WO2019000016A1

WO2019000016A1 - Milk frothing device

Info

Publication number: WO2019000016A1
Application number: PCT/AU2018/000107
Authority: WO
Inventors: Duncan Bruce HELLMERS; Stephen John Mcclean
Original assignee: Breville Pty Limited
Priority date: 2017-06-30
Filing date: 2018-06-28
Publication date: 2019-01-03

Abstract

A milk frothing device (100) that includes a base (101) that supports a vertical upright (102). Supported on the upright (102) is an electric motor (200) that rotatably drives a shaft (110) to which there is attached a milk frothing attachment (120). The attachment (120) froths milk located in a container (111). The container (111) is also heated via an induction coil (416).

Description

MILK FROTHING DEVICE

FIELD

[0001] The technology relates to milk frothing or texturing and more particular to mechanical texturing or frothing.

BACKGROUND

[0002] Texturing is adding air bubbles to milk. Heated and textured milk is needed to make popular beverages like cappuccino and latte.

[0003] The primary benefit of mechanical texturing over steam texturing is the resultant flavour of the milk. Steam tends to add some water into the milk thereby diluting it and the high temperature destroys some of the natural sweetness of the milk. Using a whisk to create a vortex thereby drawing air into the milk goes around some of the limitations over using a steamer.

[0004] Milk frothing devices are known from the following publications: Foremost B V, Publication US 2012/0017778 (Milk Frother), Aerolatte Limited, patent number US 6,558,035 (Electric Whisk), Chinese patent CN 201683731 (Fully-Automatic Milk Frother), Green Lane Designs, US8726790 (Milk Frothing Device) and Tito Ciusti, GB604048A (Improvement in or relating to Pasteurising and boiling apparatus).

[0005] A disadvantage of previous devices that heated and textured milk, for the purposes of coffee, is that the temperature and texture of the milk is not well controlled, and is not consistent in producing a desired milk product.

OBJECT

[0006] It is the object of the present invention to overcome or substantially ameliorate the above disadvantage. SUMMARY

[0007] There is disclosed herein a milk frothing device to froth milk in a container, the device including:

a base including an upwardly facing surface upon which the container is to rest, an induction coil mounted in the base and that is electrically energised to produce a magnetic field to heat the container;

an upright fixed to the base and extending upwardly therefrom;

a motor supported by the upright adjacent an upper portion of the upright;

a shaft attached to the motor so as to be rotatably driven thereby; and

a milk frothing attachment attached to a lower portion of the shaft, so as to be spaced from the motor, with the attachment being positioned by the shaft; and motor so as to be locatable adjacent the surface so as to be locatable within the container.

[0008] Preferably, the motor is mounted on the upright so as to be height adjustable relative thereto to provide for height adjustment of the milk frothing attachment relative to said surface.

[0009] Preferably, the shaft is inclined to said surface by an acute angle.

[0010] Preferably, the motor is mounted on the upright so as to be angularly adjustable.

[0011] Preferably, the base includes a weighing mechanism to weigh the container and contents thereof so as to provide a signal indicative of the weight supported by said surface.

[0012] Preferably, the device further includes a temperature sensor adjacent said surface to provide a signal indicative of the temperature of said container.

[0013] Preferably, said surface provides a depression within which the container is to rest.

[0014] There is further disclosed herein a method of operating a milk frothing device, the method including:

providing a container having a volume of milk, the volume of milk having a temperature; detecting said temperature to determine whether said temperature is below a

predetermined temperature; providing a milk whisking attachment and locating the attachment in said container so as to be submerged in the milk;

rotating the attachment at a first rotational speed for a predetermined texturing time period, if the milk temperature is below said predetermined temperature;

heating the milk for a predetermined heating time period; and

rotating the attachment at a second speed, slower than the first speed.

[0015] Preferably, said predetermined temperature is approximately 20°C.

[0016] Preferably, the attachment is rotated at said first speed until the milk reaches a temperature of 30°C.

[0017] Preferably, the attachment is rotated at said second speed for a period of time that partly overlaps with said heating time period.

[0018] Preferably, operating the attachment at said second speed crepates a vortex in the milk.

[0019] In a preferred form of the present invention, the mechanical whisking device, the angular and vertical position of a motorised whisk motor assembly combined with optional variable motor speed allows for a fine control of air integration and mixing into the milk.

[0020] In a preferred form of the present invention, the mechanical milk frother, an induction heater allows for accurate heating of the milk and in some embodiments, with no risk of temperature overshoot.

[0021 ] In some embodiments, a whisk motor assembly is attached to one or more uprights and can be moved up or down. This makes the insertion and removal of a milk jug easier.

[0022] In some embodiments, the whisk motor assembly is attached to an upright and can be tilted from operational position to a neutral position to allow a vessel such as a jug to be inserted or removed.

[0023] In some embodiments, a whisk angle can be adjusted for precise control when agitating the milk in the vessel. [0024] In some embodiments, the assembly contains an induction coil to heat the vessel containing milk. The base of the device has a temperature sensor. The direct or indirect contact between the vessel and the temperature sensor allows for accurate temperature feedback to the device's microcontroller.

[0025] In some embodiments, the assembly further contains a recess or saddle that receives the vessel.

[0026] In some embodiments, there is an LCD or other screen allowing the user to program several whisk speeds over a time interval.

[0027] In some embodiments, the device can be operated with one button, once the milk vessel is located and the agitator has been lowered into the position, the user presses a button on the user interface and the device begins to froth milk.

[0028] In some embodiments, air flow within the base flows from front to rear, to cool the electronics in the device.

[0029] In some embodiments, when the agitator or whisk is lifted, a sensor circuit detects that the agitator is no longer inside the milk. The agitator will under processor control automatically (or manually) purge by spinning thereby removing the contents of the milk through centrifugal force to the surrounding sidewalls of the vessel.

[0030] In some embodiments, the angle of the agitator can be adjusted, via 'steps'

(incrementally) or 'smoothly'. For example when the user is adjusting the agitator to be adjacent the sidewall of the vessel, a step locking detail exists that allows the user to precisely and accurately lock the angle of the agitator.

[0031] In some embodiments, the saddle for receiving a vessel includes concentric recesses that allow for easy accommodation of different sized vessels into it.

[0032] In some embodiments, the speed of the agitator depends on the feedback loop of the temperature sensor. BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0033] In order that the invention be better understood, reference is now made to the following drawing figures in which:

[0034] Figure 1 is a perspective view of a milk frothing device. [0035] Figure 2 is a perspective view of a milk frothing device.

[0036] Figure 3 is a perspective view, partially broken away, illustrating a rack and pinion arrangement in a milk frothing device.

[0037] Figure 4 is a perspective view, partially broken away, illustrating a milk frothing device having a vertical conveyer and induction heating coil.

[0038] Figure 5 is a cross-section of a milk frothing device having a temperature sensor and temperature feedback loop.

[0039] Figure 6 is a side elevation of a milk frothing device having a pivoting head.

[0040] Figure 7 is a perspective view, partially cross-sectioned illustrating a liquid detection circuit in a milk frothing device.

[0041 ] Figure 8 is a perspective view of a whisk. [0042] Figure 9 is a perspective view of a whisk.

BEST MODE AND OTHER EMBODIMENTS OF THE TECHNOLOGY

[0043] As shown in Figure 1, a milk frothing device 100 has a base 101 that supports one or more vertical uprights 102. In this example, there are two parallel uprights 102 and each is round in cross-section. They are attached to one another by an uppermost cross piece 103. The uprights 102 support a vertically adjustable mixing head 104 forming part of a whisk motor assembly. The mixing head 104 has through passageways 105 for the uprights. The head 104 also receives an electric motor enclosure 106. The head 104 may have a collar or clamp 107 so that the motor enclosure 106 may be easily removed and re-inserted. The motor in the enclosure 106 has a hub 108 that is able to removably receive a milk frothing attachment such as a whisk 109 having an elongated shaft 110.

[0044] In the lower or operational position depicted in Figure 1, the whisk's shaft 110 descends into a jug, preferably a common 600ml stainless steel frothing or texturing jug 111. Typically, a frothing vessel or jug will have a handle 1 12 and an opposing pouring spout 1 13.

[0045] The base 101 has a location 114 for receiving the jug 1 11. In preferred embodiments, the location 114 is a depression or saddle for receiving the jug 11 1. The location 114 also has an induction heater or other heater below it for heating the contents of the jug 111. The base has a user interface 1 15 having, for example, user input control or buttons 1 16 and a visual display 117. In some embodiments, an array of vents 118 is located on a front surface of the base. Air is drawn through the vents 118 so as to cool the induction heater and other internal

compartments before the cooling air is exhausted from vents located on the opposite or rear surface 1 19.

[0046] The motor enclosure 106 may be provided with power from a battery located within the head 104, from electricity supplied by fully or partially concealed electrical cabling, or by electricity transmitted through one or both uprights 102.

[0047] The assembly comprising head and motor enclosure 106 may be manually or electro- mechanically elevated from the lower or working position depicted in Figure 1 to a raised position as well as a continuous range of intermediate positions. In the lower most position, the contents of the jug 111 are able to be frothed. In one intermediate position, the working head 120 of the whisk is above the level of liquid in the jug and below the rim 121 of the jug 111. In this position, the working head 120 of the whisk can be rotated for cleaning purposes. Because the head 120 is below the rim 121 liquid flung from the head 120 is captured by the sidewalls of the jug and thus recaptured. In an uppermost position, removal of the jug 111 is easiest because of the additional clearance between the head 120 and the base.

[0048] Further to the example of Figure 1 , the device is used by lifting the head into an upper position, locating the jug 1 11 on the base, lowering the head 104 until the working head 120 is submerged, then initiating the rotation of the motor enclosure 106. The operational sequence of the aforementioned induction heating system can be independently controlled by the user using the interface 1 15. A processor 122 in the base receives information from the user interface 1 15 and sends control signals or power, as required to the various components in the device. The processor 122 can also store automated sequences or programs that a user can select for the production of milk foam at any one of a number of different textures temperatures and styles created in accordance with a texture profile. The texturing profile includes a target temperature and a motor speed profile. The motor speed profile describes, for example, a continuous or discontinuous texturing duration (with motor running) that is subdivided into three distinct texturing time intervals. Each texturing interval may have an independent motor speed and duration. For example, a texture profile may have a total duration of 130 seconds. It is subdivided into a first or aerating phase, a second or mixing phase and a third or holding phase. In the aerating phase, the motor speed is (for example) 90 per cent of maximum and has a duration of 10 seconds. This is followed by the mixing phase where the processor controlled motor speed is 75 per cent of maximum and having a duration of 30 seconds. This is followed by the holding phase having a motor speed of 60 per cent and a duration of 90 seconds. In preferred embodiments, at the same time as the aeration phase beings, the induction heater is activated and the milk jug begins to heat. Heating the contents of the jug from refrigerator temperature (approximately 4 degrees Celsius) to 60 degrees Celsius takes less than one minute so it is important that the air be integrated and mixed into the milk prior to the milk approaching 25-30 degrees Celsius. Integrating air after the milk has exceeded 25-30 degrees Celsius yields lesser quality micro foam thus, the high speed of the whisk or working tool in the early stages of the profile achieves this requirement. The motor speed and duration of the aerating phase largely determine how much air the final product will contain.

[0049] Following the aerating phase, the mixing phase usually requires that the speed be reduced slightly from the speed used during the aeration, so a vortex being formed in the jug still remains but is shallower and produces more of a folding action in the milk, this generally prevents further air from entering the milk but maintains a relatively high mixing speed so as to integrate the air with the milk and produce a homogenous blend of milk and micro foam. In the holding phase, the whisk's speed can be similar or slightly slower than in the mixing phase. The holding can be programmed to last a significant duration during which the milk and micro foam will be combined at an optimum level long after the initial aeration has been completed. This provides freedom for the user to perform other tasks until they are ready to poor the finished product. [0050] As shown in the example of Figure 2, the electric motor 200 within the motor enclosure 106 may be powered by a circuit that includes one or both uprights 102. Here, each upright 102 is independently powered 201, 202 from a power supply or an electronic control system 203 within the base 101. Electrical contacts 204, 205 are carried by the moving head 104 and make sliding contact adjacent upright 102 with which is cooperates. The sliding contacts 204, 205 supply power to leads 206, 207 carried within the head 104.

[0051] In the example of Figure 3, the motor 200 is carried by a vertically reciprocating head 300 within which are supported one or more pinion gears 301, 302. The pinion gears 301, 302 may be driven independently by their own motor, or through a gearbox 303 that is driven by the motor 200. Rotating power provided to the pinion gears 301 , 302 causes the head 300 to travel up and down the uprights 304. Each upright 304 is provided with an inward facing array of teeth 305 forming a rack that cooperates with the one or more pinions 301, 302. The rack and pinion gear arrangement formed by the uprights and pinions may be conductive so as to supply power from a source in the base 203 through an external or partially concealed lead 306 to the motor 200, the one or more motors that may be driving the pinions 301, 302 and two other components or indicators that may be located on the head.

[0052] The height of the motor assembly can be sensed by a conventional height or location sensor assembly 320. By way of example, a potentiometer may be mounted one of the pinion gears for determining rotation of the gear, and therefore a relative location of the motor and associated whisk. Alternative configurations for measuring relative height of the motor can comprise a resistive strip (or linear potentiometer) mounted with respect to the uprights and responsive to vertical movement of the motor.

[0053] In the embodiment depicted in Figure 4, the vertical movement of the head 400 and consequently the motor and its enclosure 106 is determined by a linear actuator. Here, the actuator comprises one or a pair of continuous strand or belt conveyers 401. Each conveyer 401 governs the linear, reciprocal motion of a driving magnet 402 concealed within one or both of the tubular uprights 401 . The head 400 has within in an array of one or more smaller, driven magnets 403. The driven magnets are located adjacent to the passageway 404 in the head 400 through which an upright 401 passes. [0054] The driving magnet 402 is affixed to only one of the two parallel strands 405 that pass within the upright 401. The other strand passes through an opening 406 in the driving magnet 402. In this way, the driving magnet can reciprocate up and down within the upright 401, magnetically coupling with the head 400 so that the head 400 moves in conjunction with the driving magnets 402.

[0055] The parallel strands 405 formed a continuous loop that passes around a lower pulley 407 and an upper pulley 408. In this example, the lower pulley 407 is a drive pulley and is supplied with rotating power from a bi-directional electric motor 408. Each conveyer 401 may have its own drive motor 408. In the alternative, either the lower pulleys 407, 409 or the upper pulleys 408, 410 or both of them may be connected by rigid shafts 41 1 , 412.

[0056] Figure 4 also illustrates that the upper surface 413 of the base may have a depression or contoured saddle 414 for receiving the stainless steel jug 440. The dish shaped depression in the surface forming the saddle may have distinct contours 415, 416 so that different size jugs can cooperate with the base, particularly the induction heating coil 417 located below the upper surface 413.

[0057] As shown in Figure 5, the driven magnets 500 in a linear actuator or vertical conveyer 501 are orientated and parallel with the driving magnet 502. They are equally spaced from the centre line of the upright 503. In the working orientation depicted in Figure 5, a temperature sensor 504 is located through or below the upper surface 413 of the saddle 505. In preferred embodiments, the sensor 504 makes contact with the underside of the jug 506. The sensor 504 provides temperature signals to the device's micro controller 507 creating a feedback loop that regulates the operation of the induction coil 508 so as to achieve a selected temperature and maintain it. For optimum results, the induction coil 508 must be concentric with both the saddle 505 and the jug 506.

[0058] Figure 5 also illustrates that the inside 509 of the base and the various components within it are cooled by an airflow that originates from the front vents and being discharged through rear located vents 510.

[0059] Previous examples are provided for a fixed inclination of the whisk or working tool relative to a horizontal plane. An optimum orientation for a conventional circular whisk is 18- 20 degrees from a nominal horizontal plane defined by the flat base of the jug. All of the examples of Figures 1 -5 are depicted with the whisk in this inclined orientation determined by the head 104 and the motor 200 within it. However, and as shown in Figure 6, the head 600 may have a fixed part 601 and a pivoting part 602. The pivoting part 602 carries the motor housing 603. In this way, the angle of the whisk head 604, 605 may be adjusted step-wise or continuously. The rotation of the pivoting part 602 may be governed by an electric motor 606 carried within the head. The motor is powered and controlled by a controller 607 who's operation, at least in part, may be governed by user inputs from the user interface 115.

[0060] As shown in Figure 7, a liquid sensing circuit 700 that includes the whisk 701 may be constructed. The circuit 700 may use voltage, load or capacitance methodologies to provide the device's processor 702 with a circuit state. In the open circuit state, there is no contact between the whisk 701 and a liquid 703 within the jug 704. In the closed circuit state, the circuit is closed by way of contact between the whisk 701 and the liquid 703. To accomplish this, current is carried through the whisk 701 to a lead 705 that passes through the head 706, or otherwise, to the device's controller or microprocessor 702. In this example, the lead extends through the centre of a tubular upright 707 to within the interior of the base 708. The other side of the circuit is provided by a lead 709 that extends from the processor 702 to an electrical contact 710. The contact 710 is located, for example, below the saddle 711 or protruding through an opening in the saddle so as to make direct contact with the underside of the jug 704. The contact 710 may be urged or biased upwardly by a compression spring 711. In this way, the head 706 may be lowered manually, or under processor controlled motor power until the whisk 701 first makes physical contact with the liquid 703. If the liquid level is high enough to risk spillage during frothing, a user alert is generated by the processor and displayed or audibly announced by the interface 720. The processor may also disable the motor 721 to prevent spillage. If the liquid level is too low, an alert may be similarly generated and displayed. The processor may also, in response to the low level, disable the motor 721. Both high and low liquid levels may result in an automatic motorised raising of the head 706 so the jug 704 can be removed.

[0061] It will be appreciated that the processor can calculate a volume estimate for the milk in the jug, based on a known shape or volume characteristics of the jug and the height of the whisk 701 at the time it makes first contact with the liquid in the jug to close a circuit. In an embodiment, the height of the motor assembly can be sensed by a conventional height or location sensor arrangement (for example, reference 320 of FIG. 3), and the processor can determine an estimate for the quantity of the milk in the jug. If the circuit is completed when the whisk is close to top of the jug, being an indication that the jug is full, the user can be alerted to lessen the quantity of milk in the jug. If the circuit is completed when the whisk is close to the bottom of the jug, being an indication of only small quantity of milk in the jug, the user can be alerted to increase the quantity of milk in the jug. As shown in Figure 7A, the level 730 of liquid in the jug 731 can be determined by weighing the jug and its contents. Because the device is intended to be used with a specific jug 731, the weight of the jug is known to the processor as well as the vertical depth of the liquid as it corresponds to various weight measurements. In this example, the upper surface 732 of the base 733 includes an isolated weighing platform 734 that includes the saddle for holding the one or more sized jugs adapted to cooperate with the device. The dish-like weighing platform 734 is supported by a weight sensor or load cell 735 that provides the devices processor 736 with a liquid weight indicative signal. The processor uses this signal to determine the liquid level 730. In this example, the weighing platform 734 is suspended around its rim 737 by a rubber seal 738 that prevents ingress of liquids into the interior of the base. As shown in Figure 7B, the rubber seal 738 can deflect, stretch or in the case of a rolling diaphragm, role so that the weight of the jug 731 is carried by the weight sensor 735.

[0062] Figures 8 and 9 illustrate whisks 800, 900. When the whisks are made entirely of metal, they may be used in liquid detection circuitry 700. In the example of Figure 8, the whisk 800 has an elongated central shaft 801 that terminates in a working head 802. The working head 802 has an array of radial, through-openings in the form of slots 803. The slots are arranged in a radially symmetrical array. The head 802 has a smoothly curved upper surface 804 and preferably, a flat bottom 805. The curvature is continuous from an upper part 806 of the shaft to at least the upper rim 807 of the head 802.

[0063] Figure 9 illustrates a conventional whisk 900. It is entirely metallic. Generally, an "L" shaped shaft 901 has a leg 902 that is affixed to a ring 903. A coil of agitator 904 is wrapped around the ring 903. The plane 905 that the ring 903 is in can be used to measure the angle between the whisk and the horizontal or jug's bottom or floor.

[0064] Figure 10 illustrates a methodology for texturing milk before heating 1000 and the methodology for texturing milk after heating 1001. Where the milk is textured before heating 1000, the processor first reads a signal from the temperature sensor and compares that temperature to a particular threshold, for example, 200C 1002. If the milk is below 200C 1003, a texture programme is run by the processor 1004. After the texture programme 1004 is completed, a heating program is run by the processor 1005. The texture programme consists of a number of consecutive time segments, the motor speed in each segment potentially varying as previously described. The heating programme may also be provided in the form of a profile having a distinct heating segments, each with a potentially different temperature. This allows for a slower warmup and an extended warming period, if required. At the end of the heating programme 1005, the milk is both textured and heated as required by the user 1006.

[0065] Where texturing occurs after heating 1001, the processor first uses temperature data from the temperature sensor to determine whether or not milk is at the programmed or preselected temperature 1007. If the milk is at the correct temperature 1008, the processor runs the texture programme to operate the motor 1009. If the milk is not at the correct temperature 1010, the processor runs the heating programme until the set temperature is reached 1011. After the heating programme is complete, the texturing programme 1012 is run by the processor. The completion of the texture programme results in properly heated and textured milk 1006.

[0066] It will be appreciates that, by angling the whisk causes a vortex to be created centrally inside the vessel. Because the whisk is offset the centre and angled, the air incorporated into the milk generally less when compared to use of a whisk disposed centrally and vertically in the vessel.

[0067] Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

[0068] As used herein, unless otherwise specified, the use of the ordinal adjectives "first", "second", "third", etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

[0069] Reference throughout this specification to "one embodiment" or "an embodiment" or "example" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an example" in various places throughout this specification are not necessarily all referring to the same embodiment or example, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[0070] Similarly it should be appreciated that in the above description of exemplary

embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Any claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention.

[0071] Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as "processing," "computing," "calculating," "determining" or the like, refer to the action and/or processes of a microprocessor, controller or computing system, or similar electronic computing or signal processing device, that manipulates and/or transforms data.

[0072] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0073] Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the scope of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention. [0074] While the present invention has been disclosed with reference to particular details of construction, these should be understood as having been provided by way of example and not as limitations to the scope of the invention.

Claims

CLAIMS:

1. A milk frothing device to froth milk in a container, the device including:

an upright fixed to the base and extending upwardly therefrom;

a motor supported by the upright adjacent an upper portion of the upright;

a shaft attached to the motor so as to be rotatably driven thereby; and

a milk frothing attachment attached to a lower portion of the shaft, so as to be spaced from the motor, with the attachment being positioned by the shaft and motor so as to be locatable adjacent the surface so as to be locatable within the container.

2. The device of claim 1, wherein the motor is mounted on the upright so as to be height adjustable relative thereto to provide for height adjustment of the milk frothing attachment relative to said surface.

3. The device of claim 1 or 2, wherein shaft is inclined to said surface by an acute angle.

4. The device of claim 1, 2 or 3, wherein the motor is mounted on the upright so as to be angularly adjustable.

5. The device of any one of claims 1 to 4, wherein the base includes a weighing mechanism to weigh the container and contents thereof so as to provide a signal indicative of the weight supported by said surface.

6. The device of any one of claims 1 to 5, further including a temperature sensor adjacent said surface to provide a signal indicative of the temperature of said container.

7. The device of any one of claims 1 to 6, wherein said surface provides a depression within which the container is to rest.

8. A method of operating a milk frothing device, the method including:

predetermined temperature;

providing a milk whisking attachment and locating the attachment in said container so as to be submerged in the milk;

heating the milk for a predetermined heating time period; and

rotating the attachment at a second speed, slower than the first speed.

9. The method of claim 7, wherein said predetermined temperature is approximately 20°C.

10. The method of claim 7, wherein the attachment is rotated at said first speed until the milk reaches a temperature of 30°C.

1 1 . The method of claim 7, 8 or 9, wherein the attachment is rotated at said second speed for a period of time that partly overlaps with said heating time period.

12. The method of any one of claims 7 to 11, wherein operating the attachment at said second speed creates a vortex in the milk.