Variable pressure coffee extractor and method of extracting coffee liquid

Abstract

The variable pressure coffee extractor comprises: a first container; a second container communicating with the first container and having an adjustable internal pressure, the second container accommodating coffee extract; a filter unit positioned at a communicating part between the first and second containers and configured to hold coffee grounds before extraction and to filter residues generated from the coffee grounds after extraction; and a pressure control module attachable to and detachable from the second container and provided to adjust the air pressure inside the second container, whereby the coffee grounds before extraction are supplied to the first container to form a coffee slurry by mixing the coffee grounds with hot water or the coffee extract filtered from the coffee slurry of the first container via the filter unit is discharged to the second container. Accordingly, coffee liquid can be easily extracted using the pressure change inside the second container.

Description

Pressure-type coffee extractor and coffee extracting method

[0001] Embodiments of the present invention relate to a variable pressure coffee extractor and a coffee extracting method. More specifically, embodiments of the present invention relate to a coffee extracting method that extracts coffee extract from coffee powder using changes in air pressure.

[0002] Generally, there are two methods of extracting coffee: espresso extraction using a pressurized water pump and drip extraction using water falling by gravity.

[0003] The above drip extraction method includes a method using a coffee maker and a hand drip method in which the user directly sprays water onto coffee powder to extract coffee.

[0004] The drip method using a coffee maker is simple to use, as it automatically extracts coffee by supplying coffee powder and water to the coffee maker. This method offers the advantages of simple extraction and long-term retention. However, if large quantities of coffee are extracted and retained, the taste and flavor are significantly reduced. Longer retention times can lead to a burnt taste in the coffee. Furthermore, because the water passes through the coffee powder over a long period of time to extract the coffee, harmful components in the coffee powder are extracted, and many impurities are mixed in during the extraction process, diminishing the flavor and aroma of the coffee beans.

[0005] Meanwhile, the hand drip method is a method of manually dripping coffee. After placing coffee powder in a dripper, the user pours heated water over the coffee powder using a drip pot to extract the coffee. This method has the advantage of maximizing the flavor and taste of the coffee compared to the method using a coffee maker because the water spray method can be adjusted according to the characteristics of each coffee bean and the dripper. However, because the hand drip method is a manual method, the recipe varies from person to person, and the amount, speed, and direction of water sprayed onto the coffee powder are inconsistent. In addition, it is difficult to supply a fixed amount of water for each drip. As a result, the taste of the coffee can vary greatly with each extraction, and there is a problem of great individual differences.

[0006] Therefore, there is a need for a coffee extractor capable of extracting coffee liquid from coffee powder with a consistent taste in a simple manner.

[0007] Embodiments of the present invention provide a variable pressure coffee extractor capable of extracting coffee liquid from coffee powder by changing pressure.

[0008] Embodiments of the present invention provide a coffee extraction method capable of extracting coffee liquid from coffee powder by changing pressure.

[0009] A variable pressure coffee extractor according to embodiments of the present invention includes a first container into which hot water is introduced from the outside, a second container that is connected to the first container and has an adjustable internal pressure and accommodates a coffee extract, a filter unit located in a connected portion between the first and second containers and that loads coffee powder before extraction and filters residue generated from the coffee powder after extraction, and a pressure control module that is detachably attached to any one of the first and second containers and the filter unit and that supplies the pre-extraction coffee powder into the first container by utilizing a pressure difference between the insides of the first and second containers, stirs the coffee powder in the hot water to form a coffee stirring liquid, and discharges the filtered coffee extract from the first container via the filter unit.

[0010] In one embodiment of the present invention, the pressure control module may include a first connecting portion that surrounds the outer surface of the first container and has a through hole formed in the side wall that communicates with an external pressure pump, and a second connecting portion that surrounds the lower portion of the first container below the first connecting portion and to which the filter portion can be fastened.

[0011] Here, the pressure control module may additionally be provided with a first sealing groove formed along the upper surface of the second connecting portion, and a first sealing member disposed inside the first sealing groove and configured to suppress gas leakage from the second container.

[0012] Additionally, the filter unit may include a filter body having a plurality of through grooves formed therein and a filter side wall extending upward from the outer surface of the filter body.

[0013] Here, a spiral guide groove is formed on the inner surface of the filter side wall, a guide protrusion is formed on the outer surface of the second connecting portion, and the guide protrusion is screw-fastened along the guide groove so that the second connecting portion and the filter side wall can be detachably fastened to each other.

[0014] In addition, a second sealing groove is formed at the lower end of the outer shaft of the second connecting portion, and the pressure control module may further include a second sealing member disposed inside the second sealing groove and suppressing gas leak between the filter side wall and the second connecting portion.

[0015] In one embodiment of the present invention, the first connecting portion may include a first connecting portion that is screw-connected to an outer portion of the first container and has a first diameter, a second connecting portion that is connected to a lower portion of the first connecting portion and is detachably provided with the second container and has a second diameter larger than the first diameter, and a connecting portion that interconnects the lower portion of the first connecting portion and the upper portion of the second connecting portion.

[0016] Here, a fastening groove may be formed at the lower end of the second fastening portion to be connected to the upper end of the second container.

[0017] In one embodiment of the present invention, the pressure control module includes a pressure pump connected to the second container and a controller for controlling the pressure of the pressure pump,

[0018] The controller may increase the pressure inside the second container to supply the pre-extraction coffee powder located in the filter section to the first container, stir the coffee powder in the hot water to form a coffee stirring liquid, and reduce the pressure inside the second container to discharge the coffee stirring liquid from the first container through the filter section to the filtered coffee extract into the second container.

[0019] In one embodiment of the present invention, a hot water supply unit for supplying hot water into the interior of the first container may be additionally provided.

[0020] According to embodiments of the present invention, a coffee extraction method of a coffee extractor having a first container into which hot water is introduced from the outside, a second container communicated with the first container, the second container having an adjustable internal pressure and containing a coffee extract, and a filter unit located in a portion communicated between the first and second containers and loading coffee powder before extraction and filtering the coffee powder after extraction, wherein coffee powder is placed in the filter unit, hot water is supplied to the first container, and the pressure inside the second container is increased, thereby supplying the coffee powder from the filter unit to the first container, thereby stirring the coffee powder in the hot water inside the first container to form a coffee stirring liquid. Thereafter, the pressure inside the second container is reduced, so that the coffee stirring liquid from the first container is filtered through the filter unit and extracted into the second container.

[0021] In one embodiment of the present invention, the step of supplying hot water to the first container can increase the pressure inside the receiving space of the second container to suppress the hot water from moving from the first container to the second container.

[0022] In one embodiment of the present invention, when reducing the pressure inside the second container, the pressure reduction speed can be adjusted depending on the type or grinding degree of the coffee powder.

[0023] In contrast, when reducing the pressure inside the second container, the pressure reduction speed can be controlled according to the temperature of the hot water.

[0024] A variable pressure coffee extractor according to embodiments of the present invention includes a pressure control module configured to supply pre-extraction coffee powder to the first container by utilizing the pressure difference between the insides of the first and second containers, stir the coffee powder in hot water to form a coffee stirring liquid, or discharge the coffee stirring liquid from the first container through a filter unit to form a filtered coffee extract into the second container. As a result, coffee liquid can be easily extracted from the coffee powder by utilizing the pressure difference between the first and second containers.

[0025] Additionally, the pressure control module instantaneously adjusts the pressure inside the second container, thereby reducing the coffee extraction time. Accordingly, the potential for coffee flavor degradation due to excessively long coffee extraction times can be suppressed.

[0026] FIG. 1 is a perspective view illustrating a pressure-type coffee extractor according to an embodiment of the present invention.

[0027] Figure 2 is an exploded perspective view illustrating the pressure-type coffee extractor of Figure 1.

[0028] FIG. 3 is a cross-sectional view for explaining the connection relationship between the first container, the second container, the filter unit, and the first and second connecting units of FIG. 1.

[0029] Figure 4 is a flowchart for explaining a coffee extraction method according to an embodiment of the present invention.

[0030] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below and may be embodied in various other forms. The following embodiments are provided not to fully complete the present invention, but rather to fully convey the scope of the present invention to those skilled in the art.

[0031] In embodiments of the present invention, when an element is described as being disposed on or connected to another element, the element may be directly disposed on or connected to the other element, and other elements may be interposed between them. Conversely, when an element is described as being directly disposed on or connected to another element, there cannot be another element between them. Terms such as first, second, and third may be used to describe various items, such as various elements, compositions, regions, layers, and / or parts, but the items are not limited by these terms.

[0032] The technical terms used in the embodiments of the present invention are used solely for the purpose of describing specific embodiments and are not intended to limit the present invention. Furthermore, unless otherwise specified, all terms, including technical and scientific terms, have the same meaning as would be understood by a person skilled in the art having ordinary knowledge in the technical field of the present invention. Terms such as those defined in conventional dictionaries are to be interpreted as having a meaning consistent with their meaning within the context of the relevant technology and the description of the present invention, and will not be interpreted as idealistic or overly superficially intuitive unless explicitly defined.

[0033] Embodiments of the present invention are described with reference to schematic drawings of ideal embodiments of the present invention. Accordingly, variations from the shapes of the drawings, such as variations in manufacturing methods and / or tolerances, are fully expected. Accordingly, embodiments of the present invention are not limited to the specific shapes of the regions illustrated in the drawings, but include deviations from those shapes. The elements illustrated in the drawings are purely schematic, and their shapes are not intended to describe the precise shapes of the elements, nor are they intended to limit the scope of the present invention.

[0034] Fig. 1 is a perspective view illustrating a pressure-type coffee extractor according to an embodiment of the present invention. Fig. 2 is an exploded perspective view illustrating the pressure-type coffee extractor of Fig. 1. Fig. 3 is a cross-sectional view illustrating the connection relationship between the first container, the second container, the filter unit, and the first and second connecting units of Fig. 1.

[0035] Referring to FIGS. 1 to 3, a pressure-type coffee extractor (10) according to an embodiment of the present invention includes a first container (110), a second container (120), a filter unit (130), and a pressure control module (150). The pressure-type coffee extractor (10) may correspond to, for example, an automatic coffee dripper.

[0036] The first container (110) can receive hot water from the outside. The first container (110) may include, for example, a cylindrical tube (111). The first container (110) has a first hollow space formed therein. The first hollow space is defined as a first receiving space capable of storing hot water therein.

[0037] A first screw thread (119) may be formed on the outer wall of one end of the container (110). A component of the pressure control module may be screw-connected to the first container (110) through the first screw thread (119).

[0038] The second container (120) is connected to the first container (110). The second container (120) is provided with an adjustable internal pressure. That is, the internal pressure of the second container (120) can be adjusted by the pressure control module (150). The second container (120) may be, for example, a coffee receiver, a mug, or the like.

[0039] The above second container (120) can move linearly using a vertical driving source such as a cylinder.

[0040] In the second container (120), a space for containing coffee extract is formed inside.

[0041] The filter unit (130) is located in the portion connected between the first and second containers (110, 120). A filter paper may be positioned on the upper surface of the filter unit (130) to allow the coffee powder to be positioned before extraction. Thus, the filter unit (130) can load the coffee powder before extraction and filter the coffee powder after extraction. Thus, the extracted coffee liquid can have an excellent flavor.

[0042] The pressure control module (150) is detachably mounted on the second container (120). In addition, the pressure control module (150) can seal the second receiving space of the second container (120) using a third sealing member (158), for example, an O-ring.

[0043] Meanwhile, the pressure control module (150) may be detachably fixed to the first container (110) or the filter unit (130). For example, the pressure control module (150) may be screw-fastened to the first container (110). In addition, the pressure control module (150) may be screw-fastened to the filter unit (130).

[0044] The pressure control module (150) can control the pressure inside the second container (120). The pressure control module (150) can control the pressure inside the second container (120) using a pressure pump (159), etc. At this time, the pressure control module (150) can use air having a general temperature (e.g., 20-25 degrees Celsius), i.e., room temperature.

[0045] For example, the pressure control module (150) can control the pressure of the second receiving space inside the second container (120). For example, the second receiving space can have a first pressure higher than the general atmospheric pressure. In this case, the pre-extraction coffee powder located in the filter unit (130) can rise and be supplied to the first container (110). At this time, the coffee powder can be stirred in the hot water supplied into the first container (110) to form a coffee stirring liquid. At this time, the pressure control module (150) can maintain the second receiving space at a positive pressure for a certain period of time, thereby maintaining the stirring time for stirring the coffee powder in the hot water.

[0046] Conversely, the pressure control module (150) can reduce the pressure in the second receiving space inside the second container (120).

[0047] For example, the pressure in the second receiving space inside the second container (120) can be reduced from the first pressure to a second pressure, for example, a negative pressure, that is, a pressure lower than the general atmospheric pressure. In this case, the coffee stirred liquid from the first container (110) passes through the filter unit and the filtered coffee extract descends. As a result, the coffee extract can be discharged into the second container (120), so that the coffee extract can be accommodated in the second container (120).

[0048] The variable pressure coffee extractor (10) according to embodiments of the present invention can extract coffee liquid by utilizing the pressure difference between the first container and the second container (110, 120) by variably controlling the pressure of the second container (120).

[0049] Furthermore, by directly supplying hot water from outside to the first container (110), a separate heating process for heating the water can be omitted. Furthermore, the temperature of the hot water can be precisely controlled. Consequently, a precisely controlled coffee extract can be produced in a relatively short period of time.

[0050] In addition, by precisely controlling the pressure difference between the first container (110) and the second container (120), the coffee drip time can be prevented from becoming excessively long, thereby preventing the flavor of the coffee extract from deteriorating.

[0051] The pressure control module (150) according to one embodiment of the present invention may include a first connecting portion (151) and a second connecting portion (152) in which a through hole (151d) is formed.

[0052] The first connecting portion (151) is provided to surround the outer periphery of the first container (110). For example, the first connecting portion (151) may be screw-connected to the first screw thread (119) formed on the first container (110).

[0053] A through hole (151d) is formed in the side wall of the first connecting portion (151). The through hole (151d) is connected to an external pressure pump (159). The through hole (151d) is connected to the second receiving space of the second container (120), so that the internal pressure of the second receiving space can be controlled.

[0054] The second connecting portion (152) is positioned below the first connecting portion (151). The second connecting portion (152) is provided to surround the lower end of the first container (110). The second connecting portion (152) can be screw-fastened to the first screw thread (119) formed at the lower end of the first container (110). Thus, the first and second connecting portions (151, 152) can be fastened to the first container (110).

[0055] Meanwhile, the filter unit (130) can be fixed to the second connecting unit (152).

[0056] In one embodiment of the present invention, a first sealing groove (152c) is formed along the upper surface of the second connecting portion (152). At this time, the pressure control module (150) may further include a first sealing member (156) disposed inside the first sealing groove (152c). The first sealing member (156) is provided so as to suppress gas leakage from the second container (120).

[0057] In one embodiment of the present invention, the filter unit (130) includes a filter body (131) and a filter side wall (136).

[0058] The filter body (131) may have a disk shape. The filter body (131) supports filter paper. A plurality of through grooves (131a) are formed in the filter body (131).

[0059] The filter side wall (136) extends upward from the outer edge of the filter body (131). The filter side wall (136) may have a ring shape.

[0060] At this time, a spiral guide groove (136a) is formed on the inner surface of the filter side wall (136). Meanwhile, a guide protrusion (152a) is formed on the outer surface of the second connecting portion (152). The guide protrusion (152a) moves along the guide groove (136a), thereby allowing the filter side wall (136) to be screw-fastened to the second connecting portion (152). As a result, the second connecting portion (152) and the filter side wall (136) can be detachably fastened to each other.

[0061] Meanwhile, a second sealing groove (152d) is formed at the lower end of the outer shaft of the second connecting portion (152). At this time, the pressure control module (150) may further include a second sealing member (157) that is positioned inside the second sealing groove (152d) and suppresses gas leak between the filter side wall (136) and the second connecting portion (152).

[0062] In one embodiment of the present invention, the first connecting portion (151) includes a first fastening portion (151a) having a first diameter, a second fastening portion (151b) having a second diameter, and a connecting portion (151c) that interconnects the lower end of the first fastening portion (151a) and the upper end of the second fastening portion (152).

[0063] The first fastening portion (151a) can be screw-fastened to the outer portion of the first container (110).

[0064] Meanwhile, the second fastening portion (15b) is connected to the lower portion of the first fastening portion (151a) and is detachably provided on the second container (120). At this time, the second diameter is larger than the first diameter. A through-hole (151d) that penetrates the second fastening portion (151b) and is connected to a pressure pump (159) can be formed.

[0065] Furthermore, a fastening groove may be formed at the lower end of the second fastening portion (151b) to be connected to the upper end of the second container (120). A third sealing member (158) may be inserted into the fastening groove. As a result, the third sealing member (158) may seal the second receiving space of the second container (120).

[0066] Referring to FIGS. 2 and 3, the pressure control module (150) may further include a pressure pump (159) and a controller (158).

[0067] The above pressure pump (159) is connected to the second container (120). For example, the pressure pump (159) is connected to the receiving space of the second container (120) through a through hole (151d) formed in the pipe and the first connecting portion (151).

[0068] The controller (158) controls the pressure of the pressure pump (159). The controller (158) may be located on the pipe. The controller (158) may include a switch.

[0069] The controller (158) increases the pressure inside the second container (120) to supply the pre-extraction coffee powder located in the filter unit (130) to the first container (110) and stir the coffee powder in the hot water to form a coffee stirring liquid. Alternatively, the controller (158) may reduce the pressure inside the second container (120) from a first pressure to a second pressure to discharge the filtered coffee stirring liquid from the first container (110) through the filter unit (130) into the second container (120).

[0070] In one embodiment of the present invention, a hot water supply unit (not shown) for supplying hot water into the first container (110) may be additionally provided. The hot water supply unit may supply hot water having an appropriate temperature into the first container (110). The hot water supply unit may include a hot water tank, pipes, and a temperature sensor for measuring the temperature within the temperature tank.

[0071] Figure 4 is a flowchart for explaining a coffee extraction method according to one embodiment of the present invention.

[0072] Referring to FIGS. 1, 2 and 4, a coffee extraction method according to one embodiment of the present invention uses a coffee extraction device (10) having a first container (110) into which hot water is introduced from the outside, a second container (120) which is connected to the first container (110) and has an adjustable internal pressure and accommodates a coffee extract, and a filter unit (130) which is located in a portion connected between the first and second containers and loads coffee powder before extraction and filters the coffee powder after extraction.

[0073] In the coffee extraction method using the above coffee extractor, first, coffee powder is placed in the filter unit (130). Then, after the first and second containers (110, 120) and the filter unit (130) are connected, hot water is supplied to the first container (110). The temperature of the hot water can be adjusted depending on the type of coffee powder, the degree of grinding of the coffee powder, etc.

[0074] In this way, the pressure inside the second container (120) is increased to supply the coffee powder to the first container (110). As a result, the coffee powder is stirred in the hot water inside the first container (110) to form a coffee stirring liquid.

[0075] Meanwhile, the pressure inside the second container (120) is reduced. For example, the pressure inside the second container (120) can be reduced from the first pressure to the second pressure. In this case, the coffee stirring liquid from the first container (110) can flow into the second container (120) via the filter unit (130) and be extracted as a filtered coffee extract.

[0076] According to the coffee extraction method according to embodiments of the present invention, the pressure of the second container (120) can be variably controlled. Accordingly, coffee liquid can be extracted by utilizing the pressure difference between the first container (110) and the second container (120).

[0077] Furthermore, by directly supplying hot water from outside to the first container (110), a separate heating process for heating the water can be omitted. Furthermore, the temperature of the hot water can be precisely controlled. Consequently, a precisely controlled coffee extract can be produced in a relatively short period of time.

[0078] In one embodiment of the present invention, while supplying hot water to the first container, the pressure inside the receiving space of the second container can be increased to suppress the hot water from moving from the first container to the second container.

[0079] In one embodiment of the present invention, when reducing the pressure inside the second container, the pressure reduction speed can be adjusted depending on the type or grinding degree of the coffee powder.

[0080] Meanwhile, when reducing the pressure within the second container, it can be adjusted according to the temperature of the hot water. Accordingly, by precisely controlling the pressure difference between the first and second containers, the coffee drip time can be prevented from becoming excessively long, thereby deteriorating the flavor of the coffee extract.

[0081] The pressure-type coffee extractor and coffee liquid extraction method according to embodiments of the present invention can be employed not only in home use but also in commercial coffee shops.

[0082] While the present invention has been described above with reference to preferred embodiments thereof, these are merely examples and are not intended to limit the present invention. Those skilled in the art will appreciate that various modifications and applications not exemplified above are possible without departing from the essential characteristics of the present invention. For example, each component specifically shown in the embodiments of the present invention can be modified and implemented. In addition, differences related to such modifications and applications should be construed as being included within the scope of the present invention defined in the appended claims.

Claims

1. A first container into which hot water is introduced from the outside; A second container communicating with the first container, having an adjustable internal pressure, and containing a coffee extract; A filter unit located in a connected portion between the first and second containers, which loads coffee powder before extraction and filters residue generated from the coffee powder after extraction; and A pressure control module detachably provided in one of the first and second containers and the filter unit, and using the pressure difference inside the first and second containers, supplies the pre-extraction coffee powder from the filter unit into the first container, stirs the coffee powder in the hot water to form a coffee stirring liquid, and discharges the filtered coffee extract from the first container through the filter unit into the second container; A pressure-type coffee extractor including:

2. In the first paragraph, the pressure control module, A first connecting portion having a through hole formed in the side wall that surrounds the outer periphery of the first container and is connected to an external pressure pump; and A pressure-type coffee extractor characterized by comprising a second connecting portion that surrounds the lower portion of the first container and is provided so that the filter portion can be fastened to the lower portion of the first connecting portion.

3. In the second paragraph, the pressure control module, A first sealing groove is formed along the upper surface of the second connecting portion, A pressure-type coffee extractor, characterized in that it further includes a first sealing member arranged inside the first sealing groove and capable of suppressing gas leakage from the second container.

4. In the second paragraph, the filter part A filter body having multiple through-holes formed therein; and A pressure-type coffee extractor characterized by including a filter side wall extending upward from the outer surface of the filter body.

5. In the fourth paragraph, a spiral guide groove is formed on the inner surface of the filter side wall, and a guide protrusion is formed on the outer surface of the second connecting portion. A pressure-type coffee extractor, characterized in that the guide protrusion is screw-fastened along the guide groove to detachably fasten the second connecting portion and the filter side wall to each other.

6. In the fourth paragraph, a second sealing groove is formed at the lower end of the outer shaft of the second connecting portion, A pressure control module, characterized in that it further includes a second sealing member disposed inside the second sealing groove and suppressing gas leak between the filter side wall and the second connecting portion.

7. In the second paragraph, the first connecting part A first fastening portion having a first diameter and being screw-connected to the outer side of the first container; A second fastening part connected to the lower portion of the first fastening part, detachably provided with the second container, and having a second diameter larger than the first diameter; and A pressure-type coffee extractor characterized by including a connecting portion that interconnects the lower portion of the first connecting portion and the upper portion of the second connecting portion.

8. A pressure-type coffee extractor, characterized in that in the 7th paragraph, a fastening groove is formed in the lower part of the second fastening part so as to be connected to the upper part of the second container.

9. In the first paragraph, the pressure control module a pressure pump connected to the second container; and Including a controller for regulating the pressure of the above pressure pump, A variable pressure coffee extractor characterized in that the controller increases the pressure inside the second container to supply the pre-extraction coffee powder located in the filter section to the first container, stirs the coffee powder in the hot water to form a coffee stirring liquid, and reduces the pressure inside the second container to discharge the coffee stirring liquid from the first container through the filter section to the second container as a filtered coffee extract.

10. A pressure-type coffee extractor according to claim 1, characterized in that it further includes a hot water supply unit for supplying hot water into the interior of the first container.

11. A coffee extraction method of a coffee extractor having a first container into which hot water is introduced from the outside, a second container connected to the first container and having an adjustable internal pressure for receiving coffee extract, and a filter unit located in a part connected between the first and second containers and loading coffee powder before extraction and filtering the coffee powder after extraction, A step of positioning coffee powder in the above filter section; A step of supplying hot water to the first container; A step of increasing the pressure inside the second container, supplying the coffee powder from the filter unit to the first container, and forming a coffee stirring liquid by stirring the coffee powder in the hot water inside the first container; and A coffee extraction method comprising a step of reducing the pressure inside the second container, extracting the filtered coffee extract from the first container through the filter unit, and extracting the filtered coffee extract from the first container into the second container.

12. A coffee extraction method according to claim 11, characterized in that the step of supplying hot water to the first container increases the pressure inside the receiving space of the second container to suppress the hot water from moving from the first container to the second container.

13. A coffee extraction method according to claim 11, wherein the step of reducing the pressure inside the second container is characterized in that the pressure reduction speed is adjusted according to the variety or grinding degree of the coffee powder.

14. A coffee extraction method according to claim 11, wherein the step of reducing the pressure inside the second container is characterized in that the pressure reduction speed is controlled according to the temperature of the hot water.

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