How to operate a fully automatic coffee machine and fully automatic coffee machine

Abstract

A method for producing a coffee beverage with a filter coffee flavor by means of a fully automatic coffee machine (1), the fully automatic coffee machine (1) having at least one brewing unit (2) which comprises a brewing chamber and a plunger (11) movable, in particular linearly slidable, in the brewing chamber for adjusting the brewing chamber volume, the method comprising at least the steps of a. filling the brewing chamber (12) with coffee powder, and b. supplying water to the brewing chamber (12) for the purpose of extraction within the scope of the extraction process, the at least plunger (11) being adapted to: a brewing chamber (12) in a position where the volume of the brewing chamber is greater than the volume of the coffee powder poured into the brewing chamber (12) after filling according to step a, the brewing process having a number of brewing stages (I, II, III), in which water is respectively flowed through the coffee powder at flow rates which differ in relation to the brewing stages (I, II, III), and the switching between the brewing stages (I, II, III) is performed by metrological detection and / or calculation of physical variables, in particular the electrical conductivity, the refractive index and / or the supplied amount and / or volume of the coffee powder and / or water and / or the amount of coffee extracted.

Description

[Technical Field]

[0001] The present invention relates to a method for operating the fully automatic coffee machine described in the premise of claim 1, and to the fully automatic coffee machine according to the present invention. [Background technology]

[0002] Those skilled in the art recognize fully automatic coffee machines that produce a variety of coffee variations by the espresso method, that is, under pressure.

[0003] Furthermore, conventional machines for producing filter coffee have existed for some time. These machines produce coffee with an extremely balanced flavor and aroma based on a relatively slow and low-pressure extraction process.

[0004] Traditional espresso-making involves rapid aroma development. In fully automatic coffee machines, the extraction process, typically less than 30 seconds per cup, releases more volatile oils and aromas due to a pressure of approximately 7.5–9 bar, but also releases less caffeine, tannic acid, and bitter substances due to the shorter extraction time. Both types of coffee have their enthusiasts.

[0005] German Patent No. 4240175 discloses a brewing unit with an automatically operating coffee machine. The choice of coffee production is made by the brewing position of the brewing plunger. Coffee crema is produced by tamping, while filter coffee is produced without tamping. German Patent Application Publication No. 3316157 also describes a similar adjustment between crema coffee and filter coffee.

[0006] European Patent Application Publication No. 0909542 discloses a coffee machine for selectively extracting filter coffee and espresso coffee.

[0007] U.S. Patent No. 6,513,419 and International Publication No. 2007 / 060694 disclose coffee machines for preparing various types of coffee, particularly filter coffee, respectively.

[0008] The aforementioned literature does not disclose at all that the filter coffee extraction process is divided into multiple extraction stages. Therefore, it is not possible to achieve a balanced extraction of each flavor substance.

[0009] Another prior art document, German Utility Model No. 202016008296, is provided, but it is not related to the manufacture of filter coffee.

[0010] German Patent Application Publication No. 102018116306 discloses various characteristics of filter coffee, distinct from other types of coffee, such as espresso. It does not disclose the preparation of filter coffee by multiple extraction stages, in which case the mixing of coffee grounds is carried out in parallel with the extraction process, and the water volume / volume flow rate may be constant or, advantageously, variable, and may be advantageously monitored once or continuously. [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] Therefore, the fundamental problem of the present invention is to operate an automatic coffee machine so that it can provide coffee with a flavor comparable to that of filter coffee. [Means for solving the problem]

[0012] The present invention solves this problem by providing an operating method having the features described in the feature section of claim 1, and a fully automatic coffee machine according to the present invention.

[0013] The method according to the present invention for producing a coffee beverage having the flavor of filter coffee is carried out using a fully automatic coffee machine.

[0014] A fully automatic coffee machine comprises at least one brewing unit, which includes a brewing chamber and a plunger, which is movable within the brewing chamber and particularly linearly slidable, for adjusting the volume of the brewing chamber. While such fully automatic coffee machines themselves are known, they are not generally used to produce filter coffee, but rather to produce espresso or espresso-based beverages.

[0015] The plunger is moved mechanically by an actuator, for example by a motor or hydraulically, thereby adjusting the volume of the extraction chamber.

[0016] The method according to the present invention is characterized by the following steps. a. A step of filling the extraction chamber with coffee powder, and b. A step of supplying water to the extraction chamber for the purpose of extraction within the scope of the extraction process.

[0017] At least the plunger is positioned such that, during at least one extraction stage of the extraction process, the volume of the extraction chamber is greater than the volume of coffee grounds poured into the extraction chamber after filling in step a. This poured state refers to the volume of loose material that would result if an amount of coffee grounds equal to the amount of coffee grounds in the extraction chamber based on step a were present without being compressed.

[0018] In the first position of the plunger, the volume of the extraction chamber is expanded to accommodate a suspension of coffee grounds and water. In this suspension, the coffee grounds may be settled at the bottom of the extraction chamber and / or suspended within the suspension.

[0019] At the start of step b, the coffee powder may be present in a poured state and substantially uncompressed. This principally means that it is possible to slightly compress the coffee powder for shaping purposes. Typically, the bulk material has a conical shape. However, the coffee powder can be shaped into a cylindrical form without large-scale mechanical tamping of its volume. In contrast, non-mechanical tamping and / or compression of the bulk coffee powder material, that is, tamping or compression not involving externally applied mechanical force, is inherent to the extraction method relying on the swelling of coffee powder.

[0020] After filling has been carried out, and in particular before the extraction process, the coffee powder may be compressed to some extent. However, in a preferred variant embodiment, the coffee powder is present substantially uncompressed. This means that the coffee powder is compressed by less than 15 vol%, in particular less than 10 vol%, relative to its poured state as a loose bulk material.

[0021] This very slight small compression can be carried out within the scope of shaping the coffee powder, for example to impart a cylindrical basic shape to the coffee powder, in which basic shape extraction occurs more uniformly than in the case of a conical shape that is typical for bulk materials.

[0022] Then, during at least one extraction step, water can flow through the coffee powder, with no mechanical pressing force that causes further compression relative to the poured state being applied to the coffee powder. However, even though no external mechanical pressing force is applied to the coffee powder, compression can occur based on the swelling of the coffee powder. In particular, the water supplied in step b can flow through the coffee powder substantially without applying a pressing force.

[0023] Therefore, the plunger is slidable or movable to the second position. In this second position, the plunger shapes the coffee powder preferably before the extraction process. This makes it possible to achieve a uniform distribution in the extraction chamber depending on the amount of coffee powder.

[0024] Furthermore, and likewise optionally, the plunger may be maximally retracted in the first position, whereby the volume of the extraction chamber is maximally expanded. Individual extraction steps may be carried out in such a maximally retracted position. In this case, an air space may exist between the suspension and the end face of the plunger. However, the aforementioned first position does not necessarily have to be in a maximally extended state, it may be slightly less extended.

[0025] In addition to the main extraction step, another extraction step may be provided. Preparatory steps such as coffee grinding or post-treatment steps such as subsequent cleaning by, for example, clean in place (CIP) may also be part of the method according to the present invention. In this case, CIP cleaning does not require the removal of components, and the cleaning can be performed by an automatic process within the fully automatic machine.

[0026] This method enables filter coffee production in a fully automatic coffee machine in a simple manner. The free water volume particularly allows the floating of coffee powder. Furthermore, the coffee powder can more easily flow around in an uncompressed state.

[0027] For a balanced extraction of the respective flavor substances, it is advantageous if the extraction process comprises a plurality of extraction steps, in each of which water is flowed through the coffee powder at different flow rates related to the respective extraction step.

[0028] Switching between extraction stages is advantageously performed according to the present invention by the detection and / or calculation of physical variables, particularly conductivity, refractive index, and / or the amount of coffee powder and / or water supplied, and / or the amount or volume of coffee extracted or drained. This allows for the extraction of the maximum amount of flavor substances. Coffee is a natural product, and its flavor substances can vary depending on the growing region, roasting method, storage, etc. A variation in switching with water volume controlled depending on the amount of coffee powder supplied is preferred.

[0029] The advantageous configurations of the present invention are the subject of the dependent claims.

[0030] As mentioned above, the plunger may remain in the first position, which will also be called the stop position below, during the extraction process.

[0031] Preferably, the extraction chamber volume may be at least 50% larger, and preferably twice, the volume of the coffee grounds poured in at the start of step b, especially in an uncompressed state.

[0032] More preferably and advantageously, the extraction chamber is configured such that, at the start of step b, only the coffee grounds are placed inside the extraction chamber. Rather, the loose material consisting of the coffee grounds is adjacent to the empty volume of the extraction chamber, and this empty volume is filled with hot water in step b.

[0033] In this context, the extraction process is particularly advantageous, a) A first extraction step having a second flow rate and b) A second extraction step having a first flow rate and / or preferably a third extraction step having a third flow rate. The system has such that the second flow velocity may be smaller than the first flow velocity and / or the third flow velocity.

[0034] Dividing the extraction process into at least two, preferably three, extraction stages is advantageous, and each of these extraction stages may be assigned one of at least two, preferably three, different flow rates.

[0035] For example, the second extraction stage described above may be configured as the main extraction stage. Furthermore, the first extraction stage may be configured as the extraction initiation stage, and the third extraction stage may be configured as the post-extraction stage. However, this classification or temporal sequence is not necessarily defined. Therefore, the second extraction stage described above may simultaneously be the first extraction stage or the final extraction stage of the extraction process.

[0036] These process stages take place advantageously in a sequential manner, and particularly preferably directly in a sequential manner.

[0037] The second flow velocity is preferably smaller than the third flow velocity, and the third flow velocity is preferably smaller than the first flow velocity.

[0038] The flow rate for at least one extraction step of the extraction process may be relatively slow, and may be 10 ml / second or less, preferably 2 to 5 ml / second.

[0039] Preferably, the flow rate for at least the second extraction stage of the extraction process may be 2 to 5 ml / second. Similarly, preferably, the flow rate for at least the first extraction stage of the extraction process may be 5 to 10 ml / second. Furthermore, the flow rate for at least the third extraction stage of the extraction process may be 10 to 15 ml / second.

[0040] Fully automatic coffee machines may also be equipped with a coffee grinder, the method of which includes a step of grinding coffee beans to a predetermined size for filter coffee. As is well known, the grind size for filter coffee is coarser than the grind size for espresso coffee. Therefore, advantageously, the operating parameters of the coffee grinder are automatically adjusted by the fully automatic coffee machine to the optimal grind size for filter coffee when the user desires or selects "filter coffee" as their beverage.

[0041] The grind size can be determined according to DIN 44539. DIN 44539 defines three stages for classifying grind sizes. Here, the particle size that should account for more than 50% of the grind, in this case the coffee powder, is defined. Value x 50,3 This indicates that, in the measurement protocol, 50% of the crushed material distribution is coarser than the given measurement value, and 50% is finer than the given measurement value. The calculation of individual particle size percentages is performed using the air jet sieve method according to DIN 10765. The above provisions refer to the most recent edition at the priority of the present invention.

[0042] Grinding level: "Fine grind" All particle sizes up to 0.25 mm account for more than 50% of the total. Grinding level: Medium grind Particles with a size of 0.25 mm to 0.71 mm account for more than 50% of the total. Grinding level: "Coarse grind" All particle sizes larger than 0.71 mm account for more than 50% of the total.

[0043] For this method, a grinding degree of "medium grind" or, more preferably, "coarse grind" is recommended.

[0044] It is recommended that the plunger reshape the coffee grounds before the extraction process, thereby reducing the volume of the extraction chamber while and with the intention of reshaping them.

[0045] The plunger is initially shaped and then retracted, so that it is not resting on the coffee grounds. This creates a large extraction space, which provides more room for the coffee grounds to swell upon contact with water. At the same time, uncompressed coffee grounds have less flow resistance.

[0046] This operating method can assume uncompressed flow behavior. In contrast, during the production of regular filter coffee in a coffee filter, the coffee grounds often have to settle first, which means additional time and effort. Furthermore, if the plunger is returned before the extraction process, this expands the volume of the extraction chamber again, preferably by at least 100% of the volume in its shaped state, which is advantageous as it allows for slow extraction and water flow at low pressure.

[0047] It is advantageous for the plunger to remain in the stop position throughout the entire extraction process. The plunger may be moved during the start of extraction and / or post-extraction.

[0048] Slow extraction is recommended, at least during the extraction stage.

[0049] Furthermore, fully automatic coffee machines may have filters, such as screens and permanent filters, especially those suitable for CIP (Cleaning, Immersion, and Infusion).

[0050] Modifications to the extraction stage can be made, in particular, by detecting conductivity and / or optical refractive index, with the measuring sensor for detection positioned technically downstream of the extraction unit, so that the measurement results of the finished coffee, i.e., the final product, form the basis for the modification. Alternatively and preferably, a measuring sensor may also be positioned upstream of the extraction unit to still influence the properties during preparation.

[0051] Particularly preferable, changes in the extraction stage can be made by detecting the amount of water supplied, taking into account the amount of coffee grounds supplied. The amount of coffee grounds supplied can be considered, for example, within the range of adjustment of the grinding power. The grinding power in mg / s at a pre-adjusted grinding degree can be adapted to the amount of water according to the customer's requirements for a specified volume of filtered coffee.

[0052] Furthermore, the extraction pressure during the extraction process is preferably less than 2.5 bar.

[0053] Preferably, the extraction chamber is closed except for the outlet for the coffee during the extraction process. In some cases, the hot water supply outlet may also be open.

[0054] Preferably, the flow rate is adjusted in stages during the extraction process to switch between two extraction stages. Preferably, the switching between all other extraction stages in the extraction process can also be performed in stages.

[0055] The fully automatic coffee machine may further have a bypass pipeline from the hot water boiler to the dispensing unit, equipped with one or more adjustment mechanisms, to deliver hot water, preferably simultaneously with the extraction process and / or simultaneously with the delivery of coffee from the extraction unit, in order to achieve a predetermined coffee volume. One or more valves can be used as adjustment mechanisms, each valve defining a different flow rate from one another.

[0056] Furthermore, according to the present invention, a fully automatic coffee machine is proposed, comprising at least one extraction unit, the extraction unit having a linearly slidable plunger for adjusting the volume of the extraction chamber of the extraction unit, and a control and / or evaluation unit configured to carry out a method according to the present invention.

[0057] A fully automatic coffee machine may, advantageously, have a hot water boiler, and a flow limiter for adjusting the flow rate is placed between the hot water boiler and the brewing unit. This makes it possible to adjust the flow rate according to each of the first, second, and / or third brewing stages, and / or possibly according to another arbitrary brewing stage.

[0058] The flow limiter may have multiple adjustment mechanisms, such as valves, configured to adjust the flow rate in steps to ensure an extraction process having multiple extraction stages with different flow rates. Stepped adjustment allows for very direct adjustment of the desired flow rate in this case, whereas stepless adjustment often allows for less-than-optimal metering due to after-effects that are difficult to detect.

[0059] The present invention will be described in detail below with reference to the following drawings, based on embodiments of the method according to the present invention. [Brief explanation of the drawing]

[0060] [Figure 1a] This is a schematic diagram showing the structure of the first variation of the fully automatic coffee machine according to the present invention. [Figure 1b] This is a schematic diagram showing the structure of a second variation of the fully automatic coffee machine according to the present invention. [Figure 1c] This is a schematic diagram showing the structure of a third variation of the fully automatic coffee machine according to the present invention. [Figure 2] Figures a to g are detailed diagrams showing extraction units of a fully automatic coffee machine having plungers in different operating positions during the implementation of the method according to the present invention. [Figure 3] This figure shows the measurement of various physical quantities according to the progress of the extraction process when implementing the method according to the present invention. [Figure 4] This is a measurement diagram illustrating an exemplary coffee extraction process, for example, by conductivity, according to a first implementation variation of the method according to the present invention, which comprises multiple extraction steps. [Figure 5]This is a measurement diagram illustrating an exemplary coffee extraction process, for example, by conductivity, according to a second implementation variation of the method according to the present invention, which comprises multiple extraction steps. [Modes for carrying out the invention]

[0061] Figure 1 illustrates the basic structure of the fully automatic coffee machine 1 according to the present invention.

[0062] The fully automatic coffee machine 1 has a central component unit consisting of a brewing unit 2 and a hot water boiler 3. To supply water, the fully automatic coffee machine has a water inlet 4. The water inlet 4 may be, for example, a removable water reservoir or a connection to a water pipe.

[0063] Furthermore, the fully automatic coffee machine 1 has a water pump 5 for pressurizing the supplied water into the hot water boiler 3.

[0064] Furthermore, the fully automatic coffee machine 1 has a measuring device 6 for determining the flow rate. In this embodiment, this measuring device 6 is located upstream of the hot water boiler 3 in terms of flow technology, allowing for adjustment of the amount of water supplied to the boiler at this location. Alternatively or additionally, a similar measuring device for determining the flow rate may be located between the hot water boiler 3 and the brewing unit 2, and / or downstream of the brewing unit 2 in terms of flow technology. The measuring device 6 for determining the flow rate may, advantageously, be configured as an impeller-type flow meter.

[0065] Furthermore, the supply pipeline has a check valve (Rueckstossventil) 7 on the upstream side of the hot water boiler 3.

[0066] Next, the hot water boiler 3 heats the supplied water to a temperature of preferably 80-96°C. Within this temperature range, the water temperature can be variably adjusted according to the desired hot beverage. Furthermore, the fully automatic coffee machine may have a pipeline (not shown) for mixing in cold water to achieve product-specific adjustment of the extraction temperature. The water thus heated is then preferably metered and sent to the extraction unit 2.

[0067] Unless a metering device is already provided in the hot water boiler 3 or, alternatively, in the extraction unit 2, a flow limiter 8 may be provided between the hot water boiler 3 and the extraction unit 2 to more accurately meter the flow rate of hot water required in each step.

[0068] The flow limiter shown in Figure 1a allows for stepwise adjustment, particularly stepwise control, of the flow rate of the hot water supplied to the extraction unit 2. For this purpose, Figure 1a is provided with three extraction valves 8a to 8c, each of which may have a different cross-section and therefore exhibit different flow rates to the extraction unit. Preferably, one extraction valve is open while the other two are closed.

[0069] In the variation shown in Figure 1b, the flow limiter 8 is implemented by two extraction valves 8a and 8b. In this variation as well, at least three flow velocities can be adjusted by opening either the individual extraction valve 8a or extraction valve 8b, or by opening both valves 8a and 8b simultaneously. Preferably, in the variation shown in Figure 1b, the flow velocity can be adjusted steplessly by cross-section and thus by valves, such as manually adjustable needle valves. Thus, stepless flow rate adjustment is possible for a water supply that would otherwise be adjusted stepwise.

[0070] Figure 1c discloses a variation in which a continuously variable valve 8d is used to adjust the flow rate. However, for direct and rapid adjustment, stepped switching of the flow rate is preferable. Furthermore, for reasons of redundancy, the stepped variation still ensures emergency operation for coffee supply with reduced selection options in the event of valve failure. In addition, the stepped adjustments shown in Figures 8a and 8b allow for rapid supply and withdrawal with clear or unambiguous switching conditions.

[0071] While espresso machines often have a pressure limiter in this location, the present invention preferably provides a flow limiter, such as a throttle, preferably a variably driveable throttle. Alternatively, the functions of the pressure limiter and flow limiter can be performed together within the adjustment mechanism, thereby allowing the fully automatic coffee machine to be used to produce a wider variety of coffee variations.

[0072] The extraction unit 2 preferably has an extraction chamber 12, the volume of which is adjustable by a linearly movable plunger 11. The plunger position is variably adjustable. Furthermore, the extraction unit 2 has a filter 15, preferably a permanent filter. The permanent filter is preferably suitable for CIP. The permanent filter may be a microfine screen in particular. Particularly preferably the screen is 1 × 10⁻¹⁶ 3 The material may have at least 30,000 holes, preferably at least 40,000 holes, per mm.

[0073] The coffee grounds can be filled into the extraction unit by manual filling, for example, by directly feeding the grounds through a supply vertical hole, or by grinding whole beans immediately before supplying them to the extraction unit. For this purpose, a fully automatic coffee machine may have a coffee mill (not shown). Since coffee grounds for filter coffee are usually coarser than espresso grounds, it is advantageous for the built-in coffee mill to be equipped to produce a variable grind. The grind is tailored to the type of coffee and the type of filter, especially the permanent filter. Corresponding parameters are, for example, fineness or distribution. Further details of coffee mills with variable grinds can be read from DIN 44539 (the latest version at the time of filing), which is referenced within the scope of this application. The grind can be varied by, for example, changing the grinding time, rotation speed, pressure of the grinding element and / or the coarseness of the grinding element.

[0074] In addition to or alternative to the flow limiter 8, the fully automatic coffee machine 1 may have a measuring sensor 9, in particular a physical measuring sensor for determining coffee characteristics. This measuring sensor is preferably located downstream of the brewing unit 2 in terms of flow technology. This coffee characteristic may preferably be conductivity, refractive index, pressure and / or temperature. One variation of the measurement in this context is described in detail, in particular, in German Patent Application Publication No. 102018116306, and is therefore referred to therefor. Alternatively, and particularly preferably, the measuring sensor may also determine the volumetric flow rate of coffee leaving the brewing unit.

[0075] Finally, the coffee is sent to the dispensing unit 10. Additionally, the fully automatic coffee machine 1 may have further shut-off valves and / or deflection valves at various positions.

[0076] In particular, the fully automatic coffee machine has a bypass pipe 17 between the hot water boiler 3 and the dispensing unit 10 for supplying hot water to the dispensing unit 10 without the hot water flowing through the extraction unit 2 beforehand. In particular, the bypass pipe 17 allows for a reduction in coffee preparation time based on the parallel supply of hot water to the coffee. Especially in the post-extraction stage, since flavor substances may not be extracted at all, the preparation time is shortened by supplying hot water to reach the desired volume. Bitter substances, which may occur in the extraction unit when the extraction time is relatively long, are not supplied via the bypass pipe 17. Nevertheless, the desired volume can be maintained.

[0077] The hot water supply to the discharge unit can be carried out at a predetermined number of inflow velocities, in which case an adjustment mechanism 16, such as bypass valves 16a and 16b, is provided to adjust the flow rate. The flow rate and inflow volume can preferably be controlled depending on values ​​determined by the measuring sensor 9 or depending on the flow rate.

[0078] The operation of the extraction unit 2 and / or the hot water boiler 3 is controlled via the control and / or evaluation unit 13. The control and / or evaluation unit preferably includes a calculation unit and a data memory, which stores one or more datasets or databases that are called when the method according to the present invention is implemented.

[0079] The present invention provides a method for producing a coffee beverage with the characteristics of filter coffee, comprising several steps. An extraction unit 2 configured as a plunger unit and another core component of a fully automatic coffee machine are used for fully automatic filter coffee production.

[0080] A predetermined amount of coffee grounds is supplied to the extraction chamber 12, and hot water is passed through these coffee grounds at a small volumetric flow rate when the plunger is retracted. Coffee extracted under these conditions has characteristics unique to freshly extracted filter coffee. Studies have shown that the produced coffee beverage has results directly comparable to, for example, the production of filter coffee in a glass filter. The method according to the present invention will be described in detail below with respect to one implementation variation.

[0081] In the first step, the user inputs their desired beverage. The desired beverage can be communicated electronically, for example, via a mobile phone app, or by operating an operating element, such as an operating field or button on an automatic coffee machine.

[0082] Next, in an optional second step, the coffee beans are ground by a coffee grinder to the optimal size for filter coffee. In machines with multiple storage tanks for espresso beans or coffee beans, for example, the type of beans to be fed into the coffee grinder can also be optionally selected.

[0083] Alternatively, coffee grounds can be supplied to the extraction unit by directly adding them before or after the first step.

[0084] In the third step shown in Figures 2a and 2c, the extraction chamber 12 of the fully automatic coffee machine 1 is filled. For example, the extraction chamber 12 is opened via the opening of the slider 14 (see Figures 2a and 2b), and ground coffee powder is supplied (see Figures 2b and 2c). Subsequently, in Figure 2c, the coffee powder is in a conical shape.

[0085] In the fourth step illustrated in Figure 2c, the extraction chamber is then closed, for example by operating the slider 14, thereby sealing the extraction chamber 12. The plunger 11 of the extraction unit 2 can be operated for a short time depending on the amount of coffee grounds to shape the coffee grounds. This is done in Figure 2d. The coffee grounds are simply slightly compressed and shaped into a cylindrical form to achieve more uniform extraction. After that, the plunger is returned to its original position to increase the volume of the extraction chamber.

[0086] Next, the extraction chamber 12 is expanded to introduce water, creating a space in which the coffee grounds can swell upon contact with the water. This can be seen in Figures 2d and 2e.

[0087] In the fifth step, hot water is supplied at a first flow rate. This step is referred to, for example, as the first extraction stage in the extraction initiation stage. In this first extraction stage, the extraction chamber is partially and rapidly filled. To ensure phase transition of aromatic substances, some holding time may be optionally provided. Preferably, the flow rate during the extraction initiation is 9-12 ml / second. After the rapid supply in the extraction initiation stage, a holding time may be provided in which the volumetric flow rate is reduced but one or more extraction valves remain open. This holding time may preferably be at least 3 seconds.

[0088] Next, in the sixth step, a new supply of hot water is provided in the second extraction stage at the second flow rate. This step may be, for example, the main extraction stage. In this case, the hot water is supplied slowly, preferably at a flow rate of less than 5 ml / second, and particularly preferably less than 3 ml / second. Uniform extraction is achieved by the slow flow, which also incorporates soluble substances.

[0089] At the end of the sixth step, the transfer of most of the aromatic substances into the water is complete. The duration of the extraction step may be controlled depending on time, volume (volume or mass of water supplied), pressure and / or particularly preferably conductivity.

[0090] Finally, in the seventh step, the flow rate is increased again, for example, to 5-10 ml / second. The concepts of flow rate or flow velocity should be understood synonymously in the context of this application. This third flow rate corresponds to a third extraction step, which may be a so-called post-extraction step. This step is suitable for obtaining a balanced extraction result.

[0091] Finally, in the eighth step, the coffee grounds are discharged from the extraction chamber.

[0092] During each individual extraction stage, the extraction chamber may remain open on the outlet side, thereby releasing the coffee into the coffee cup after each stage, i.e., during preparation.

[0093] The coffee in the extraction chamber can be supplied to the dispensing unit by closing the plunger as needed.

[0094] Preferably, a pressure of 4 bar or especially 2.5 bar is not exceeded during the production of coffee throughout all extraction stages. Rather, the preparation of the coffee can be carried out, particularly preferably, without additional pressure from the plunger 11 during the extraction stage.

[0095] The transitions between different extraction stages may depend on the following physical variables, and may vary depending on the amount of coffee grounds and the total amount of water. a) Time control based on dataset values, or time control based on a pre-set time x [seconds] after the elapsed time. This variation depends particularly on the amount of coffee, the volume of water, and / or the desired coffee volume. b) Quantity control based on dataset values, or quantity control based on / pre-set by quantity x[ml]. c) Conductivity control based on dataset values, or conductivity control by pre-setting after the proportion of conductive substances [mS / cm] measured during the extraction process falls below a certain level. In this variation, it is possible to identify, in particular, when the majority of the conductive material was extracted.

[0096] The volumetric flow rate of hot water or steam during each extraction stage may be controlled (adjusted) in a closed loop or in an open loop, and may vary depending on the amount of coffee grounds and the total amount of water.

[0097] Manufacturing is preferably carried out in a "cup format," and storage in a warming chamber inside a fully automatic coffee machine upstream of the dispensing unit is also possible.

[0098] The inclusion of large particles (commonly known as grounds) from coffee powder into the beverage is preferably prevented by using a filter.

[0099] The extraction chamber volume can be variably, preferably automatically, changed before extraction, to match the desired coffee delivery volume.

[0100] The extraction pressure can preferably be determined upstream and / or downstream of the extraction chamber 12 for the purpose of collecting measurement data.

[0101] The following describes a specific preparation sequence as one implementation variation.

[0102] Extraction stage I. 0~8 seconds [80ml] Start extraction II. 8~40 seconds [70ml] Extraction III. 40~70 seconds [150ml] Post-extraction parameters Quantity: 300ml Duration: 70 seconds Weighing amount: 10g Conductivity: 2.45mS / cm(φ) Extraction pressure: 0.5 bar Extraction temperature: 92℃

[0103] Under these conditions, the measurement graph in Figure 3 was created. In extraction initiation stage I, a pressure increase was observed due to the rapid supply of water, and plunger 11 could only generate a small pressure.

[0104] During the main extraction stage II, it is observed that the majority of the contents have migrated based on an increase in conductivity (Figure 3b). The flow velocity (Figure 3c) is significantly lower than the velocity at the start of the extraction stage I. As can be seen from the pressure curve, the main extraction stage is carried out with virtually no pressure increase (Figure 3a).

[0105] This pressure increases again in post-extraction stage III. The flow rate is also increased accordingly. The conductivity is lower than in the main extraction stage and decreases further as time progresses.

[0106] Figure 4 illustrates the first variation, in which the extraction process proceeds through three distinct extraction stages I, II, and III. Volumetric flow rate Q 抽出 The flow rates a, b, and c, and consequently the first, second, and third flow rates, also change according to the extraction stage. Based on conductivity, the extraction of flavor substances can be tracked. In particular, it can be observed that only a small amount of flavor substances are extracted in the third extraction stage III.

[0107] The suitable flow rates or volumetric flow rates for each extraction stage shown in Figure 4, and for other method variations, are as follows: First flow velocity: Q 抽出 a: 2~5ml / sec Second flow velocity: Q 抽出 b: 5~10ml / sec Third flow velocity: Q 抽出 c:10~15ml / sec

[0108] Figure 5 shows an alternative second variation of the method according to the present invention. In this method, two extraction steps I and II are performed using the same volume flow rate Q through the extraction chamber. 抽出 The procedure is carried out in a, and the third extraction stage III is performed with a different volumetric flow rate Q. 抽出c, the volume flow Q of hot water through the bypass line バイパス is performed simultaneously with a. In this third extraction step III, in addition to the possible remaining extraction of some bitter substances in some cases, the desired volume of the coffee is in particular also achieved.

[0109] As can be seen from Figure 5, the method according to the present invention does not necessarily need to include three extraction steps with three different volume flow rates or flow velocities, but including three extraction steps makes it possible to achieve a more balanced flavor.

[0110] Bypass volume flow Q バイパス b can be connected, for example, in the second extraction step II, or at the end of the extraction process after completion of the third extraction step III. Description of Reference Numerals

[0111] 1 Fully automatic coffee machine 2 Brewing unit 3 Hot water supply boiler 4 Water inlet 5 Water pump 6 Measuring device for determining flow rate 7 Check valve 8 Flow restrictor 8a to 8c Extraction valves 9 Measuring sensor 10 Discharge unit 11 Plunger 12 Brewing chamber 13 Control and / or evaluation unit 14 Slider 15 Filter 16 Adjusting mechanism 16a to 16b Bypass valves 17 Bypass Figure 3a Pressure measurement over the course of extraction Figure 3b Conductivity over the course of extraction Figure 3c Flow rate measurement over the course of extraction I First extraction step II Second extraction step III Third extraction step

Claims

1. A method for producing a coffee beverage having the flavor of filter coffee using a fully automatic coffee machine (1), wherein the fully automatic coffee machine (1) has at least one extraction unit (2), and the extraction unit (2) comprises an extraction chamber and a plunger (11) that is movable, particularly linearly slidable, within the extraction chamber for adjusting the volume of the extraction chamber, wherein the method is a. A step of filling the extraction chamber (12) with coffee powder, b. A step of supplying water to the extraction chamber (12) for the purpose of extraction within the scope of the extraction process, It has at least, At least the plunger (11) is positioned such that, during at least one extraction stage of the extraction process, the volume of the extraction chamber (12) is greater than the volume of the coffee powder poured into the extraction chamber (12) after filling in step a, and the extraction process has a plurality of extraction stages (I, II, III), in which water is flowed through the coffee powder at different flow rates in relation to each extraction stage (I, II, III), and the switching between the extraction stages (I, II, III) is performed based on the detection and / or calculation by a measuring instrument of a physical variable including at least one of the following: 1) the conductivity of the extracted coffee, 2) the refractive index of the extracted coffee, 3) the amount and / or volume of the supplied coffee powder, 4) the amount and / or volume of the supplied water, and 5) the amount of extracted coffee, and on the comparison of the detected and / or calculated physical variable with a threshold value of the physical variable. The extraction steps (I, II, III) are changed by detecting the measured value by the measuring sensor (9), and the measuring sensor (9) for detection is positioned either downstream or upstream of the extraction unit (2) with respect to the flow. The fully automatic coffee machine has a bypass pipeline (17) from a hot water boiler to a delivery unit (19) equipped with one or more adjustment mechanisms (16) for adjusting the flow rate, and the hot water is delivered to achieve a predetermined coffee volume, and the adjustment of the flow rate is performed depending on a measurement value obtained by the measuring sensor (9). A method characterized by the following features.

2. The method according to claim 1, wherein the change in the extraction stage (I, II, III) is caused by detecting the amount of water supplied, taking into account the amount of coffee powder supplied.

3. The method according to claim 1 or 2, wherein the water is passed through the coffee powder during the at least one extraction step without applying any mechanical pressure to the coffee powder that further compresses it in the state in which it has been poured.

4. The method according to any one of claims 1 to 3, wherein the coffee powder, in the poured state, is substantially uncompressed at the start of step b.

5. The method according to any one of claims 1 to 4, wherein the volume of the extraction chamber is at least 50% greater than the volume of the poured coffee powder at the start of step b.

6. The method according to any one of claims 1 to 5, wherein the extraction chamber is configured such that, at the start of step b, only the coffee powder is placed inside the extraction chamber.

7. The method according to any one of claims 1 to 6, wherein the extraction process comprises a first extraction step (I) having a second flow velocity, a second extraction step (II) having a first flow velocity, and a third extraction step (III) having a third flow velocity, wherein the second flow velocity is smaller than the first flow velocity and / or the third flow velocity.

8. Flow rate (Q) for at least one extraction step of the extraction process. 抽出 a or Q 抽出 b) The method according to any one of claims 1 to 7, wherein the flow rate is 10 ml / second or less.

9. Flow rate (Q) for at least the first extraction step (I) of the extraction process. 抽出 b) The method according to claim 7, wherein the flow rate is 5 to 10 ml / second.

10. Flow rate (Q) for at least the second extraction step (II) of the extraction process. 抽出 a) The method according to claim 7, wherein the flow rate is 2 to 5 ml / second.

11. Flow rate (Q) for at least the third extraction step (III) of the extraction process. 抽出 c) The method according to claim 7, wherein the flow rate is 10 to 15 ml / second.

12. The method according to any one of claims 1 to 11, wherein the fully automatic coffee machine (1) is equipped with a coffee grinder, and the method includes the step of grinding coffee beans to a predetermined size for filter coffee.

13. The method according to any one of claims 1 to 12, wherein the plunger (11) shapes the loose coffee grounds before step b without substantial compression of the loose coffee grounds, thereby reducing the volume of the extraction chamber (12) while shaping is taking place.

14. The method according to claim 13, wherein, before the extraction process, the plunger (11) is returned to the first position, thereby expanding the volume of the extraction chamber (12) again.

15. The method according to any one of claims 1 to 14, wherein the plunger (11) remains in the first position throughout the entire extraction process.

16. The method according to claim 14, wherein the plunger (11) is movable to a second position, and in the second position, the plunger (11) is placed on the coffee powder along its end face without applying any pressing force to the coffee powder, particularly while shaping it.

17. The method according to claim 14, wherein the plunger (11) is extended to its maximum extent in the first position, limited by the structural configuration of the extraction unit (2).

18. The method according to any one of claims 1 to 17, wherein the fully automatic coffee machine (1) has a filter (15).

19. The method according to any one of claims 1 to 18, wherein the extraction pressure during the extraction process is less than 4 bar.

20. The method according to any one of claims 1 to 19, wherein the extraction chamber (12) is closed during the extraction process, except for an inlet for hot water and / or an outlet for coffee.

21. The method according to any one of claims 1 to 20, wherein the stepwise adjustment of the flow rate during the extraction process is performed for switching between two extraction stages.

22. A fully automatic coffee machine (1) comprising: an extraction unit (2) having at least one extraction unit (2) equipped with a linearly slidable plunger (11) for adjusting the volume of the extraction chamber (12) of the extraction unit (2); and a control and / or evaluation unit (13) configured to carry out the method according to any one of claims 1 to 21.

23. The fully automatic coffee machine according to claim 22, wherein the fully automatic coffee machine (1) has a hot water boiler (3), and a flow rate limiter (8) for adjusting the flow rate is located between the hot water boiler (3) and the extraction unit (2).

24. The fully automatic coffee machine according to claim 23, wherein the flow limiter (8) is configured to adjust the flow rate in stages to ensure an extraction process having a plurality of extraction stages having different flow rates.

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