Abstract:
An apparatus for the storage and aging of wine that comprises of a disposable flexible bladder contained within a rigid support container. The flexible bladder has a fill/drain port connected to an internal dip tube that allows the bladder to be filled and emptied repeatedly without any contact with air. This allows the wine to remain fresh and unoxidized during storage and aging. The apparatus can be used in multiple support containers, such as barrels, IBCs, and tanks. The apparatus has no moving parts and uses disposable contact materials that eliminate washing and water usage. Single-use components ensure sanitary operation and this combined with the elimination of oxygen in contact with the wine produces consistently higher quality product.

Description:
FIELD 
     The disclosed embodiments relate to systems and methods for the storage and aging of wine. 
     BACKGROUND 
     Proper storage of wine has been a problem for hundreds of years. Containers used for storage range from amphorae in ancient times to wooden barrels and metal tanks in modern usage. When wine is exposed to air, compounds in the wine react with the oxygen in the air. These oxidized compounds substantially reduce and impair the quality of the wine. In the manufacture, and especially storage of wine, there is a continual need to prevent contact with air and hence reduce oxidation. This problem is particularly difficult to prevent in the conventional rigid barrels and tanks that are typically used for storage and aging. Due to sampling and evaporation, these containers are often partially full and the residual air in the headspace of the barrel or tank reacts with the remaining stored wine degrading it. Enormous effort is spent in wineries worldwide “topping” off these containers with fresh wine to keep them full to the brim. Wooden barrels have the additional problem that they are porous, and air can diffuse into the wine through the wood. In addition to the quality reduction due to oxidation, contact with air can also cause contaminating bacteria to grow, making the wine sour and undrinkable. This can lead to major loss and wastage. 
     Better methods for the storage of wine are essential because wine must often be stored for several years in order to develop characteristic flavors. It is essential during this aging process that the wine does not oxidize or spoil. 
     SUMMARY 
     Modern polymer materials have been developed that have low oxygen permeability. At least one disclosed embodiment uses these materials in a novel manner to provide an inexpensive apparatus for the storage and aging of wine that overcomes all the aforementioned problems. 
     The present disclosure relates to systems and methods for storage and aging of wine that minimizes contact with air during all operations with minimal operating labor and the elimination of wine required for “topping” off. The system provides a container that minimizes washing and waste water generation, yet is sanitary and does not introduce any contaminants such as bacteria or fungi into the stored wine. Finally, the apparatus must be easy to use and economical to operate. 
     Accordingly, disclosed embodiments may provide a flexible bladder comprising of an inert polymeric film that has very low oxygen permeability. This flexible bladder is placed inside a rigid container. This rigid container only serves to support the bladder and can be of any shape—vertical cylinder, cubic box, or horizontal barrel/drum. The material of construction of the rigid container is not important as the wine is contained inside the flexible bladder and does not contact the rigid container. The flexible bladder has a single fill/drain port. This port has two connections. One connection leads to a flexible tube inside the bladder that rests on the bottom of the bladder. This connection is used to fill wine into the bladder, and is also used to remove wine out of the bladder. The second connection is a vent that is used to exhaust air out of the bladder. 
     In operation, a new empty bladder may be placed inside the rigid container, and wine may be pumped in through the fill/drain port until a small amount of wine is seen coming out of the vent. This may indicate that the bladder is full of wine and that no air is present in the bladder. The vent is then closed. Wine may then be freely removed when necessary by pumping out of the fill/drain port. Unlike a barrel or tank, the bladder collapses as wine is withdrawn so there is no headspace where deleterious air could be introduced. Since the fill/drain port tube extends down to the bottom of the bladder, the entire contents can be pumped out without disturbing the bladder. This ensures that settled sediments are not re-suspended during sampling and removal. 
     In accordance with at least some embodiments, aging of wine includes development of a tannic flavor or “oaking.” This may be performed by introducing an appropriate type and quantity of wood staves into the bladder. Oaking may easily be terminated when desired by transferring the wine to another bladder not containing wood staves. In some instances, micro oxygenation has been found to impart characteristic flavors. 
     In accordance with at least some disclosed embodiments, the bladder containing the wine may be resistant to oxygen permeation, so a precise amount of desired oxygen can be introduced by simply sparging oxygen into the bladder. The bladder may be designed to be disposable and inexpensive. The single use bladder ensures cleanliness and avoids any cross-contamination. 
     The above description, as well as additional objects, features, and aspects of the disclosed embodiments, will be more fully appreciated by reference to the following detailed description, including the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the disclosed embodiments illustrating the bladder placed within a rigid support container. 
         FIG. 2  is a side sectional view of the bladder and support container shown in  FIG. 1 . 
         FIGS. 3A-3B  are side sectional view showing the operation of the invention during filling in  FIG. 3A  and removal of wine in  FIG. 3B . 
         FIG. 4  is a perspective view of at least one disclosed embodiment in a horizontal barrel or drum format. 
         FIG. 5  is a side sectional view of the bladder inside a pressurized drum full of inert gas. 
         FIG. 6  is a perspective view of at least one disclosed embodiment in a cubic box format. 
         FIG. 7  is a perspective view of at least one disclosed embodiment in vertical cylinder (tank) format. 
         FIG. 8  is a side sectional view of at least one disclosed embodiment showing a check valve to allow generated gases to vent without the possibility of air entering the bladder. 
     
    
    
     DETAILED DESCRIPTION 
     As discussed above, in operation, an empty bladder may be placed inside a rigid container, and wine may be pumped in through the fill/drain port until a small amount of wine is seen coming out of the vent. This may indicate that the bladder is full of wine and that no air is present in the bladder. The vent is then closed. Wine may then be freely removed when necessary by pumping out of the fill/drain port. Unlike a barrel or tank, the bladder collapses as wine is withdrawn so there is no headspace where deleterious air could be introduced. Since the fill/drain port tube extends down to the bottom of the bladder, the entire contents can be pumped out without disturbing the bladder. This ensures that settled sediments are not re-suspended during sampling and removal. 
     Referring to the drawings,  FIG. 1  is a perspective view of an embodiment showing a bladder  20  containing wine placed inside rigid container  10 . The bladder  20  may be attached via a connector  30  extending through an opening  8  the container  10  to a fill connector  32  and a vent  31 . Bladder  20  may be made of various suitable materials. The bladder must be flexible and not impart any flavors or color to the wine. Modern polymer materials have been developed that have low oxygen permeability. 
     In general, FDA materials approved for long term food contact may be used. The bladder material must also be inert to ethanol (up to 20% v/v). Multi-ply metalized films are preferred because of their very low oxygen permeability. Accordingly, the flexible bladder may be placed inside a rigid container. This rigid container only serves to support the bladder and can be of any shape—vertical cylinder, cubic box, or horizontal barrel/drum. The material of construction of the rigid container is not important as the wine is contained inside the flexible bladder and does not contact the rigid container. 
     The flexible bladder has a single fill/drain port. This port has two connections. One connection leads to a flexible tube inside the bladder that rests on the bottom of the bladder. This connection is used to fill wine into the bladder, and is also used to remove wine out of the bladder. The second connection is a vent that is used to exhaust air out of the bladder. 
     In more detail in  FIG. 2 , the flexible bladder  20  is placed inside the rigid support container  10 . The bladder has a fill/drain port  22 . This is a molded plastic port that is thermally welded to the bladder  20 . Port  22  has a female thread and is configured to be screwed on to a distal end of a mating connector  30  extending through opening  8  to make a gas and liquid tight connection between the inside of the fill/drain port  22  and connector  30 . In some embodiments, the connector  30  may be integrally formed in the rigid support container  10 . 
     Mating connector  30  is connected at a proximal end to a flange  45  by means of a clamp  24  and a gasket  25  creating a gas and liquid-tight connection. Flange  45  includes molded fill connector  32  and vent connector  33  extending away from connector  30 . Vent connector  33  is attached to a vent  31 . Fill connector  32  may be connected via threads  35  to an external wine source or a cap  50  to seal the fill connector  32  when not in use. Vent  31  may be a valve that can be opened and closed to provide provides venting of air from inside the bladder  20  to the atmosphere. 
     Flange  45  may also be connected to a flexible silicone rubber dip tube  40 . Dip tube  40  is connected to flange  45  by inserting it into the barbed fitting  46  located in flange  45 . A stainless steel weight  41  is connected to and extends around the other end of the rubber dip tube  40 . This weight  41  has perforations  42  to allow liquid, such as wine  11 , to enter dip tube  40  but prevent sediments on the bottom inside surface of the bladder  20  from being sucked out during removal of the stored wine. The rubber tube  40  is inserted into bladder  20 . The weighted end  41  ensures that the dip tube rests on the inside bottom of the bladder  20 . 
     In accordance with the disclosed embodiments, systems and methods for storage and aging of wine may minimize contact with air during all operations with minimal operating labor and the elimination of wine required for “topping” off. Thus, the system provides a container that minimizes washing and waste water generation, yet is sanitary and does not introduce any contaminants such as bacteria or fungi into the stored wine. Finally, the apparatus must be easy to use and economical to operate. 
       FIG. 3A  shows how bladder  20  is filled with wine  11  through port  22 . As the bladder fills, any air inside the bladder is expelled through the open vent valve  31 . Dip tube  40  ensures that liquid is not expelled until the bladder is completely full and which point liquid will escape out of the vent  31 . At this point, the filling is stopped and vent valve  31  closed to prevent any air from backflowing into the full bladder. In the case of a partially filled bladder, an aspirator (not shown) may be connected to the vent valve  31  and a vacuum applied to remove any air from inside the bladder. Here as before, once liquid is detected coming out of the vent, vent valve  31  is closed and the vacuum aspirator is removed. During transfer operations, it is possible for air to get entrained into the wine. It is also possible for dissolved gases to come out of solution. In all these cases, using the vacuum aspiration technique as described earlier will serve to remove any air or gases from the bladder, leaving only wine in the bladder with no deleterious air-wine interface. 
     When removing wine from the bladder as shown in  FIG. 3B , it is not necessary to open vent valve  31 . As wine is withdrawn using a pump, the bladder will simply collapse on itself. In this manner no headspace is generated and no air is introduced to degrade the wine. 
     The flexible bladder  20  and connector  30  system are able to be used in various rigid containers as seen in  FIGS. 4-7 .  FIG. 4  shows an example where the rigid container  10  is a barrel or drum. This type of container is common in wineries and suitable racks/shelving already exists. Unlike conventional barrels, however, the presently disclosed rigid support containers do not contact the wine and they may be made of stainless steel, wood, or any suitably rigid and strong material chosen mainly for esthetic purposes. 
     As seen in  FIG. 5 , a wine filled bladder  20  may be placed inside a stainless steel drum container  10 . Connector  30  may be integrally formed with the container  10  or may be sealed to opening  8  in drum to form an airtight seal using conventional sealants. While the bladder may be manufactured using low oxygen permeability plastic film (&lt;0.06 cc/100 in^2/day) a sealed outer drum container  10  may be used to reduce the possibility of oxidation over long storage periods. The drum container  10  is filled with inert gas (nitrogen or argon) using valve  60  in communication with the interior of the drum container  10  and maintained at a slight positive pressure (&gt;0.1 psig). Since the environment outside the bladder may be completely oxygen free, even the slight oxygen permeability of the plastic bladder may be of no concern and the wine remains entirely free of oxygen as long as the outer rigid container remains pressurized with inert gas. This would enable the wine to be stored without damage for many decades. 
     Another container that may be used with the bladder  20  is an intermediate bulk container  10  (IBC). These are commonly used for the transport and storage of liquids.  FIG. 6  shows an example where the rigid support container  10  is an IBC cubic box. Due to the design of the single top entering fill/drain port  22  with integral dip tube  40 , no expensive bottom discharge port is needed. All fill and drain operations are possible using the special fill/drain port  22  described in at least one disclosed embodiment. IBC containers  10  provide versatility as they can be moved around the winery using forklifts. Since the wine  11  does not contact the IBC container  10  itself, they can be made of cheaper non-food contact materials and they do not need to be washed, saving wash water and labor. Many IBC containers  10  are certified for truck shipment. Thus, wine in storage may be easily shipped for blending and bottling without the need to be transferred to another container. Eliminating these unnecessary transfer operations also reduces the possibility of deleterious air contact resulting in fresher and better quality wine. 
     A vertical open top cylindrical tank  80  may also be used as a rigid support container as shown in  FIG. 7 . This option is useful for wineries that have existing vertical metal storage tanks. With at least one disclosed embodiment, a bladder  20  and connector  30  can simply be placed inside an existing vertical open top tank  80  and all the benefits of wine storage and aging without air contact are immediately available. The bladder can be sampled and wine removed without the danger of introducing air into the headspace as would be the case when wine is stored directly inside a rigid tank. There is no need for “topping off”. In addition, as the wine now no longer contacts the metal tank walls directly, there is no need to wash the tank between batches. This reduces wash water usage, reduces cleaning labor, eliminates waster waste generation, and yet utilizes the existing installed tankage. The bladders are simply discarded after each use and the plastic itself can be recycled. 
       FIG. 8  is an embodiment of the assembly that can be used in fermentation. In certain types of wines, fermentation may continue during storage. This fermentation will generate gases that need to be vented to prevent the bladder from overpressure. In this situation, the vent valve  31  is left open as shown in  FIG. 8 . A check valve  65  is installed at the outlet of vent valve  31 . This check valve enables generated gases to escape from the bladder headspace  15 , but does not allow air from the outside environment to enter the bladder. This ensures that the bladder cannot overpressurize, but also ensures that air cannot enter to deteriorate the wine. 
     In some embodiments, aging of wine includes development of a tannic flavor or “oaking.” This may be performed by introducing an appropriate type and quantity of wood staves into the bladder. Oaking may easily be terminated when desired by transferring the wine to another bladder not containing wood staves. In some instances, micro oxygenation has been found to impart characteristic flavors. The bladder containing the wine is resistant to oxygen permeation, so a precise amount of desired oxygen can be introduced by simply sparging oxygen into the bladder, for example, through fill connector  32 . The bladder is designed to be disposable and inexpensive. The single use bladder ensures cleanliness and avoids any cross-contamination. 
     In accordance with at least one disclosed embodiment, a method of aging wine may include oaking. During oaking, staves may be introduced into the bladder through fill/drain port  22  ( FIG. 2 ) prior to filling the bladder with wine. The wine may be sampled frequently during the oaking period. When the winemaker determines that the oaking is complete, the wine can be simply transferred to another bladder that does not contain oak staves via perforations  42  in the dip tube  40  and application of a vacuum to the fill/drain port to remove the wine so that sediments in the wine are not re-suspended and wood staves and sediment are not transferred during removal. By using fresh staves in each batch, it is possible using the disclosed embodiments to get perfectly or substantially reproducible oaking of each batch of wine. Wood products such as oak chips, pellets, and powders can also be used instead of staves. The equivalent oaking characteristics of a cask can be easily determined by computing the ratio of surface area of the staves or chips to the volume of wine in the bladder. 
     Wines are often matured in oak casks as the wood imparts tannic flavors to the wine. These casks are very expensive and can only be used 3-5 times before the wood is no longer effective. At least one disclosed embodiment can produce the same oaking effect in a much more cost effective and reproducible manner as described above using oak staves (wood sections used to make casks). These staves can be made from different wood species and can be toasted to provide different oaking characteristics. 
     It has been postulated that certain wines requires minute levels of oxygenation during aging in order to develop characteristic flavors. This is a fine balance, as it is well established that excess oxygen will ruin the wine. In traditional practice, this micro oxygenation is the result of oxygen permeating through the wooden casks or barrels typically used for aging. These wooden barrels are quite unpredictable in their oxygen permeability and this leads to a hit or miss process. In at least one disclosed embodiment, all accidental sources of oxygen are minimized and controlled. Oxygen required for micro oxygenation can be introduced in precise and reproducible amounts. This can be done by calculating the oxygen required per unit volume and then sparging in a metered volume of air or oxygen based on the wine volume in the bladder. This is a reproducible and controllable method as this is the only exposure to oxygen in the process. 
     Traditional winemaking uses sodium metabisulfite to combat the oxidation of wine due to poor practices and archaic technology. It is used to suppress oxidation caused by unavoidable contact with air inherent in traditional winemaking. The sodium bisulfate neutralizes free oxygen that is introduced in the winemaking and aging process and helps keeps the wine fresher and last longer. However, the introduction of sulfite does result in a discernable sulfurous odor, and causes allergic reactions in many individuals. This has lead to the requirement for a government warning about the sulfite content of wine to be posted on every bottle of wine. With at least one disclosed embodiment, oxygen is eliminated in the entire storage and aging process. This minimizes or can even eliminate the need to add sulfites to “stabilize” the wine, leading to a healthier and better quality product. 
     Although described with respect to containing wine, the container and bladder system may be used with any fluid that is desired to be kept in an oxygen controlled environment. Though the disclosed embodiment has been described by way of a detailed description in which various embodiments and aspects of the invention have been described, it will be seen by one skilled in the art that the full scope of the invention is not limited to the examples presented herein.