JP2020025512A - Method for producing fermented coffee beans - Google Patents

Abstract

To provide a method for producing coffee beans in which caffeine is reduced while leaving bitter taste unique to coffee, and odor is also reduced.SOLUTION: A method for producing fermented coffee beans has: a fermentation process of fermenting coffee beans; a hot water treatment process of treating coffee beans having passed through the fermentation process by hot water; and a roasting process of roasting coffee beans having passed through the hot water treatment process. It is preferable that the hot water treatment process is performed by immersing coffee beans having passed through the fermentation process into hot water in a container. Further, the roasting process may include a dewatering process of dewatering coffee beans after the hot water treatment process, and may have a washing process of washing coffee beans having passed through the hot water treatment process between the hot water treatment process and the roasting process.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing fermented coffee beans.

  Patent Document 1 discloses a method for treating coffee fruit, which includes a hot water treatment step of treating coffee fruit with hot water, and a microorganism capable of assimilating the coffee fruit and components contained in the coffee fruit after the hot water treatment step. It is described to have a fermentation step of contacting and fermenting. It is described that a hot water treatment step is performed to sterilize and remove living bacteria attached to the surface of the coffee fruit.

  Patent Literature 2 describes a method for roasting coffee beans, in which raw beans that have undergone a fermentation step are placed in a closed container, and pressurized steam of 5 bar or more is applied in the closed container. It describes that coffee beans are roasted in a short time by opening a closed container and rapidly reducing the pressure in the container after applying pressurized steam. It is described that coffee beans are roasted in a short time to suppress by-products such as benzopyrene that are generated with heating during roasting.

International Publication No. WO 2006/126588 Japanese Patent Publication No. 9-502099

  Fermentation of coffee beans has been performed to obtain coffee beans with reduced caffeine while leaving the bitterness unique to coffee. However, when coffee beans are fermented, odor may be generated, and reduction of odor is required. The method for treating coffee fruit of Patent Document 1 is intended to remove indigenous bacteria in the coffee fruit before the fermentation step, and does not consider reduction of the odor associated with fermentation at all. The method of roasting coffee beans disclosed in Patent Document 2 is aimed at suppressing by-products generated by heating during roasting, and does not consider reduction of odor due to fermentation at all.

  A method for producing a fermented coffee bean for solving the above-mentioned problems includes a fermentation step of fermenting coffee beans, a hot water treatment step of treating coffee beans having passed through the fermentation step with hot water, and a hot water treatment step. A roasting step of roasting coffee beans.

  According to this configuration, by including the hot water treatment step of treating the coffee beans that have undergone the fermentation step with hot water, it is possible to reduce the odor generated due to the fermentation of the coffee beans. Therefore, it is possible to produce coffee beans with reduced caffeine and reduced odor while leaving the bitterness peculiar to coffee.

  In the method for producing fermented coffee beans, the hot water treatment step is preferably performed by immersing the coffee beans that have undergone the fermentation step in hot water in a container. According to this configuration, the coffee beans that have undergone the fermentation process can be more uniformly treated with hot water.

  In the method for producing fermented coffee beans, it is preferable that the roasting step includes a dehydration step of dehydrating the coffee beans after the hot water treatment step. According to this configuration, by including the dewatering step, it becomes easy to remove the odor components from the coffee beans that have undergone the hot water treatment step.

  The method for producing fermented coffee beans preferably includes a washing step of washing the coffee beans that have passed through the hot water treatment step between the hot water treatment step and the roasting step. According to this configuration, by having the washing step, the odor component can be more reliably removed from the coffee beans that have undergone the hot water treatment step.

  ADVANTAGE OF THE INVENTION According to this invention, while reducing the caffeine while leaving the bitterness peculiar to coffee, it is possible to produce coffee beans with reduced odor.

Hereinafter, embodiments embodying the present invention will be described in detail.
Fermented coffee beans are produced by sequentially passing through a fermentation step, a hot water treatment step, a washing step, and a roasting step described below.

(Fermentation process)
The fermentation step is a step of fermenting coffee beans.
Hot water is added to green coffee beans and stirred to produce a mixture of green beans and hot water. Bacteria (microorganisms) are added to the stirred product. Fermentation is carried out by maintaining the agitated material containing the bacteria under predetermined conditions. The temperature of the hot water added to the green beans is preferably, for example, 60 to 100 ° C, and more preferably 70 to 90 ° C. The amount of hot water to be added to the green beans is, for example, preferably 100 to 10,000 cc, more preferably 1,000 to 5,000 cc for 10 kg of green beans.

  The amount of bacteria to be used can be appropriately set in consideration of time and cost. For example, the amount is preferably 0.1 g to 20 g, and more preferably 1 g to 10 g, for 10 kg of green coffee beans. As the fermentation conditions, for example, it is preferable to keep the stirred mixture containing the bacteria at 30 to 45 ° C. for 30 minutes to 48 hours.

  Raw beans used in the fermentation step are not particularly limited. For example, after harvesting the coffee fruit, dried beans may be unhulled to remove the outer skin, pulp, inner rind, silver skin, etc., and so-called non-washed green beans may be used. After harvesting the coffee fruit, sink it in a water tank to remove impurities, remove the rind and pulp with a pulp remover, then sink it in water to dissolve and remove the sticky substance, wash it with water, and then dry it. Raw beans isolated by a so-called water-washing method, in which shells are removed to remove endocarp and silver skin, may be used.

  As the bacteria used for fermentation, for example, yeast, lactic acid bacteria, mold and the like can be used. As the yeast, for example, yeast for brewing such as yeast for wine fermentation and yeast for beer fermentation can be used. As the lactic acid bacteria, for example, known bacteria used for producing fermented milk, lactic acid bacteria drinks, cheese fermented milk and the like can be used. As the mold, for example, koji mold used for producing fermented foods such as sake, shochu, miso, and soy sauce can be used.

  In addition to the bacteria used for fermentation, assimilable components that can be used by the bacteria used for fermentation may be used. Examples of the assimilation component include pulp, fruit juice, sugars, cereals, a medium, and the like. As the pulp, for example, coffee pulp, grape pulp, cherry pulp, peach pulp and the like can be used. Grape juice, peach juice, apple juice and the like can be used as fruit juice. As saccharides, monosaccharides, disaccharides, polysaccharides and the like obtained from plants such as sugarcane and sweet potato can be used. As cereals, wort obtained by saccharifying malt or the like can be used. As the medium, those used for ordinary microorganism culture can be used. Further, a pH adjuster such as citric acid or malic acid may be used.

(Hot water treatment process)
The hot water treatment step is a step of immersing coffee beans that have undergone the fermentation step in hot water.
The fermented coffee beans are put into a container containing boiling hot water, and the coffee beans are boiled while stirring. As the container containing the hot water, a container equipped with a known stirrer can be used. Using a container without a stirrer, boiling may be performed while stirring using a manual stirring jig. The temperature of the hot water is preferably, for example, 80 to 100 ° C. The boiling time is preferably, for example, 5 to 60 minutes, more preferably 10 to 20 minutes.

(Washing process)
The washing step is a step of washing the coffee beans that have undergone the hot water treatment step.
The coffee beans that have undergone the hot water treatment step are transferred to a known washing container and washed with water. As the washing container, for example, a known grain washing machine can be used. The coffee beans that have undergone the hot water treatment process are put into a washing machine and washed. The temperature of the water used in the washing step is not particularly limited, and is preferably, for example, 5 to 40 ° C. The washing time is preferably, for example, 1 to 15 minutes. When the coffee beans are washed by the hot water in the hot water treatment step, the washing step may be omitted.

(Roasting process)
The roasting step is a step of heating and roasting the coffee beans that have undergone the washing step. The roasting step includes a dehydration step of dehydrating coffee beans that have passed through the washing step, a drying step of further removing water from the coffee beans that have passed through the dehydration step, and a heating step of heating the coffee beans that have passed through the drying step. .

[Dehydration process]
The dehydration step is a step of removing water contained in the coffee beans that have passed through the washing step.
In the dehydration step, a known dehydrator, for example, a known batch dehydrator can be used.

Put the coffee beans after the washing process into a special net, and put the net into a dehydrator to dehydrate. The dehydration time is preferably, for example, 1 to 15 minutes.
[Drying process]
The drying step is a step of further removing water contained in the coffee beans that have undergone the dehydration step.

  In the drying step, a known continuous dryer can be used. As the continuous dryer, for example, a known shelf-type continuous automatic dryer can be used. Further, a known batch dryer may be used. The drying condition is preferably, for example, at 60 to 180 ° C. for 30 to 90 minutes.

  If water is not forcibly removed from the coffee beans after the washing step, the dehydration step and the drying step may be omitted. That is, moisture may be naturally removed from the coffee beans that have undergone the washing step. One of the dehydration step and the drying step may be omitted.

[Heating process]
In the heating step, a known roaster, for example, a known hot-air roaster can be used. The roasting conditions are preferably, for example, at 190 to 260 ° C. for 10 to 30 minutes.

By performing the above steps, fermented coffee beans can be obtained.
The operation and effect of the present embodiment will be described.
(1) It has a fermentation step of fermenting coffee beans, a hot water treatment step of treating coffee beans having undergone the fermentation step with hot water, and a roasting step of roasting coffee beans having undergone the hot water treatment step.

  By having a hot water treatment step of treating coffee beans that have undergone the fermentation step with hot water, it is possible to reduce the odor generated due to the fermentation of the coffee beans. Therefore, it is possible to produce coffee beans with reduced caffeine and reduced odor while leaving the bitterness peculiar to coffee. In addition, since the amount of caffeine is reduced, it is possible to produce coffee beans capable of extracting a coffee beverage that is easy to drink even for people who are not good at caffeine.

  (2) The hot water treatment step is performed by immersing coffee beans that have undergone the fermentation step in hot water in a container. Hot water treatment can be performed more uniformly on coffee beans than in a mode in which hot water is sprayed on coffee beans in a container. Therefore, the hot water treatment step can be performed more efficiently.

  (3) The roasting step includes a dehydration step and a drying step. By including the dehydration step, it becomes easy to remove the odor components from the coffee beans that have undergone the washing step. Further, by including the drying step, the moisture contained in the coffee beans can be removed in a short time. Therefore, by including the dehydration step and the drying step, the odor component can be efficiently removed and the time of the roasting step can be shortened, so that the productivity of fermented coffee beans can be improved.

  (4) A washing step is provided between the hot water treatment step and the dehydration step to wash the coffee beans that have passed through the hot water treatment step. By having the washing step, the odor components can be more reliably removed from the coffee beans that have undergone the hot water treatment step. Further, impurities such as dust can be removed.

This embodiment can be implemented with the following modifications. Further, the configuration of the above-described embodiment and the configuration shown in the following modified examples can be appropriately combined and implemented.
The hot water treatment step is not limited to a mode in which coffee beans that have undergone the fermentation step are immersed in hot water in a container. After filling the container with the coffee beans that have undergone the fermentation step, hot water treatment may be performed by introducing hot water into the container.

  -Apart from the hot water treatment step of treating coffee beans that have undergone the fermentation step with hot water, hot water treatment may be performed on the coffee beans before the fermentation step. By performing the hot water treatment on the coffee beans before the fermentation step, it is possible to sterilize and remove the living bacteria adhering to the surface of the coffee beans.

-The washing step is not limited to the mode performed between the hot water treatment step and the roasting step. A washing step may be performed between the fermentation step and the hot water treatment step.
-The roasting step may be performed plural times. For example, the first roasting may be performed, and then the roasting may be performed twice.

The technical ideas that can be grasped from the above-described embodiment and its modifications will be described below together with their effects.
Separately from the hot water treatment step (second hot water treatment step) of treating coffee beans that have undergone the fermentation step with hot water, a hot water treatment step (first hot water treatment step) performed on coffee beans before the fermentation step ). By having the first hot water treatment step, it is possible to sterilize and remove inhabitants that adhere to the surface of the coffee beans.

Claims (4)

Fermentation process to ferment coffee beans,
A hot water treatment step of treating the coffee beans that have undergone the fermentation step with hot water,
A roasting step of roasting the coffee beans that have undergone the hot water treatment step.   The method for producing fermented coffee beans according to claim 1, wherein the hot water treatment step is performed by immersing the coffee beans that have undergone the fermentation step in hot water in a container.   The method for producing fermented coffee beans according to claim 1 or 2, wherein the roasting step includes a dehydration step of dehydrating the coffee beans after the hot water treatment step. The method for producing fermented coffee beans according to any one of claims 1 to 3, further comprising a washing step of washing the coffee beans that have passed through the hot water treatment step between the hot water treatment step and the roasting step.