Abstract:
The present invention relates to a beverage including dissolved and partially dissociated carbon dioxide present in an amount of 2-10 g/liter, such as 3-8 g/liter, preferably 4-6 g/liter, most preferably about 5.5 g/liter and establishing an equilibrium pressure at 10° C. of 0.5-3 bar above atmospheric pressure, such as 1-2 bar, preferably about 1.5 bar. The present inventions further relates to a water insoluble or hydrophobic constituent present in molecular form or in molecular aggregated form and in an amount capable of generating ultra fine bubbles including gaseous carbon dioxide. The ultra fine bubbles are present in an amount exceeding 10 10  ultra fine bubbles per millilitre, such as 10 12 -10 18  ultra fine bubbles per millilitre, preferably 10 15 -10 17  ultra fine bubbles per millilitre, most preferably about 10 16  ultra fine bubbles per millilitre, when the beverage is exposed to an external isostatic pressure exceeding the equilibrium pressure of the beverage by at least 1.0 bar, preferably 1.2-60 bar, more preferably 1.5-10 bar, most preferably about 2 bar, the ultra fine bubbles having a major dimension smaller than 100 nm, such as 20-60 nm, preferably about 40 nm.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a national phase filing, under 35 U.S.C. §371(c), of International Application No. PCT/EP2012/059873, filed on May 25, 2012, the disclosure of which is hereby incorporated by reference in its entirety. 
     
    
     FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable 
       BACKGROUND 
       [0003]    The present invention relates to a beverage, a beverage container including a beverage, a method of producing a beverage and a beverage production plant. 
         [0004]    Producers of carbonated beverage, in particular breweries, constantly seek to improve the flavour of their beverage. It is well known that humans perceive the flavour of e.g. beverage via taste buds located on the tongue. Thus, in order to alter the flavour of the beverage, the chemical composition of the beverage may be changed in order to influence the taste buds differently. Other ways of changing the taste of the beverage not involving changing the chemical composition of the beverage include modifying the temperature at which the beverage is served. Carbonated beverages are generally served cool, at about 10° C. At lower temperatures, the taste buds are generally less sensitive to flavours whereas at higher temperatures, carbonated beverages do generally appear less “fresh”. The “freshness” of the beverage may also be increased by increasing the carbonization of the beverage and thus making the beverage slightly prickling on the tongue of the drinker, however, beyond a certain carbonization level the taste of the beverage will be negatively influenced by the large amount of bubbles in the beverage causing a strong prickling effect on the tongue of the drinker and by the sour taste of the carbon acid generated. It is of course contemplated that there are no strict rules when discussing the taste of a beverage, since the taste experience may vary significantly between individual beverage drinkers. 
         [0005]    In experiments it has been observed that when certain beverages are submitted to isothermal compression then, contrary to the general expectation of the incompressibility of watery phases, a compressibility of about 0.1% per bar can be measured. It has also been observed that when certain beverages are submitted to an abrupt deceleration, such as can happen when the beverage container is accidentally dropped to the floor, a sudden pressure jump of about 2 bar can be measured inside the container, after which a slow reversal to the initial lower pressure conditions can be observed at a rate approximating 1 mbar/min. In both of the above situations it was observed that the beverages at all times remained clear and void of opaque components during the above experiments. 
         [0006]    It is contemplated that the above experimental findings can be rationalized according to the following model, wherein the presence of CO 2 -filled ultra fine bubbles within the observed beverages which have sizes below the Abbe-diffraction limit of about 80 nm and are present in equilibrium with dissolved and partially dissociated CO 2  is proposed. Such ultra fine bubbles would be compressible, non-visible and have access to the surplus of CO 2 -gas necessary to undergo the observed abrupt pressure increase when abruptly decelerated. Usually, as such ultra fine bubbles are not expected to be stable as their sizes are below the LaPlace-limit given by P=2*γ/r, wherein P is the pressure inside the bubbles, γ the surface tension of the beverage and r the radius of the bubble, it is further contemplated that amphiphilic components in the beverages such as fatty acids and the like could contribute to lowering the surface tension to such levels that the presence of the proposed ultra fine CO 2 -bubbles in the examined beverages can exist through either thermodynamical or kinetical stabilization. Potentially, such an amphiphilic layer could contribute to an additional dissolution of CO 2  within the amphiphilic layer, further serving as a reservoir for CO 2  within the beverage. 
         [0007]    Calculations based on the above reported experimental results have shown that the number of bubbles in one litre of beverage prepared according to the invention can be as high as 10 15  to 10 21  bubbles per litre of beverage, which corresponds to molar concentrations ranging from about 0.1 ppb and up to about 100 ppm. It is contemplated without otherwise considering the below presented model restrictive for the contents of the invention, that the stability of the bubbles created inside the beverages examined can be rationalized by one or several thermodynamical models of bubble-nucleation. E.g. in one such model, commonly classified as a self-consistent theory of nucleation (see e.g. S. L. Girshick, C.-P. Chiu, J. Chem. Phys., 93(2), pp 1273-1277, 1990), it is proposed that stable nucleation cores, such as i.e. micro-bubbles, may exist within homogeneous and heterogeneous phases, such as the watery phase of the beverages examined, when the surface tension of the nucleation cores is balanced by the degree of supersaturation up to a limiting concentration of nucleation cores whereupon macroscopic nuclei are observed such as e.g. visible carbon dioxide bubbles in carbonated beverages. 
         [0008]    In beverages prepared according to the present invention, supersaturation of the carbon dioxide pressure is achieved by applying additional pressure to the beverages, thereby substantially reducing or even eliminating any development of headspace above the beverages prepared according to the present invention. The relatively high pressures used to achieve this effect surprisingly cause less bubbles to form when the beverages prepared according to the present invention are poured, which permits a stronger carbonization desirable in e.g. beers of various varieties while maintaining or surprisingly even enhancing the effervescent effect of carbon dioxide upon drinking through an observed faster release of macroscopic bubbles. 
         [0009]    Surprisingly and most importantly, it has now been realized by the inventors that the isostatic compression of some kinds of beer and other CO 2 -containing beverages (such as e.g. soft drinks) fulfilling certain specific requirements that were already at equilibrium pressure with a gaseous CO 2 -phase external to the aqueous phase (a headspace), upon compression to the above described super-equilibrium pressure (whereby the headspace is substantially reduced or even eliminated) has a profound influence on the taste, which becomes sweeter, milder and less prickling on the tongue. Further beverages prepared according to the present invention have been found to be acceptable to drink at higher temperatures compared to their regular counterparts, consequently allowing the beverages prepared according to the present invention to be served at increased temperatures as compared to their regular counterparts. This represents another advantage of the beverages prepared according to the present invention as the cooling of beverages to palatable pleasant temperatures constitutes a major economic and environmental limitation within the beverages industry. 
         [0010]    The generation of the bubbles in carbonated beverages and other liquids has been the subject of intense research. Some prior art documents relating to carbonated beverages and similar liquids, as well as containers for holding such beverages and liquids, are presented below: 
         [0011]    In the scientific paper titled “Superstability of Surface Nanobubbles” of the “Physical review letters” of the American Physical Society dated 18 May 2007, it has been revealed that nanobubbles are stable for hours even when reducing the water pressure. 
         [0012]    The scientific paper titled “Surface Tension Module” by John W. M. Bush of the Department of Mathematics, MIT, teaches that the pressure within the bubble is higher than that outside by an amount proportional to the surface tension, and inversely proportional to the bubble size. 
         [0013]    In the scientific paper titled “Bubble population phenomena in acoustic cavitation” by T. G. Leighton, Ultrasonics Sonochemistry 1995 Vol 2 No 2, it is suggested that the size of the bubble and the nature of the local sound field determine whether the bubble oscillations are spherical or non-spherical. 
         [0014]    In the scientific paper “CO 2 —Hydrophobin structures acting as nanobombs in beer”, published in Monatsschrift für Brauwissenschaft vol: 63 issue: ¾ pages: 54-61, it is suggested that the hydrophobins&#39; association to CO 2  nanobubbles is acting as “nanobombs” and perhaps as “nucleation sites” causing overfoaming of the carbonated beverage. 
         [0015]    In the book titled “The Acoustic Bubble” of T. G. Leighton, Institute of Sound and Vibration Research, The University of Southampton, UK, published by Academic Press Limited, it is suggested that organic impurities such as fatty acids may accumulate on the wall of a bubble. In this manner, a bubble nucleus would be stabilized against dissolution. 
         [0016]    WO 2009/071085 of the applicant company discloses an adapter set for use in combination with a collapsible beverage container and a beverage dispensing system. The beverage dispensing system includes an inner chamber, a pressurizing device and a cooling device. 
         [0017]    EP 2014432 and EP 2242636 disclose a multi container comprising an inner stretch blow moulded part being loosely positioned within an outer stretch blow moulded part. Further documents disclosing various multi containers or bag-in-kegs include U.S. Pat. No. 6,209,344, US 2010/0243596, WO 2011/002293, WO 2008/129012, WO 2008/129015, WO 2008/129018 and WO 2008/087206. 
         [0018]    EP 2080709 discloses an assembly of a container and a closure. The closure comprises two access ports. 
         [0019]    WO 2010/119056 of the applicant company discloses a self regulating and constant pressure maintaining product dispenser. The dispenser is inherently capable of substantially maintaining the initial pressure in the pressure space by releasing or adsorbing propellant gas. 
         [0020]    WO 2008/000271 discloses the use of insoluble gas in beverage to provide a more pleasant and smooth mouth feeling experience perceived by the drinker. 
         [0021]    U.S. Pat. No. 6,209,855 discloses a method for mixing discrete microscopic portions of gas in a liquid. 
       SUMMARY OF THE INVENTION 
       [0022]    The object of the present invention is therefore to improve the taste of a carbonated beverage without requiring a significant changing of the chemical composition of the carbonated beverage. 
         [0023]    It is an advantage according to the present invention that the beverage having an improved taste may be enjoyed at a relatively higher temperature and/or may include less CO 2  while retaining an acceptable taste of the carbonated beverage. Thus, refrigerators holding the carbonated beverage according to the present invention will have a lower power consumption compared to conventional refrigerators and consequently results in less energy needed to operate refrigerators and less CO 2  will be emitted into the environment. 
         [0024]    Further features according to the present invention include the provision of systems and methods for improving the taste of a carbonated beverage and containers for holding a carbonated beverage according to the present invention. 
         [0025]    The above object, the above features and the above advantage together with numerous other objects, advantages and features, which will be evident from the below detailed description of the present invention, are according to a first aspect of the present invention obtained by a beverage including:
       dissolved and partially dissociated carbon dioxide present in an amount of 2-10 g/litre, such as 3-8 g/litre, preferably 4-6 g/litre, most preferably about 5.5 g/litre and establishing an equilibrium pressure at 10° C. of 0.5-3 bar above atmospheric pressure, such as 1-2 bar, preferably about 1.5 bar, and   a water insoluble or hydrophobic constituent present in molecular form or in molecular aggregated form and in an amount capable of generating ultra fine bubbles including gaseous carbon dioxide, the ultra fine bubbles being present in an amount exceeding 10 10  ultra fine bubbles per millilitre, such as 10 12 -10 18  ultra fine bubbles per millilitre, preferably 10 15 -10 17  ultra fine bubbles per millilitre, most preferably about 10 16  ultra fine bubbles per millilitre, when the beverage is exposed to an external isostatic pressure exceeding the equilibrium pressure of the beverage by at least 1.0 bar, preferably 1.2-60 bar, more preferably 1.5-10 bar, most preferably about 2 bar, the ultra fine bubbles having a major dimension smaller than 100 nm, such as 20-60 nm, preferably about 40 nm.       
 
         [0028]    The beverage according to the first aspect is in the state before the ultra fine bubbles have been generated as will be discussed below. The beverage may be e.g. beer or cola or any other beverage including a water insoluble or hydrophobic constituent. The amount of dissolved and partially dissociated carbon dioxide is an amount which is typical for most carbonated beverage and which is generally accepted as enhancing the flavor of the beverage to a substantial degree while preventing a too strong prickling effect on the tongue of the drinker. The equilibrium pressure is known to be temperature dependent, thus, in the present context, the equilibrium pressure is defined at 10° C., which is the typical serving temperature for most carbonated beverages. Atmospheric pressure is in the present context considered to correspond to 1 ATM. The equilibrium pressure is governed by Henry&#39;s law which states that at a constant temperature, the amount of a given gas that dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid. At equilibrium, the amount of CO 2  dissolved in the beverage is equal to the amount of CO 2  released from the beverage. When the pressure surrounding the beverage sinks, e.g. by opening a sealed beverage container, the beverage will start releasing more CO 2  than is being dissolved. On the contrary, when the pressure in the head space is increased, e.g. by increasing the amount of gas in the head space without increasing the volume of the head space, CO 2  will be dissolved in the beverage until a new equilibrium pressure is achieved. 
         [0029]    A short theoretical explanation of the scientific work leading to the present invention will now follow together with the inventors&#39; current views of the physical effects involved, however, the theoretical explanations must not in any way be construed as limiting the present invention to these explanations. 
         [0030]    According to the LaPlace bubble theory, the pressure is derived according to the equation P=(2*G)/r, wherein P is the pressure in the bubble, G being gamma is the surface tension of the beverage and r is the radius of the bubble. Below a certain radius, the surface tension will pull the bubble to be even smaller and finally the bubble will disappear. The limit for beer is about r=0.1 um (100 nm) or less. In case the radius is smaller, the bubble will collapse and disappear. However, the inventors have found out that there is still some amount of elasticity in the beverage. dV/dP at constant T is around 0.001/bar or 0.1% per bar. The elasticity may be explained by bubbles still remaining in the beer, despite the LaPlace collapse. 
         [0031]    Beer is not a pure solution or a pure liquid but contains insoluble species such as fatty acids and possibly insoluble proteins. The insoluble species are hydrophobic and tend to form aggregates with themselves (micelles). Given the opportunity, the hydrophobic molecules tend to reside in a thermodynamically favourable surface layer in which the molecule can orient itself so that most of the molecule will be located within the bubble and not adjacent the liquid. 
         [0032]    The pH in beer is around 4.3, so the hydrophobic species, (fatty acids) are in the form of fully protonated acids, i.e. fully hydrophobic. They will at a certain pressure form a monolayer, which will not allow the bubble wall to be compressed further. A bubble thus stabilised will not collapse to zero. At a certain higher pressure the hydrophobic species may form a double layer, creating a new higher pressure plateau. Now a third layer of hydrophobic species may form and so on. The bubble itself comprises CO 2  and some water vapour. CO 2  is a linear symmetric stiff non-polar neutral molecule which can mingle in between the fatty acids in the wall. 
         [0033]    The inventors have surprisingly found out that beer and some other carbonated beverages contain 3 “kinds” or guises of CO 2 , the first “kind” or guise of CO 2  being the above described, dissolved and partially dissociated CO 2  in accordance with Henry&#39;s law, the second “kind” or guise of CO 2  being the more complex physical dispersion of bubbles elucidated above, representing the ordinary gas inside the bubble which is responsible for the elasticity and the third “kind” or guise of CO 2  being the much more densely packed CO 2  in the bubble wall. 
         [0034]    The CO 2  in the bubble wall may very rapidly (fraction of a microsecond) migrate into the CO 2  gas inside the bubble. An “instantaneous” pressure increase of about 2 bar may be observed when dropping a PET bottle containing beer from one meter onto a concrete floor. Still, even so, the bubbles are invisible, i.e. there is no visible diffraction of even violet visible light, indicating that the bubble size must be less than the Abbe limit. The Abbe limit stipulates that the limits of visible light which may be observed by a microscope is ¼ of the wavelength of the light. The human eye can only see the octave from 400 to 800 nm, thus the Abbe limit for humans is 100 nm. 
         [0035]    Thus the size of the bubbles before the expansion (the drop) must be smaller than 50 nm, such as smaller than 40 nm and most likely about 10 nm in diameter. This implies that beer may, at least theoretically, contain 10E21 bubbles per litre. 
         [0036]    According to the realization, in case the beer is compressed, the size of the bubbles will be reduced, such as from aforementioned 50 nm or 10 nm to something like 25 nm or 5 nm. The inventors have surprisingly found out that applying an isostatic compression of beer, which already was at equilibrium pressure, thereby achieving a super equilibrium pressure, results in a profound influence on the taste. The taste gets sweeter, milder less prickling on the tongue. The inventors have determined that the sweeter taste is due to the spherical smaller bubbles. The taste effect is verified for both beers and colas produced by the applicant company. 
         [0037]    In the present context it should be noted that beverage dispensing at pressures significantly above the equilibrium pressure is not suitable because of the increased velocity of the beverage when leaving the beverage container. 
         [0038]    The insoluble or hydrophobic constituents are generally in the form of fully protonated acids such as fatty acids or hydrophobic proteins. The insoluble or hydrophobic constituents may be in molecular form within the beverage, however, they are typically forming aggregates of several substantially identical acids, so-called micelles. The bubbles may have a spherical shape or similar such as elipsoidic shape. The major dimension of the ultra fine bubbles should be understood to be a straight line in-between the two points on the bubble surface which is furthest apart. 
         [0039]    It has been surprisingly found out that by subjecting the carbonated beverage to an external isostatic pressure of at least 1.0 bar exceeding the equilibrium pressure of the beverage, ultra fine bubbles are generated, i.e. produced and maintained, or provided, in an amount exceeding 10 10  ultra fine bubbles per millilitre of beverage. External isostatic pressure should in the present context be understood as a pressure applied. The pressure should thus be applied as a force acting on the outside of the beverage container in an inwardly direction, i.e. squeezing the beverage container. It should thereby not be understood to encompass a gas pressure, such as a carbon dioxide gas pressure, which is applied directly onto the beverage surface, since such pressure would influence the CO 2  pressure equilibrium such that more carbon dioxide is dissolved in the beverage resulting in a sour and prickling effect during drinking. Further, the expression ‘external isostatic pressure’ should not necessarily be construed to mean an evenly applied force onto the beverage container, since even though the force is applied at specific locations on the outside of the beverage container, due to the fact that the beverage is constricted within the beverage container, the pressure will be evenly applied onto the beverage via the beverage container. 
         [0040]    The above object, the above features and the above advantage together with numerous other objects, advantages and features, which will be evident from the below detailed description of the present invention, are according to a second aspect of the present invention obtained by a beverage including:
       dissolved and partially dissociated carbon dioxide present in an amount of 2-10 g/litre, such as 3-8 g/litre, preferably 4-6 g/litre, most preferably about 5.5 g/litre and establishing an equilibrium pressure at 10° C. of 0.5-3 bar above atmospheric pressure, and   a water insoluble or hydrophobic constituent present in molecular form or in molecular aggregated form and having established ultra fine bubbles including gaseous carbon dioxide, the ultra fine bubbles being present in an amount exceeding 10 10  ultra fine bubbles per millilitre, such as 10 12 -10 18  ultra fine bubbles per millilitre, preferably 10 15 -10 17  ultra fine bubbles per millilitre, most preferably about 10 16  ultra fine bubbles per millilitre, the ultra fine bubbles having a major dimension smaller than 100 nm, such as 20-60 nm, preferably about 40 nm.       
 
         [0043]    The beverage according to the second aspect of the invention is identical to the beverage according to the first aspect of the invention, except that the beverage according to the second aspect of the invention has been subjected to the above mentioned isostatic pressure which has caused the above mentioned ultra fine bubbles to generate. It has been surprisingly found out that a majority of the ultra fine bubbles may remain stable for an extended period of time, such as one month or even two months. The beverage thus includes three guises of CO 2 , the well known dissolved and partially dissociated CO 2 , the ordinary CO 2  gas within the bubble and the more densely packed CO 2  in the bubble wall. 
         [0044]    The ultra fine bubbles will include carbon dioxide and some water vapour. The ultra fine bubbles will remain stable due to the fact that the insoluble or hydrophobic constituents, due to thermodynamic effects, will tend to reside at the bubble surface layer, in which the constituents may orient themselves such that a majority of the individual molecules making up the constituents may be outside of the liquid phase, i.e. located within the bubble. The insoluble or hydrophobic constituents will at a certain pressure form a monolayer, which will help stabilize the bubble and prevent it from collapsing. 
         [0045]    The carbon dioxide in the bubble surface will be much more densely packed than the carbon dioxide within the bubble. However, the carbon dioxide in the bubble surface may rapidly migrate into the bubble in case the beverage is subjected to a shock, i.e. by dropping the beverage onto a hard surface. This explains the sudden pressure increase experiences after dropping a beverage bottle onto a concrete surface. 
         [0046]    Since the ultra fine bubbles are smaller than the Abbe limit, the ultra fine bubbles are invisible, i.e. there is no visible diffraction of even violet visible light. The Abbe limit is given as |Y|=0.82λ/(n sin (θ)), in which |Y| is the smallest distance two particles can have in order to be individually distinguishable, λ is the wavelength, n is the refractive index (in water close to 1.33) and sin (θ) is the viewing angle The resulting minimum bubble size in an aqueous substance which may be visually observed using a good microscope is thus about 80 nm. 
         [0047]    The beverage according to the second aspect of the present invention will taste milder and sweeter due to the ultra fine bubbles. Tests have shown that such beverage may be enjoyed at significantly higher temperatures compared to the same beverage without or with less ultra fine bubbles. Thus, a carbonated beverage intended to be served at 5° C. may now be served at 10° C. which will result in reduced costs for cooling beverages. 
         [0048]    According to a further embodiment, the beverage has a compressibility in the range between 10 −4  bar −1  and 10 −2  bar −1 , preferably between 5*10 −4  bar −1  and 5*10 −3  bar −1 , such as about 10 −3  bar −1 . Beverage includes a majority of water which is essentially non-compressible having a compressibility not exceeding the magnitude of 10 −5  bar −1 . Other constituents of the beverage is either present in very small quantities or are equally non-compressible. The beverage including ultra fine bubbles will have a larger compressibility due to the ultra fine bubbles which include carbon dioxide which is compressible. The compressibility may be used as a test for determining the amount of ultra fine bubbles present in the beverage, since the more ultra fine bubbles present in the beverage, the greater the compressibility of the beverage. 
         [0049]    According to a further embodiment, the water insoluble or hydrophobic constituent comprises oily substances, fatty acids or proteins, which are either originally present in the beverage or alternatively added to the beverage. The insoluble or hydrophobic constituents are typically present naturally in the beverage as a result of the beverage production, e.g. the brewing process. Alternatively, or in order to enhance the effect of the already present insoluble or hydrophobic constituents, additional insoluble or hydrophobic constituents may be added to the beverage after production. The insoluble or hydrophobic constituents may e.g. constitute nutrients. They may also add or alter the flavour of the beverage. 
         [0050]    The above object, the above features and the above advantage together with numerous other objects, advantages and features, which will be evident from the below detailed description of the present invention, are according to a third aspect of the present invention obtained by a beverage container including a beverage according to any of the first and second aspects, the beverage container defining a beverage space and a head space, the head space defining no more than 5.0%, preferably no more than 2.0% and more preferably no more than 1.5%, of the internal volume of the beverage container. The beverage either according to the first aspect or the second aspect is typically shipped within a sealed and essentially airtight beverage container. The head space typically contains carbon dioxide. In order to prevent additional gas from being dissolved into the beverage when increasing the external pressure, the head space should be kept as small as possible, i.e. no more than 2.0% of the total volume of the beverage container when the beverage container is filled by beverage. In this way, only a small amount of carbon dioxide may dissolve into the beverage. The head space is defined as the gaseous space in direct contact with the beverage. 
         [0051]    According to a further embodiment, the beverage container is adapted to expose the beverage to an external isostatic pressure exceeding the equilibrium pressure of the beverage by at least 1.2 bar, preferably 1.2-60 bar, more preferably 1.5-10 bar, most preferably about 2 bar. The beverage according to the first aspect may in principle be shipped in any airtight container, which has a shelf life of typically one year or more. The beverage according to the second aspect will only have a shelf life of about 2 months, since the ultra fine bubbles have a typical half life in the range of some months. The beverage according to the second aspect may thus preferably be shipped in a specially adapted beverage container which is capable of maintaining the external isostatic pressure during transport and storage in order to maintain the amount of ultra fine bubbles essentially unchanged and thereby prolong the shelf life of the product. It is contemplated that an external pressure of at least 1.2 bar exceeding the equilibrium pressure will ensure the preservation of a sufficient amount of ultra fine bubbles in order to have the desired positive taste effect several months after production of the beverage. It is contemplated that for safety reasons the external pressure should not exceed 60 bar above the equilibrium pressure of the beverage. 
         [0052]    According to a further embodiment, the beverage container is made of a flexible material and the external isostatic pressure is applied outside the beverage container. The container is typically a bottle or can made of thin material, which may be compressed when subjected to the external isostatic pressure. 
         [0053]    According to a further embodiment, the beverage container defines a radial dimension and an axial dimension, the external isostatic pressure is applied as a pressure force in the radial dimension and/or in the axial dimension. The external pressure may e.g. be applied by clamping the beverage container. The clamping may be removed by the user just prior to consumption of the beverage. 
         [0054]    According to a further embodiment, a container assembly is provided including a beverage container and an outer container completely encapsulating the beverage container and defining a space in-between the beverage container and the outer container, the space being filled by a gas, the gas subjecting the beverage container to the external isostatic pressure. In a preferred embodiment, a so-called double container is used in which the flexible container is enclosed by a pressure tight outer container, which may or may not be flexible. The external container is pressurised in order to subject the beverage container to the external isostatic pressure. The external container may be de-pressurized immediately prior to consumption of the beverage. Preferably, the openings of the beverage container and the outer container, respectively, are connected such that the pressure in the outer container is released when the beverage container is opened. 
         [0055]    According to a further embodiment, the external isostatic pressure is applied as a mechanical pressure within the beverage container. The external isostatic pressure may e.g. be applied by means of a spring, which is included inside the beverage container and which may contract the beverage container or otherwise apply an isostatic pressure onto the beverage. 
         [0056]    According to a further embodiment, the beverage container includes a lid, the lid subjecting the beverage to the isostatic pressure. Alternatively, the lid may include a pressurized balloon or spring, which applies the isostatic pressure onto the beverage. By removing the lid, the isostatic pressure is released. This embodiment has the advantage that the lid may be made tamper-proof, i.e. any opening of the lid will be immediately visible since it may be impossible or at least difficult to re-apply the lid or at least the pressure when the lid has been opened. 
         [0057]    According to a further embodiment, the lid includes a flexible pouch initially including expanding agents for producing the isostatic pressure. The expanding agent may e.g. include citric acid and bicarbonate included in a flexible pouch, e.g. a plastic pouch. The flexible pouch is included in the beverage container and the citric acid and bicarbonate are mixed when the beverage container is capped, thereby causing the generation or gas for pressurizing the pouch, which in turn applies the isostatic pressure on the beverage. 
         [0058]    According to a further embodiment, the beverage container comprises plastics or metal. Plastic and metal are both materials which may be made both flexible and essentially pressure- and air-tight. 
         [0059]    The above object, the above features and the above advantage together with numerous other objects, advantages and features, which will be evident from the below detailed description of the present invention, are according to a fourth aspect of the present invention obtained by a method of improving the taste of a beverage, the method comprising:
       providing a beverage including:
           dissolved and partially dissociated carbon dioxide present in an amount of 2-10 g/litre, such as 3-8 g/litre, preferably 4-6 g/litre, most preferably about 5.5 g/litre and establishing an equilibrium pressure at 10° C. of 0.5-3 bar above atmospheric pressure, such as 1-2 bar, preferably about 1.5 bar, and   a water insoluble or hydrophobic constituent present in molecular form or in molecular aggregated form and in an amount capable of generating ultra fine bubbles including gaseous carbon dioxide, the ultra fine bubbles being present in an amount exceeding 10 10  ultra fine bubbles per millilitre, such as 10 12 -10 18  ultra fine bubbles per millilitre, preferably 10 15 -10 17  ultra fine bubbles per millilitre, most preferably about 10 18  ultra fine bubbles per millilitre, when the beverage is exposed to an external isostatic pressure exceeding the equilibrium pressure of the beverage by at least 1.0 bar, preferably 1.2-60 bar, more preferably 1.5-10 bar, most preferably about 2 bar, the ultra fine bubbles having a major dimension smaller than 100 nm, such as 20-60 nm, preferably about 40 nm, and,   subjecting the beverage to an external isostatic pressure exceeding the equilibrium pressure of the beverage by at least 1.0 bar, preferably 1.2-60 bar, more preferably 1.5-10 bar, most preferably about 2 bar.   
               
 
         [0064]    The method according to the fourth aspect of the present invention may be used for producing a beverage according to the second aspect from a beverage according to the first aspect. The method may be applied in the brewery, i.e. immediately after the beverage has been produced and before the beverage is packed. Alternatively, the method is applied during dispensing of beverage from a beverage dispensing system. 
         [0065]    The above object, the above features and the above advantage together with numerous other objects, advantages and features, which will be evident from the below detailed description of the present invention, are according to a fifth aspect of the present invention obtained by a beverage production plant or beverage treatment assembly for improving the taste of a beverage, the beverage production plant or beverage treatment assembly including:
       a vessel or beverage supply tube for accommodating a beverage, the beverage comprising:
           dissolved and partially dissociated carbon dioxide present in an amount of 2-10 g/litre, such as 3-8 g/litre, preferably 4-6 g/litre, most preferably about 5.5 g/litre and establishing an equilibrium pressure at 10° C. of 0.5-3 bar above atmospheric pressure, such as 1-2 bar, preferably about 1.5 bar, and   a water insoluble or hydrophobic constituent present in molecular form or in molecular aggregated form and in an amount capable of generating ultra fine bubbles including gaseous carbon dioxide, the ultra fine bubbles being present in an amount exceeding 10 10  ultra fine bubbles per millilitre, such as 10 12 -10 18  ultra fine bubbles per millilitre, preferably 10 15 -10 17  ultra fine bubbles per millilitre, most preferably about 10 16  ultra fine bubbles per millilitre, when the beverage is exposed to an external isostatic pressure exceeding the equilibrium pressure of the beverage by at least 1.0 bar, preferably 1.2-60 bar, more preferably 1.5-10 bar, most preferably about 2 bar, the ultra fine bubbles having a major dimension smaller than 100 nm, such as 20-60 nm, preferably about 40 nm, and   
           a pressure generating device capable of subjecting the beverage to an external isostatic pressure exceeding the equilibrium pressure of the beverage by at least 1.2 bar, preferably 1.0-60 bar, more preferably 1.5-10 bar, most preferably about 2 bar.       
 
         [0070]    The beverage production plant or beverage treatment assembly according to the fifth aspect of the present invention may be used for carrying out the method according to the fourth aspect. The production plant may be used in the brewery, i.e. immediately after the beverage has been produced and before the beverage is packed. Alternatively, the production plant is supplied as an accessory or upgrade to a beverage dispensing system. The external isostatic pressure may either be applied while storing the beverage in a vessel such as a large keg or alternatively in a continuous process when the beverage is transported in a flexible beverage tube. The external isostatic pressure should be applied constantly and should not be used in order to dispense the beverage from the vessel or tube. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0071]      FIGS. 1A-1C  illustrate various beverage containers according to the present invention. 
           [0072]      FIGS. 2A-2E  illustrate the production of a beverage container according to the present invention. 
           [0073]      FIGS. 3A-3E  illustrate an alternative mode of producing a beverage container according to the present invention. 
           [0074]      FIGS. 4 ,  4 A, and  4 B illustrate the opening of a beverage container made of glass and having a metal cap according to the present invention. 
           [0075]      FIGS. 5 ,  5 A, and  5 B illustrate the opening of a plastic beverage container according to the present invention. 
           [0076]      FIGS. 6 ,  6 A and  6 B illustrate the opening of a metal beverage container according to the present invention. 
           [0077]      FIGS. 7 ,  7 A, and  7 B illustrate the opening of an beverage container having a twist off cap according to the present invention. 
           [0078]      FIGS. 8A-8C  illustrate a multipack comprising seven beverage containers. 
           [0079]      FIG. 9  illustrates a refrigerator for storing a plurality of beverage containers made of metal. 
           [0080]      FIG. 10  illustrates another multipack comprising six beverage containers. 
           [0081]      FIGS. 11A-11G  illustrate a bag-in-bottle beverage container according to the present invention. 
           [0082]      FIGS. 12A-12H  illustrate a delaminated beverage container according to the present invention. 
           [0083]      FIG. 13  illustrates a beverage dispensing system for dispensing beverage according to the present invention. 
           [0084]      FIG. 14  illustrates a further beverage dispensing system for dispensing beverage according to the present invention. 
           [0085]      FIG. 15  illustrates yet a further beverage dispensing system for dispensing beverage according to the present invention. 
           [0086]      FIG. 16  illustrates a beverage production plant for producing beverage according to the present invention, and 
           [0087]      FIG. 17  illustrates an empirically derived curve describing the ultra fine bubble generation and collapse over time. 
       
    
    
     DETAILED DESCRIPTION 
       [0088]    The below detailed description discloses various specific embodiments according to the present invention for the generation and maintenance of ultra fine bubbles in carbonated beverages. 
         [0089]      FIG. 1A  shows a first embodiment of a self pressurized beverage container  10  filled by beverage  20  according to the present invention. The beverage container  10  comprises a cylindrical wall  12  and a circular bottom  14  being made of glass or plastics. The beverage container  10  has a metal cap  16 . The cap  16  includes a pouch  18  made of flexible material such as plastics or rubber and oriented towards the interior of the beverage container  10 . The pouch  18  is separated from the beverage  20  and is pressurized by gas. The pouch  18  applies, together with the wall  12  and the bottom  14 , an isostatic pressure onto a beverage  20  stored within the container  10 . The beverage may be any carbonated beverage as described above including the above mentioned insoluble or hydrophobic constituents. The isostatic pressure applied by the pouch  18  on to the beverage  20  is at least 1 bar above the equilibrium pressure of the beverage  20 . The beverage  20  has an equilibrium pressure at 10° C. of about 0.5-3 bar, corresponding to an amount of dissolved and partially dissociated carbon dioxide of about 5.5 g/litre and establishing an equilibrium pressure at 10° C. of about 1.5 bar. The carbonated beverage  20 , being e.g. a beer, champagne, tonic, cola or similar beverages, is further including a water insoluble or hydrophobic constituent, which may be a fatty acid. The insoluble or hydrophobic constituent may be naturally present in the beverage or provided as an additive and may e.g. constitute a nutrient or flavour to the beverage or may be a flavorless additive. The insoluble or hydrophobic constituent in combination with the carbon dioxide and the external isostatic pressure applied by the pouch  18  allow the beverage  20  to generate and maintain a substantial amount of ultra fine bubbles including gaseous carbon dioxide. The ultra fine bubbles have a major dimension of about 40 nm and are therefore invisible and the number of ultra fine bubbles present in the beverage amounts to about 10 16  ultra fine bubbles per millilitre. 
         [0090]      FIG. 1B  shows a beverage container  10 ′ according to the present invention. The beverage container  10 ′ comprises a flexible aluminium can having a cylindrical wall  12 ′, a circular bottom  14 ′ and a cylindrical cap  16 ′. The beverage container  10 ′ is filled with carbonated beverage (not shown) similar to the embodiment shown in  FIG. 1A . The present beverage container has no pressurized pouch as described above in connection with the previous embodiment, but instead the cylindrical wall  12 ′ is surrounded by bars  22  extending in the longitudinal direction along the outer surface of the cylindrical wall  12 ′. The bars  22  are made of metal or alternatively rigid plastics. The bars  22  are configured to apply a substantially uniform radial pressure onto the cylindrical wall  12 ′. The bars  22  are joined together by straps  24 , which are clamped together at high strain by the use of a clamping mechanism  26 . The aluminium can  12 ′ may optionally also be clamped in the longitudinal direction by applying further straps and a clamping mechanism between the cap  16 ′ and the bottom  14 ′. The beverage container  10 ′ remains clamped during transport and storage. The total mechanical pressure applied to the beverage container  10 ′ results in an external pressure on the beverage of at least 1 bar above the equilibrium pressure of the carbonated beverage (not shown) included in the beverage container  10 ′. Other similar arrangements e.g. shrink-wrapping of the beverage container or an internal clamping mechanism capable of contracting the beverage container may be contemplated for achieving similar result. It is understood that the clamping mechanism should be removed before opening the container in order to avoid spillage. 
         [0091]      FIG. 1C  shows a beverage container  10 ″ according to the present invention. The beverage container  10 ″ comprises a cylindrical wall  12 ″ and a circular bottom  14 ″ being made of flexible plastic material. The beverage container  10 ″ has a cap  16 ″ made of rigid plastics. The beverage container  10 ″ is filled with carbonated beverage  20  similar to the embodiment shown in  FIG. 1A . The beverage container  10 ″ does not have a pressurized pouch but is surrounded by an outer container  28  made of plastics. The outer container  28  is pressurized at 1 bar or more above the equilibrium pressure of the beverage  20 , thereby applying an external isostatic pressure onto the beverage  20 . When the beverage  20  is about to be consumed, the pressure is released from the outer container  28 , the beverage container  10 ″ is removed from the outer container  28  and the cap  16 ″ is removed. 
         [0092]      FIG. 2A  shows the filling of a beverage container  10  as described in connection with  FIG. 1A . The beverage container  10  is filled by introducing a filling pipe  30  into the beverage container  10  and introducing the carbonated beverage  20 . About 1.5% of the volume of the beverage container  10  should be constituted by head space and the remaining about 98.5% of the volume should be filled by beverage  20 . The beverage filling typically takes place at low temperature just above freezing temperature and within a carbon dioxide atmosphere in order to achieve a suitable level of carbon dioxide within the beverage container  10 . 
         [0093]      FIGS. 2B and 2C  show the beverage container  10  when it has been filled and capped but prior to pasteurization. In the close-up view, the cap  16  is shown in detail. The cap  16  includes the pouch  18 , which is oriented towards the beverage  20  and is a part of the sealing between the cap  16  and the cylindrical wall  12  of the beverage container  10 . The pouch  18  is shown in contracted state and includes expanding agents  32  capable of generating pressurizing gas such as e.g. solid carbon dioxide or alternatively foaming material. 
         [0094]      FIGS. 2D and 2E  show the beverage container  10  during pasteurization. The beverage container  10  is thus located within a pasteurization plant  34 . The heat from pasteurization is thereby used as initiator for causing the expanding agents  32  to generate pressurized gas. The pouch  18  is thereby inflated and subjects the beverage  20  to the external isostatic pressure described above. 
         [0095]      FIG. 3A  shows the filling of a slightly modified beverage container  10  as described in connection with  FIG. 1A . The beverage container  10  is filled by introducing a filling pipe  30  into the beverage container  10  and introducing the carbonated beverage  20  similar to  FIG. 2A . 
         [0096]      FIGS. 3B and 3C  show the beverage container  10  when it has been filled and capped but prior to pasteurization. In the close-up view, the cap  16  is shown in detail. The cap  16  includes an alternative pouch  18 ′, which is oriented towards the beverage  20  and is a part of the sealing between the cap  16  and the cylindrical wall  12  of the beverage container  10 . The pouch  18  is shown in contracted state and includes a pressurization device  36  including expanding agents. The pressurization device  36  includes a first chamber including a first reactant  38  and a second chamber including a second reactant  40 . The reactants are separated by a rupturable membrane  42 . The second chamber further includes a piercing device oriented towards the rupturable membrane  42 . The first reactant  38  may e.g. constitute citric acid and the second reactant  40  may e.g. constitute bicarbonate. 
         [0097]      FIGS. 3D and 3E  show the beverage container  10  during pasteurization. The beverage container  10  is thus located within a pasteurization plant  34 . The pressure from pasteurization is thereby used as initiator for causing the piercing device  44  to rupture the rupturable membrane  42 , thereby allowing the first and second reactants  38 ,  40  to mix and generate pressurization gas such as carbon dioxide for pressurizing the pouch  18  and thereby apply the external isostatic pressure onto the beverage  20 . 
         [0098]      FIGS. 4 and 4A  show the upper part of the cylindrical wall  12  and the cap  16  of the glass beverage container  10 . The metal cap  16  is clamped around a mouth  46  located at the end of the cylindrical wall  12  of the beverage container  10 . The pouch  18  is part of the sealing between the cap  16  and the mouth  46 . 
         [0099]      FIG. 4B  shows the upper part of the cylindrical wall  12  and the cap  16  of the beverage container  10 . When the beverage container  10  is to be opened, the cap  16  is bent upwardly by the use of a generally known bottle opener. When doing so, the sealing between the mouth  46  and the cap  16  is broken and at the same time the pouch  18  is opened and the pressurized gas located therein is released before any beverage  20  is allowed to escape. The release of the pressure causes the pouch  18  to deflate and the pouch  18  is removed together with the cap  16 . 
         [0100]      FIGS. 5 and 5A  show shows the upper part of the cylindrical wall  12 ′″ and the cap  16 ′″ of a plastic beverage container  10 ′″ being similar to the previous embodiment; however, the threaded plastic cap  16 ′″ is screwed around a threaded mouth  46 ′ located at the end of the cylindrical wall  12 ′ of the beverage container  10 ′″. The pouch  18  is part of the sealing between the cap  16 ′ and the mouth  46 ′. 
         [0101]      FIG. 5B  shows the upper part of the cylindrical wall  12 ′″ and the cap  16 ′″ of the beverage container  10 ′″. When the beverage container  10 ′″ is to be opened, the cap  16 ′″ is turned. When doing so, the sealing between the mouth  46 ′ and the cap  16  is broken and at the same time the pouch  18  is opened and the pressurized gas located in the pouch  18  is released via the generally available depressurization slits of common screw bottles before any beverage  20  is allowed to escape. The release of the pressure causes the pouch  18  to deflate and the pouch  18  is removed together with the cap  16 ′″. 
         [0102]      FIGS. 6 and 6A  show the upper part of the cylindrical wall  12   IV  and the cap  16   IV  of a beverage container  10   IV  being similar to the previous embodiment, however the beverage container  10   IV  constitutes a metal can and the cap  16   IV  includes a tab  48  for opening the beverage container  10   IV . The pouch  18  is part of the cap  16   IV . The pouch  18  is located adjacent the tab  48  and oriented towards the beverage  20 . 
         [0103]      FIG. 6B  shows the upper part of the cylindrical wall  12   IV  and the cap  16   IV  of the beverage container  10   IV . When the beverage container  10   IV  is to be opened, the tab  48  is operated in order to open the cap  16   IV  along a predetermined breaking line (not shown). The predetermined breaking line is arranged such that the resulting opening initially only allows access to the pouch  18  so that the pressurized gas located in the pouch  18  is released. By operating the tab  48  further, the opening widens such that the beverage may flow out. 
         [0104]      FIGS. 7 and 7A  show the upper part of the cylindrical wall  12   V  and the cap  16   V  of a beverage container  10   V  being similar to the embodiment shown in connection with  FIG. 5 , i.e. the threaded cap  16   V  is screwed around a threaded mouth  46 ″ located at the end of the cylindrical wall  12   V  of the beverage container  10   V . The pouch  18  is also part of the sealing between the cap  16   V  and the mouth  46 ″. However, the cylindrical walls  12   V  and the bottom  14   V  are both made of glass and the cap  16   V  is made of metal. This is generally known as a twist-off cap. 
         [0105]      FIG. 7B  shows the upper part of the cylindrical wall  12   V  and the cap  16   V  of the beverage container  10   V . When the beverage container  10   V  is to be opened, the cap  16   V  is twisted. When doing so, the sealing between the mouth  46 ″ and the cap  16   V  is broken and at the same time the pouch  18  is opened and the pressurized gas located in the pouch  18  is released before any beverage  20  is allowed to escape. The release of the pressure causes the pouch  18  to deflate and the pouch  18  is removed together with the cap  16   V . The deflated pouch will prevent the cap  16   V  from being replaced on the mouth  46 ″ and thus the present beverage container  10   V  is tamper-proof although the cap  16   V  as such may be left without any other traces of being opened. 
         [0106]      FIG. 8A  shows an exploded perspective view of a multipack  50  of seven flexible metal beverage containers  10   a - g  configured with one central beverage container  10   a , a spacer  52  enclosing the central beverage container  10 ′ and six beverage containers  10   b - g  distributed around the spacer  52 . The beverage containers  10   a - g  have no inherent pressurization devices. The six beverage containers  10   b - g  are joined together by a strap  24 ′, which is clamped together at high strain by the use of a clamping mechanism  26 ′. The flexible metal beverage containers  10   a - g  may optionally also be clamped in the longitudinal direction by applying further straps and a clamping mechanism between the caps and the bottoms of the flexible metal beverage containers  10   a - g . The multipack  50  remains intact during transport and storage. The total mechanical pressure force applied to each of the seven flexible metal beverage containers  10   a - g  results in an external pressure on the beverage of at least 1 bar above the equilibrium pressure of the carbonated beverage (not shown) included in the beverage containers  10   a - g . Other similar arrangements, e.g. shrink-wrapping of a multipack may be contemplated for achieving similar result. It is understood that the multipack  50  should be disassembled by releasing the clamping mechanism  26 ′ before opening one of the seven flexible metal beverage containers  10   a - g  in order to avoid spillage. It should be noted that flexible plastic bottles are equally feasible in the present context. 
         [0107]      FIG. 8B  is a side perspective view of the multipack  50  of  FIG. 8A . 
         [0108]      FIG. 8C  is a top view of the multipack  50  of  FIG. 8A . 
         [0109]      FIG. 9  shows a perspective view of a refrigerator  54 . The refrigerator  54  comprises a door  56 , which may be closed to form a hermetically sealed inner space  58 . The inner space  58  includes standard flexible beverage containers  10   a - g  in the form of metal cans, however, flexible plastic bottles are equally feasible. The cans or bottles are without any inherent pressurization devices such as pouches as described above. The inner space  58  may be pressurized to at least 1 bar above the equilibrium pressure of the carbonated beverage (not shown) included in the beverage containers  10   a - h  by means of an air compressor  60 . The inner space  58  may further be chilled to 10° C. or lower by means of a cooling device  62 . The door is secured by means of a lock  64 . When a user desires a beverage container  10   a - h , the user will press the “open” button  66  in order to decompress the inner chamber  58  after which the door  56  is automatically or manually opened. When the user has removed one or more of the beverage containers  10   a - h , the user closes the door  56  and pushes the “close” button  68  in order to re-pressurize the inner space  58  by means of the compressor  60 . The beverages are thus kept at a pressure condition, which favours the generation and maintenance of ultra fine bubbles. 
         [0110]      FIG. 10  shows another multipack  50 ′ comprising a pressure tight outer container  28 ′. The outer container  28 ′ defines an inner space  58 ′ including six standard flexible beverage containers  10   a - f . The multipack further comprises a removable lid  70  for closing off the inner space  58 ′ of the outer container  28 ′. The inner space  58 ′ of the outer container  28 ′ is pressurised during transport and storage to at least 1 bar above the equilibrium pressure of the carbonated beverage (not shown) included in the beverage containers  10   a - f . When a user desires a beverage, the user pulls a tab  48 ′ to remove the lid  70  to access the flexible beverage containers  10   a - f . By removing the lid  70 , the user at the same time depressurises the multipack, however, the ultra fine bubbles will remain within the unopened beverage containers  10   a - f  for a time period of about one month or more. 
         [0111]      FIG. 11A  shows the filling of a bag-in-bottle beverage container  10   VI . The beverage container  10   VI  comprises a cylindrical wall  12   VI , a circular bottom  12   VI  and a flexible pouch  18 ′ located within the cylindrical wall  12   VI  and the circular bottom  12   VI . The flexible pouch  18 ′ and the cylindrical wall  12   VI  are joined at a mouth  46 ′″ constituting the opening of the beverage container  10   VI . An expanding agent  32  is located between the pouch  18 ′ and the cylindrical wall  12   VI /circular bottom  12   VI . The beverage container  10  is filled by introducing a filling pipe  30  into the flexible pouch  18 ′ of the beverage container  10  through the mouth  46 ′″ situated at the upper portion of the cylindrical wall  12   VI  and the flexible pouch  18 ′ and introducing the carbonated beverage  20  similar to  FIG. 2A . 
         [0112]      FIG. 11B  shows the capping of the bag-in-bottle beverage container  10   VI . After filling, a cap  16   VI  is applied onto the mouth  46 ′″ sealing off both the flexible pouch  18 ′ and the expanding agent  32 . 
         [0113]      FIG. 11C  shows the pasteurization of the beverage container  10   VI . During pasteurization, the expanding agent  32  will initiate due to the heat produced by the pasteurization and form pressurized gas, which will subject the flexible pouch  18 ′ to a pressure of at least 1 bar above the equilibrium pressure of the carbonated beverage  20  included in the pouch  18 ′. The head space within the pouch  18 ′ will thereby be reduced and the pouch  18 ′ will be slightly compressed. 
         [0114]      FIGS. 11D and 11E  show the beverage container  10   VI  when closed off by the cap  16   VI . As can be seen from the close-up view, a seal  72  of the cap  16   VI  seals off both the pouch  18 ′ and the cylindrical wall  12   VI  at the mouth  46 ′″. A small gap  74  is present between the pouch  18 ′ and the cylindrical wall  12   VI  at the mouth  46 ′″. 
         [0115]      FIGS. 11F and 11G  show shows the beverage container  10   VI  when being opened. The mouth  46 ′″ has an outer threading and the cap  16   VI  has an inner threading, thus the cap  16   VI  is removed by turning it in relation to the mouth  46 ′″. When the cap  16   VI  has been turned a specific distance, the seal  72  will separate from the mouth  46 ′″ such that the gas located between the pouch  18 ′ and the cylindrical wall  12   VI  may escape through the gap  74  and the depressurization slots located in the threading of the cap  16   VI  and the mouth  46 ′″, thus depressurising the pouch  18 ′ in order to avoid any spillage of beverage. When the cap  16   VI  has been completely removed, the user may enjoy the beverage. 
         [0116]      FIG. 12A  shows the filling of a delaminated beverage container  10   VII . The delaminated beverage container  10   VII  comprises a cylindrical wall  12   VII , a circular bottom  14   VII  and a delaminated flexible pouch  18 ″ located within the cylindrical wall  12   VII  and the circular bottom  14   VII . The flexible pouch  18 ″ and the cylindrical wall  12   VII  are joined at a mouth  46   IV  constituting the opening of the beverage container  10   VII  such that the flexible pouch  18 ″ is accessible via the mouth  46   IV . The space in-between the pouch  18 ″ and the cylindrical wall  12   VII  will only be accessible via a bore  76  extending through the cylindrical wall  12   VI  at the mouth  46   IV . The beverage container  10   VII  is filled by introducing a filling pipe  30  into the flexible pouch  18 ″ of the beverage container  10   VII  through the mouth  46   IV  situated at the upper portion of the cylindrical wall  12   VII  and the flexible pouch  18 ″ and introducing the carbonated beverage  20  similar to  FIG. 2A . 
         [0117]      FIG. 12B  shows the capping of the delaminated beverage container  10   VII . After filling, a cap  16   VII  is applied onto the mouth  46   IV  sealing off the flexible pouch  18 ″. 
         [0118]      FIG. 12C  shows the pressurization of the beverage container  10   VII . During pressurization, the beverage container  10   VII  is put into a pressure chamber  78 , thereby pressurized gas, such as air, having a pressure of at least 1 bar above the equilibrium pressure of the carbonated beverage  20  included in the pouch  18 ″ will enter the space in-between the pouch  18 ″ and the cylindrical wall  12   VII . The head space within the pouch  18 ″ will thereby be reduced and the pouch  18 ″ will be slightly compressed. 
         [0119]      FIG. 12D  shows the beverage container  10   VII  when a cover  80  is applied outside the cap  16   VII . The cover  80  seals the bore  76 . 
         [0120]      FIGS. 12E and 12F  show the beverage container  10   VII  when closed off by the cap  16   VII . As can be seen from the close-up view, the cap  16   VII  will not extend as far as to seal the bore  76 . The bore  76  is instead hermetically sealed by the cover  80  applied outside the cap  16   VII . The cover  80  may e.g. be shrink-wrapped onto the cap  16   VII . In an alternative embodiment, the cap  16   VII  may extend to seal off the bore  76  as well 
         [0121]      FIG. 12F  shows the beverage container  10   VII  when being opened. First of all, the cover  80  is removed such that the gas located between the pouch  18 ′ and the cylindrical wall  12   VI  may escape through the bore  76 , thus depressurising the pouch  18 ″ in order to avoid any spillage of beverage. The mouth  46   IV  has an outer threading and the cap  16   VII  has an inner threading, thus, secondly, the cap  16   VII  is removed by turning it in relation to the mouth  46 ′″. When the cap  16   VII  has been turned a specific distance, the seal  72  will separate from the mouth  46   IV . When the cap  16   VII  has been completely removed, the user may enjoy the beverage. 
         [0122]      FIG. 13  shows a beverage dispensing system  82  comprising a tap column  84  located on a bar counter  86 . The tap column  84  comprises a dispensing valve operated by a handle  88  for controlling the beverage dispensing. The dispensing valve of the tap column  84  is connected to a beverage treatment assembly  88  via a tapping line  90 . The beverage treatment assembly  88  comprises an outer vessel  92 . The tapping line  90  is connected to a flexible line part  94  extending within the vessel  92 . The flexible line part  94  is supplied with beverage from a steel keg  96  by a pump  98  and tapping line parts  90 ′ and  90 ″, all of which being located outside the beverage treatment assembly  88 . The vessel  92  may be pressurized to pressure of at least 1 bar above the equilibrium pressure of the carbonated beverage in the steel keg  96  by an air compressor  60 ′. The beverage is thus continuously during dispensing subjected to a pressure sufficient for generating ultra fine bubbles within the beverage. The tapping line may include a pressure reduction valve or constriction in order to avoid an excessive pressure within the tap column. The pump  98  may include a counter valve to avoid a reverse flow of beverage. 
         [0123]      FIG. 14  shows a beverage dispensing system  82 ′ similar to the beverage dispensing system  82  of the previous embodiment, however, differing in the layout of the treatment assembly. The treatment assembly  88 ′ of the beverage dispensing system  82 ′ includes a vessel  92 ′. The vessel  92 ′ includes a flexible bag  100 , which is connected to the tapping line  90 . The flexible bag  100  is supplied with beverage from a steel keg  96  by a pump  98 . The vessel  92  may be pressurized to pressure of at least 1 bar above the equilibrium pressure of the carbonated beverage in the steel keg  96  by an air compressor  60 ′. The beverage may thus be filled into the flexible bag  100  for treatment over an extended time period, e.g. from some minutes to several days, to a pressure sufficient for generating ultra fine bubbles within the beverage. 
         [0124]      FIG. 15  shows a beverage dispensing system  82 ″ similar to the beverage dispensing system  82 ′ of the previous embodiment, however, differing in the layout of the treatment assembly. The treatment assembly  88 ″ of the beverage dispensing system  82 ″ includes a vessel  92 ″. The vessel  92 ″ is connected to the tapping line  90 . The vessel  92 ″ is supplied with beverage from a steel keg  96  by a pump  98 . The vessel  92 ″ may be pressure filled with beverage to pressure of at least 1 bar above the equilibrium pressure of the carbonated beverage in the steel keg  96  by use of the pump  98 . The beverage should preferably be transferred completely from the steel keg  96  into the vessel  92 ″ for treatment over an extended time period, e.g. from some minutes to several days, to a pressure sufficient for generating ultra fine bubbles within the beverage. When the beverage has been treated, the beverage may be supplied to the tapping column  84  via a dispensing pump  102  operated via the handle  88 . 
         [0125]      FIG. 16  shows a beverage production plant  104  comprising a vessel  92 ″, a beverage inlet  108 , a filling pipe  30 ′ and a flexible line part  94 ′ extending within the vessel  92 ′″ between the beverage inlet  108  and the filling pipe  30 ′. The beverage inlet is connected directly to the output line of a production facility (not shown), in which a beverage having dissolved and partially dissociated carbon dioxide present in an amount of 2-10 g/litre and establishing an equilibrium pressure at 10° C. of 0.5-3 bar is produced. The beverage further includes a water insoluble or hydrophobic constituent present in molecular form or in molecular aggregated form. The vessel  92 ′″ further includes a pressure inlet for introducing a pressure of at least 1 bar above the equilibrium pressure of the carbonated beverage within the vessel  92 ′″ for continuously generating ultra fine bubbles including gaseous carbon dioxide. The filling pipe  30 ′ is part of a filling assembly in which continuous beverage containers  10   VIII  are filled with beverage. Experiments have shown that the ultra fine bubbles may remain within a capped beverage container at equilibrium pressure for at least one month. 
         [0126]      FIG. 17  shows an experimentally verified curve describing the ultra fine bubble generation and collapse over time. It is thereby shown that the generation of ultra fine bubbles when the beverage is subjected to an external isostatic pressure of 1 bar above the equilibrium pressure of the beverage defines a growth towards an equilibrium value (from time 0 to T in the plot), while the collapsing of the ultra fine bubbles when the beverage is subjected to a pressure equal to the pressure equilibrium of the beverage defines an exponential decay of about the second order (from T to t). It has been experimentally verified that the half life of the ultra fine bubbles is about one month at equilibrium pressure. 
         [0000]    
       
         
               
             
               
               
             
           
               
                   
               
               
                 LIST OF PARTS WITH REFERENCE TO THE FIGURES 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                  10. Beverage container 
               
               
                   
                  12. Wall 
               
               
                   
                  14. Bottom 
               
               
                   
                  16. Cap 
               
               
                   
                  18. Pouch 
               
               
                   
                  20. Beverage 
               
               
                   
                  22. Bars 
               
               
                   
                  24. Strap 
               
               
                   
                  26. Clamping mechanism 
               
               
                   
                  28. Outer container 
               
               
                   
                  30. Filling pipe 
               
               
                   
                  32. Expanding agents 
               
               
                   
                  34. Pasteurization plant 
               
               
                   
                  36. Pressurization device 
               
               
                   
                  38. First reactant 
               
               
                   
                  40. Second reactant 
               
               
                   
                  42. Rupturable membrane 
               
               
                   
                  44. Piercing device 
               
               
                   
                  46. Mouth 
               
               
                   
                  48. Tab 
               
               
                   
                  50. Multipack 
               
               
                   
                  52. Spacer 
               
               
                   
                  54. Refrigerator 
               
               
                   
                  56. Door 
               
               
                   
                  58. Inner space 
               
               
                   
                  60. Air Compressor 
               
               
                   
                  62. Cooling device 
               
               
                   
                  64. Lock 
               
               
                   
                  66. “Open” button 
               
               
                   
                  68. “Close” button 
               
               
                   
                  70. Lid 
               
               
                   
                  72. Seal 
               
               
                   
                  74. Gap 
               
               
                   
                  76. Bore 
               
               
                   
                  78. Pressure chamber 
               
               
                   
                  80. Cover 
               
               
                   
                  82. Beverage dispensing system 
               
               
                   
                  84. Tap column 
               
               
                   
                  86. Bar counter 
               
               
                   
                  88. Handle 
               
               
                   
                  90. Tapping line 
               
               
                   
                  92. Vessel 
               
               
                   
                  94. Flexible line part 
               
               
                   
                  96. Steel keg 
               
               
                   
                  98. Pump 
               
               
                   
                 100. Flexible bag 
               
               
                   
                 102. Dispensing pump 
               
               
                   
                 104. Beverage production plant 
               
               
                   
                 106. Pressure inlet 
               
               
                   
                 108. Beverage inlet