking: 210℃ to 220℃ / 11 to 15 minutes, color value 65 to 75; Dark baking: 225℃ to 240℃ / 15 to 20 minutes, color value below 55; During the baking process, the fire pressure is adjusted in stages to complete dehydration at 170℃ to 190℃.

6. The coffee bean roasting method based on temperature control according to claim 1, characterized in that: The step five includes testing the coffee beans for indicators at 1 hour, 12 hours, 24 hours, 48 ​​hours, and 72 hours after the roasting is completed.

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