WO2019185718A1

WO2019185718A1 - System and method for controlling nitrogen level in a beverage container

Info

Publication number: WO2019185718A1
Application number: PCT/EP2019/057724
Authority: WO
Inventors: Jonas Christiansen; Beata WOJTYSZYN
Original assignee: Carlsberg Breweries AS
Current assignee: Carlsberg Breweries AS
Priority date: 2018-03-27
Filing date: 2019-03-27
Publication date: 2019-10-03
Anticipated expiration: 2020-09-27

Abstract

Method for maintaining the nitrogen content of a beverage being dispensed from a collapsible beverage container within the required specifications of the beverage. Beverage dispensing system for dispensing beverage stored in a collapsible beverage container wherein the beverage upholds a predetermined nitrogen and carbon dioxide content, wherein the system is configured for maintaining a predetermined nitrogen content in said beverage by controlling the equilibrium of the nitrogen and carbon dioxide within the beverage by adapting a dispensing pressure and/or a temperature of the beverage while inside said collapsible beverage container on the basis of equilibrium pressure calculated according to: nitrogen containing gas, C02, or nitrogen containing gas + C02 chemical equilibrium data.

Description

System and method for controlling nitrogen level in a beverage container

The present invention relates to a beverage dispensing system and method for maintaining the nitrogen content of a beverage being dispensed from a collapsible beverage container within the required beverage specifications.

Background of invention

Beverage dispensing systems are typically used in beverage dispensing

establishments for efficiently dispensing large quantities of beverage. Typically, beverage dispensing systems are used to dispense carbonated alcoholic beverages such as draught beer and cider. However, also non-alcoholic beverages such as non- alcoholic beers, soft drinks and non-carbonated beverages such as wine and fruit juice may be dispensed using a beverage dispensing system. Beverage dispensing systems are mostly for professional users such as in establishments like bars, restaurants and hotels, however, increasingly also for private users such as in private homes.

Professional beverage dispensing systems typically dispense beverage provided in large beverage kegs. Such beverage kegs may hold 20-50 L or even up to 500 L of beverage for a professional beverage dispensing system for allowing typically 50-100 beverage dispensing operations before needing to exchange the beverage keg.

Typically, beverage kegs are made of solid materials such as steel and re-filled a number of times. However, the dispensing of beverage from such steel kegs requires elaborate dispensing assemblies which are capable of both pressurizing and cooling the beverage. The pressurization is typically made by means of a carbon dioxide cartridge connected to the keg during dispensing. The carbon dioxide cartridge provides the dispensing pressure and allows the beverage to remain carbonized until the beverage is being dispensed.

Hence, with conventional rigid kegs, such as steel kegs, an outside source of pressure in the form of a gas containing carbon dioxide needs to be applied on the beverage inside the keg in order to enable the beverage to flow out of the keg. As a

consequence, the gas is mixed into the beverage during dispensing. This is also the case when dispensing beverages, in particular beers which contain nitrogen, i.e.

nitrogenated beers or simply nitro beers. The nitrogen is included with the carbon dioxide in the beer and is responsible for providing a so-called nitrogen head, or simply head, i.e. a creamy or foaming froth on top of the beer after pouring, as well as providing a so-called surge pour while dispensing the beer. These beers include typically English style beers such as ales, stouts, and porters.

Applicant company of the present invention has realized that when dispensing beers from collapsible beverage containers, such as PET-kegs, in particular single use collapsible beverage containers, nitrogen has a strong tendency to interact with the gas-filled head space of such containers, not only during the beverage dispensing operation but also during their transportation, i.e. while no dispensing operation takes place. The gas-filled head space, or simply head space, is the space or volume above the level of beverage within a beverage container.

When utilizing collapsible beverage containers, hereinafter also referred as collapsible kegs, during beverage dispensing no external gas enters into the keg to press the beverage out, and rather the dispensing pressure is provided by an outside pressure fluid such as compressed air. Such beverage dispensing systems using a collapsible keg typically have the collapsible keg installed in a pressure chamber. When dispensing beverage from the beverage dispensing system, the pressure fluid is allowed to enter the pressure chamber. The pressure fluid then acts on the beverage container wall and forces the beverage out of the beverage container. The collapsible keg shrinks, i.e. collapses, while dispensing the beverage and the volume of the collapsible keg is reduced corresponding to the amount of dispensed beverage. The beverage flows out of the beverage container into a tapping line, which then leads to a tapping device comprising a tapping head typically including a beverage dispensing control means such as a tapping handle and a tapping valve for allowing an operator to control the tapping valve and thereby the beverage dispensing operation. The operator, such as a bartender or barmaid, uses the tapping handle to control the rate of beverage dispensing. The collapsible kegs are preferably made of flexible and disposable material such as plastic.

US 2017305731 discloses a device for infusing liquids, such as beer or wine, at a desired temperature and pressure. The invention comprises a fillable container to contain the infusing material and the liquid to be infused, a cooling system to maintain the temperature of the liquid at a desired level during infusion, and a pressurization system to facilitate dispensing the liquid after infusion. US 2017113915A seeks to maintain the carbonation level within a beverage in a rigid container by a compressed gas comprising mixed gas (CO2 and N2), means for regulating the pressure and a temperature control system.

US 5029733 discloses a dispensing system for nitro beers comprising a flexible bag. The dispensing system requires introducing carbon dioxide or nitrogen during the beverage dispensing to provide the desired level of froth or head of the beverage as dispensed.

WO 2014209785 describes a storage for maintaining the carbonation in beverages by using a flexible bag, temperature and pressure control means. To dispense the beverage, and external source of gas such as carbon dioxide and nitrogen is used to feed gas directly into the flexible container portion.

WO 2016146749 discloses a method and system for introducing nitrogen into a collapsible beverage container filled by a pre-carbonized beverage, i.e. this citation simply discloses how to get nitrogen into a collapsible beverage container and how to close it.

US 5565149 and US 6138995 are concerned with solutions to the problem of controlling dissolved N2 and CO2 in beer in connection with steel kegs, as the pressure in the beverage container of the beverage dispensing system is applied on the head space of the beverage container by an external gas source. Further, the nitrogenation of the beer takes place upon dispensing through a so-called contactor module, which is a membrane device in fluid communication with a N2 and CO2 source.

Hence, the prior art is silent about the issue of keeping the level of nitrogen within the beverage in collapsible kegs while dispensing the beverage.

Since nitrogen is 50-100 less soluble than carbon dioxide in beer, the nitrogen gas is normally sustained in the beer via the dispensing system when utilizing rigid kegs. Thus, while in rigid kegs external addition or removal of CO2 and N2 into the beverage during dispensing is possible, in collapsible kegs the nitrogen is pre-soluted or pre- dissolved in the beverage, or as used herein pre-mixed, and therefore there is no external addition of CO2 or N2 into the beverage, either during transport or during dispensing. This creates formidable challenges in terms of keeping the nitrogen of the beverage at a specified level. In particular, as the head space of a collapsible keg, i.e. space above the level of the beverage in a collapsible keg, changes due to the flexibility of the keg material, there is a risk that the nitrogen content in the beverage also changes. For instance, if the head space becomes suddenly too large during the collapsing of the keg as beverage is being dispensed, nitrogen may actually tend to migrate into such space. If the head space becomes suddenly too small during the collapsing, nitrogen may be forced into the beverage. In both instances, the required specifications of the dispensed beverage are not met, thus resulting in beverages being served with undesired appearance, and which may need to be discarded.

A poor control of the nitrogen and carbon dioxide in the collapsible keg may not only result in a poor surge of beverage being dispensed and too small a head in the dispensed beverage then served to the customer, which is undesirable. A nice surge or good surge means that the coloring of a beer changes gradually yet relatively quick e.g. within a minute or so, from white, indicating a significant presence of foam, to a dark coloring, indicating the presence of beer with less content of foam, yet still providing a nice creamy head. However, striking the balance between ending with a serving (poured beer) which is not completely colored white due to the presence of foam, or completely dark due to no surge, represents a significant challenge. A poor control of the nitrogen and carbon dioxide in the collapsible keg may also result in an uncontrolled surge and then too much head in the dispensed beverage due to too much foaming. By way of example, while in some geographies, a head of about 5-20% of the height of a beer glass may be desired, heads of 25% or more, for instance about 33% or more, of the height of the beer glass may be undesirable and may occur if the concentration of CO2 and particularly N2 in the collapsible keg is not controlled properly. Yet in other geographies, a head of 33% or more, say up to 40% may be desired. Even small variations in the concentrations of N2 and CO2 away from the prescribed specifications of the beverage may cause a significant change in the amount of foam, surge, height of the head and flavor of the dispensed beverage.

It is an object of the present invention to be able to maintain the content of nitrogen of a beverage being dispensed from collapsible beverage containers at the required specifications of a given beverage so that nitrogen does not migrate to the head space of the collapsible beverage container or from the head space into the beverage. It is another object of the present invention to provide a beverage system and method which in a simple way, without the use of separate units or modules for providing the required nitrogenation of the beverage and/or without adding nitrogen into the beverage while dispensing the beverage.

It is yet another object of the present invention to provide a beverage system and method in which the head of the beverage glass after dispensing is within desired ranges, for instance about 5-20% of the height of the glass.

Summary of the invention

The above mentioned objects and more can be achieved by the presently disclosed method of dispensing a beverage stored in a collapsible beverage container in a beverage dispensing system, said collapsible beverage container defining a beverage- filled space, a gas-filled head space and a beverage outlet in communication with said beverage-filled space for extracting said beverage from said beverage-filled space, in which said beverage upholds a predetermined nitrogen and carbon dioxide content, and in which said beverage upholds a beverage temperature while inside said collapsible beverage container.

Generally seen this can be provided by maintaining a predetermined nitrogen content in said beverage by controlling the equilibrium of the nitrogen and carbon dioxide within the beverage by adapting a dispensing pressure and/or the temperature of the beverage while inside said collapsible beverage container on the basis of equilibrium pressure calculated according to: nitrogen containing gas, CO2, or nitrogen containing gas + CO2 chemical equilibrium data.

The present disclosure further relates to a beverage dispensing system for dispensing beverage stored in a collapsible beverage container wherein the beverage upholds a predetermined nitrogen and carbon dioxide content. The system is configured for maintaining a predetermined nitrogen content in said beverage by controlling the equilibrium of the nitrogen and carbon dioxide within the beverage by adapting a dispensing pressure and/or the temperature of the beverage while inside said collapsible beverage container on the basis of equilibrium pressure calculated according to: nitrogen containing gas, CO2, or nitrogen containing gas + CO2 chemical equilibrium data. Control of the equilibrium of the nitrogen and carbon dioxide within the beverage and adaptation of the dispensing pressure and/or the temperature of the beverage, can for example be provided by a processing unit, e.g. in a computing device associated with the system.

The presently disclosed system may further comprise a pressure chamber for accommodating the beverage container, the pressure chamber comprising a base part including a beverage container connector for connecting to a beverage outlet of said collapsible beverage container, and a lid connectable to said base part, said lid and said base part thereby defining an inner space for accommodating the collapsible beverage container, and accommodating and encapsulating said collapsible beverage container.

The presently disclosed system may further comprise a tapping device comprising one or more tapping heads for extracting said beverage from said beverage-filled space and a tapping line extending from said container connector to said one or more tapping heads, said tapping line comprising one or more beverage lines. The system may also comprise

The presently disclosed system may also comprise pressure generation means in fluid communication with said inner space, thereby defining a dispensing pressure for collapsing said collapsible beverage container and forcing said beverage from said beverage-filled space through said tapping line and out through said one or more tapping heads.

The features described herein of the presently disclosed method and corresponding system may be combined in any way.

The dispensing pressure of the beer is typically the dispensing pressure inside the pressure chamber holding the collapsible beverage container, i.e. the pressure in the inner space defined by the base part and the lid. This pressure can for example be measured by a pressure sensor mounted somewhere on the pressure chamber and configured to measure the pressure in in the inner space. However, it may is not always necessary to actually measure the dispensing pressure, because the pressure chamber may have been characterized such that a certain configuration of a connected pressure generation means, e.g. a pump or a compressor, is known to result in a certain pressure in the inner space. I.e. preferably the presently disclosed system is configured to suitably adapt the dispensing pressure based on the requirements for the specific beverage.

The temperature of the beverage can likewise be measured by measuring the temperature in the inner space, e.g. by a temperature sensor. But as with the pressure above it may not be necessary to actually measure the temperature of the beer, because there may be integrated cooling in the system that is adapted to cool the pressure chamber to a certain temperature, or the system may be located in a room with climate control providing a certain predefined temperature, such that the temperature of the beverage is maintained at that temperature.

By the term“said beverage upholds a predetermined nitrogen and carbon dioxide content” it is meant that the nitrogen and carbon dioxide have been pre-mixed into said beverage. The nitrogen and carbon dioxide are pre-mixed into the beverage before transporting the beverage container to the place of consumption.

Nitrogen and/or carbon dioxide content means concentration in the beverage, for beer suitably in ppm units for N₂ and in g/L units for C0₂. For instance, the beverage may contain 25-70 ppm by weight N₂, 2-3 g/L C0₂ which corresponds to about 1 -1.5 C0₂ volumes per volume of beer (v/v), since 2 g/L C0₂ is about 1 v/v. The carbon dioxide content is also referred to as carbonation level.

In one embodiment of the method according to the present disclosure, the nitrogen containing gas is N₂ and/or N₂0. For instance, N₂+C0₂ chemical equilibrium data in water or in beer; or N₂ chemical equilibrium data, such is in the form of N₂-solubility in water or in beer at different pressures and temperatures. Hence, suitably said dispensing pressure is the equilibrium pressure calculated according to N₂, C0₂ or N₂+C0₂ chemical equilibrium data. Such equilibrium data is readily available in the literature. Alternatively, or in addition to N₂, other gases such as N₂0 may also be used as nitrogen containing gas. The dispensing pressure enables not only the collapsing of the keg and dispensing of the beverage, but also keeps the needed equilibrium pressure for maintaining the required N₂ and C0₂ in the beverage, as specified for the beverage in the keg. In one embodiment said beverage is pre-mixed with nitrogen and carbon dioxide so that nitrogen and carbon dioxide ratio is respectively in the range 60-75 to 30-40, and in which the sum of nitrogen and carbon dioxide ratios is 100. Preferably, the nitrogen to carbon dioxide ratio is 70 to 30. The ratio corresponds to the partial pressures of nitrogen and carbon dioxide in the collapsible beverage container.

This enables keeping the right pressurization for correct equilibrium of the gas, so that nitrogen remains within the beverage and thus satisfies the required specification of the beverage. In a simple manner, it is thereby ensured that the concentration of nitrogen (N2) remains within the beverage and is maintained at the required level of 25-70 ppm N2. In other words, the presently disclosed approach enables a beverage, in particular beer or coffee such as a cold coffee, from a collapsible beverage container being dispensed, i.e. served, with the nitrogen content having the prescribed specifications of the beverage.

By for instance setting the temperature of the beverage in the collapsible keg, i.e. the temperature of the beverage while inside the collapsible beverage container, and which is suitably in the serving range of 3-6°C, the N2 to CO2 ratio in the beverage to a desired value, as well as the specified concentration of nitrogen, or carbon dioxide in equilibrium at such temperature, the total pressure may be calculated and the dispensing pressure be adapted accordingly, as shown in the accompanying examples. Alternatively, the temperature of the beverage in the collapsible keg may be adapted when a given suitable dispensing pressure is being set.

Detailed description of the invention

The presently disclosed method may further comprise the step of providing a base part including a beverage container connector for connecting to said beverage outlet of said collapsible beverage container.

A tapping device comprising one or more tapping heads for extracting said beverage from said beverage-filled space may further be provided. And a tapping line extending from said container connector to said one or more tapping heads, the tapping line preferably comprising one or more beverage lines, may also be provided.

A lid connectable to said base part may also be provided. The lid and the base part preferably defining an inner space for accommodating the collapsible beverage container, and accommodating and encapsulating said collapsible beverage container. In one embodiment the lid is flexible, alternatively it may be rigid.

The presently disclosed method advantageously includes the step of installing a pressure generation means in fluid communication with said inner space thereby defining a dispensing pressure for collapsing the collapsible beverage container and forcing the beverage from the beverage-filled space and for example through the tapping line and out through the one or more tapping heads.

When installed in a beverage dispensing system like the applicant’s DraughtMaster™, the beverage container is typically oriented in a predetermined position such as an “upside down” position, i.e. the beverage outlet is oriented in a downward direction so that the head space is thereby oriented in an upwards direction. The base part is typically rigid and suitable for supporting the weight of the beverage container, and the beverage container connector forms a fluid-tight connection between the beverage outlet and the tapping line.

The tapping head typically comprises at least one tapping valve, which is controlled by a beverage dispensing control means, such as a pushing button or preferably a tapping handle. A user wishing to dispense beverage will for example move the handle from a vertical position to a horizontal position and thereby operate and open the valve for allowing a flow or stream of beverage from the beverage filled space via the tapping line to the tapping head.

The lid is connectable to the base part in a fluid-tight fashion in order to be able to form a hermetically sealed inner space, which has a suitable volume for encapsulating the beverage container.

The base part may be made of rigid material in order to support the collapsible beverage container. In the context of the present patent application, rigid material should be understood as being capable of supporting the weight of the beverage without bulging. Pressure is applied to the collapsible beverage container in order to apply a dispensing pressure for forcing the beverage from the beverage filled volume via the tapping line to the tapping head when the tapping valve is open as a result of the tapping handle being moved from its original vertical (close) position. The pressure should be sufficiently great to overcome the crumpling pressure of the collapsible beverage container plus the gas pressure of brewage, i.e. the pressure required for collapsing the beverage container, and as well overcome the pressure losses in the dispensing line, e.g. for elevating the beverage from a cellar located below a bar.

Finally, a certain pressure at the tapping head is required for allowing a suitable flow velocity, however, too much flow or too small pressure may cause undesired foaming.

In the case of a flexible lid the pressure generation means is provided to apply a force onto the collapsible beverage container, i.e. thereby defining the dispensing pressure for collapsing said collapsible beverage container and forcing said beverage from the beverage-filled space, for example through the tapping line and out through the one or more tapping heads. The flexible lid may be made of an elastic material such as rubber or alternatively said made of a non-elastic flexible material such as plastic. Flexible in the context of the present patent application is understood to mean that it is made of a material, which will be deformed when a force is applied to the material, the material will yield and conform to the applied force without breaking. Dispensing by means of a flexible lid and using vacuum is disclosed in applicant’s pending PCT application No. PCT/EP2018/083423 entitled Systems and methods for dispensing a beverage stored in a collapsible beverage container.

By the term“pressure generation means in fluid communication with said inner space for causing said flexible lid to apply a force onto said collapsible beverage container” means that a pressure generation means, i.e. a pressure source, such as an air compressor, is provided for pressurizing the inner space defined by the lid and the base part. This is well known in the art and within the immediate reach of the skilled person, as also is adapting the dispensing pressure. An example illustrating one way of using such a pressure generation means and adapting the dispensing pressure is disclosed in applicant’s patent application WO2012/010659.

The beverage may be selected from the group consisting of: beers, soft drinks, coffees and wines. Coffee is preferably cold coffee, pre-mixed with nitrogen, so that a creamy head at the top of the served coffee is achieved, thus increasing appeal and flavor for the customer.

In one embodiment the beers are selected from the group consisting of: ales, stouts and porters. Preferably the carbonation level of these beers is 1.8-3.0 g/L CO2, often 2.0-3.0 g/L CO2. As described above, the carbonation levels in g/L may be converted to v/v by using a factor of 2. Thus, 2 g/L CO2 corresponds to 1 v/v CO2 and 3 g/L CO2 corresponds to 1.5 v/v CO2. At the above ranges, a nice surge pure during dispensing of the beer and a nice head are obtained. For instance, for an ale beer, the

predetermined nitrogen content is preferably in the range 25-40 ppm by weight such as 30-35 ppm, and the carbon dioxide content 2.0-2.9 g/L CO2 such as 2.1-2.7 g/L CO2. For a stout beer, the predetermined nitrogen content is preferably in the range 40-70 ppm by weight and the carbon dioxide content 1.8-2.4 / L CO2.

In one embodiment of the presently disclosed approach, the dispensing pressure is higher than the equilibrium pressure of the beverage, preferably 0.1 -0.5 barg higher than the equilibrium pressure of the beverage. While the dispensing pressure may then be adapted so that the pressure generation means, such as an air compressor, provides a pressure corresponding to the equilibrium pressure of nitrogen and carbon dioxide, the present specific embodiment invites to apply a dispensing pressure 0.1 -0.5 barg higher. This further ensures that nitrogen stays within the beverage and thus keeps generating a foaming froth at the top of the beer after dispensing, while at the same time accounting also for any other pressure loss within the system, for instance in the tapping line, or for a higher alcohol content of the beverage, since the higher the alcohol content the lower the solubility of CO2 in the beverage.

It would be understood that“barg” denotes gauge pressure in bar and represents the difference between the absolute pressure provided onto the collapsible keg and the atmospheric pressure. Thus, an absolute pressure of 3 bar (3 bara) corresponds to approximately 2 barg.

In one embodiment of the presently disclosed approach, said collapsible beverage container is a single-use collapsible beverage container, i.e. a single-use collapsible keg. This eliminates the need of having gas cylinders around for supplying nitrogen and carbon dioxide, and eliminates the need for cleaning the keg.

Applicant company has also found that it is actually desirable to have the required level of nitrogen in the beer strictly within the specification of a specific beer, or in other words, that the surge and/or appearance of head in a beer upon dispensing is indeed sensitive to its particular concentration of nitrogen. It may thus necessary to maintain the beer at 30-40 ppm N₂ when for instance dispensing an ale, while for another type of nitro beer, such as stout, 50-65 ppm N₂ will be required to provide the nice surge and head.

A measuring device for at least retrieving information about said beverage may be provided installing in any of said collapsible beverage container, said base part, said lid, and said tapping line. Accordingly, one embodiment the presently disclosed approach comprises the step of installing in any of said collapsible beverage container, said base part, said lid, and said tapping line, a measuring device for at least retrieving information about said beverage. Further, an electronic sensor device in the form of an analogue sensor, a digital sensor, or combinations thereof, may be installed in said base part and/or said lid for reading said information from said measuring device thereby establishing digital data representing said information about said beverage.

The presently disclosed approach may therefore enable that the right surge and/or head for the specific beer being dispensed is provided.

In a particular embodiment, the presently disclosed method comprises the step of installing in said collapsible beverage container, a measuring device for at least retrieving information about said beverage. Similarly an electronic sensor device in the form of an analogue sensor, a digital sensor, or combinations thereof, may be installed in said base part and/or said lid for reading said information from said measuring device thereby establishing digital data representing said information about said beverage.

The term“a measuring device” means as used herein one or more measuring devices. The measuring device may be in the form of an analogue sensor, a digital sensor or combinations thereof. Preferably, the digital sensor is a wireless electronic device, in particular a RFID-tag, a bar code, or combinations thereof.

The electronic sensor device for reading said information from said measuring device in the form of a digital sensor may be a RFID-reader, a bar code reader, or

combinations thereof. Accordingly, the presently disclosed method encompasses also installing a digital sensor in the form of digital identifier, preferably an RFID-tag or NFC- tag, on said collapsible beverage container. The digital identifier, preferably RFID-tag or NFC-tag, is readable by a sensor, e.g. NFC/RFID-sensor, in said base part and/or said lid. Since a pressure chamber is defined by said base part and said lid, the digital sensor in the form of a digital identifier, e.g. RFID-tag, is readable by a sensor, e.g. RFID-sensor, in the pressure chamber.

RFID-tags (Radio Frequency Identification tags), also known as RFID-chips may retrieve i.e. receive, store and optionally process e.g. transmit, information. RFID enables uniquely identifying items using radio waves.

Hence, information in term of the properties or parameters of the beverage, including content of beverage in said collapsible beverage container may be measured and thereby identified. In particular, information about the type of beverage and beverage temperature in the collapsible keg may be measured and identified. Accordingly, the beverage temperature in the collapsible keg and the type of beverage, this for instance being an ale beer, stout, porter, or any other beverage having specific requirements for content of nitrogen and/or carbon dioxide, may be retrieved. The retrieved information from a measuring device is then stored, read, and optionally processed by the electronic sensor device, preferably a digital sensor device, included in the base part and/or the lid.

Depending on the type of beer, the dispensing pressure is adapted. For instance, if the beer type is identified as an ale with a specification of 35 ppm N2 and 2.5 g/L CO2, it is kept in the collapsible keg at 5°C and dispensed also at 5°C, the dispensing pressure is adapted to about 2.3 bara (1.3 barg), which is the sum of the partial pressures of N₂ and CO2 at this temperature, as this is the pressure at which the required specification of 35 ppm N2 with 2.5 g/kg CO2 for this specific type of beer is maintained. See Table 1 and Example 1. A nice serving, e.g. a nice surge and/or head, for specifically this beer is thereby also obtained.

Similarly, if the beer type is identified as a stout beer and the nice surge and head are wanted, a specification of 60 ppm N2 and 1.9 g/L CO2 may be required; see Table 2 and Example 2. If the beverage is kept in the collapsible keg at say 5°C by a suitable internal cooling, no further cooling e.g. in the tapping line may be required so that the dispensing (serving temperature) is also 5°C. The dispensing pressure is adapted to about 3.1 bara (2.1 barg), which is the sum of the partial pressures of N2 and CO2 at this temperature, as this dispensing pressure is the pressure at which the required specification of N2 and CO2 is maintained. The type of the beverage may be stored or an identification for a database with other information about the beverage, e.g. whether the beverage is a beer, a specific beer type, soft drink, coffee, wine or other, the name of the beverage as well as other information relevant to the user or customer such as the alcohol percentage if applicable. The information may then be displayed automatically at for instance the tapping head. In particular RFID tags or bar codes may store some or all of this information in a convenient way.

The collapsible beverage container typically includes a closure adapted to cooperate with said beverage container connector, wherein an identification tag, e.g. NFC or RFID-tag, can be mounted on the rim of said closure, sealing of said closure, or internally in said closure, and optionally the NFC/ RFID-reader is mounted on the base part adjacent to said closure. By“internally in said closure” is meant at the internal face of said closure, thus the identification tag is mounted in a less visible location. Hence, the present disclosure further relates to a collapsible beverage container, preferably single use, for use in the presently disclosed beverage dispensing system, said collapsible beverage container comprising a closure and an identification tag, such as a NFC / RFID tag and/or a barcode. The closure is preferably configured to cooperate and/or engage with the beverage container connector disclosed herein. The ID tag may be mounted on the rim of said closure, sealing of said closure, or internally in said closure. One or more visible bar codes may be printed or attached on the rim, closure and/or body of the collapsible beverage container.

Correspondingly the presently disclosed method further comprises the steps of:

installing in said collapsible beverage container a closure adapted to cooperate with said beverage container connector, and mounting an RFID-tag on the rim of said closure, sealing of said closure or internally in said closure. The RFID-reader may be mounted on the base part adjacent to said closure.

By“internally in said closure” is meant at the internal face of said closure, thus the RFID-tag is mounted in a less visible location. The provision of an RFID-tag enables identification of the keg and improved inventory management, as already discussed above and further explained below. The RFID-tag may be mounted prior to filling a collapsible keg so that after filling, the tag is logged centrally, a production label is written to the tag and/or ID from the tag is correlated in a database or data-logging system with all information, including the specific type of beverage. The terms“installing” and“mounting” are used interchangeably throughout the present disclosure.

A data logging system for retrieving and storing said digital data may be provided. In one embodiment the presently disclosed the method further comprises the step of installing a data logging system for retrieving and storing said digital data. In a particular embodiment, said data logging system is a computer system, said nitrogen containing gas, CO2, or N2+CO2 equilibrium data are equilibrium data of a specific beverage, e.g. according to publicly available data, on solubility of the nitrogen gas and/or carbon dioxide (e.g. in water or beer or wine or coffee), and said computer system is adapted to store the nitrogen containing gas, CO2, or N2+CO2 equilibrium data of said specific beverage, and also calculate said dispensing pressure. The nitrogen containing gas is N2 or N2O, preferably N2.

This enables proper control of the dispensing pressure and/or temperature for different types of beverages. For instance, an ale beer may be identified as the beverage in the collapsible keg via the RFID-tag requiring a particular specification of nitrogen and carbon dioxide in the beer. Then, the data logging system, e.g. the computer system, stores the specific equilibrium data for this specific ale beer and calculates the dispensing pressure and in order to adapt the dispensing pressure accordingly, e.g. by providing a dispensing pressure equal to the calculated equilibrium pressure (absolute pressure) at a given temperature of the beverage. If the beverage is identified as a wine or beer with a higher level of alcohol via the RFID-tag and requiring a specific content of nitrogen and carbon dioxide, the data logging system stores the specific equilibrium data specific for this wine or beer having a high alcohol content (say 11 % in contrast to normally about 4-6% v/v) and calculate the dispensing pressure and thereby adapt the dispensing pressure accordingly, e.g. by providing a dispensing pressure equal to the calculated equilibrium pressure at a given temperature of the beverage.

Due to the presence of significantly higher percentage of alcohol in wine, the equilibrium data is different compared to equilibrium data in water or beer, since the solubility of CO2 decreases with increasing alcohol content. The proper dispensing pressure corresponding to the specific beverage, here wine, at a given temperature of the beverage is thereby obtained. If the beverage in the collapsible keg is identified via the RFID-tag as coffee requiring a specific content of nitrogen and carbon dioxide, the equilibrium data for CO₂, N₂, or N₂+CO₂ may also vary with respect to that of beer or wine. The proper dispensing pressure, calculated according to the specific equilibrium data for coffee, is thereby obtained. Problems related to too much or too little foam in the beverage recipient regardless of the type of beverage dispensed are thus mitigated.

A further embodiment of the present disclosure relates to a collapsible beverage container for use in presently disclosed beverage dispensing system, the collapsible beverage container comprising a collapsible body and a closure with a beverage outlet configured for engagement with the beverage container connector of the beverage dispensing system, the collapsible beverage container further comprising at least one identification tag mounted on a rim of said closure, a sealing of said closure or internally in said closure, and/or on the body of said container, said identification tag readable by a corresponding reader in the beverage dispensing system. As stated above the identification tag may be a radio frequency identification tag, such as RFID / NFC, a visible / optical tag, such as a barcode, or a combination thereof. The identification tag may comprise identification information for uniquely identifying said container. The identification tag may further comprise information selected the group of: type of the beverage, producer of beverage, origin of beverage, production date of beverage, production place of beverage and shipping date of beverage. And the identification tag may further comprise at least one of one or more predefined codes for approval by the beverage dispensing system.

The present disclosure further relates to a kit of parts of the presently disclosed beverage dispensing system and the presently disclosed collapsible beverage container.

The provision of an identification tag enables identification of the keg and improved inventory management, and also for determining the type of beer - and in case of a nitro beer the system thereby knows the required pressure and/or temperature requirements. The ID tag may be mounted prior to filling a single use collapsible keg so that after filling, the tag is logged centrally, a production label is written to the tag and/or ID from the tag is correlated in a database or data logging system with all information. Inventory management is improved, since each collapsible keg has a unique ID, i.e. identification concerning what, when and where it is produced, as well as when it is shipped, to whom, when it is emptied or opened, etc. In addition, each serving incident on the system can be logged to the specific tag and unknown tags may be identified and if necessary, rejected. The beverage dispensing system according to this embodiment optionally comprises an RFID-reader, e.g. a high frequency RFID-reader such as NFC (Near-Field Communication) reader, mounted preferably on the base part adjacent to a closure.

Description of drawing

The sole accompanying figure shows a schematic representation of beverage dispensing system 10 comprising a single collapsible beverage container 12 contained in the inner space 14, base part 16, a tapping line 18 and tapping device 20. In the beverage dispensing system 10, the pressure chamber comprises lid 22 and base part 16. The base part 16 is rigid. The lid 22 and base part 16 are sealed together establishing the inner space or inner volume 14 of the pressure chamber including the filled single use collapsible beverage container 12. The beverage container 12, also known as a keg, is of the collapsible type made of a collapsible polymeric material, thus the term collapsible beverage container. The collapsible beverage container 12 defines a beverage-filled space containing the beverage 24, typically being a carbonated beverage such as beer. The beverage container 12 also defines a gas-filled head space 26 at its top portion, above the level of the beverage inside the beverage container 12. The lid 22 and the rigid base part 16 are separable but during operation they are sealed together, thereby forming the pressure chamber. The base part 14 is also connected to a pressure generation means or pressure source, such as an air compressor 28. The compressor 28 enables pressurizing the sealed inner volume 14 defined by the lid 22 and base part 16 and which accommodates and encapsulates the collapsible beverage container 12. When the tapping device 20 is enabling beverage flow, the pressure applied onto the beverage container 12 will result in its gradual collapse, as beverage is forced out and towards the tapping device 20.

The beverage dispensing system 10 includes a pressure sensor 30. The beverage container 12 includes a digital identifier, such as an RFID tag 32, which is readable by an RFID sensor (not shown) in the pressure chamber or any other suitable location in the beverage dispensing system 10. The pressure sensor 30 is provided for continuously measuring the pressure within the inner space 14 during dispensing. An additional pressure sensor (not shown) may also be provided for continuously measuring the pressure inside the beverage container. Temperature sensor(s) (not shown) may also be adapted for continuously measuring the temperature of the beverage. The dispensing pressure is suitably the pressure provided by sensor 30. The RFID-tag 32 in the collapsible beverage container 12 includes information about the kind of beverage, e.g. beer, which kind of beer, e.g. ale, lager etc. and the specification of the beverage, e.g. alcoholic content. This will enable automatic processing of the information. The information may be stored locally or communicated to data logging system at a central data storage location e.g. at the brewery.

Tables 1 and 2 below present equilibrium data in the form of concentration tables for N2, CO, and N2+CO2 in water in chemical equilibrium for the dispensing of two types of beers: an ale beer having the specification 35 ppm N2, 2.5 g/L CO2 and a stout beer having specification 60 ppm N2, 1.9 g/L CO2.

The partial pressures of nitrogen (P_N2) and carbon dioxide (Pco2) in the tables are calculated by Henry’s law, by which at a given temperature the amount of a given gas, here N2 or CO2, that dissolve in the beverage, here water, is directly proportional to the partial pressure of that gas in equilibrium with the beverage. Henry’s law constants for N2 and CO2 are readily available at e.g. the NIST Chemistry Webbook at

https://webbook.nist.gov/chemistry/

By selecting“Name” under the Search Options therein, then type“nitrogen” or“carbon dioxide” as the chemical species and selecting Henry’s law, the corresponding Henry’s law constants in water are found. These are reproduced below.

Hence, for nitrogen:

kH_N2 = (kH_N2|Tr_ef)^*exp(C_N2 ^*(1 /T-1 /T r_ef)), mol/(kg^*bar)

kH _N2_|Tref ^— 0.00065 mol/(kg bar), Henry s law constant for nitrogen at T_ref

T_ref = 298 K (25°C)

C_N2 = 1300 K is the temperature dependent constant for nitrogen Then, P_N2 = [N₂] / kH_N2 (1 )

where [N2] = X_N2 / MW_N2 / 1000, is the concentration of nitrogen in water, mol/kg

X_N2 is the concentration of nitrogen in water, ppm weight

MW_N2 is the molar weight of nitrogen, 28 g/mol

P_N2 is the partial pressure of nitrogen, bara (absolute pressure)

Similarly, for carbon dioxide: kHco2 = (kH_Co2_|Tre_f)*exp(Cco2*(1 /T-1 /T re_f)) mol/(kg^*bar)

kHco2_|Tref = 0.035 mol/(kg^*bar), Henry’s law constant for nitrogen at T_ref

T_ref = 298 K (25°C)

Cco2 = 2400 K is the temperature dependent constant for carbon dioxide

Then, Pco2 = [C0₂] / kH_C02 (2)

where [CO2] = Xco2 / MWco2, is the concentration of carbon dioxide in water, mol/kg Xco2 is the concentration of carbon dioxide in water, g/L

MWCO2 is the molar weight of nitrogen, 44 g/mol

P _C02 is the partial pressure of carbon dioxide, bara (absolute pressure)

Based on the above equations, for any given type of required specification of the beverage in terms of its nitrogen and carbon dioxide concentration, the required total pressure PT = PN2+PCO2 may be found and the dispensing pressure thus adapted accordingly, i.e. by using PT as the dispensing pressure.

Table 1 : Required specification of beer, 35 ppm N2, 2.5 g/L CO2

Table 2: Required specification of beer, 65 ppm N₂, 1.9 g/L C0₂

Examples

Example 1

An ale beer requires the specification 35 ppm N₂ and 2.5 g/L C0₂ during serving in order to provide a nice surge and head. For a temperature of the beer while in the collapsible beverage container of 5°C, which corresponds to a preferred dispensing (serving) temperature of the beer, i.e. serving temperature, such cooling suitably provided by cooling via an integrated cooling system, the dispensing pressure according to the equilibrium data for N₂ and C0₂ of Table 1 , is adapted to PT=2.3 bara (1.3 barg). This corresponds to N₂/C0₂ of about 60/40 at this temperature, which is readily calculated from P_N2/P_T (1.4/2.3^*100). The surge of the beer during dispensing as well as the head formed after dispensing provides the proper serving of this type of beer in accordance with the specifications. The changes of the headspace of the collapsible beverage container during the dispensing becomes rather insignificant, as the right equilibrium of nitrogen and/or carbon dioxide is sustained for the beer during its dispensing.

Example 2

A stout beer requires the specifications 60 ppm N₂ and 1.9 g/L C0₂ during serving in order to provide a nice surge and head. For a temperature of the beer while in the collapsible beverage container of 5°C, which corresponds to a preferred dispensing (serving) temperature of the beer, i.e. serving temperature, such cooling suitably provided by cooling via an integrated cooling system of the container, the dispensing pressure according to the equilibrium data for N₂ and C0₂ of Table 2, is adapted to PT=3.1 bara (2.1 barg). This corresponds to N₂/C0₂ of about 77/23 at this temperature, which is readily calculated from P_N2/P_T. The surge of the beer during dispensing as well as the head formed after dispensing provides the proper serving of this type of beer in accordance with the specifications. The changes of the headspace of the collapsible beverage container during the dispensing becomes rather insignificant, as the right equilibrium of nitrogen and/or carbon dioxide is sustained for the beer during its dispensing.

Example 3

A beer requires specifications of 60 ppm N₂, it is stored in a collapsible beverage container at a serving temperature of 3°C and pre-mixed with a N₂ to C0₂ ratio of 70 to 30 (ratio of partial pressure of N₂ to C0₂). Following Table 2 for the equilibrium data of N₂ in water, at this temperature the nitrogen partial pressure (P_N2) is 2.3 bara. Since the ratio of N₂ to C0₂ is known (70 to 30), then the partial pressure of C0₂ can be readily calculated as Pco2 = (30/70)*PN2 = (30/70)^*2.3 = 0.985 bara, say 1 bara. At 3°C and solving for the concentration of C0₂ in equation (2), this partial pressure of C0₂ corresponds to Xco2= 2.9 g/L C0₂. The total pressure PT is PT=PN2+PCO2= 2.30 + 1 =

3.3 bara (2.3 barg). Then by adapting the dispensing pressure to 3.3 bara, the beer may be served at 3°C with the specified amount of nitrogen, here 60 ppm and sustaining the pre-mixed N₂/C0₂ ratio of 70/30.

Points of the invention

1. A method of dispensing a beverage stored in a collapsible beverage container in a beverage dispensing system, said collapsible beverage container defining a beverage-filled space, a gas-filled head space and a beverage outlet in communication with said beverage-filled space for extracting said beverage from said beverage-filled space, in which said beverage upholds a

predetermined nitrogen and carbon dioxide content, and in which said beverage upholds a beverage temperature while inside said collapsible beverage container, the method comprising:

- providing a base part including a beverage container connector for

connecting to said beverage outlet of said collapsible beverage container, providing a tapping device comprising one or more tapping heads for extracting said beverage from said beverage-filled space,

providing a tapping line extending from said container connector to said one or more tapping heads, said tapping line comprising one or more beverage lines, and

providing a lid connectable to said base part, said lid and said base part defining an inner space for accommodating said collapsible beverage container, and accommodating and encapsulating said collapsible beverage container,

the method further comprising:

o installing a pressure generation means in fluid communication with said inner space for causing said flexible lid to apply a force onto said collapsible beverage container, thereby defining a dispensing pressure for collapsing said collapsible beverage container and forcing said beverage from said beverage-filled space through said tapping line and out through said one or more tapping heads, o maintaining a predetermined nitrogen content in said beverage by controlling the equilibrium of the nitrogen and carbon dioxide within the beverage by adapting said dispensing pressure and/or the temperature of the beverage while inside said collapsible beverage container on the basis of equilibrium pressure calculated according to: nitrogen containing gas, CO2, or nitrogen containing gas + CO2 chemical equilibrium data. Method according to point 1 , wherein said nitrogen containing gas is N2 and/or N2O. Method according to any preceding point, wherein said beverage is selected from the group consisting of: beers, soft drinks, coffees and wines. 4. Method according to point 3, wherein said beers are selected from the group consisting of: ales, stouts and porters.

5. Method according to any preceding point, wherein said beverage is a beer which is pre-mixed with nitrogen and carbon dioxide so that nitrogen and carbon dioxide ratio is respectively in the range 60-75 to 30-40, and in which the sum of nitrogen and carbon dioxide ratio is 100.

6. Method according to any preceding point, wherein said dispensing pressure is higher than the equilibrium pressure of said beverage, preferably 0.1 -0.5 barg higher than the equilibrium pressure of the beverage.

7. Method according to any preceding point, further comprising:

installing in any of said collapsible beverage container, said base part, said lid, and said tapping line, a measuring device for at least retrieving information about said beverage, and

installing in said base part and/or said lid an electronic sensor device in the form of an analogue sensor, a digital sensor, or combinations thereof, for reading said information from said measuring device thereby establishing digital data representing said information about said beverage.

8. Method according to point 7, wherein the measuring device is in the form of an analogue sensor, a digital sensor or combinations thereof. 9. Method according to point 7, wherein the digital sensor is a wireless electronic device, in particular an RFID-tag, a bar code, or combinations thereof.

10. Method according to any of points 7-9, wherein said electronic sensor device for reading said information from said measuring device in the form of a digital sensor is an RFID-reader, a bar code reader, or combinations thereof.

1 1. Method according to any preceding point, further comprising:

installing in said collapsible beverage container, a closure adapted to cooperate with said beverage container connector,

- mounting an RFID-tag on the rim of said closure,

sealing of said closure or internally in said closure, and optionally mounting the RFID-reader on the base part adjacent to said closure. Method according to any of the preceding points, further comprising: installing a data logging system for retrieving and storing said digital data. Method according to point 12, wherein said data logging system is a computer system, said nitrogen containing gas, CO2, or N2+CO2 equilibrium data are equilibrium data of a specific beverage on solubility of nitrogen and/or carbon dioxide, and adapting said computer system to store the nitrogen containing gas, CO2, or N2+CO2 equilibrium data of said specific beverage, and also to calculate said dispensing pressure. Method of dispensing a beverage stored in a collapsible beverage container in a beverage dispensing system, said collapsible beverage container defining a beverage-filled space, a gas-filled head space and a beverage outlet in communication with said beverage-filled space for extracting said beverage from said beverage-filled space, in which said beverage upholds a

providing a base part including a beverage container connector for connecting to said beverage outlet of said collapsible beverage container, providing a tapping device comprising one or more tapping heads for extracting said beverage from said beverage-filled space,

installing a pressure generation means in fluid communication with said inner space for pressurizing said inner space, thereby defining a dispensing pressure for collapsing said collapsible beverage container and forcing said beverage from said beverage-filled space through said tapping line and out through said one or more tapping heads,

maintaining a predetermined nitrogen content in said beverage by controlling the equilibrium of the nitrogen and carbon dioxide within the beverage by adapting said dispensing pressure and/or the temperature of the beverage while inside said collapsible beverage container on the basis of equilibrium pressure calculated according to: nitrogen containing gas, CO2, or nitrogen containing gas + CO2 chemical equilibrium data.

Claims

1. A beverage dispensing system for dispensing beverage stored in a collapsible beverage container wherein the beverage upholds a predetermined nitrogen and carbon dioxide content, wherein the system is configured for maintaining a predetermined nitrogen content in said beverage by controlling the equilibrium of the nitrogen and carbon dioxide within the beverage by adapting a dispensing pressure and/or a temperature of the beverage while inside said collapsible beverage container on the basis of equilibrium pressure calculated according to: nitrogen containing gas, CO2, or nitrogen containing gas + CO2 chemical equilibrium data.

2. The system of claim 1 , further comprising

a base part including a beverage container connector for connecting to a beverage outlet of said collapsible beverage container, and

- a lid connectable to said base part, said lid and said base part defining an inner space for accommodating said collapsible beverage container, and accommodating and encapsulating said collapsible beverage container.

3. The system of claim 2, wherein the lid is flexible and wherein a pressure

generation means is provided for causing said flexible lid to apply a force onto said collapsible beverage container, thereby defining the dispensing pressure for collapsing said collapsible beverage container and forcing said beverage from said beverage-filled space through said tapping line and out through said one or more tapping heads.

4. The system of claim of any of the preceding claims, comprising

a tapping device comprising one or more tapping heads for extracting said beverage from said beverage-filled space, and

a tapping line extending from said container connector to said one or more tapping heads, said tapping line comprising one or more beverage lines.

5. The system of claim of any of the preceding claims, comprising a pressure generation means in fluid communication with said inner space, thereby defining a dispensing pressure for collapsing said collapsible beverage container and forcing said beverage from said beverage-filled space through said tapping line and out through said one or more tapping heads.

6. The system of claim of any of the preceding claims, wherein said nitrogen

containing gas is N₂ and/or N₂0.

7. The system of any of the preceding claims, wherein said beverage is selected from the group consisting of: beers, soft drinks, coffees and wines.

8. The system of any of the preceding claims, wherein said beverage is a beer selected from the group consisting of: ales, stouts and porters.

9. The system of any of the preceding claims, wherein said beverage is a beer which is pre-mixed with nitrogen and carbon dioxide so that nitrogen and carbon dioxide ratio is respectively in the range 60-75 to 30-40, and in which the sum of nitrogen and carbon dioxide ratio is 100.

10. The system of any of the preceding claims, configured such that said

dispensing pressure is higher than the equilibrium pressure of said beverage, preferably 0.1 -0.5 barg higher than the equilibrium pressure of the beverage.

1 1. The system of any of the preceding claims, further comprising a measuring device for at least retrieving information about said beverage, and an electronic sensor device in the form of an analogue sensor, a digital sensor, or combinations thereof, for reading said information from said measuring device, thereby establishing digital data representing said information about said beverage.

12. System according to claim 1 1 , wherein the measuring device is in the form of an analogue sensor, a digital sensor or combinations thereof.

13. System according to claim 1 1 , wherein the digital sensor is a wireless electronic device, in particular a RFID-tag, a bar code, or combinations thereof.

14. System according to any of claims 11-13, wherein said electronic sensor device for reading said information from said measuring device in the form of a digital sensor is a RFID-reader, a bar code reader, or combinations thereof.

15. System according to any preceding claim, further comprising a closure adapted to cooperate with said beverage container connector, the closure comprising a an RFID-tag, preferably mounted on a the rim of the closure.

16. System according to claim 15, wherein said electronic sensor device is

mounted on the base part adjacent to said closure.

17. System according to any of the preceding claims, further comprising a data logging system for retrieving and storing said digital data.

18. System according to claim 17, wherein said data logging system is a computer system, said nitrogen containing gas, CO2, or N2+CO2 equilibrium data are equilibrium data of a specific beverage on solubility of nitrogen and/or carbon dioxide, and adapting said computer system to store the nitrogen containing gas, CO2, or N2+CO2 equilibrium data of said specific beverage, and also to calculate said dispensing pressure.

19. A method of dispensing a beverage stored in a collapsible beverage container in a beverage dispensing system, said collapsible beverage container defining a beverage-filled space, a gas-filled head space and a beverage outlet in communication with said beverage-filled space for extracting said beverage from said beverage-filled space, in which said beverage upholds a

the method further comprising:

o installing a pressure generation means in fluid communication with said inner space, thereby defining a dispensing pressure for collapsing said collapsible beverage container and forcing said beverage from said beverage-filled space through said tapping line and out through said one or more tapping heads,

o maintaining a predetermined nitrogen content in said beverage by controlling the equilibrium of the nitrogen and carbon dioxide within the beverage by adapting said dispensing pressure and/or the temperature of the beverage while inside said collapsible beverage container on the basis of equilibrium pressure calculated according to: nitrogen containing gas, CO2, or nitrogen containing gas + CO2 chemical equilibrium data.

20. Method according to claim 19, wherein said nitrogen containing gas is N2 and/or N2O.

21. Method according to any preceding claim, wherein the lid is flexible and wherein the pressure generation means is provided for causing said flexible lid to apply a force onto said collapsible beverage container, thereby defining the dispensing pressure for collapsing said collapsible beverage container and forcing said beverage from said beverage-filled space through said tapping line and out through said one or more tapping heads.

22. Method according to any preceding claim, wherein said beverage is selected from the group consisting of: beers, soft drinks, coffees and wines.

23. Method according to claim 22, wherein said beers are selected from the group consisting of: ales, stouts and porters.

24. Method according to any preceding claim, wherein said beverage is a beer which is pre-mixed with nitrogen and carbon dioxide so that nitrogen and carbon dioxide ratio is respectively in the range 60-75 to 30-40, and in which the sum of nitrogen and carbon dioxide ratio is 100.

25. Method according to any preceding claim, wherein said dispensing pressure is higher than the equilibrium pressure of said beverage, preferably 0.1-0.5 barg higher than the equilibrium pressure of the beverage.