Method and machine for preparing coffee beverages

Abstract

A method for a machine (10) for preparing a coffee beverage, in which a dose of coffee powder is supplied to an infusion chamber (14), and a pre-infusion step and subsequently an infusion step of said powder dose is performed in order to dispense the beverage. The method provides to perform at least a first optimization of the operating parameters of said machine (10) comprising receiving an indication regarding an origin and a roasting level of said beans and executing an algorithm to define at least a weight of a quantity of coffee (Q coffee) to be used for said dose of powder, and a quantity of water (Q water) to be used in said pre-infusion step. Embodiments disclosed herein further relate to a machine for preparing beverages which implements such a method.

Description

[0001] "METHOD AND MACHINE FOR PREPARING COFFEE BEVERAGES"

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a method for a machine for preparing coffee beverages, and to a relative machine, of domestic or semi-professional type, implementing such a method, which provide to automatically adapt the parameters of a pre-infusion step as a function of the characteristics of the coffee beans used and / or the granulometry level of a coffee powder.

[0004] BACKGROUND OF THE INVENTION

[0005] It is known that preparing a coffee beverage by the infusion of a coffee powder requires setting and controlling a plurality of different setting parameters, related to one or more components of the machine, which can affect the infusion process. In fact, the setting parameters set, in turn, influence and determine the operating parameters of the machine, on which the quality of the prepared beverage depends.

[0006] It is also known to perform a pre-infusion step of the coffee powder before the actual infusion step, in order to evenly and uniformly wet the coffee powder and prevent the formation of preferential channels for the water through the dose of coffee, so as to optimize the extraction quantity of the soluble solids from the roasted coffee.

[0007] It is also known to modify the parameters of the pre-infusion and / or infusion step in order to optimize the quality of the beverage in the cup, especially in professional machines, but a high level of experience is generally necessary in order to make the changes in an effective manner.

[0008] To this end, professional, or even domestic, types of machines for the production of coffee are known which allow to manually modify one or more machine setting parameters, such as the pressure of the infusion chamber, the temperature and / or the quantity of infusion water, or possibly also the granulometry of the coffee powder and the quantity of coffee used for each beverage, going to modify the settings of one or more components, such as the heating means, the water feed means, or the coffee powder grinding device, the dosing device and others.

[0009] WO-A-2022 / 003743, WO-A-2021 / 259548, WO-A-2021 / 199096 and US-A- 2020 / 093321 disclose known machines and methods for preparing coffee beverages. Automatic machines for preparing coffee beverages are also known which provide to automatically set the setting parameters on the basis of defined profiles, for example, on the basis of the type of coffee beans used or even on the tastes of a user.

[0010] However, such known solutions generally provide to set specific predefined parameters that remain substantially fixed over time, or are modified as a result of commands provided by a user.

[0011] A drawback of the known solutions is given by the fact that the extraction of a beverage depends on numerous factors, some of which may change over time, for example due to the wear of one or more components, such as the grinders of a grinding device, or the accumulation of limestone in a boiler, or still others.

[0012] There is therefore a need to perfect a method and a relative machine for preparing coffee beverages, which can overcome at least one of the disadvantages of the state of the art.

[0013] In particular, a purpose of the present invention is to provide a method and a machine for preparing coffee beverages which allow to adapt the functioning of the machine that also allow an inexperienced user to obtain a good coffee beverage in objective terms without requiring onerous attempts to modify by successive approximations the settings of one or more operating parameters of the machine.

[0014] A further purpose is to devise a method that allows to obtain an optimal extraction of the aromatic substances from the coffee powder for each selection made by the user.

[0015] A further purpose of the present invention is to provide a machine for preparing coffee beverages that allows to always obtain a coffee beverage that has certain properties identifying a high-quality coffee beverage regardless of the type of coffee beans that are used.

[0016] A further purpose is to devise a method for preparing coffee beverages that allows setting the setting parameters and then adjusting the functioning of the machine automatically.

[0017] A further purpose of the present invention is to provide a method and a machine for preparing coffee beverages that allow to keep the setting parameters constant over time and possibly compensate for minimum deviations thereof with respect to predetermined values. Still another purpose of the invention is to provide a machine and to devise a method for preparing coffee beverages that are capable of minimizing the wear of the components of the grinding device.

[0018] A further purpose of the present invention is to provide a method and a machine for preparing coffee beverages which is capable of optimizing the extraction of a coffee beverage, adapting the functioning thereof in relation to a granulometry of the coffee powder.

[0019] The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

[0020] SUMMARY OF THE INVENTION

[0021] The present invention is set forth and characterized in the independent claims. The dependent claims describe other characteristics of the present invention or variants to the main inventive idea.

[0022] In accordance with the above purposes and to resolve the technical problem disclosed above in a new and original way, also achieving considerable advantages compared to the state of the prior art, a method for a machine for preparing a coffee beverage comprises:

[0023] - providing an infusion chamber with a dose of coffee powder;

[0024] - performing a pre-infusion step and subsequently an infusion step of said dose of powder and dispensing the beverage.

[0025] According to an aspect of the present invention, the method provides to perform at least a first optimization of the operating parameters of said machine as a function of the type of coffee beans and the roasting level thereof, in which said first optimization comprises receiving in a control unit an indication regarding the variety and the roasting level of said beans and executing an algorithm for defining both a weight of a quantity of coffee to be used for said dose of powder as a function of at least one beverage to be prepared and the variety of said beans, and a quantity of water to be used in said pre-infusion step which is determined at least as a function of said defined quantity of coffee and a stoichiometric ratio value dependent on the roasting level of said beans.

[0026] According to embodiments, "variety" of the beans means the species, in particular "Arabica" or "Robusta", although solutions can also be provided in which, in addition to the main species, any minor species such as "Liberica", "Excelsa", etc., are also considered.

[0027] According to embodiments, the first optimization can provide to define the coffee powder based on both the variety and the origin of the beans, in which "origin" of the beans means information comprising one or more of place of origin and cultivation, cultivation altitude, or type of dry or wet treatment to which the beans are subjected, for example drying or washing which may influence the characteristics of the coffee powder obtained, in particular the density.

[0028] According to another aspect of the invention, the method provides to perform an algorithm for monitoring at least one extraction parameter of said machine over time during the preparation of said beverages to verify that it remains close to a specific defined target value for the set operating parameters, and to automatically modify one or more operating parameters of said pre-infusion step in order to compensate for any detected deviations of said at least one extraction parameter with respect to the defined target value.

[0029] According to embodiments, a single algorithm can be provided, comprising different groups of instructions related to the different optimizations of the parameters, or specific algorithms can also be provided for each.

[0030] According to an aspect of the present invention, the extraction parameter monitored is the flow rate during the extraction step of a beverage and the algorithm comprises a step of defining a target value for said flow rate for said coffee powder, and a subsequent step of verifying that said flow rate remains around said target value during the extraction of a beverage prepared with coffee powder having a defined granulometry.

[0031] According to a further aspect of the invention, the step of verifying that the flow rate remains around the defined target value provides to compare a current flow rate value with the previously defined target value and if said current value deviates from said defined target value by more than a given quantity, provides to consider a volume of a pod used for preparing a previous drink, measured before and after the pre-infusion step, verifying whether the volume of the dry pod is greater or less than the volume of the wet pod and, as a function of the outcome of the comparison, automatically changing one of said quantity of coffee and said quantity of water.

[0032] The current flow rate value can be the flow rate value measured during the preparation of the last prepared beverage, or an average flow rate value, calculated based on a certain number of measured flow rate values.

[0033] In particular, the method allows to optimize and adapt the functioning of the machine in order to obtain the best possible beverage as a function of such a measured parameter and the defined granulometry, minimizing any adjustments of the grinding device and thus of the granulometry level.

[0034] According to embodiments, the method comprises initially modifying one of said quantity of coffee or water by a predetermined quantity and subsequently comparing said modified quantity with a respective maximum or minimum value to assess whether the modification made is sufficient or whether the other of said quantity of water or coffee also needs to be modified by a predetermined quantity.

[0035] In accordance with another aspect of the invention, the step of defining said target value for said flow rate provides to verify whether a measured flow value is within or outside a range of predefined values.

[0036] If such a measured value is within said predefined values, the method can provide to receive feedback from the user on a beverage prepared during the flow rate value measurement and to determine whether to define a new target value for said flow rate, and which, so as to make a subsequent beverage corresponding to the taste of the consumer. In such a case the current granulometry value can be maintained as the defined granulometry level.

[0037] If such a measured value is outside the range of predefined values, the method can automatically define a given predefined target value comprised in said range of predefined values.

[0038] If the measured value is outside the range of predefined values, the method can also provide to verify the granulometry level set for the coffee powder and, if it is not already set at a limit level, or close thereto, it provides to automatically vary it to decrease it or respectively increase it by one position, depending on whether the measured flow value is less than or respectively greater than the range of predefined values, so as to bring the granulometry level back towards an intermediate value between the limit positions.

[0039] According to a further aspect of the invention, the method provides to calculate an activation and deactivation duty cycle with which to command water feed means to supply said defined quantity of water in said chamber in order to keep a duration of said pre-infusion step constant. In other words, the duty cycle is varied as a function of the quantity of water defined from time to time, so as to feed into the chamber all the pre-infusion water required always in a same time interval.

[0040] Embodiments described herein further relate to a machine for preparing coffee beverages, comprising a coffee bean container, a grinding unit for grinding said beans with different granulometry levels, and an infusion unit provided with a chamber suitable to receive and contain a dose of coffee powder to be infused, which is connected to water feed means and beverage dispensing means, and a user interface by which at least information on the type of coffee beans to be used can be acquired. Said machine also comprises a control unit configured to implement a method according to the invention.

[0041] DESCRIPTION OF THE DRAWINGS

[0042] These and other aspects, features and advantages of the present invention will become clear from the following disclosure of some embodiments, provided merely by way of non-limiting example, with reference to the accompanying drawings in which:

[0043] - fig. 1 is a schematic view of a machine for preparing coffee beverages according to the present invention;

[0044] - fig. 2 shows in a graph the trend of the granulometry in relation to the density for different types of coffee beans;

[0045] - fig. 3 is a block diagram of a method for preparing coffee beverages according to the present invention;

[0046] - fig. 4 is a block diagram of an algorithm part followed by the method according to the invention for the definition of target values and the possible correction of the operating parameters;

[0047] - fig. 5 is a block diagram of an algorithm part followed by the method according to the invention for monitoring the operating parameters;

[0048] - fig. 6 is a block diagram of the verification step of fig. 5.

[0049] We must clarify that in the present description the phraseology and terminology used, as well as the figures in the attached drawings also as described, have the sole function of better illustrating and explaining the present invention, their function being to provide a non-limiting example of the invention itself, since the scope of protection is defined by the claims. To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can be conveniently combined or incorporated into other embodiments without further clarifications.

[0050] DESCRIPTION OF SOME EMBODIMENTS OF THE

[0051] PRESENT INVENTION

[0052] With reference to fig. 1 , a machine 10 for preparing a coffee beverage according to the present invention comprises, in a known manner, a coffee bean container 11, a grinding unit 12 for grinding the beans with different granulometry levels, and an infusion unit 13 provided with a chamber 14 suitable to receive and contain a dose of coffee powder to be infused, which is connected to water feed means 15 and to dispensing means 16 of a beverage for dispensing the beverage into a suitable container 37.

[0053] The grinding unit 12 can comprise a grinding chamber 21 in which grinding means 22 are arranged, for example two grinders 22a, 22b whose mutual distance can be adjusted to grind the coffee beans with differentiated granulometry as a function of needs. In particular, a plurality of different grinding levels can be provided, for example in a number between 2 and 15.

[0054] The machine 10 can further comprise a dosing device 28 configured to dose the quantity of coffee powder to be used for preparing a beverage.

[0055] Such a dosing device 28 can be placed upstream, or downstream, of the grinding device 12, and configured to measure the weight and / or volume of the coffee beans before grinding or, respectively, of the already ground coffee powder.

[0056] The feed means 15 can comprise, in known manner, a tank 17 and a hydraulic circuit 18 connecting the tank 17 to the chamber 14, along which water feed means 19, for example a pump, and heating means 20, for example a boiler, can be present.

[0057] According to embodiments, the machine 10 can further comprise a plurality of sensors 29, each configured to measure a certain extraction parameter during the preparation of a beverage. For example, the machine 10 can comprise a flow rate detector 23, for example a flow meter, arranged along the hydraulic circuit 18 downstream of the chamber 14, and one or more among a temperature sensor 24 associated with the heating means 20 or the hydraulic circuit 19 downstream thereof, a pressure sensor 25 associated with the chamber 14, and possibly a further flow rate detector 26 placed downstream of the chamber 14, or one or more sensors suitable for measuring the flow time, i.e., the dispensing time of a beverage, or other parameters.

[0058] According to embodiments, the machine 10 can comprise granulometry acquisition means 27, configured to acquire data related to the granulometry level set for the coffee powder.

[0059] According to possible embodiment solutions, the granulometry acquisition means 27 can be made in the form of a sensor, or can be made on a user interface 30.

[0060] For example, the sensors 29 can comprise a granulometry detector 38 associated with the grinding device 12. The granulometry detector 38 can be made as a position detector, for example configured to detect a distance between the grinders 22a, 22b, or the position of a mechanical adjustment member, such as a lever or a ring nut, not illustrated, connected to said grinding means 22.

[0061] According to possible variants it can also be provided that the granulometry detector 38 comprises an optical reader, such as a camera suitable for acquiring an image of the coffee powder, or a beam reflected therefrom and a processing unit suitable for receiving data from the optical reader and estimating the granulometry level on the basis of such data.

[0062] The machine 10 further comprises an interface 30 by means of which information can be acquired on the characteristics of the type of coffee beans used for preparing the beverage, i.e., of the coffee beans that are introduced and / or are present in the container 11. Such information preferably comprises at least the variety and roasting level of the coffee beans, but can also comprise information regarding the origin and place of cultivation, cultivation altitude, and the like.

[0063] Information related to the granulometry level set on the machine 10, which in this case can be directly provided by the user, can also be acquired by means of the interface 30. In this case the interface 30 itself can act as acquisition means of the granulometry 27.

[0064] According to embodiments, the interface 30 can comprise a touch-sensitive screen, or commands by which a consumer can command the start of preparation of a beverage, select one or more characteristics of the beverage to be prepared, such as taste intensity, beverage "length", or other. According to embodiments, the interface 30 can be installed on the machine 10, for example installed on a frame 31.

[0065] According to possible embodiments, the interface 30 can be provided, additionally or alternatively, on an electronic device 32, for example a smartphone, a tablet or other similar device, on which a dedicated software application can be implemented.

[0066] The machine 10 comprises a control unit 35, which is connected to the interface 30 and is configured to adjust the setting parameters of the machine 10, i.e., of one or more of its components, in order to obtain a beverage with certain properties.

[0067] In the case of an interface 30 made on an electronic device 32, it can be provided that it communicates directly with the control unit 35 or by means of a "cloud" type platform 33 through a wireless communication network by means of an Internet provider.

[0068] According to further embodiments, the control unit 35 can comprise a command unit 35a provided in the machine 10 and a processing unit 35b provided in the platform 33, which can communicate directly with each other, or through the software application implemented on the electronic device 32.

[0069] In other embodiments, both the command unit 35a and the processing unit 35b can be provided on the machine 10, or on the platform 33 or even on the electronic device 32.

[0070] The control unit 35 is configured to adjust the pre-infusion parameters of a dose of coffee powder as a function of at least the variety and the roasting level of the beans and possibly also their granulometry level.

[0071] According to embodiments, the control unit 35 is configured to implement an algorithm for determining at least one quantity of coffee powder and at least one pre-infusion parameter for said quantity of powder as a function of the variety, the roasting level of the beans and possibly a granulometry level of the coffee powder in order to perform at least a first optimization of the operating parameters of the machine 10.

[0072] According to embodiments, the at least a first optimization of the operating parameters of the machine 10 can be performed on the basis of a beverage to be prepared.

[0073] According to an embodiment, said beverage to be prepared can be a specific reference beverage, for example a normal Espresso coffee, i.e., neither lungo nor ristretto, and on the basis of such optimization, specific modifications can subsequently be provided in relation to different types of beverages, such as lungo, ristretto, strong, weak, double, or other coffee.

[0074] In particular, according to embodiments, the at least a first optimization can be performed following a request to start an optimization procedure by a user, for example provided by means of the interface 30.

[0075] According to other embodiments, the at least a first optimization can be performed for each beverage preparation, as a function of the characteristics of the beverage selected from time to time.

[0076] The control unit 35 can also be configured to implement an algorithm based on artificial intelligence, which monitors the extraction parameters of the machine 10 over time to verify that they remain consistent with the set parameters and automatically adjusts at least the pre-infusion parameters so as to compensate for any detected deviations of the extraction parameters with respect to set parameters and to defined target parameters.

[0077] In particular, the control unit 35 adjusts the pre-infusion parameters in order to minimize the adjustments of the grinder 12 to modify the granulometry of the coffee powder. The control unit 35 provides to verify and / or adjust in advance the distance between the grinders 22a, 22b, so as to set the granulometry at a desired level, preferably an intermediate level, away from limit values and subsequently modify other parameters such as the quantity of coffee or the quantity of water to be used at least during a pre-infusion step.

[0078] Thanks to the implemented algorithm, the control unit 35 is in particular configured to automatically adjust the quantity of coffee powder and / or the quantity of pre-infusion water as a function of a deviation between the value of an extraction parameter measured with respect to a target value defined for such an extraction parameter.

[0079] Moreover, the control unit 35 can also be configured to implement an algorithm so as to perform a second and finer optimization of the operating parameters on the basis of the at least one extraction parameter measured during the preparation of a beverage and of feedback provided by the consumer on such a beverage.

[0080] The machine 10 can also comprise a memory unit 34 in which the algorithm can be stored, together with any operating parameters, coefficients, or reference values related to the characteristics of the coffee beans and / or powder to be used.

[0081] The memory unit 34 can be installed on-board the machine, and can be physically connected to the control unit 35, or can be physically separate therefrom, but connected by means of a wireless communications network.

[0082] The functioning of the machine 10, which also corresponds to a method according to the invention, comprises:

[0083] - receiving a command for preparing a beverage;

[0084] - providing an infusion chamber with a dose of coffee powder;

[0085] - performing a pre-infusion step of said dose of powder;

[0086] - performing an infusion step of said dose of powder and dispensing the beverage.

[0087] According to embodiments, the method according to the invention comprises at least one adjustment step which provides to perform at least a first optimization of the operating parameters of the machine 10 as a function of the type of coffee beans and a second optimization step comprising a first step of defining a target value for an extraction parameter and a subsequent step of verifying that a current value of the extraction parameter measured during the operation of the machine remains around the defined target value.

[0088] In particular, the method according to the invention in the first optimization provides to receive an indication regarding the variety and the roasting level of the beans and to run an algorithm to define at least one quantity of coffee Q coffee of coffee powder to be used for the dose of powder and a quantity of water Q water to be used in the pre-infusion step as a function of the indications received.

[0089] The method can provide to define the quantity of coffee Q coffee as a function at least of the variety of the beans and the selected beverage (e.g., a single-dose, or double-dose, long, ristretto, normal coffee, or possibly a cappuccino, or other), and the quantity of water Q water to be used at least as a function of the quantity of coffee Q_coffee defined and the roasting level of the beans.

[0090] According to embodiments, the quantity of coffee Q coffee can be defined only on the basis of the variety of the coffee beans and the type of beverage. For example, it can be provided that for coffee beans of "Arabica" origin a first quantity is defined, for coffee beans of "Robusta" origin a second quantity is defined, preferably greater than the first quantity, and for coffee beans that provide a mixture of Arabica and Robusta a third quantity is defined, preferably comprised between the first and the second quantity, and so on if further varieties of beans are also provided.

[0091] According to other embodiments, the quantity of coffee Q coffee can also be defined in relation to one or more of the origin of the beans, the roasting level of the beans and / or the granulometry. In such a case, for each combination of two or more parameters considered, a different quantity of coffee can be defined. This allows to obtain a more punctual optimization.

[0092] According to embodiments, the indication on the variety, on the possible origin and on the roasting level of the beans can be received by mean of the interface 30, for example input by a user, or even acquired by scanning a barcode or QR code, or downloaded from a website.

[0093] According to further embodiments, and as will be better described later in the description, the method according to the invention provides to perform a second optimization of the machine parameters so as to improve the performance thereof and obtain high-quality beverages.

[0094] According to embodiments, the method provides to monitor one or more extraction parameters of the machine 10 over time in order to verify that the values remain close to specific defined target values for the set operating parameters, and possibly to automatically modify at least the pre-infusion parameters in order to compensate for any deviations of at least one detected extraction parameter with respect to respective set target values.

[0095] Fig. 3 exemplarily illustrates a flow chart of the procedure executed by the algorithm.

[0096] According to embodiments, to carry out the first optimization, the method provides to select and / or define a specific stoichiometric ratio value as a function of at least the roasting level of the beans, in which "stoichiometric ratio" means the ratio between a quantity of water to be used during the pre-infosion step and the quantity of coffee Q coffee for a dose, and to define the quantity of water Q water on the basis of the stoichiometric ratio.

[0097] For example, a plurality of stoichiometric ratio values can be stored in the memory unit 34, each related to a specific roasting level, e.g., "light", "medium", "dark", or any intermediate levels, and the control unit 35 can select the correct value from time to time on the basis of the received indications.

[0098] The method according to the present invention can further provide to receive an indication regarding a granulometry level set for said coffee powder and to perform a correction of the value of the stoichiometric ratio as a function of said granulometry level.

[0099] According to embodiments, the granulometry level can be provided by a user by means of the interface 30.

[0100] Alternatively, or in addition, it can be provided that the control unit 35 receives the indication of the granulometry level by means of the granulometry detector 27, for example on the basis of the position between the grinders 22a, 22b.

[0101] According to possible variations, the method can also provide to define the quantity by weight of coffee powder for a dose also in relation to the roasting level and / or granulometry.

[0102] According to embodiments, the method provides to define the quantity of coffee powder Q coffee according to the following formula:

[0103] Q-.coffe = a • granulometry- ■ volume (1) in which the coefficients a and 0 depend on the roasting level.

[0104] The volume can correspond to the volume of a dry pod, i.e., the volume occupied by a dose of dry and compressed coffee powder.

[0105] By way of example, the coefficient a can range from about 5 for a light roasting level, to about 10 for a dark roasting level.

[0106] By way of example, the coefficient 0 can range from about 0.3 for a light roasting level, to about 0.6 for a dark roasting level.

[0107] According to embodiments, the method provides to define the quantity of preinfusion water Q_water according to the following formula:

[0108] Q_water = Q_coffe ■ stoichiometric ratio (2)

[0109] According to further embodiments, the method provides to define the quantity of pre-infusion water Q water also as a function of the granulometry. In such a case, the quantity of water Q_water can be calculated based on the following formula: Fig. 2 exemplarily illustrates a graph in which a density of the coffee powder is reported in abscissa, while the granulometry is reported in ordinate. The curves indicate the trend of the relationship between the density of a dry powder pod, the granulometry and the roasting level for different types of coffee beans.

[0110] The density of the powder, which influences the volume of the pod, can also vary in relation to the origin of the beans. For example, "Arabica" beans are less dense than "Robusta" beans.

[0111] According to further variants of embodiment, in addition to the variety of the beans, for example of the "Arabica" or "Robusta" species, their mixtures or possibly other minor species, further information is also considered regarding the actual place of origin of the beans or the altitude at which the beans are cultivated, which can influence their density and the algorithm can be configured to also take into account this further information, if available.

[0112] The curves basically follow a cubic type relationship, according to the following formula: granulometry — C ■ density3(4) where C is a coefficient that depends on the roasting level and the origin of the beans.

[0113] The rightmost curves refer to beans having a light roasting level, while the leftmost curves refer to beans having a light roasting level. In particular, the curves C1-C8 correspond to the following types of beans:

[0114] Table 1

[0115] In the table, A. refers to "Arabica", R. refers to "Robusta" and G2, G5 and G7 refer to three different granulometry levels, indicatively between 250-300 gm, 460- 490 gm and 740-760 gm.

[0116] As can also be seen in the graph of fig. 2, considering a granulometry range between about 200 gm and about 750 gm, the density of the coffee powder can vary overall up to 30-35%. Considering an intermediate granulometry range between 400 gm and 500 gm, corresponding to that of commercially available coffee powder, the density can also vary by 10-13 % within such a range.

[0117] It is therefore very important to also consider granulometry as a parameter on the basis of which to correct the stoichiometric ratio and thus the quantity of preinfusion water to be used.

[0118] In fact, the absorption capacity of coffee powder is related to both the roasting level and the granulometry. In particular, the absorption capacity increases as the roasting level increases, so dark beans, i.e., very roasted, absorb more than light beans, which are not very roasted.

[0119] Furthermore, the absorption capacity also increases with the increase of the granulometry, so that a very fine powder absorbs less liquids than a coarser powder.

[0120] The parameters of quantity by weight of coffee powder, quantity of pre-infusion water, corrective factors for stoichiometric ratio as a function of granulometry, or others, can be stored in the memory unit 34, or calculated from time to time based on data and tables stored therein.

[0121] For example, for each possible combination of variety, roasting level and granulometry level, and possibly origin of the beans, specific sets of operating parameters SI,..., SN to be used can be stored in the memory unit 34, which comprise at least the quantity by weight of powder and the quantity of pre-infusion water.

[0122] As can be seen in the graph of fig. 3, the method can also provide to set a different temperature of the pre-infusion water, which can possibly also be maintained for the infusion step, as a function of the roasting level. This allows to obtain an optimal extraction of the aromatic substances for each type of bean.

[0123] In particular, for light beans that are hardly roasted, the temperature of the water T can be decreasing between a maximum and a minimum value as the roasting level increases. Exemplarily, the temperature can be set to about 96 °C for light beans, about 94 °C for intermediate roasted beans and about 92 °C for dark beans. According to embodiments, once the quantity of pre-infusion water to be used has been defined, the method provides to calculate a duty cycle with which to control the water feed means 19, in the case of the pump, in order to maintain the time, or duration, of the pre-infusion step constant.

[0124] Thereby, in every situation and for all types of coffee, a sufficient contact time between the water and the coffee powder is ensured, without requiring extending the pre-infusion time, thus ensuring the dispensing of the beverage according to the times established by the rules.

[0125] Duty cycle means the fraction of time in which the pump is kept on within a defined period of time. The larger the fraction, the greater the quantity of water that the pump feeds in the unit of time.

[0126] By way of example, the pre-infusion time At j>i can be kept constant at a value between 4 and 5 seconds.

[0127] According to embodiments, the duty cycle can be calculated based on the following formula:

[0128] , , , Q_water 1 duty cycle = - : - - (5)

[0129] ' maximum pump flow rate At_pt where the maximum pump flow rate is a fixed parameter defined by design, Q water is a value that can be calculated using one of the formulae (2) or (3) above and At_pi is the desired value for the duration of the infusion time.

[0130] By turning the pump on and off periodically according to the defined duty cycle, it is thus possible to provide the correct quantity of water Q water in the preinfusion time At_pi from time to time.

[0131] According to embodiments, the duty cycle for each possible combination of coffee bean types and granulometry level can also be stored in the memory unit 34 together with the other operating parameters S1,...,SN.

[0132] Below, Table 2 shows by way of example some values of quantity of powder Q coffee, quantity of water Q water, stoichiometric ratio and duty cycle for different types of coffee beans.

[0133] Table 2

[0134] Once the operating parameters have been determined, or selected by the memory unit 34, the method then provides to start the grinding device 12 and / or the dosing device 28 to supply the desired quantity of powder Q coffee in the chamber 14, and subsequently to activate the water feed means 19 according to the defined duty cycle to start the pre-infiision step.

[0135] Before the activation of the water feed means 19, the powder can be compressed to obtain a pod.

[0136] Once the pre-infusion step is complete, the infusion step can be started, during which the water feed means 19 are activated to feed a quantity of water consistent with the type and quantity of beverage requested by a user.

[0137] The operating parameters used for dispensing the beverage can be stored and memorized in the memory unit 34.

[0138] According to embodiments, the method can further comprise measuring the volume of the coffee powder pod in the chamber 14 before and after the preinfusion step, and comparing the two values to verify that the volume of the dry pod is correctly greater than the volume of the wet pod.

[0139] According to further embodiments, the method can further provide to store the data related to the volume of the pod in the memory unit 34 in order to be able to perform further checks on the functioning of the machine 10.

[0140] According to an aspect of the invention, the method provides to measure as an extraction parameter, a flow rate, or a flow time, or dispensing time, of a beverage, during the infusion step, and possibly to store the data in the memory unit 34.

[0141] According to embodiments, the step of defining a target value for an extraction parameter provides to define a target value FR target for the flow rate.

[0142] In accordance with embodiments, the definition step provides to verify if a flow value measured during the preparation of a beverage is within or outside a range of predefined values.

[0143] In the diagram shown in fig. 4, a part of the algorithm dedicated to the definition of the target value FR target is shown.

[0144] In particular, the verification step provides to measure a flow rate FR during the infusion of the prepared beverage and to compare it with predefined threshold values FRmin, FRmax that delimit an ideal range of values within which the flow rate value FR should fall during a normal and correct functioning of the machine 10.

[0145] According to embodiments, if the measured flow rate value FR is outside the range of values FRmin-FRmax, the method can provide to automatically define as the predefined target value FR target a reference value FR ref comprised between the threshold values FRmin, FRmax.

[0146] For example, the reference value FR ref can be an average value between the minimum FRmin and maximum FRmax threshold values.

[0147] If the measured flow rate FR is outside the range, the method can also provide to verify the granulometry level GL set for the coffee powder and, if such a granulometry value GL is not already set at a limit level GLmin, GLmax, or close thereto, GL1, GL2, it provides to automatically vary it.

[0148] Such an automatic variation preferably occurs without performing further checks in advance.

[0149] In particular, in the case of an overly fast flow, the method provides to decrease the granulometry level GL in order to obtain a finer powder, while in the case of an overly slow flow, it provides to increase the granulometry level GL in order to increase the grain size of the powder.

[0150] In any case, the modification performed on the granulometry level GL has the purpose of returning or maintaining the latter in the most central values among those available, so as to require few and minimal changes in the distance between the grinders 22a, 22b.

[0151] According to embodiments, if the flow rate value FR measured is within the threshold values FRmin, FRmax, the method provides to receive feedback from a consumer on one or more characteristics of a beverage prepared during the flow value measurement and the control unit 35 can define a specific target value FR target, so as to make a subsequent beverage corresponding to the taste of a consumer.

[0152] According to embodiments, the user interface 30 can be configured to display one or more questions for the consumer in relation to the characteristics of a beverage to be prepared for which feedback is to be received and to transmit the answers provided by the consumer to the control unit 35.

[0153] On the basis of the feedback received, the control unit 35 is configured to determine, by means of the implemented algorithm, whether to define a new target value FR target, in order to make a next drink corresponding to the taste of the consumer.

[0154] According to embodiments, the characteristics can relate to one or more of the quantity of cream, the colour of the cream, the structure of the body, or even others, such as the colour of the coffee, the temperature of the coffee, the quantity of beverage, or the aroma. The questions can be of the multiple-choice type so as to facilitate both the acquisition and processing thereof.

[0155] For example, if the measured flow rate value FR is between FRmin and FRmax and the consumer feels that the taste is "balanced", then the control unit 35 assumes the measured flow rate value as the new target value FR target.

[0156] When instead the measured flow rate FR falls within the threshold values FRmin, FRmax, but the consumer provides negative feedback judging the taste of the beverage "weak" or respectively "strong", then the control unit 35 can increase or decrease the target value FR target to make the flow respectively slower, or faster, setting new target values FR1, FR2, which can for example assume values respectively comprised between the threshold value FRmin and the reference value FR ref, or between the reference value FR ref and the threshold value FR max.

[0157] According to embodiments, the consumer feedback is considered only if the measured flow rate value FR results in the range of predefined threshold values.

[0158] The new target flow rate values FR target can be stored in the memory unit 34 and subsequent comparisons will be made with respect thereto.

[0159] The possible new granulometry level GL defined can also be stored in the memory unit 34 to be used in the subsequent operations of beverage preparation and in the step of verifying machine operation.

[0160] Fig. 5 exemplarily illustrates a part of the algorithm followed by the method according to the invention for monitoring the extraction parameters over time and evaluating whether and how to modify them to compensate for any deviations of one or more extraction parameters with respect to the respective target values.

[0161] Such an algorithm is preferably based on artificial intelligence and allows, in particular, to adapt the operating parameters of the machine 10, in particular those of pre-infusion, in order to obtain the best possible result for a certain predefined granulometry level. Only if it is not possible to suitably modify the pre-infusion parameters without compromising the functioning of the machine 10, the algorithm and therefore the method according to the invention, provides to modify the granulometry level.

[0162] The method that follows the algorithm based on artificial intelligence provides to receive the data stored in the memory unit 34, related to the quantity of coffee Q coffee, quantity of water Q water, duty cycle, comparison between dry pod volume Vol_A and wet pod volume Vol_B, and the data related to the flow rate FR measured during the infusion and to suitably process them to perform the verification step of the second optimization.

[0163] The verification step provides to compare a current flow rate value with the defined target value FR target and to verify the extent of the difference AFR between the current value and the target value FR target, in which the current value can be the last measured value or an average value FR med.

[0164] In this latter case, the method provides to calculate the average value FR med of the last N measured flow rates FR, subtracting it from the target value FR target to calculate the difference AFR and to verify that such a difference AFR remains within an acceptable range, for example if it corresponds to FR target ± 0.2-0.4g / s, or a percentage value such as ±10-15%.

[0165] In the event of a positive result, the method provides to keep the operating parameters already set.

[0166] In the event of a negative result, the method provides to evaluate whether and how to modify one or more pre-infusion operating parameters, selected among the quantity of coffee Q coffee or the quantity of water Q water, to return the flow rate to the target value FR target.

[0167] If necessary, the method provides to possibly calculate and define the new operating parameters to be used and to store them in the memory unit 34 to be used in the beverage preparation operations.

[0168] Fig. 6 shows in detail the verification step and any modification of the preinfusion operating parameters, in particular Q coffee and Q water.

[0169] The step of verifying provides to compare the current flow rate value with the previously defined target value and if the current value deviates from the defined target value by more than a given quantity AFR*, for example 0.2-0.4g / s, provides to consider a volume of a pod used for preparing a previous beverage, measured before and after the pre-infusion step, and verify whether the volume of the dry pod Vol_A is greater or less than the volume of the wet pod Vol_B and, as a function of the outcome of the comparison, automatically change one among the quantity of coffee Q coffee and the quantity of water Q water.

[0170] In particular, the method according to the invention can provide to initially modify only one among the quantity of coffee Q coffee or water Q water by a predefined quantity AQC, AQW and subsequently to compare the modified quantity from time to time with respective maximum or minimum values QCmax, QWmax, QCmin, QWmin to evaluate whether the modification made is sufficient or it is necessary to modify a predefined quantity AQW, AQC equal to, or different from the previous one, also the other of the quantity of water Q water or coffee Q coffee.

[0171] For example, the predefined quantity of water AQW can be about 2cc, while the predefined quantity of coffee AQC can be about 5g.

[0172] As can be seen in the graph of fig. 6, if the flow rate value FR is greater than the target value FR target, i.e., the flow is too fast, and the volume of the dry pod Vol_A is greater than the volume of the wet pod Vol_B, the method provides to automatically modify the quantity of coffee Q coffee by increasing it by the predefined quantity AQC and otherwise, i.e., if the volume of the dry pod Vol_A is less than that of the wet pod Vol_B, it provides to automatically modify the quantity of water Q water by a predefined quantity AQW.

[0173] If the flow rate value FR is less than the target value FR target, i.e., the flow is too slow, and the volume of the dry pod Vol_A is greater than the volume of the wet pod Vol_B, the method provides to automatically modify the quantity of water Q water by decreasing it by the predefined quantity AQW and otherwise to automatically modify the quantity of coffee Q coffee by decreasing it by the predefined quantity AQC.

[0174] According to embodiments, if the value of the modified quantity Q coffee or Q water exceeds the respective maximum or minimum value QCmax, QWmax, QCmin, QWmin, the method provides to set the quantity of coffee or water to the respective maximum or minimum value and also to modify the other quantity among the quantity of water or coffee Q water, Q coffee by a respective predefined quantity AQW, AQC.

[0175] In the case of also modifying the other among the quantity of water or coffee Q water, Q coffee, the method can provide to also compare such other modified quantity with the respective maximum or minimum values QCmax, QWmax, QCmin, QWmin and, if said other modified quantity exceeds the respective maximum or minimum values, to provide an indication as to the impossibility of carrying out the second optimization.

[0176] According to further embodiments, the method according to the invention can also provide to suggest to the consumer to change the type of beans used if it is not possible to suitably modify the quantity of coffee or water to bring the flow value within the threshold values, or possibly to try to modify the granulometry level.

[0177] For example, a message may be displayed by means of the interface 30 when during the verification step both the quantity of coffee and the quantity of water have been modified and both modifications have resulted in exceeding the maximum or minimum values, respectively.

[0178] According to embodiments, the suggestions to the user can also be provided by means of indication of a website, or other information, displayed on a user interface 30, e.g., installed on the machine 10, in written form with alphabetical characters, or in encoded form in a code readable by an electronic device 32 such as a smartphone, by a dedicated software application, e.g., a QR code, a barcode or other.

[0179] In contrast, when the values of the modified quantities remain within the respective maximum or minimum values, such modified quantities are stored in the memory unit 34 to be used in subsequent beverage preparations.

[0180] According to embodiments, the method according to the invention provides to repeat at least said second optimization upon receipt of a command from a consumer, for example received by means of the user interface 30. According to further embodiments, the method can also provide to decrease the amount of the predefined quantities AQW, AQC as a function of the state of use of the machine 10, starting with higher values in an initial stage and continuing with lower values in subsequent stages. For example, with regard to the predefined quantity of coffee, it can be provided that in the initial stages a quantity of about 1g will be considered, while in subsequent stages a lower quantity, for example about 0.5g.

[0181] According to embodiments, if the stoichiometric ratio and / or the quantity of water Q water is varied, the method provides to calculate and to update the new duty cycle for the pump, always in order to keep the pre-infusion time At_pi constant.

[0182] Therefore, the method according to the invention changes the granulometry level only if that set is very coarse or very fine, while for the intermediate levels, it provides to modify one or more operating parameters chosen from quantities of coffee, quantities of water, or stoichiometric ratio. Thereby, only rare and minimal adjustments are made to the distance between the grinders 22a, 22b, thus helping to extend the useful life thereof and to reduce the wear thereof.

[0183] It is clear that modifications and / or additions of parts may be made to the method and to the machine 10 disclosed herein, without departing from the scope of the present invention as defined by the claims.

[0184] It is also clear that, although the present invention has been described with reference to some specific examples, a person skilled in the art will be able to make many other equivalent forms of method and machine 10 for preparing coffee beverages, having the characteristics expressed in the claims and therefore all of which falling within the scope of protection defined thereby.

[0185] In the following claims, the references in parentheses have the sole purpose of facilitating reading and must not be considered as limiting factors of the scope of protection defined by the claims themselves.

Claims

CLAIMS1. Method for a machine (10) for preparing a coffee beverage, in which a dose of coffee powder is supplied to an infusion chamber (14) and a step of pre-infusion and subsequently a step of infusion of said dose of powder are performed in order to dispense said beverage, characterized in that said method performs at least a first optimization of the operating parameters of said machine (10), in which a control unit (35) receives an indication regarding the variety and the roasting level of said beans and executes an algorithm able to define both the weight of a quantity of coffee (Q coffee) to be used for said dose of powder as a function at least of a beverage to be prepared and the variety of said beans, and a quantity of water (Q water) to be used in said pre-infusion step, which is determined by said quantity of coffee (Q coffee) and by a stoichiometric ratio value that depends on the roasting level of said beans, in which said method also provides to perform a second optimization of said operating parameters, in which said control unit (35) executes an algorithm to monitor in time at least one flow rate (FR) during the preparation of one or more beverages, in which said algorithm comprises at least a step of defining a target value (FR target) for said flow rate (FR) and a granulometry (GL) for said coffee powder and a subsequent verification step to verify that a value of said flow rate (FR) measured during the extraction of a beverage prepared with coffee powder having said granulometry (GL), remains around said defined target value (FR target), in which said verification step provides to compare a current flow rate value with said defined target value (FR target) and if said current flow value deviates from said defined target value (FR target) by more than a given quantity (AFR*), it provides to consider a volume of a pod used for the preparation of a previous beverage, measured before and after said pre-infusion step, to verify whether the volume of the dry pod (Vol_A) is greater or less than the volume of the wet pod (Vol_B) and, as a function of the result of the comparison, directly and automatically modify one among said quantity of coffee (Q coffee) and said quantity of water (Q water) to be used in a subsequent preparation of a beverage.

2. Method as in claim 1, characterized in that it provides to initially modify only one among said quantity of coffee or water (Q coffee, Q water) by a predefined quantity (AQC, AQW) and subsequently to compare said modified quantity withrespective maximum or minimum values (QCmax, QWmax; QCmin, QWmin) to evaluate whether the modification made is sufficient or it is necessary to modify by a predefined quantity (AQW, AQC) also the other of said quantity of water or coffee (Q water, Q coffee).

3. Method as in claim 1 or 2, characterized in that if said measured flow rate value (FR) is greater than said target value (FR target) and said dry pod volume (Vol_A) is greater than said wet pod volume (Vol_B), the method provides to automatically modify said quantity of coffee (Q coffee) by increasing it by a predefined quantity (AQC) and otherwise to automatically modify said quantity of water (Q water) by a predetermined quantity (AQW), while if said measured flow rate value (FR) is less than said target value (FR target) and said dry pod volume (Vol_A) is greater than said wet pod volume (Vol_B) it provides to automatically modify said quantity of water (Q water) by decreasing it by a predetermined quantity of water (AQW) and otherwise to automatically modify said quantity of coffee (Q coffee) by decreasing it by a predefined quantity (AQC).

4. Method as in one or the other of claims 2 or 3, characterized in that if the value of the modified quantity (Q coffee, Q water) exceeds the respective maximum or minimum value (QCmax, QWmax, QCmin, QWmin), said method provides to set the quantity of coffee or water to the respective maximum or minimum value and also to modify the other quantity among the quantity of water or coffee (Q water, Q coffee) by a respective predefined quantity (AQW, AQC).

5. Method as in claim 4, characterized in that in the case of also modifying said other quantity of water or coffee (Q water, Q coffee) it also provides to compare said other modified quantity with said respective maximum or minimum values (QCmax, QWmax; QCmin, QWmin) and if said other modified quantity exceeds said respective maximum or minimum values, to provide an indication as to the impossibility of carrying out said second optimization.

5. Method as in one or the other of the preceding claims, characterized in that it provides to repeat at least said second optimization upon receipt of a command by a user.

6. Method as in one or the other of the preceding claims, characterized in that it provides to decrease the amount of said predefined quantities (AQW, AQC) as a function of the state of use of said machine (10), starting with higher values in aninitial stage and continuing with lower values in subsequent stages.

7. Method as in any of the preceding claims, characterized in that said step of defining said target value (FR target) provides to verify whether a measured flow rate value (FR) is within a range of predefined values, and in the event of a positive outcome, to receive feedback from the user on a beverage prepared during the measurement of said flow rate value (FR) and to determine whether to define a new target value for said flow rate, and which, in order to make a subsequent beverage corresponding to the taste of the consumer, maintaining the current granulometry value can be maintained, while in the event of a negative outcome provides to both automatically set a target value (FR target) at a reference value (FR ref) and to increase or respectively decrease a granulometry level (GL) for said coffee powder.

8. Method as in any claim hereinbefore, characterized in that it provides to calculate an activation and deactivation duty cycle with which to command water feed means (19) to supply said quantity of water (Q water) in said chamber (14) in order to keep the duration of said pre-infusion step constant.

9. Method as in any claim hereinbefore, characterized in that it provides to suggest to the consumer to change the type of beans used in the event that it is not possible to suitably modify one or more operating parameters to adapt the beverage to the consumer's tastes without compromising the functioning of said machine (10), wherein said suggestion comprises one or more of a message or an indication to a website displayed on a user interface (30) in written form with alphabetical characters, or in encoded form in a code readable by an electronic device (32), such as a barcode or a QR code.

10. Method as in any claim hereinbefore, characterized in that said algorithm is configured to define the weight of the quantity of said coffee (Q coffee) on the basis of the variety and the roasting level of the beans and possibly also of the origin of said beans.

11. Method as in any claim hereinbefore, characterized in that it provides to receive an indication also regarding a granulometry level for the coffee powder and said algorithm is configured to define the weight of the quantity of said coffee (Q coffee) on the basis of the variety of the beans, the roasting level and said granulometry level.

12. Method as in any claim hereinbefore, characterized in that said variety of said beans comprises at least the species, preferably chosen from "Arabica", "Robusta", or a mixture of both.

13. Machine (10) for preparing beverages comprising a container (11) for coffee beans, a grinding unit (12) for grinding said beans with different granulometry levels, and an infusion unit (13) provided with a chamber (14) suitable to receive and contain a dose of coffee powder to be infused, which is connected to water feed means (15) and to means (16) for dispensing a beverage, a user interface (30) by means of which at least information on the type of coffee beans to be used can be acquired, characterized in that said machine (10) comprises at least one flow rate detector (23, 26) suitable for detecting at least one flow rate (FR) of a flow during a preparation of a beverage and a control unit (35) configured to implement a method as in any claim hereinbefore, in order to determine at least one quantity of coffee (Q coffee) and at least one pre-infusion parameter for said quantity of coffee (Q coffee) as a function at least of the origin and roasting level of said beans and to perform said first and second optimization of the operating parameters of said machine (10).

14. Machine (10) as in claim 13, characterized in that it is provided with granulometry acquisition means (27) and said control unit (35) is configured to receive from the latter an indication regarding a set granulometry level and consequently adjust said pre-infusion parameters to adapt the functioning of said machine (10) on the basis of said set granulometry level.

15. Machine (10) as in claim 13 or 14, characterized in that said user interface (30) is configured to display one or more questions to the consumer in relation to one or more characteristics of a beverage and to transmit the answers provided by the consumer to said control unit (35).

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