Beverage gasifier and beverage maker

Abstract

A beverage gasifier is disclosed comprising a pressurised water supply, a gas supply, a flavoured beverage supply, and a Venturi device. The Venturi device comprises a first wider pipe section, a narrower pipe section fluidly connected to the first wider pipe section and narrower than the first wider pipe section, and a second wider pipe section wider than the narrower section fluidly connected to the narrower section. The first wider pipe section is connected to the pressurised water supply, and the flavoured beverage supply is connected to narrower pipe section. The Venturi device is connected to the gas supply and configured such that flow of pressurised water from the first wider pipe section through the narrower pipe section to the second wider pipe section induces suction causing flavoured beverage from the flavoured beverage supply to be sucked into the Venturi device and gasified.

Description

[0001] "BEVERAGE GASIFIER AND BEVERAGE MAKER"

[0002] FIELD

[0003] The present invention relates to a beverage gasifier, a beverage maker comprising such beverage gasifier and a method of preparing a gasified beverage.

[0004] BACKGROUND

[0005] In the field of beverage makers, it is desirable to provide machines capable of preparing flavoured beverages that effervesce. Importantly, achieving satisfactory effervescence requires absorption of gas into the beverage, and not mere mixing of gas with the beverage, otherwise sustained effervescence does not occur as mixed but not absorbed gas quickly bubbles out of the mixture.

[0006] Existing solutions for providing effervescent beverages typically involve a water storage tank in which water that is gasified (that is, has a gas, such as carbon dioxide, nitrogen, or other suitable gas, dissolved in it, such that the gas will visibly effervesce from the beverage under atmospheric pressure) is stored. The water provided is either pre-gasified before it is placed in the water tank, or gasified in the water tank (using gas provided by a pressurised gas-tank or dedicated gaspump. Gasified water in the storage tank is, where flavouring is desired, either preflavoured prior to gasification, or mixed with flavourant after gasification.

[0007] This has the drawback that the water must be stored under pressure. A sealed water tank must therefore be provided that is capable of maintaining the necessary pressure to avoid the water becoming de-gassed (that is, losing the gas to the extent that it substantially no longer effervesces).

[0008] Alternatively, if the water tank is not sealed, then the water must be repeatedly gasified to maintain gasification. Additionally, as the tank becomes more empty, more and more gas must be provided to maintain the pressure necessary to prevent de-gasing, resulting in wasted gas greatly in excess of the amount actually dissolved in the water. A further problem is that refreshing of the water in the tank is greatly complicated by the need to either maintain pressure during refreshing of the water, or re-establish pressurisation after refreshing of the water. An additional issue is that mixing of gas with the water is very slow unless agitation is provided, either externally by the consumer shaking the container in which the water is being gasified, or with agitating element such as a mixing impeller. This is cumbersome, inefficient, and difficult to provide.

[0009] A particular issue in the art is providing a nitrogenated (or anyway gasified) beverage, such as so-called “nitro coffee”, having effervescence such that a reverse-cascade effect (i.e., bubbles falling at the sides of the glass as they rise in the centre) is visible to the consumer for a sustained period of time. Ideally this results in a head of foam forming at the top of the beverage having a pleasing appearance, thickness, consistency, and mouth-feel, and allowing patterns to be drawn in it by the server, such as, for example, simple logos or symbols. Providing such a beverage on-demand is a particular problem given the extensive time required to brew such coffee, and the difficulties of providing suitable gasification given the pressures and agitation needed to allow gases, particularly nitrogen gas, to dissolve in the beverage quickly enough and in sufficient quantity.

[0010] One solution of the prior art for providing a carbonated / nitrogenated beverage is shown in pat. pub. no. WO2019166785A1 to Kenwood Ltd. However, this does not resolve all of the above-discussed issues.

[0011] EP 0472272 A2, WO 2006 / 135864 A2, EP 2672865 Bl disclose known coffee beverage makers provided with means for producing milk froth by means of steam.

[0012] WO 01 / 00308 Al discloses a known fluid mixing device.

[0013] The present invention aims to at least partially ameliorate the above-described problems of the prior art.

[0014] SUMMARY OF THE INVENTION

[0015] In an aspect of the present invention, a beverage gasifier is disclosed comprising a pressurised water supply, a gas supply, and a flavoured beverage supply. The beverage gasifier further comprises a Venturi device comprising a first wider pipe section, a narrower pipe section fluidly connected to the first wider pipe section and narrower than it, and a second wider pipe section fluidly connected to the narrower pipe section. The first wider pipe section of the Venturi device is connected to the pressurised water supply, and the flavoured beverage supply is connected to the narrower pipe section. The Venturi device is connected to the gas supply and configured such that a flow of pressurised water from the first wider pipe section through the narrower pipe section to the second wider pipe section induces suction, causing flavoured beverage from the flavoured beverage supply to be sucked into the Venturi device and gasified therein with gas from the gas supply.

[0016] This is advantageous as gasification of a beverage can thus be achieved without the need for moving parts in the gasifier using only pressurised water to drive the process.

[0017] Optionally, the gas supply is connected to the narrower pipe section. The gas can thus be sucked in to the Venturi device by the Venturi effect. This can avoid the need for a pressurised air supply and can enhance mixing.

[0018] Preferably, the gas supply supplies air. As air is abundant this can reduce cost, and as air contains nitrogen abundantly this allows nitrogenated beverages to be prepared. Preferably, the gas supply supplies air at atmospheric temperature and / or pressure.

[0019] The gas supply optionally further comprises a filter configured to filter air flowing therethrough. Impurities and debris in the air may thus be excluded, potentially enhancing the safety and hygiene of the resulting beverage.

[0020] In an optional configuration the gasifier may comprise a mixing chamber fluidly connected to the second wider pipe section, the mixing chamber being shaped and configured to promote mixing of a gas / beverage mixture flowing therethrough. This can enhance mixing, resulting potentially in better absorption of gas into the beverage.

[0021] Preferably, the Venturi device is fluidly connected to the pressurised water supply by a spray-head inlet. This may enhance mixing.

[0022] Optionally the gas supply comprises a gas inlet pipe that extends into a pressurised water flow path defined through the Venturi device. This may promote mixing of the gas and the flavoured beverage.

[0023] The narrower pipe section preferably has a width of approximately 0.3mm to 1mm, and more preferably approximately 0.3mm-0.4mm. These dimensions can result in good results in terms of absorption of gas in to the beverage.

[0024] Preferably, a ratio between the width of the narrower pipe section and the first wider pipe section is at least 3 :4, and more preferably at least 1 :2, and even more preferably at least 1 :4. This can also result in good absorption of gas into the beverage.

[0025] Preferably, the beverage gasifier is one of a carafe lid and a wand attachment. These are both potentially convenient for the user. A beverage machine optionally comprises the beverage gasifier. The pressurised water supply comprises a pump connected to a water supply, preferably a water tank, preferably wherein the pump is one of a vibration pump and a diaphragm pump. The pump may thus be available for other functions of the beverage machine.

[0026] Optionally, the gas supply is connected to the pump, and the pump is configured to supply gas to the Venturi device entrained in the pressurised water. More gas may thus be provided, and potentially the need for a separate gas-inlet in the beverage gasifier avoided. The beverage machine preferably further comprises a user interface configured to receive user beverage-selections, including gasified and non-gasified beverage options. The beverage machine may be configured to activate the pump to supply pressurised water to the beverage gasifier responsive to user selection of a gasified beverage option, and to activate the pump to supply water to a non-gasified beverage preparation component responsive to a user selection of a non-gasified beverage option. The non-gasified beverage preparation component may be one of a steam generator or a brewing module. In this way the pump can be used for preparing both gasified and unjustified beverages.

[0027] Optionally, the flavoured beverage supply comprises a brewing module configured to prepare flavoured beverage, wherein the beverage machine is configured to control the brewing module to automatically prepare a stronger beverage where the user beverage-selection is a gasified beverage with respect to the beverage to be prepared where the user beverage-selection is a non-gasified beverage. In this way dilution of the beverage by the pressurised water may be compensated for.

[0028] Preferably, the beverage machine may further comprise a cooling element configured to cool at least one of the pressurised water and flavoured beverage supply. In this way absorption of gas into the beverage can be enhanced.

[0029] Preferably the gas used by the gasifier is nitrogen, more preferably the gas is atmospheric nitrogen.

[0030] Preferably the gasifier is associated with an identifier, such as, for example, an RFID tag, and the beverage machine is capable of identifying the presence or absence of the identifier and entering a gasifying mode based on that identification. Preferably the pressurised water is supplied at a pressure in the range of 3 bar to 10 bar, and more preferably 5-7 bar, and even more preferably at 6 bar.

[0031] Preferably the brewing module is associated with a sensor configured for sensing a concentration of flavourant in a flavoured beverage being prepared, such as, for example, a TDS sensor.

[0032] Preferably the beverage machine comprises a sterilising module for sterilising water received from the pressurised water supply, preferably a UV-C steriliser.

[0033] Preferably a proportion between flavoured beverage and pressurised water is between 1 :1 and 1 :9 in the resulting beverage. Preferably the beverage machine has a removably-attachable water tank.

[0034] Preferably the water tank has a rigid construction to facilitate attachment and removal.

[0035] Preferably the water tank is connected to the external atmosphere to equalise pressure as water drains from it. Preferably the water tank has a top-up aperture to allow filling without it being removed.

[0036] In another embodiment of the invention, a beverage machine is disclosed having a user interface and a gasifier, wherein the beverage machine is controllable by the user interface to prepare, dependent on user selection, either a gasified beverage and a non-gasified beverage.

[0037] Preferably the beverage machine has a brewing module with a heating element configured, when preparing a non-gasified beverage, to heat the beverage, and when preparing a gasified beverage not to heat the beverage, and preferably to cool the beverage. Preferably the brewing module is configured to cyclically apply higher and lower pressure in response to a user request for a cold-brewed beverage, preferably a cold-brew gasified beverage.

[0038] Preferably the beverage machine is configured to prepare a cold-brew gasified beverage, preferably a cold-brew nitro beverage, producing in a glass of standard size (e.g., a cylindrical glass having a height of 8-20cm, a width of 6-12cm) a reverse cascade lasting at least 2 minutes.

[0039] Preferably the beverage machine is configured to prepare a cold-brew gasified beverage, preferably a cold-brew nitro beverage, producing in a glass of standard size (e.g., a cylindrical glass having a height of 8-20cm, a width of 6- 12cm) a head of foam having at least 2mm thickness from effervescence within the beverage.

[0040] Preferably the beverage machine is one of a filter coffee machine, a fully automatic coffee machine (i.e., a coffee machine having an integral grinder), a pump espresso coffee machine, and a capsule coffee machine.

[0041] In a further embodiment of the invention, a method of preparing a gasified beverage is disclosed. This method comprises the steps of providing a Venturi gasifier, flowing pressurised water through a widening thereof to create suction, connecting a narrowing thereof to a flavoured beverage supply, connecting a gas- supply to the Venturi gasifier, and collecting the gasified beverage produced.

[0042] Any apparatus feature as described herein may also be provided as a method feature, and vice versa. As used herein, means plus function features may be expressed alternatively in terms of their corresponding structure, such as a suitably programmed processor and associated memory. Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. In particular, method aspects may be applied to apparatus aspects, and vice versa. Furthermore, any, some and / or all features in one aspect can be applied to any, some and / or all features in any other aspect, in any appropriate combination. It should also be appreciated that particular combinations of the various features described and defined in any aspects of the invention can be implemented and / or supplied and / or used independently.

[0043] In this specification the word 'or' can be interpreted in the exclusive or inclusive sense unless stated otherwise. Furthermore, features implemented in hardware may generally be implemented in software, and vice versa. Any reference to software and hardware features herein should be construed accordingly.

[0044] Whilst the invention has been described in the field of domestic food processing and preparation machines, it can also be implemented in any field of use where efficient, effective and convenient preparation and / or processing of material is desired, either on an industrial scale and / or in small amounts. The field of use includes the preparation and / or processing of: chemicals; paints; building materials; clothing materials; agricultural and / or veterinary feeds and / or treatments, including fertilisers, grain and other agricultural and / or veterinary products; oils; fuels; dyes; cosmetics; plastics; tars; finishes; waxes; varnishes; beverages; solders; alloys; effluent; and / or other substances, and any reference to “food” herein may be replaced by such working mediums.

[0045] BRIEF DESCRIPTION OF DRAWINGS

[0046] One or more aspects will now be described, by way of example only and with reference to the accompanying drawings having like-reference numerals, in which:

[0047] Fig. 1 is a side-on, highly-schematic drawing of a beverage machine according to an embodiment of the invention;

[0048] Fig. 2 is a side-on, highly-schematic drawing of a carafe attachment for the beverage machine of Fig. 1;

[0049] Fig. 3a is a top-down, plan drawing of a beverage machine according to another embodiment of the invention;

[0050] Fig. 3b is a side-on drawing of the beverage machine of Fig. 3a;

[0051] Fig. 3c is a side-on, cut-away drawing of the beverage machine of Fig. 3a in a section along the line A- A;

[0052] Fig. 3d is a side-on, cut-away drawing showing the area B of Fig. 3c is detail;

[0053] Fig. 4 is a side-on, cut away drawing of the beverage machine of Fig. 3a in a different configuration; and,

[0054] Fig. 5 is a side-on, cut-away drawing of a beverage-making attachment according to another embodiment of the invention.

[0055] SPECIFIC DESCRIPTION

[0056] Fig. 1 depicts a beverage machine 100 (in this case, a coffee machine) according to an embodiment of the invention. The beverage machine 100 has a housing 1 10 with a user interface 111 (e.g., a touch-screen user interface) for receiving user instructions. The housing 110 also includes a processor module 112 which is in electronic communication with the user interface 111 and all electronically- controllable elements of the beverage machine 100 such that it can carry out the user instructions to, e.g., prepare a beverage selected by the user on the user interface 111 based on that information and / or information stored in a memory of the processor module 1 12. The processor module 112 may include a wireless communication module so that it can communicate with external servers to obtain information about how to prepare beverages, receive wireless user instructions from portable devices, receive software updates, and transmit status information of the beverage machine 100 to external servers and to portable devices of the user.

[0057] The beverage machine 100 comprises multiple connecting pipes shown in Fig.

[0058] 1 in thick lines. Each pipe is of sufficient size and suitable material to carry air, water, steam, and flavourant for adding to beverage, and comprises suitable valves controllable by the processor 112 to allow or prevent transport of material along them. Where appropriate, UV sterilisation elements may be provided within the pipes to suppress bacterial / fungal growth within them, and substantially sterilise material flowing through them. A water tank 120 is at least partially contained within the housing 110. The water tank 120 contains the water from which beverages are prepared by the beverage machine 100, meaning that the beverage machine 100 can operate independently of mains water. The water tank 120 is preferably a removable water tank 120 provided with check-valves (e.g., spring- loaded valves provided opened by probe-elements provided within the housing 110) that prevent water flowing out of it when it is removed from the housing 110, so that it can be removed by the user for filling and cleaning and re-attached to the housing 110. The water tank 120 is preferably rigid in construction for safe handling, and made of a food-safe and dishwasher-safe material such as Nylon or polycarbonate plastic. The water tank 120 is preferably open to the outside atmosphere to allow air to flow in to the water tank 120 as it drains, one way of providing this is to provide a filling aperture 121 through which water can be poured into the tank 120, and through which air can also enter. The filling aperture 121 can either be provided directly on an exposed surface of the tank 120, or (as shown in thick line on Fig. 1) connected to the tank 120 by a suitable pipe. Additionally or alternatively a mains-water supply can be provided, either flowing into the tank 120 as it empties, or directly connected to the elements of the beverage machine 110 requiring water supply.

[0059] A flavourant container 130 is provided in the housing 110 near the top, in which flavourants (i.e., flavourings that can dissolve in water) are stored for use in making beverages. For some flavourants, for example infusants (that is, solid matter used to infuse water with flavourant) such as coffee beans or tea leaves, these will require treatment before being added to water to create beverages. For flavourants requiring further preparation, a preparing module 140, such as, for example, a grinder (e.g., a burr-grinder, roller-grinder, auger-grinder or similar) and / or roaster, is provided connected to the flavourant container 130 by suitable connecting pipes 131 shown in thick lines in Fig. 1. Coffee beans in the flavourant container 130 can be ground to create coffee powder in the preparing module 140, prior to being mixed with the water in a brewing module 150 to infuse it with flavourant to create a flavoured beverage.

[0060] In an alternative configuration, the flavourant container 130 may contain coffee pods containing prep-prepared coffee material such as the NespressoTM coffee pods available from the NestleTM SA company of Vevey, Vaud, Switzerland. In this case roasting / gr inding is not needed and the preparing module 130 may be bypassed via the bypass pipe 132 or omitted, with the pods being pierced and injected with water in the brewing module 150. In a further alternative configuration, the flavourant container 130 may contain pre-ground coffee, in which case again this ground coffee may be transported directly to the brewing module 150 via suitable pipes. Indeed the flavourant container 130 may contain different types of flavourant in different compartments and dispense them either directly to the brewing module 150 or first via the preparing module 140 depending on a beverage requested by the user using the user interface 111. In yet a further alternative, the beverage machine 100 may be a filter-coffee-style machine, in which case the user simply places the flavourant (e.g., ground coffee) directly into the brewing module 150. The brewing module 150 may also include a removably- attachable portafilter for preparing espresso coffee.

[0061] The brewing module 150 is supplied with water from the water tank 120 and flavourant prepared by the preparing module 140 (or directly from the flavourant container 130) and brews the water and flavourant together such that sufficient flavourant becomes dissolved in the water before dispensing it. Depending on whether an effervescent beverage has been requested by the user via the user interface 111 , the beverage may be dispensed directly without gasification through a bypass pipe 152 via the beverage outlet 180 into a glass / cup 181, or firstly via connecting pipes 151 into the gasifier 160 in which gas is mixed with the flavoured beverage in order to obtain an effervescent flavoured beverage prior to dispensing via the beverage outlet 180. Alternatively, to deliver an ungasified beverage, the gasifier 160 may be controlled by the processor 112 to simply not act on the beverage to gasify it before delivery through the outlet 180.

[0062] Brewing of the beverage by the brewing module 150 may take different forms and involve different processes and temperature / pressure / water-flavourant ratios / water or flavourant volumes depending on the beverage requested by the user via the user interface 111. Infusion of the beverage using flavourant in an infusant (i.e., a solid material containing a flavourant such as e.g., tea leaves or coffee grounds / beans) may require varying of the temperature. For this purpose the brewing module 150 can be provided with heating elements (e.g., resistive heaters, induction heaters, thick or thin-film heaters, microwave heaters, etc.), cooling elements (compression-cycle coolers, Peltier / thermoelectric coolers, etc.), filters of varying mesh for filtering out infusant (i.e., a solid that includes flavourant that dissolves into water when steeped in it such as e.g., coffee grounds or tea leaves) from the beverage prior to dispensing, etc. depending on the beverage-options provided by the user interface 111.

[0063] Brewing of some beverages by the brewing module 150 requires variation in the pressure within it. To vary the pressure within the brewing module 150 a pump 170 is attached to the brewing module 150 by pipes 171, to the water tank 120 by pipe 172, and to the external atmosphere by pipes 173, where all pipes are shown in thick lines in Fig. 1. The pump 170 may be connected to the water tank 120 to add water to pressurise, or to the external atmosphere to add air to pressurise and / or remove air to create a partial vacuum, or to provide water mixed with air. Both pressurising and depressurising have been deployed successfully as ways of accelerating the brewing of cold-brew coffee. Pressurising works as it creates a similar effect to heating whilst allowing the beverage to remain relatively cool, and depressurising works as it causes gaseous voids within the coffee to become filled thus increasing the surface area in contact with the water. Indeed, both pressurising and depressurising could be used in a cyclical fashion under the control of the processor 112. Further acceleration of brewing can be provided by an agitating impeller within the brewing module, or by cycling of the water over the infusant.

[0064] Pressurised air and / or water from the pump 170 may also be used to drive the beverage onwards from the brewing module 150 as required.

[0065] A by-pass pipe 133 may connect the gasifier 160 directly to the flavourant container 130. In this way flavourants can be dispensed directly to the gasifier 160 and mixed with water there, without intermediate processing by the brewing module 150 or the preparing module 140.

[0066] The pump 170 can be a pump of any suitable type. This includes vibration pumps, diaphragm pumps, impeller pumps, and reciprocating piston pumps. Ideally it should be an electrically-powered, electronically-controlled pump, capable of creating a pressure suitable for gasification, but also for other purposes, including, for example, preparing pump-espresso coffee (i.e., developing a pressure in the brewing chamber of the brewing module 150 of at least 9 bar and preferably up to 12 bar). It should also preferably be capable of suction so as to create a partial vacuum of 25% atmospheric pressure or lower.

[0067] Where the user has selected an effervescent beverage such as, for example, “nitro” cold- brew coffee via the user interface 111, the processor 112 controls the brewing module 150 to prepare the selected beverage, and then controls the inter- connecting pipe 151 to dispense the beverage into the gasifier 160. The gasifier 160 then operates on the beverage to gasify it, using air supplied from the external atmosphere via the pipe 161, to obtain an effervescent beverage. To avoid contamination of the beverage by external odours or contaminants in the external atmosphere, a filter 162 may be provided in the pipe 161 connecting the gasifier 160 to the external atmosphere. This filter 162 may be, for example, an activated carbon filter, or simple mesh filter.

[0068] Gasification by the gasifier 160 may be performed in a number of different ways.

[0069] One way of gasifying the beverage by the gasifier is using a Venturi gasifier, where flow of pressurised water supplied by the pump 170 is passed through a narrowing in a tube, resulting in an instantaneous decrease in pressure at the narrowing (the “Venturi effect”). This decrease at the narrowing leads to suction which is used to suck flavoured beverage prepared by the brewing module 150 into the water. Simultaneously air is sucked into the narrowing from the external atmosphere via pipe 161 (or other gas supply). Once the resulting water, gas, and flavoured beverage mixture passes past the narrowing into a tube-section of similar width to the section preceding the narrowing, the previous high pressure resumes. At this higher pressure the gas entrained in the mixture is absorbed into the liquid within it, resulting in a flavoured effervescent beverage. Where air is used, this can result in nitrogenation of the beverage to achieve e.g., “nitro” cold brew, using abundantly-available atmospheric nitrogen, though gas from a gas cylinder or other gas source can be used if required. This method is particularly advantageous as it provides near- instantaneous mixing and absorption of the gas into the beverage without requiring additional agitation or moving parts.

[0070] The same pump 170 used to pressurise / d epressurise the brewing module and drive other functions of the coffee machine 100 can be used to drive the process of the Venturi gasifier, thus saving components and cost. Alternatively or additionally to the air drawn directly into the V enturi gasifier through the air pipe 161 , the pump 170 may have its own air-inlet pipe through which it can draw in air and, instead of just water, provide instead an air-water mix to the Venturi gasifier. However, control and operation of the pump 170 is simplified by it operating with water only as this means it is operating on a homogenous substance, and also noise is reduced. Giving the pump 170 its own dedicated air inlet can also increase the complexity of the machine. Similar concerns, particularly noise and complexity, apply even more strongly with supplying pure air into the Venturi gasifier from the pump in order to create suction.

[0071] In another alternative, the pump 170 could pump flavoured beverage (either stored in a tank or prepared by the brewing module 150) instead of water into the gasifier 160. However this results in the problem of the pump 170 becoming contaminated with residue from the flavourant that is hard to clean from within the pump 170 without disassembly, and which may decompose if not cleaned resulting in a health hazard, and hence water from the water tank 120, optionally sterilised by an intervening UV steriliser, is preferred.

[0072] Whilst pressurised water is described as being supplied by the pump 170, other supplies of pressurised water may be used such as, for example, a tank of water pressurised with gas from either a pump or a store of pressurised gas. However, using the pump 170 to pump the pressurised water directly is preferred as this can be done on-demand, independently of additional elements, and the pump 170 can be used for other purposes within the beverage machine 100.

[0073] An alternative way of rapidly gasifying the beverage is using an impeller gasifier. An impeller gasifier operates by a rotating impeller fed with the flavoured beverage from the brewing module 150 and gas (e.g., air) from the pipe 161. The resulting mixture of gas and beverage is then driven by the impeller through a restricted pipe at sufficient pressure to allow the beverage to absorb the gas. This, however, requires a dedicated motor and moving parts to implement. Whilst gasification has been discussed as occurring within the housing 110 of the beverage machine 100, it could also occur at least partially externally to it. The beverage machine 100 includes a steam-generator 190 (e.g., an in-line steam generator in which water provided by the water tank 120 by pump 170 through interconnecting pipe 173 is instantaneously heated into steam) that provides steam through a steam outlet 191 to removably attached attachments. One such attachment is a removably-attachable carafe 192 which steam from the steam generator 190 is provided to and used to froth e.g., milk contained within the carafe 192. Another such attachment is a steam wand 193, which can be inserted into a cup to froth milk therein. However, as shown in Fig. 2, the carafe 192 can also function to deliver an effervescent beverage. In this case, rather than supplying steam to the carafe 192, the steam generator 190 is deactivated by the processor 112 (or alternatively bypassed via bypass pipe 174) and a mixture of gas and water from the pump 170 is supplied directly to the carafe 192 via the steam outlet 191. The carafe 192 has a gasifying lid 192-1 attached to it in place of its normal steam- frothing lid, such that flavoured beverage contained in the lower part of it 192-2 closed by the lid 192-1 is gasified. Gasification is achieved by gasifier 192-3, which can be a Venturi gasifier as previously described, fed by the pressurised water from the pump 170 via the water pipe 192-5, and gas via the air pipe 192-6, and sucking up the flavoured beverage via a pipe 192-4 to dispense effervescent beverage via the dispensing tap 192-7 into the glass / cup 181. Advantageously this allows “nitro” coffee or other effervescent beverages to be provided by the beverage machine 100 without the need for an internal gasifier 160, meaning that the user potentially can prepare gasified beverages using an existing beverage machine 100 that has simply had its internal logic operating on the processor 112 updated to pump water out via the steam outlet 192 in response to a user input in the user interface 111 requesting an effervescent beverage. Additionally, as the carafe 192 is attached to the steam outlet 191, it can be cleaned so as to substantially sterilise and clean (i.e., flush debris out of) the interior pipes and gasifier 192-3 by flowing steam from the steam generator 190 through them, either in response to a user input in the user interface 111, or automatically under the control of the processor 112 at the end of a beverage-making cycle. In order for the beverage machine 100 to be able to automatically adapt to having a gasifying carafe lid 192-1 attached to it without the user having to control the machine 100 to be in a gasifying mode, the beverage machine 100 should be able to identify the gasifying carafe lid 192-1. To this end the gasifying carafe lid 192-1 is equipped with an identifier 192-8. The identifier 192-8 is recognised by the machine 100 and allows the processor 112 to control the machine 100 to enter a gasifying mode where pressurised water is sent through the steam outlet 192 rather than steam. The identifier 192-8 can be an RFID tag (or similarly wirelessly- read tag) read by a corresponding RFID reader of the beverage machine 100, or a magnet that triggers a reed-switch of the beverage machine 100, or a probe that actuates a corresponding micro-switch of the beverage machine 100, or another form of identifier. The identifier 192-8 may identify specific operating characteristics of the carafe lid 192-1, including the pressure with which the pressurised water should be supplied, and the temperature and volume of it.

[0074] As the above-described gasification using the gasifiers 160, 192-3, can result in dilution of the beverage thus prepared. To compensate for this the processor 112 can control the brewing module 150 to prepare stronger beverage in order to compensate for this, such that the resulting beverage has a strength substantially the same as an ungasified beverage having the same strength-rating selected through the user interface 111. For example, if the user selects “medium” strength for a gasified beverage in the user interface 111, the brewing module 150 and / or preparing module 140 should be controlled to vary one or more brewing / preparing characteristics by the processor 112 so as to deliver a gasified beverage having, after gasification, substantially the same strength as an ungasified beverage having “medium” strength. Strength here refers to the concentration of flavourant within the beverage and can be measured, e.g., in terms of total dissolved solids (TDS).

[0075] The brewing module 150 may be provided with a sensor for sensing the strength of the beverage such as the TDS sensor, and stop brewing once the desired TDS is reached, or brewing may be controlled according to a pre-determined relationship between the brewing time and other characteristics and the resulting TDS.

[0076] Other steps may be taken by the brewing module 150 to enhance the beverage delivered to the user in response to the user selecting a gasified beverage. For example, as gas is more easily dissolved in cooler liquids, the flavoured beverage delivered to the gasifier 160 may be cooled (e.g., to 10 degrees centigrade or lower), or at least not substantially heated, by the brewing module 150.

[0077] Brewing characteristics that can be varied in the brewing module 150 to increase strength of the resulting beverage to compensate for dilution during gasification include brewing temperature, brewing time, brewing pressure, pre-brewing (i.e., the “wetting” of infusant with a relatively small amount of water for a period prior to brewing with more water), and water quantity. Preparation characteristics that can be varied within the preparing module 140 include the quantity of flavourant delivered to the brewing module 150, the grain-size of e.g., coffee grounds produced delivered to the brewing module 150, and the type of flavourant delivered to the brewing module 150 (e.g., coffee grounds from beans having a stronger flavour than those used for non-gasified beverages).

[0078] Figs. 3a to 3c illustrate a beverage machine 200 operating according to the same essential principle as beverage machine 100.

[0079] The beverage machine 200 has a water tank 210 from which water is pumped by a pump 220 having a non-retum valve to prevent back-flow. Pump 220 can be a vibration pump or other pump as previously discussed in relation to the pump 170. Water is pumped via the pipes 221 and 224 towards the gasifier 240. A safety valve 222 may be provided between and interconnecting the pipes 221 and 224 to prevent excessive pressure in them. A gauge 223 may also be provided along the pipes 221 and 224 to measure the pressure of the water therein for better control of the beverage machine 200. Pressure in the pipes 221 and 224 is ideally in the range of 3 to 10 bar, more preferably 5-7 bar, and with the best results being obtained with water at room temperature at a pressure of approximately 6 bar. A UV steriliser 220a (for example a UV-C steriliser) may optionally be provided between the pump 220 and the water tank 210 to sterilise the water as it flows through it.

[0080] The gasifier 240 then gasifies previously-prepared flavoured beverage drawn from a flavoured beverage container 230 using air via a feed pipe 241. The resulting gasified and effervescent beverage is then dispensed through dispensing tap 250 into the receptacle 260. The walls of the receptacle 260 are preferably made of a heat-insulating and transparent material, such as a transparent plastic having an insulating gap between and inner and outer wall (not shown). Transparency is desirable so that the user can observe the effervescent beverage 262 within the receptacle, which should display a visually-attractive GuinnessTM- style reverse cascade of bubbles for up to 2 minutes. The user will also be able to observe the attractive head of foam 263 at the top of the beverage, of, e.g., 2mm or more thickness. The operation of the gasifier 240 is shown in more detail in Fig. 3d. The gasifier 240 is a Venturi gasifier, i.e., a gasifier that uses the Venturi effect to mix gas and liquid together such that the gas is simultaneously mixed into and absorbed by the liquid. The gasifier 240 is connected by a sealed connection to the pipe 224 from which it receives water under pressure by the connecting pipe 242a of the connector 242. The connector 242 is connected to the first widening 243 of the Venturi gasifier 240 by a connection sealed by a sealing ring 242b. The opening of the connector 242 into the first widening 243 of the Venturi gasifier 240 can form a spray-head 242c (i.e., a narrowing and extension into chamber such that water emerging from it sprays outwards from the opening) to enhance turbulence and hence mixing. The Venturi gasifier 240 forms a narrow section or choke-point 244 after the first widening 243 in the direction of flow of the water, and before the second widening 245. As a result of the Venturi effect, a pressure-drop is caused in the narrow section 244 as water flows between the first widening 243 and the second widening 245, causing air to be sucked through the air-inlet pipe 246 that connects to the narrow section 244, and flavoured beverage to be sucked through the feed pipe 241 to form a mixture of water, air, and flavoured beverage. The quantity of air sucked in through the air-inlet pipe 246 can be controlled using the valve 246a, which may be a button valve, electronically-controlled valve, or similar. The air-inlet pipe 246 may extend part-way into the middle of the narrow section 244 to further enhance turbulence as water flows around it. As the water returns to its previous high pressure in the second widening 245, the air in the mixture is absorbed into the water and flavoured beverage mixture. The resulting gasified beverage then flows into the dispensing tap 250, which is connected to the second widening 245 with a connection sealed by a sealing ring 245 a. In order to enhance mixing, a widened mixing chamber 251 can be formed within it between narrower sections where the change in the diameter of the tap results in turbulence that further enhances mixing. The width of the narrow section 244 is preferably in the range 0.3mm to 1mm, and more preferably 0.4mm or less. A ratio between the width of the narrower section 244 and the first and second widenings 243 and 245 is preferably at least 3:4, and more preferably at least 1:2, and more preferably still at least 1:4. The flow-rate of the resulting effervescent beverage from the dispensing tap 250 is preferably in the range of approximately 5 grams per second to 8 grams per second.

[0081] Satisfactory reverse-cascade effects were observed with concentrations of nitrogen in the resulting beverage of between approximately 8 parts per million and approximately 40 parts per million.

[0082] The water pumped by the pump 220 of the beverage machine 200 can produce effervescence in beverages even if it is at temperatures up to 99 degrees centigrade, though preferably the water is less than 50 degrees centigrade to avoid the creation of acidic flavour in e.g., coffee, and more preferably still the water is room temperature (20 degrees centigrade) or lower. The ratio between the volume of water pumped by the pump 220 through the Venturi gasifier 240, and the volume of flavoured beverage sucked through the feed pipe 241 from the beverage container 230, was between 1:9 and 1:1, with good results being obtained at approximately 3:7 (i.e., a resulting effervescent beverage of which for every 100ml of effervescent beverage ~30ml were contributed by the pumped water and ~70ml by the flavoured beverage). Fig. 4 shows the beverage machine 200 in a different configuration than in Figs. 3a-3d. Here, both the feed pipe 241 of the gasifier 240, and the dispensing tap 250, are located within the receptacle 260. In this configuration, flavoured beverage placed within the receptacle 260 is gasified by the gasifier 240 and dispensed back into the receptacle 260, resulting in continuous gasification of the beverage. The user may thus continue gasification until the beverage in the receptacle 260 is satisfactorily effervescent.

[0083] Fig. 5 shows a beverage making attachment 300 that operates according to the same essential principle as beverage machines 100 and 200. The attachment 300 receives pressurised water via the inlet pipe 310 from, e.g., the steam outlet 191 of the beverage machine 100 in place of the steam wand 193, or from the pump 220 of the beverage machine 200, to which it is attached using a sealed attachment such as, for example, screw-thread on the inlet 310 interengaging with corresponding screw-thread on the steam outlet 191. The pressurised water then flows along the curved pipe 320 (which may optionally be a flexible pipe for greater convenience), and then through a spray-head 330 similar to the spray- head 242c into the gasifier 340. As the curved pipe may be heated / cooled, and may be made of metal, a grip 321 may be formed on the pipe 320 made of a heat-resistant material such as rubber. In this case again the gasifier 340 is a Venturi gasifier, to the narrow section of which are attached a feed-pipe 341 and an air inlet 342. The air inlet 341 extends back along the curved pipe 320 and the feed pipe extends further forwards in the direction of extension of the curved pipe 320. In this way, when partially submerged vertically into flavoured beverage in a receptacle 350 similar to the receptacle 260, the feed-pipe 341 extends downwards into the flavoured beverage and sucks beverage from there to be gasified by the gasifier 340, whilst the air inlet 342 extends above the beverage to suck in air. Gasified beverage is then dispensed into the container 350 through an opening in a mixing chamber 343 similar to the mixing chamber 251. In an alternative, the gasifier 340 could be provided separately and simply fitted sealingly (e.g., with screw-thread, or a clamp) to the end of an existing steam wand such as the steam wand 193, and the beverage machine to which the steam wand is attached reconfigured to supply pressurised water to the wand. In this way an existing steam wand can be converted into a gasifier. The attachment 300 may also have an identifier that is recognised by the beverage machine to which it is attached, similarly to the identifier 192-8 already described above.

[0084] As used herein, the term "removable attachment" (and similar terms such as “removably attachable”), as used in relation to an attachment between a first object and a second object, preferably connotes that the first object is attached to the second object and can be detached (and preferably re-attached, detached again, and so on, repetitively), and / or that the first object may be removed from the second object without damaging the first object or the second object; more preferably the term connotes that the first object may be re-attached to the second object without damaging the first object or the second object, and / or that the first object may be removed from (and optionally also re-attached to) the second object by hand and / or without the use of tools (e.g. screwdrivers, spanners, etc.). Mechanisms such as a snap-fit, a bayonet attachment, and a hand-rotatable locking nut may be used in this regard.

[0085] “Food safe” in this context means any substance that does not shed substances harmful to human health in clinically significant quantities if ingested. For example, it should be BPA-free.

[0086] “Dishwasher safe” means that it should be physically and chemically stable during prolonged exposure to the conditions prevailing within a dishwasher machine. For example it should be able to withstand exposure to a mixture of water and a typical dishwasher substance (e.g., washing with Fairy TM or FinishTM dishwasher tablets and water, at temperatures of 82 degrees centigrade for as long as 8 hours without visibly degrading (e.g., cracking)). ft will be understood that the present invention has been described above purely by way of example, and modifications of detail can be made within the scope of the invention.

[0087] Each feature disclosed in the description, and (where appropriate) the claims and drawings may be provided independently or in any appropriate combination.

[0088] Reference numerals appearing in the claims are by way of illustration only and shall have no limiting effect on the scope of the claims.

Claims

CLAIMS:

1. A beverage gasifier (160, 192-1, 240, 300) comprising: a pressurised water supply (171, 192-5, 224, 320), a gas supply (161, 192-6, 246, 342), a flavoured beverage supply (151, 192-4, 241, 341), a Venturi device (192-3, 240, 340) comprising a first wider pipe section (243), a narrower pipe section (244) fluidly connected to the first wider pipe section (243) and narrower than the first wider pipe section, and a second wider pipe section (245) wider than the narrower section fluidly connected to the narrower section (244), wherein the first wider pipe section of the Venturi device is connected to the pressurised water supply, and the flavoured beverage supply is connected to narrower pipe section, and the Venturi device is connected to the gas supply and configured such that flow of pressurised water from the first wider pipe section through the narrower pipe section to the second wider pipe section induces suction causing flavoured beverage from the flavoured beverage supply to be sucked into the Venturi device and gasified therein with gas from the gas supply.

2. The beverage gasifier of claim 1, wherein the gas supply is connected to the narrower pipe section.

3. The beverage gasifier of any preceding claim, wherein the gas supply supplies air.

4. The beverage gasifier of claim 3, wherein the gas supplies atmospheric air and further comprises a filter (162) configured to filter air flowing therethrough.

5. The beverage gasifier of any preceding claim, further comprising a widened mixing chamber (251, 343) fluidly connected by means of a narrower section to the second wider pipe section, the mixing chamber being shaped and configured to promote mixing of a gas / beverage mixture flowing therethrough.

6. The beverage gasifier of any preceding claim, wherein the gas supply comprises a gas inlet pipe that extends into a pressurised water flow path defined through the Venturi device, for promoting mixing of the gas and the flavoured beverage.

7. The beverage gasifier of any preceding claim, wherein the Venturi device is fluidly connected to the pressurised water supply by a spray-head inlet (242c).

8. The beverage gasifier of any preceding claim, wherein the narrower pipe section(244) has a width of approximately 0.3mm to 1mm, and more preferably approximately 0.3mm-0.4mm.

9. The beverage gasifier of any preceding claim, wherein a ratio between the width of the narrower pipe section (244) and the first wider pipe section (243) is at least 3:4, and more preferably at least 1 :2, and even more preferably at least 1 :4.

10. The beverage gasifier of any preceding claim, wherein the beverage gasifier is one of a carafe lid (192-1) and a wand attachment (300).

11. A beverage machine (100, 200) comprising the beverage gasifier of any preceding claim, and wherein the pressurised water supply comprises a pump (170, 220) connected to a beverage container (230) or a water source (120), preferably wherein the water source is a water tank, preferably wherein the pump is one of a vibration pump and a diaphragm pump.

12. The beverage machine of claim 11, wherein the gas supply is connected to the pump, and the pump is configured to supply gas to the Venturi device entrained in the pressurised water.

13. The beverage machine of any one of claims 11-12, wherein the beverage machine comprises a user interface (111) configured to receive user beverageselections, including gasified and non-gasified beverage options, and wherein the beverage machine is configured to activate the pump to supply pressurised water to the beverage gasifier responsive to user selection of a gasified beverage option, and to activate the pump to supply water to a non-gasified beverage preparation component (150, 190) responsive to a user selection of a non-gasified beverage option, preferably wherein the non-gasified beverage preparation component is one of a steam generator or a brewing module.

14. The beverage machine of claim 13, wherein the flavoured beverage supply comprises a brewing module (150) configured to prepare flavoured beverage, wherein the beverage machine is configured to control the brewing module on the basis of a selection received by the user interface (111) to automatically prepare a stronger beverage where the user beverage-selection is a gasified beverage with respect to a beverage to be prepared where the user beverage-selection is a nongasified beverage.

15. The beverage machine of any one of claims 11-14, further comprising a cooling element configured to cool at least one of the pressurised water and flavouredbeverage supply.

16. The beverage machine of any one of claims 11-15, wherein the beverage gasifier is associated with an identifier, preferably an RFID tag, and the beverage machine is configured to identifying the presence or absence of the identifier and entering a gasifying mode based on that identification.

17. Method of preparing a gasified beverage comprising the steps of providing a Venturi gasifier, flowing pressurised water through a widening thereof to create suction, connecting a narrowing thereof to a flavoured beverage supply, connecting a gas-supply to the Venturi gasifier, and collecting the gasified beverage produced.

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