Method for producing milk-air emulsions

Abstract

The invention relates to a method in which a milk-air emulsion is produced from milk using an apparatus for producing a milk-air emulsion. Said method has at least the following steps: providing the apparatus, providing a receptacle (2) and providing milk, filling the receptacle (2) with the milk and arranging the receptacle (2) such that the steam wand (1) is or can be immersed in the milk when it is moved, and introducing air and steam through the steam wand (1) into the milk located in the receptacle (2), wherein the air system (8) and the steam system (7) are actuated by the control device with the program for producing the milk-air emulsion, in accordance with at least one prestored milk-air emulsion production profile, in order to produce the milk-air emulsion, wherein, as the program for producing the milk-air emulsion proceeds, the height of the outlet of the steam wand (1) is adjusted at least once and wherein, as a function of the milk-air emulsion production profile, the vertical position of the steam wand, in particular the vertical position of the outlet of the steam wand (1) within the receptacle (2), is additionally adjusted and / or reset once or a number of times.

Description

[0001] METHOD FOR PRODUCING MILK-AIR EMULSIONS

[0002] The invention relates to a method for producing a milk-air emulsion, preferably a milk foam.

[0003] It is known to create a milk / air emulsion, in particular milk foam, in a container such as a pitcher filled with milk using a steam lance, which may have a steam and an air line. To do this, a person preparing the coffee with a coffee machine usually holds the pitcher under the steam lance until the temperature and consistency of the milk foam is satisfactory. This is therefore a manual process in which the steam lance is immersed in the pitcher filled with an appropriate amount of milk and is foamed using a special process or method - possibly including suitable movements - until the required temperature and consistency are reached. Such prior art is disclosed, for example, in EP 2 075 270 A2, which also discloses a height-adjustable steam lance for frothing milk.

[0004] The object of the invention is to create an optimized method for producing a milk-air emulsion while maintaining the principle of the steam lance immersed in the milk in a vessel.

[0005] The invention solves this problem by a method having the features of claim 1.

[0006] The method uses a device for producing a milk-air emulsion, which comprises at least one steam wand having at least one outlet opening and which is designed to be immersed, at least with one outlet opening, into a vessel that can be completely or partially filled with milk and is preferably open at the top, wherein steam and air can be guided through the steam wand and its outlet opening into the milk, wherein the steam wand has a device for height adjustment that is designed such that the vertical position of the steam wand, in particular the vertical position of the outlet of the steam wand, is adjustable, the device for height adjustment of the steam wand has a drive device that has an electric motor, and the device for height adjustment is coupled to a control device with which the device for height adjustment can be controlled,wherein a milk-air emulsion generation program is stored and executed on the control unit, which has access to a memory on which at least one or more milk-air emulsion generation profiles are stored, so that the steam and the air can be directed into the milk according to a respectively selected milk-air emulsion generation profile in order to automatically generate the milk / air emulsion in the vessel, wherein the milk-air emulsion generation program has a program part for controlling and / or regulating the vertical position of the outlet of the steam lance.

[0007] The method of claim 1 comprises at least the following steps: providing the device for producing the milk-air emulsion, providing a vessel and providing milk,

[0008] Filling the vessel with the milk and arranging the vessel in such a way that the steam wand is or can be immersed in the milk when it is moved; and

[0009] Introducing air and steam through the steam lance into the milk in the vessel, wherein the air system and the steam system are controlled by the control unit with the milk-air emulsion generation program according to the at least one or more pre-stored milk-air emulsion generation profile(s) in order to generate the milk-air emulsion, wherein the height of the outlet of the steam lance is adjusted at least once during a run of the milk-air emulsion generation program.

[0010] According to a preferred embodiment, it can further be provided that, depending on the one or more milk / air emulsion generation profile(s), during the execution of the milk-air emulsion generation program, the vertical position of the outlet of the steam lance within the vessel is set several times and, if necessary - if a movement relative to a current position is necessary - is adjusted.

[0011] A number of advantages arise according to claims 1 and 2, respectively. Since the frothing result when frothing "milk" - in the sense of animal milk or plant-based milk substitutes - is significantly determined by the immersion depth of the steam nozzle (= steam / air outlet opening(s) of the steam lance), the height adjustability or the height adjustment of the steam lance allows an optimal immersion depth to be reached once or multiple times for each individual product, regardless of the vessel or pitcher (frothing jug or similar) and regardless of its geometry and the amount of milk. This makes it possible to improve and automate the result of the milk / air emulsion production while still maintaining the principle of milk production in a vessel into which a steam lance is immersed.For this purpose, it is preferably provided that the device for height adjustment is designed to move the outlet of the steam lance to different vertical positions within the vessel, in particular to a position which is selected such that the at least one outlet is below the upper level or the level of the milk.

[0012] It is particularly advantageous that the height adjustment device be designed to move the steam lance outlet to various vertical positions inside and outside, or inside the vessel. The latter is additionally advantageous in order to create clearance, if necessary, for example, for large pitchers or to facilitate cleaning.

[0013] According to a further option, it can then advantageously be provided that, during milk-steam emulsion generation, the position of the outlet of the steam lance for milk-air emulsion generation is determined by means of a sensor for medium detection, which is then adjusted accordingly by a motor.

[0014] Another option can advantageously be provided for a cleaning position to be approached after the milk / steam emulsion has been generated, and for the steam lance to be cleaned. This allows for easy and straightforward fully automatic cleaning.

[0015] According to a further option, it can then be advantageously provided that the steam lance is cleaned particularly easily by means of a jet of water.

[0016] And according to another advantageous option, it can be further advantageously provided that the steam lance is moved into a rest position after cleaning.

[0017] According to a further advantageous embodiment of the method according to the invention, it can be provided that during the production of the milk-air emulsion, the amount of air which is introduced into the milk is kept constant over time and / or the temperature.

[0018] According to another advantageous embodiment of the method according to the invention, however, it can be provided that during the production of the milk-air emulsion, the amount of air which is introduced into the milk is varied over time and / or the temperature.

[0019] According to a further advantageous embodiment of the method according to the invention, it can be provided that during the production of the milk-air emulsion, the amount of steam which is introduced into the milk is kept constant over time and / or the temperature or is varied.

[0020] According to a further advantageous embodiment of the method according to the invention, it can be provided that after starting the milk-air emulsion production program, a preselection of the milk quantity and / or the milk type and / or the consistency of the milk-air emulsion to be produced takes place via a data input.

[0021] According to a further advantageous embodiment of the method according to the invention, it can be provided that the foam consistency is adjusted by adjusting the amount of air added.

[0022] According to a further advantageous embodiment of the method according to the invention, it can be provided that the target temperature is set by defining the switch-off temperature for the steam addition.

[0023] According to a further advantageous embodiment of the method according to the invention, it can be provided that the milk temperature in the vessel is determined during the production of the milk / air emulsion and that this measured value is included in the process control.

[0024] The vessel is preferably open vertically. Before the milk / air emulsion is created, it is partially filled with milk to a milk level.

[0025] On the one hand, it is conceivable for the height adjustment device to be designed as a manually operated, mechanically designed device for height adjustment, in which an operator can manually move the steam lance and its outlet vertically using an adjustment mechanism such as a spindle drive. However, it appears even more advantageous - since the method for producing milk / air emulsion can thus be further automated - if the height adjustment device according to a preferred embodiment of the invention has a drive device and an adjustment mechanism and if it is designed to move the outlet of the steam lance to various vertical positions, in particular within the vessel. However, it is also conceivable for the steam lance to be able to be pulled out of the vessel completely. The vessel is usually placed on a drip tray.It is usually open at the top and overall high enough to be filled with milk in such a way that at least one outlet can be moved below the milk level.

[0026] According to a particularly preferred embodiment, the drive device comprises an electric motor. This can, for example, act on the adjustment mechanism, in particular an adjustment gear such as a spindle drive or a rack and pinion gear, to effect the height adjustment in a motorized manner.

[0027] Optionally, it can also be provided that the vertical movement can be superimposed by a movement of the steam lance or its outlet in another direction (e.g. a horizontal movement or a rotational movement).

[0028] With the help of the motorized height adjustment, preferably in combination with sensory medium detection, the optimal immersion depth can be determined regardless of the geometry of the vessel (pitcher, frothing jug, etc.) and the milk quantity, and can be adjusted to the desired depth for each product. Furthermore, the lance can be automatically positioned for rinsing or cleaning purposes, as well as moved to a convenient resting position. The flexibility of using the steam lance is significantly increased, milk loss is reduced, and handling is simplified for the user.

[0029] Since the height adjustment device is coupled to a control unit with which the height adjustment device can be controlled, an important prerequisite for automated height adjustment of the steam lance outlet during milk / air emulsion production is created in a simple manner.

[0030] A milk-air emulsion generation program is stored on the control unit, which is executed and which has access to a memory on which at least one or more milk-air emulsion generation profiles are stored, so that the steam and the air can be directed into the milk according to a respectively selected milk-air emulsion generation profile in order to automatically generate the milk-air emulsion in the vessel according to an optimized flow profile.

[0031] It is advantageous and expedient for the milk-air emulsion generation program to include the program section for controlling and / or regulating the vertical position of the steam lance outlet. This is advantageous because it allows for optimal, automated adjustment of the vertical position of the steam lance outlet at a particularly suitable location—e.g., just below the surface or the milk level. The optimal position changes due to the increase in volume during the frothing process.

[0032] In order to further optimise the production of the milk / air emulsion, it can then advantageously be provided that one or more sensor devices are provided which are coupled to the control unit and whose output signals are used to adjust the vertical height of the outlet of the steam lance.

[0033] It has proven expedient for the one or more sensor devices to comprise one or more of the following sensors: a temperature sensor and / or a milk sensor. In particular, it should be possible to detect whether milk is present in the container and, if so, to what level. In this respect, the use of a collision sensor as a milk sensor is also conceivable.

[0034] In summary, especially with the aid of the sensors mentioned, it is possible to easily and automatically produce a milk-air emulsion according to a flow chart after filling the vessel, while maintaining the "steam lance principle." Production is preferably terminated after a limit value contained in the chart is reached (e.g., a time limit or a temperature limit). In a very simple configuration, the at least one chart can contain constant steam and air supply quantities over a defined period of time. However, it can also be more complex, which will be explained below using examples.

[0035] Above and below, the terms "milk-air mixture," "milk-air emulsion," and "milk foam" are used synonymously. The term "milk" should not be defined too narrowly. It encompasses, in particular, animal milk as well as fully or partially plant-based dairy products (e.g., oat milk and soy milk).

[0036] It can be expediently provided if the air system has at least the following: at least one or more air throttles, at least one controllable air pump connected to the control unit, and an air line. Then, according to one variant, it can be provided, particularly expediently and advantageously, that the at least one air throttle is connected to the control unit and that it is designed as a controllable motor-driven air throttle. According to a further advantageous variant, it can also be provided alternatively or optionally that the delivery rate of the air pump can be automatically changed and adjusted by the control unit. This type of control is simple and reliable. And according to another variant, it can be advantageously and structurally simple for the multiple air throttles to be designed as static air throttles, to which one or more air selection valves connected to the control unit and controllable by the latter are assigned.On the device - in particular on a coffee machine with the device - there is preferably a display for outputting information during the program sequence and an input unit - e.g. in the form of a touch display - for entering data, e.g. for pre-selection and pre-setting of the type of milk and the like.

[0037] It can further advantageously be provided that the steam system has at least one steam boiler, at least one controllable steam valve and a steam line.

[0038] It is also possible for the air line and the steam line to flow into a common combined steam-air line, which is guided through the steam lance, which can be immersed in the milk in the vessel.

[0039] It is also conceivable, however, for the air line and steam line to be routed separately through the steam lance, which can be immersed in the container containing the milk, or for the air line and steam line to be routed separately through the steam lance and an air lance, each of which can be immersed in the milk with its respective outlet in the container. In this case, the steam lance and air lance can also be adjustable. In this case, the term "steam lance" encompasses both the actual steam lance and the air lance.

[0040] According to an advantageous further development, it is also advantageous if the storage is a local storage or a cloud storage. The "connections" within the scope of this document, if they are designed or can be designed as data connections, can be wireless or wired.

[0041] The flow chart can also be changed or created from scratch, for example manually or adaptively, e.g. in response to one or more measurement results.

[0042] A drinks vending machine, in particular a coffee machine, with at least one device according to the type described above is also provided.

[0043] It is then conceivable and advantageous if the milk / air emulsion generation profile is adapted to one or more operating parameters during the production of the milk foam. For this purpose, at least one or more operating parameters can be determined once or several times during the process, which are used to adapt the milk / air emulsion generation profile.

[0044] A wide variety of control and process profiles can be generated and used. According to an advantageous milk-to-air emulsion generation profile, the control of the air system comprises several phases. In a first phase, no air is added up to a temperature value of "1." Then, in a second phase, a small amount of air is added up to a temperature value of "2." Then, in a third phase, a large amount of air is added up to a temperature value of "3." Then, in a fourth phase, a very small amount of air is added starting at a temperature value of "4."

[0045] Within the scope of the present invention, the method and / or device according to the invention can be used in a device for dispensing, and in particular also for preparing, a beverage. Such a device is preferably designed as a fully automatic coffee machine.

[0046] Further advantageous embodiments are mentioned in the remaining claims.

[0047] The invention will be described in more detail below with reference to the drawings using exemplary embodiments. It should be emphasized that these exemplary embodiments are not to be understood as limiting. The invention is implemented particularly advantageously in this exemplary embodiment. The individual features of these exemplary embodiments can be advantageously used in combination with the respective further features of the exemplary embodiments. However, they can also be combined with other exemplary embodiments shown or not shown and are also suitable as advantageous embodiments of the subject matter described in one or more of the main and subclaims. It shows:

[0048] Fig. 1 shows a device according to the invention for producing milk-air emulsions, in particular milk foam;

[0049] Fig. 2 in a) and b) two different states of a section of an apparatus for producing a milk-air emulsion;

[0050] Fig. 3 is a flowchart illustrating an exemplary method for producing a milk-air emulsion. Various embodiments are described in the following figure description.

[0051] Fig. 1 shows a first exemplary structure of a device for the automated production of milk-air emulsions. The device can form an integral component of a beverage vending machine, in particular a coffee machine. This coffee machine can be designed in a variety of ways. However, it can also form a separate unit, which is placed, for example, as a standalone device next to a beverage vending machine. This is because the device for producing milk foam—whether integrated into the beverage vending machine or designed separately—is essentially designed separately from a section of the coffee machine with which the coffee is produced.

[0052] The devices in Fig. 1 for producing milk-air emulsions serve to produce a milk-air emulsion, in particular in the manner of a milk foam, from a medium such as milk 3, which is preferably poured "untreated" or from a package or a tank into a container 2, by means of at least one steam lance 1 immersed in the container 2, with the aid of air and steam which are passed into the milk through the steam lance 1, and with the aid of automated control of the addition of air and steam to the milk. The term "milk" should not be defined too narrowly. It includes animal milks but also non-animal plant-based milk substitutes such as soy milk or oat milk or the like.

[0053] This milk foam can then be used to prepare a coffee specialty. For example, the milk foam can be poured into a cup that has previously been partially filled with coffee, or one that will be topped up with coffee afterward, to prepare a cappuccino or similar beverage.

[0054] The steam lance 1 can have an elongated shape, which allows it to be immersed from above into a vessel 2, such as a mug or pitcher. It can have an outer casing in the manner of a tube. This outer casing can be made of metal or another material, such as ceramic. A combined steam / air line 4 is routed through the steam lance 1. This line has an outlet at its end, which can be configured as a steam nozzle 22.

[0055] A temperature sensor 5, for example a thermometer, can also be formed in or on the steam lance 1. This can be connected to a control unit 9 (which can be configured as a CPU) via a data link such as a line 21 or wirelessly. It is arranged such that the free end of the steam lance 1 is typically immersed in the medium, such as milk, contained in the vessel 2.

[0056] A milk sensor 24, for example a conductivity sensor, can also be arranged in or on the steam lance 1. This can also be connected to the control unit 9 (which can be embodied as a CPU) via a data link such as a cable or wirelessly. The milk sensor 24 is also arranged such that it can generally be immersed with the free end of the steam lance 1 into the medium, such as milk, in the vessel 2. To do so, it must be immersible vertically (direction V) into the vessel 2 up to or below the milk level or the upper milk level.

[0057] The milk can - for example in the embodiment of Fig. 1 - be filled into the vessel 2 - here the pitcher - from a separate container or - and this is particularly preferred - from a tank and an outlet of the beverage machine.

[0058] The air system 8 can be designed or constructed in various ways. Exemplary embodiments are shown in Fig. 1. However, the invention is not limited thereto. The air system 8 could also be constructed in other ways.

[0059] According to Fig. 1, according to an advantageous embodiment, the air system 8 has an air inlet for air from an "air source 12," which can be formed from a tank or, for example, from the ambient air. This air source 12 can be followed in the air line 14 by at least one throttle 13, in particular a motorized air throttle, and an air pump 11, thereby providing means by which the air from the air source 12 can be conveyed through the air line 14 into the steam-air line 4.

[0060] Preferably, the amount of air fed into the steam / air line 4 can be varied by appropriate control by the control unit 9. For this purpose, the motorized air throttle 13 and / or the air pump 11 can be controllable and connected to the control unit 9 at least via a control path (a wired line or wirelessly configured).

[0061] Alternatively, no controllable air throttle 13 may be provided. To ensure that the amount of air fed into the steam / air line 4 can still be varied, multiple throttles may be provided. It is also conceivable for the at least one controllable air pump to be designed such that its delivery rate can be varied during operation of the air pump, for example, adjustable using the control unit.

[0062] The steam system 7 can also be designed in various ways. Its function is to generate steam from water and, if necessary, via an intermediate line such as the steam / air line 4, to feed it into the steam lance 1. A particularly preferred variant is shown in Figs. 1 and 2a, 2b.

[0063] The steam system 7 may be connected to a water source 16, which may be formed, for example, from a water pump or other water supply.

[0064] Downstream of this water source 16, a flow meter 17, a controllable filling valve 18, a steam boiler 15, and a steam line 20 with a steam shut-off and vent valve 19 may preferably be provided. The steam line 20 may open into the steam / air line 4.

[0065] However, the steam system 7 can also be constructed in a different way. For example, according to an alternative embodiment not shown here, the steam pressure in the steam line could be adjustable or controlled directly or via a motorized throttle in the steam channel 20 (corresponding profiles for air and steam can be stored).

[0066] The steam system 7 and the air system 8 are preferably each controllable by the control unit 9, on which a milk-air emulsion generation program is loaded and executable, wherein the control unit has access to a memory on which at least one or more milk-air emulsion generation profiles are stored, so that the steam and the air can be directed into the milk according to a respectively selected milk-air emulsion generation profile in order to automatically generate the milk-air emulsion in the vessel 2.

[0067] A device for height adjustment is then formed on the steam lance 1, which is designed such that the vertical position of the steam lance 1, in particular the vertical position of the outlet 22 of the steam lance 1, can be changed at least within the vessel 2 and optionally also outside the vessel. In particular, it is provided that the device for height adjustment is designed to move the outlet of the steam lance to different vertical positions within the vessel 2 (i.e. to different positions at or below the milk level at the top or the upper milk level). Optionally, it can also be provided that the steam lance is completely retracted from a vessel, e.g. into a rest and / or cleaning position on or in the drinks machine.

[0068] It can advantageously be provided that the device for adjusting the height of the steam lance 1 comprises a drive device for this purpose. This can be designed in various ways. Preferably, the drive device comprises an electric motor 23.

[0069] It can then further be provided that the device for height adjustment is also coupled to the control unit 9, with which the device for height adjustment can be controlled.

[0070] It can also be advantageously provided that the steam lance has one or more sensor devices, which are arranged, for example, close to the outlet 22. These sensor devices can include the aforementioned temperature sensor 5, a milk sensor 24 (for "medium detection"), and / or a milk level sensor 25. The milk sensor 24 can, for example, be designed as a conductivity sensor.

[0071] One, several, or all of these sensor devices can be connected to the control unit via a data transmission connection 21. This data transmission connection 21 can be, for example, an electrically or optically designed line for data transmission, or a radio link or the like.

[0072] Air can be fed into the steam-air line 4 with the air system 8 through an air line 14 and steam can be fed together or individually through the steam-air line 4 into and through the steam lance 1 into the vessel 2 with the steam system 7 through a steam line 20.

[0073] The air and steam can each be fed into the steam / air line 4 in a controlled or regulated manner. According to a first embodiment, the air and steam addition can be constant according to a pre-stored time schedule. Alternatively, the schedule can be changed or created entirely anew, for example, manually or adaptively in response to one or more measurement results. This will be explained in more detail below using examples. The air and steam can, for example, each be fed individually, with a time delay, or simultaneously into the steam / air line 4. For this purpose, the steam system 7 and the air system 8 are each connected to the control unit 9 (CPU). This can have a CPU and a memory or be connected to one - locally or via, for example,a network or cloud connection - and can be provided with a control and / or regulation program with which the steam-air supply through the steam-air supply line 4 into the vessel 2 can be controlled or regulated.

[0074] It is possible to use the control and / or regulating program to implement a sequence control of the method for the automated generation of a milk-air emulsion. The sequence control preferably also includes one or more instructions for adjusting the vertical position of the outlet 22 of the steam lance, which is adjusted according to the milk level during the milk-air emulsion generation.

[0075] This is described in more detail below using examples.

[0076] The device 1 can, for example, be advantageously used as follows to produce a milk-air emulsion.

[0077] The medium 3 to be heated and / or frothed, preferably milk or a milk substitute, is manually or automatically placed into the vessel 2 - e.g. the pitcher - and positioned under the steam lance 1, wherein the steam lance 1 and especially the nozzle with the steam outlet openings 22 should be immersed within the medium.

[0078] The steam generated in the steam system 8 in a steam boiler 15 is, when triggered with a preset steam product, directed through a line located in the coffee machine through the lance into the milk 3. The control of the steam generation as well as the required valve position is controlled by the control unit 9—the one computing unit—and also the position of the steam lance outlet. This control unit preferably simultaneously records the duration / process time of the milk foam production and / or the medium temperature measurement with the temperature sensor 5, and which preferably also records the milk level.

[0079] The temperature measurement is performed here, for example, using a sensor / probe 5, which has a tube that runs through the steam lance 1 and a measuring tip that can be positioned parallel to the steam-air mixture outlet or parallel to the outlet 22 4, even outside the steam lance. The measurement can thus advantageously be performed directly in the medium 3.

[0080] The addition of steam and / or air can then be controlled depending on parameters, for example depending on preset time and / or temperature values, which can be done via the control unit 9.

[0081] The air is preferably added by means of the air pump 11, which, as required, is activated by the computing unit or the control device 9 and supplies a defined amount of air to the steam flow according to the respectively selected flow pattern—also called the control profile or milk / air emulsion generation profile. The steam-air mixture 6 is guided through the one steam-air line 4 or several internal pipes in the steam lance 1 to the steam outlet opening(s) in the manner of (at least) one steam nozzle 22 or several steam nozzles (23) and foams the medium 3 in the vessel—in particular in a pitcher—2 during and after the outlet.

[0082] It is possible to set individual switch-off temperatures for the air and steam addition, which are preferably between 50°C and 70°C.

[0083] It is also possible to set individual process times for the addition of air and steam, which depend on the respective amount of milk, for example 30 seconds of steam addition followed by 20 seconds of air addition for 180 ml of milk.

[0084] Additionally, the milk sensor 24 can be used to measure the vertical position of the milk surface. It is also conceivable to measure the depth of the milk in the container. It is also conceivable to use the conductivity sensor to determine its conductivity.

[0085] In this way, these parameters can also be taken into account when producing the milk-air emulsion.

[0086] Especially for milk-air emulsion production, the vertical position of the milk lance outlet can be optimally adjusted using the height adjustment device, depending on the temperature and / or milk quality and / or the vertical position of the milk level. Instead of a fixed / static air flow rate, it is also possible to vary the air flow before and during foam preparation. Dynamic adjustment of the air flow allows for adaptation to individual requirements, fluctuating ambient conditions, and specific framework conditions, ensuring ideal foam results regardless of these conditions.

[0087] The air addition control is preferably carried out as a function of the temperature and / or time (and / or other measurable physical quantities) and can also be adjusted to the type of milk, the milk temperature, the target consistency, the target foam quantity and the target temperature.

[0088] The milk foam produced in this way can then be used to make a specialty drink.

[0089] The milk temperature and steam pressure are internal machine measurement data and are included as initial conditions in the presetting of the control unit in its process control.

[0090] Examples include:

[0091] The foam quantity can be adjusted by adjusting the duration of the air addition (pump running time).

[0092] Adjusting the foam consistency by adjusting the amount of air added (opening cross-section).

[0093] Setting the target temperature by defining the switch-off temperature for steam addition.

[0094] And preferably, the milk level is detected with the milk sensor 24 and the vertical position of the outlet is adjusted to one or more different height positions during the milk-air emulsion production.

[0095] Such an example of milk / air emulsion production using a device of the type shown in Fig. 1 will be described in more detail below with reference to Figs. 2a, b and 3.

[0096] The starting point is a state in which no milk-air emulsion is produced with the device of Fig. 1. In this state, the steam lance 1 may have been moved into a (e.g. upper) rest position (see Fig. 2a, distance 28 to the milk level 27).

[0097] If a control command “Create milk foam” is now entered on an input device of the coffee machine, it may be useful to issue a “warning” and confirmation “Medium provision” that either a container 2 filled with milk is placed under the steam wand 1 or that such a container is filled with it.

[0098] Then, in an operating mode or step 1, the lance can be moved for medium detection until it is detected (e.g. with the help of the conductivity sensor) that the steam lance 1 is immersed in the milk.

[0099] Then, in an operating mode or step 2, the steam lance can be moved to the start frothing position. For the actual milk foam production, it is preferable to move to a position where the steam lance outlet 22 is just below the milk level (Fig. 2b, immersion depth 27). This is because the introduction of steam and / or air at this point generally produces a very appealing, delicious milk foam in terms of appearance, consistency, and taste.

[0100] However, it is also conceivable to approach different heights during the preparation process during the milk-air emulsion production, which are optimally suited for individual phases of milk production, e.g. depending on the temperature and / or the conductivity.

[0101] Once this start frothing position is reached, the milk-air emulsion can be created in a time-controlled operating mode or step 3 by adding air and / or steam. A frothing profile is then run according to the preset settings.

[0102] When the preparation of the milk foam is finally completed, the preparation can be completed

[0103] The container can then be removed and the milk foam used to prepare a beverage. The steam wand can then be cleaned, for example, in a "purge" operating mode or process step, using a burst of water and / or steam from the lance.

[0104] Moving to this “purge position” (for example, a position within a drip tray, which is reached by moving out into the drip tray) makes it possible to prevent hot water splashes even better and to further reduce the risk of scalding.

[0105] After the “Purge” operating mode has been completed, the steam wand either remains in this position or it is moved to another rest position, e.g. in a housing of the beverage preparation machine.

[0106] Thus, it is particularly preferably provided that a milk-air emulsion generation program is stored and executable on the control unit, which has access to a memory on which at least one or more milk-air emulsion generation profiles are stored, so that the steam and the air can be guided into the milk according to a respectively selected milk-air emulsion generation profile in order to automatically generate the milk-air emulsion in the vessel 2, wherein the position of the outlet 22 of the steam lance 1 is preferably adjusted and / or changed at least once or several times during the generation of the milk-air emulsion.

[0107] Alternatively, the position of the steam lance 1 or its outlet 22 can be adjusted manually.

[0108] Another advantage is that the height-adjustable steam wand makes it possible to process even the smallest amounts of milk, which are associated with a correspondingly low milk level around the pitcher, into milk foam.

[0109] It is also conceivable to adjust the lance so that it can be moved to a cleaning and / or purge position (e.g. in the drip grid) and / or a rest position (lance retracted for easier handling).

[0110] It is also conceivable that particularly suitable positions for the outlet of steam lance 1 could be learned and stored, so that they can be recalled and accessed when generating a milk / air emulsion. This makes sense, for example, if the same container is used repeatedly and is always filled to approximately the same level (e.g., with water or milk). This can be further optimized by medium detection for optimal lance adjustment and / or automatic start (automatic operation) or the cleaning position in a type of lance garage.

[0111] This takes into account the fact that the frothing result when frothing animal milk or plant-based milk substitutes is largely determined by the immersion depth of the steam nozzle (steam-air outlet openings of the steam lance).

[0112] The motorized height adjustment, preferably in combination with medium detection, allows the optimal immersion depth to be achieved for each product, regardless of the pitcher (frothing jug, etc.) geometry and the milk quantity. Furthermore, automatic positioning of the lance for rinsing or cleaning purposes, as well as a convenient rest position, are possible. The flexibility of using the steam lance is significantly increased, milk loss is reduced, and handling is simplified for the user.

[0113] List of reference symbols

[0114] 1. Dam plant

[0115] 2. Vessel (preferably pitcher)

[0116] 3. Medium (preferably milk or milk substitute)

[0117] 4. Steam / air line

[0118] 5. Temperature sensor

[0119] 6. Steam-air mixture

[0120] 7. Steam system

[0121] 8. Air system

[0122] 9. Computing unit

[0123] 10. Steam / air mixing connector (steam jet nozzle)

[0124] 11. Air pump

[0125] 12. Air source

[0126] 13. Air throttle

[0127] 14. Air / Air line

[0128] 15. Steam boiler

[0129] 16. Water supply / water pump

[0130] 17. Flow meter

[0131] 18. Filling valve

[0132] 19. Vapor barrier and ventilation valve

[0133] 20. Steam / steam line

[0134] 21 . Data transmission connection

[0135] 22. Outlet opening

[0136] 23. Motor height adjustment

[0137] 24. Milk sensor

[0138] 25. Milk level

[0139] 26. Steam outlet opening

[0140] 27. Immersion depth

[0141] 28. Distance between milk level and steam outlet

Claims

Patent claims 1. A method for producing a milk-air emulsion from milk using a device for producing a milk-air emulsion, which device comprises at least one steam wand (1) having at least one outlet opening (22) and which is designed to be immersed, at least with the outlet opening (22), into a vessel (2) filled with milk, wherein, with the aid of a steam system (7) and with the aid of an air system (8), steam and air can be guided through the steam wand (1) and its outlet opening (22) into the milk, wherein the steam wand (1) has a device for height adjustment designed such that the vertical position of the steam wand, in particular the vertical position of the outlet of the steam wand, is adjustable, wherein the device for height adjustment of the steam wand further comprises a drive device having an electric motor, and wherein the device for height adjustment is coupled to a control device (9),with which the height-adjustable device can be controlled, wherein a milk-air emulsion generation program is stored and executed on the control unit, which has access to a memory on which at least one or more milk-air emulsion generation profiles are stored, so that the steam and the air can be directed into the milk according to a respectively selected milk-air emulsion generation profile in order to automatically generate the milk-air emulsion in the vessel (2), wherein the milk-air emulsion generation program has a program section for controlling and / or regulating the vertical position of the outlet of the steam lance, which method comprises at least the following steps: i. Providing the device, providing a vessel (2) and providing milk, ii. Filling the vessel (2) with the milk and arranging the vessel (2) such that the steam lance (1) is or can be immersed in the milk,when it is moved; and iii. Introducing air and steam through the steam lance (1) into the milk in the vessel (2), wherein the air system (8) and the steam system (7) are controlled by the control unit with the milk-air emulsion generation program according to the at least one pre-stored milk-air emulsion generation profile in order to generate the milk-air emulsion, iv. wherein the height of the outlet of the steam lance (1) is adjusted at least once during the execution of the milk-air emulsion generation program.

2. Method according to claim 1, characterized in that, depending on the one or more milk / air emulsion generation profile(s), the vertical position of the outlet of the steam lance (1) within the vessel (2) is adjusted several times during the course of the milk-air emulsion generation program.

3. Method according to claim 1 or 2, characterized in that during the control at least one or more operating parameters are determined once or several times, which are used to adapt the milk / air emulsion production profile during the course of the milk-air emulsion production program.

4. Method according to claim 1, 2 or 3, characterized in that the position of the outlet (22) of the steam lance is adjusted by a motor.

5. Method according to claim 4, characterized in that during milk-steam emulsion production, the position of the outlet (22) of the steam lance for milk-air emulsion production is determined by means of a sensor for medium detection, which is then adjusted accordingly by motor.

6. Method according to one of the preceding claims, characterized in that after the milk-steam emulsion production, a cleaning position is approached and that a cleaning of the steam lance takes place.

7. Method according to claim 6, characterized in that the steam lance is cleaned by means of a water jet.

8. Method according to claim 6 or 7, characterized in that the steam lance is moved into a rest position after cleaning.

9. A method according to any one of the preceding method claims, characterized in that during the production of the milk-air emulsion, the amount of air introduced into the milk is kept constant over time and / or the temperature.

10. A method according to any one of the preceding method claims, characterized in that during the production of the milk-air emulsion, the amount of air introduced into the milk is varied over time and / or temperature.

11. A method according to any one of the preceding method claims, characterized in that during the production of the milk / air emulsion, the amount of steam introduced into the milk is kept constant or varied over time and / or temperature.

12. Method according to one of the preceding method claims, characterized in that after starting the milk-air emulsion production program, a preselection of the milk quantity and / or the milk type and / or the consistency of the milk-air emulsion to be produced takes place via data input.

13. Method according to one of the preceding method claims, characterized in that the foam consistency is adjusted by adjusting the amount of air added.

14. Method according to one of the preceding method claims, characterized in that the target temperature is set by defining the switch-off temperature for the steam addition.

15. Method according to one of the preceding method claims, characterized in that the milk temperature in the vessel (2) is determined during the production of the milk / air emulsion and that this measured value is included in the process control.

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