A coffee green bean flavor optimization roasting method based on a thermal compensation model for adapting all-specification direct-fired equipment

Abstract

The application discloses a coffee green bean flavor optimization roasting method based on a heat compensation model and suitable for full-specification direct fire equipment, and belongs to the technical field of coffee roasting processes. The method calibrates the preheating temperature by measuring the temperature loss value of the equipment, adopts 145-155 DEG C as the unified target bean temperature, adopts phased fire regulation to complete roasting, and adopts forced rapid cooling to lock the flavor after the roasting is completed. The application does not need to transform the equipment, can be suitable for 200g to industrial full-specification direct fire roasting machines, can effectively improve the problems of uneven astringency, smoky miscellaneous flavor and unstable batch flavor of coffee beans, and the finished product has prominent sweetness, clean flavor and obvious origin characteristics, is suitable for various high-quality coffee roasting production, and has strong practicality and popularization value.

Description

Technical Field

[0001] This invention relates to the field of coffee roasting technology, specifically to a method for optimizing the flavor of green coffee beans based on a heat compensation model and adapted to all types of direct-fire equipment. Background Technology

[0002] Direct-fire roasting, which primarily uses heat radiation and conduction, can fully bring out the aroma and sweetness of coffee beans, making it the mainstream roasting method in the specialty coffee industry. However, existing direct-fire roasting processes have significant limitations: the heat capacity and temperature drop characteristics of direct-fire equipment with different capacities and heat sources vary significantly, making it difficult to apply a single roasting curve universally, resulting in poor versatility of roasting solutions; the preheating process lacks quantitative calibration logic, leading to large temperature fluctuations when adding beans, which can easily cause problems such as uneven acidity, burnt exterior and undercooked interior, and smoky off-flavors; the roasting process is highly dependent on the operator's experience, making it difficult to stably replicate and mass-produce.

[0003] Existing improvements mainly focus on optimizing the structure of roasting equipment, such as improving drums, air ducts, and heating components. However, these improvements are costly and only compatible with a limited number of models, failing to achieve universal and standardized roasting across all specifications of direct-fire equipment from a process perspective. Therefore, this invention, based on the principle of heat compensation, establishes a coffee bean roasting method that does not rely on equipment modifications, is universally applicable across specifications, and exhibits strong flavor stability, thus addressing the pain points of existing technologies. Summary of the Invention

[0004] Purpose of the invention Overcoming the shortcomings of existing direct-fire roasting processes, such as poor adaptability, insufficient stability, and high dependence on human experience, this method achieves stable roasting results with clean coffee bean flavor, prominent sweetness, low acidity and astringency, and obvious regional characteristics. At the same time, it makes the roasting process adaptable to all specifications of direct-fire equipment from small-scale trials to commercial and industrial-grade applications, improving the versatility and replicability of the process. Technical solution

[0005] A method for optimizing the flavor of green coffee beans based on a heat compensation model and adapted to all types of direct-fire equipment includes the following steps: 1. Equipment preheating and calibration The temperature drop value of the target direct-fire roasting equipment was measured. Temperature changes were recorded by feeding test green beans, and the actual temperature loss after the roasting equipment was preheated to the set temperature was obtained. The formula is as follows: Preheating temperature = Target bean temperature + Equipment temperature loss value Set the preheating parameters and run them stably, with the target bean temperature controlled at 145–155℃.

[0006] 2. Bean-laying start-up phase Place the green coffee beans into the preheated roasting chamber. Once the bean temperature has stabilized, heat the beans at 80%–100% of the equipment's rated heating power for 2 ± 0.5 minutes to quickly establish a thermal field within the beans and lock in their basic sweetness.

[0007] 3. Flavor Transformation Stage After the high-heat stage, switch to a medium-low heat of 40%–60% of the equipment's rated heating power and continue heating for 7–9 minutes to allow the coffee beans to fully dehydrate and undergo Maillard reactions, thus building the flavor base.

[0008] 4. Aroma Development and Finishing Stages After the flavor conversion stage, switch to medium-high heat at 60%–80% of the equipment's rated heating power until the coffee beans experience a dense first crack; then switch to low heat at 20%–40% power for continuous heating until the first sound of the second crack is heard, then stop heating 10±5 seconds later.

[0009] 5. Forced rapid cooling Immediately after roasting, the beans are removed and cooled using a combination of forced air cooling and a perforated metal container. Within 3–5 minutes, the bean temperature is reduced to below 50°C, stopping the thermal reaction and locking in the final flavor. Beneficial effects

[0010] 1. The preheating temperature is calibrated using a thermal compensation model, which can eliminate the temperature loss differences of direct-fired equipment of different specifications and heat sources, and achieve universal compatibility for all models from 200g to industrial grade.

[0011] 2. Precise fire control in stages, combined with key control at the first and second cracks, results in clean and stable coffee bean flavor, low acidity and astringency, strong sweetness, no off-flavors, and prominent regional characteristics.

[0012] 3. The process parameters are quantifiable and replicable, significantly reducing reliance on human experience, making it suitable for small-batch boutique baking and large-scale production.

[0013] 4. No equipment modification is required, implementation costs are low, compatibility is strong, and it has high practicality and promotional value. Detailed Implementation

[0014] The present invention applies to green coffee beans with a moisture content of 9.0% to 12.0%, including Arabica, Canifola (including Robusta), Liberica, and green beans from common specialty coffee producing regions.

[0015] Example 1: 200g Gas-fired Direct-fire Baking Machine The equipment temperature drop value is 100℃, the target bean temperature is 150℃, and the preheating temperature is set to 250℃.

[0016] After adding the beans, heat over high heat (90% power) for 2 minutes, then heat over medium-low heat (50% power) for 8 minutes, then heat over medium-high heat (70% power) until the first crack is dense, then heat over low heat (30% power) until 10 seconds after the first crack, then force-cool for 4 minutes until the bean temperature drops below 45℃.

[0017] The resulting coffee beans have a bright floral aroma, a clean sweetness, and no sour or astringent tastes.

[0018] Example 2: 1kg Electric Direct-Fire Baking Machine The equipment temperature drop value is 70℃, the target bean temperature is 150℃, and the preheating temperature is set to 220℃.

[0019] After adding the beans, heat over high heat (85% power) for 2.5 minutes, then heat over medium-low heat (45% power) for 7.5 minutes, then heat over medium-high heat (65% power) until the first crack is dense, then heat over low heat (25% power) until 8 seconds after the first crack, then force-cool for 5 minutes.

[0020] The resulting coffee beans have a rich fruity aroma and a sweet, smooth taste.

[0021] Example 3: 6kg Biomass Direct-Fire Roasting Machine The equipment temperature drop value is 50℃, the target bean temperature is 148℃, and the preheating temperature is set to 198℃.

[0022] After adding the beans, heat over high heat (95% power) for 1.8 minutes, then heat over medium-low heat (55% power) for 9 minutes, then heat over medium-high heat (75% power) until the first crack is dense, then heat over low heat (35% power) until 12 seconds after the first crack, then force-cool for 3 minutes.

[0023] The resulting coffee beans exhibit high batch-to-batch consistency and a rich, stable flavor. Attached Figure Description

[0024] Figure 1 This is a flowchart of the baking method of the present invention. 1—Equipment preheating calibration 2—Bean-laying start-up stage 3—Flavor Transformation Stage 4—Induction and Finishing Stages 5—Forced rapid cooling.

Claims

1. A method for optimizing the flavor of green coffee beans based on a thermal compensation model, adaptable to all types of direct-fire equipment, characterized in that... Includes the following steps: (1) Equipment preheating calibration: Measure the temperature loss value of the target direct fire roasting equipment, put in a specified amount of test beans and record the temperature change to obtain the actual temperature loss value of beans after the equipment is heated to the set temperature. Set the equipment preheating parameters according to the formula "preheating temperature = target bean temperature + equipment temperature loss value" and run it stably; the target bean temperature is 145-155℃; (2) Bean feeding start-up stage: Put the green coffee beans into the preheated roasting chamber. After the bean temperature stabilizes in the target range, start the high-heat heating for 2±0.5 minutes. The high-heat heating is 80%-100% of the rated heating power of the equipment. (3) Flavor transformation stage: After the high-heat start-up stage, switch to medium-low heat for 7-9 minutes, where the medium-low heat is 40%-60% of the equipment's rated heating power; (4) Aroma enhancement and finishing stage: After the flavor transformation stage, switch to medium-high heat until the coffee beans show a dense first crack phenomenon, then immediately switch to low heat and continue heating until the first sound of the second crack is heard, and stop heating 10±5 seconds later; the medium-high heat is 60%-80% of the rated heating power of the equipment, and the low heat is 20%-40% of the rated heating power; (5) Forced rapid cooling: Take out the coffee beans after step (4) and use a combination of forced air cooling and metal container heat dissipation to reduce the bean temperature to below 50°C within 3-5 minutes to complete the roasting.

2. The baking method according to claim 1, characterized in that, The green coffee beans are selected from at least one of Arabica, Canephora (including Robusta), and Liberica varieties; the moisture content of the green coffee beans is 9.0% to 12.0%.

3. The baking method according to claim 1, characterized in that, The direct-fire roasting equipment includes commercial specifications of 200g, 500g, 1kg, 3kg, and 6kg, as well as industrial-grade large-scale direct-fire coffee roasting equipment; the heat sources of the equipment include gas direct-fire, electric direct-fire, and biomass fuel direct-fire.

4. The baking method according to claim 1, characterized in that, In step (5), the forced air cooling wind speed is ≥3m / s, and the metal container is a pair of interlocking hollow metal baskets with a hole diameter of 0.5-1cm.

5. The baking method according to claim 1, characterized in that, "Dense bursts" means ≥3 bursts per second, and "first sound of the second burst" means a crisp bursting sound that is clearly different from the first burst.

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