Abstract:
A method and apparatus for dry hopping a beverage contained in a fermentation tank can include providing a hops vessel defining an interior space. The method can include adding hops to the interior space of the hops vessel, sealing the interior space of the hops vessel from ambient atmosphere, and propelling at least a portion of the hops from the interior space of the hops vessel into a supply hose, closing an exit port valve, and opening a bypass valve which is in fluid communication with a top portion of the hops vessel and the supply hose thereby propelling hops remaining in the supply hose into the fermentation tank.

Description:
LIST OF RELATED APPLICATIONS 
     This application and invention claims the priority benefit under 35 U.S.C. §119 of U.S. Provisional Patent Application No. 61/595,147 filed on Feb. 5, 2012, which is hereby incorporated in its entirety by reference. 
    
    
     BACKGROUND 
     1. Field 
     The presently disclosed subject matter relates to an apparatus, system and method for adding hops to a beverage, and more specifically relates to an apparatus, system and method for adding hops to a fermentation tank while preventing oxygen infiltration during a process for making a beverage, such as beer. 
     2. Description of the Related Art 
     Typically, the brewing process includes a series of sequential (and sometimes non-sequential) steps, which can include one or more of the following: malting, in which barley is converted to malt having a distinct flavor and containing a large amount of enzyme; milling, in which the malt is milled in order to make malt flour; mashing, in which the milled malt is mixed with water so as to form a mash; brewing the mash by applying a precise heating cycle to the mash while stirring; filtration, in which the mash is filtered in order to separate the wort (liquid containing the soluble matter dissolved in the water during the brewing) from the draff (insoluble matter); and cooking, in which the wort is subjected to heating/boiling, during which hops, which gives the beer its bitterness, can be added; fermentation, in which the wort is inoculated with a yeast of the Saccharomyces genus, which will, through fermentation, convert fermentable sugars to alcohol and to carbon dioxide; and standing, in which the beverage is stored at approximately 32° F./0° C. for a period which varies from a few days to a few weeks. The resulting beverage is a young beer, or ale, that can be filtered to remove the yeasts and any particulate residue or matter in suspension (precipitates of polyphenols, proteins, carbohydrates, etc.). The beer is then ready for tapping off, in which the beer is pasteurized and placed in barrels, bottles, growlers, cans, or alternative storage receptacles. 
     During some of the above processes, there is a risk of oxidation of the subject ingredients, thereby leading to a possibility of depreciated taste and/or freshness of the final product. For example, oxidation of the mash (the mixture of crushed malt and water) may occur at the time of brewing, oxidation of the wort may occur during the cooking step, and oxidation of the hops can occur during introduction of the hops in the cooking process. 
     Currently, brewers take many precautions to avoid oxidation of ingredients during the above processes. In particular the hops are typically pelletized, bathed in nitrogen, and then stored in vacuum packed oxygen-barrier materials (such as aluminum packs) to ensure little or no contact with oxygen after the hops are made ready for use. It is only just before introduction of hops into a fermentation tank does the vacuum packed seal get broken and the hops delivered to the fermentation tank. The fermentation tank is then immediately re-sealed after the hops are delivered. Venting of the carbon dioxide that is produced during the fermentation process is then allowed to continue via a check-valve style vent arm attached to the fermentation tank that also prevents atmosphere/oxygen from entering the fermentation tank. 
     With regard to the hops ingredient, hops are generally known as a primary ingredient in the manufacture of beer. The art of using hops in beer has been changing over the last decades from the direct addition of hops to the wort during its boil, to the use of solvent extracts of hops and of hop pellets, to the use of preisomerized purified hop iso-alpha acids (isohumulones), and now to the use of carbon dioxide hop extracts. The direct introduction of hops or pelletized hops into the fermented beer is commonly known as “dry hopping.” An alternative way to introduce hops to the brewing ingredients is by injecting a hops extract into the fermentation tank. The extract can be transferred to the fermentation tank via a closed system in which the hops extract in liquid form is injected into the fermentation tank directly from a hops extract tank, thus minimizing exposure of the hops extract to oxygen. 
     The resin complex of hops includes humulones (alpha-acids), lupulones (beta-acids), uncharacterized soft resins and ‘hard resins’ (oxidation products of alpha- and beta-acids). During heating or other processing in the brewery, the water-insoluble humulones are converted into soluble isohumulones. The isohumulone content plays a role in determining the level of bitterness in the final beverage product. 
     It is these alpha-acids that may be subject to deterioration by oxidation during hop storage, hop transfer, and hop use. When oxidation occurs, the alpha-acids complex is then converted into hard resins. In the past, in order to prevent this oxidation, the hops have been pelletized and packaged under vacuum in pellet bags as described above, which slows down the rate of deterioration. However, traces of oxygen remain after evacuation and sealing of the pellet bags, and the residual oxygen is capable of causing some further product deterioration. In addition, during transfer of the hops to the fermentation tank, the hops and the ingredients in the fermentation tank can be exposed to a significant amount of oxygen. 
     In the past, brewers have added an antioxidant material to the hops, such as ascorbic acid (vitamin C). In this case, the ascorbic acid is preferentially oxidized and prevents the hops from oxidizing. Brewers have also attempted to transfer the hops into the fermentation tanks in an environment that does not include oxygen by using elaborate storage and transfer structures. 
     Despite all of these efforts there remains a long felt need to continually reduce the amount of exposure of hops and other ingredients in the brewing process to oxygen during the brewing process. 
     SUMMARY 
     In accordance with an aspect of the disclosed subject matter, a method for dry hopping a beverage contained in a fermentation tank can include providing a hops vessel having a top portion and a bottom portion and defining an interior space, a fill port located at the top portion of the hops vessel, an inert gas port located at the top portion of the hops vessel, an inert gas port valve located adjacent the inert gas port, an exit port located at the bottom portion of the hops vessel, an exit port valve located adjacent the exit port, a branch tube connected to the exit port via the exit port valve, and a bypass tube in fluid communication with the top portion of the hops vessel and connected to the branch tube via a bypass valve. The method can further include closing the exit port valve of the hops vessel, adding hops to the interior space of the hops vessel, sealing the interior space of the hops vessel from ambient atmosphere, connecting a pressurized inert gas supply to the inert gas port such that inert gas is in fluid communication with the interior space of the hops vessel, purging the hops vessel of ambient atmosphere using the pressurized inert gas supply, connecting a supply hose between the exit port of the hops vessel and the fermentation tank, pressurizing the interior space of the hops vessel with the pressurized inert gas supply, opening the exit port valve and thereby propelling at least a portion of the hops from the interior space of the hops vessel into the supply hose, closing the exit port valve, and opening the bypass valve which is in fluid communication with the top portion of the hops vessel and the supply hose thereby propelling hops remaining in the supply hose into the fermentation tank. 
     In accordance with another aspect of the disclosed subject matter, a system for adding hops to a fermentation tank can include a hops vessel having a top and a bottom and defining an interior space configured to receive hops. A fill port can be located at the top of the hops vessel and in communication with the interior space. A cover can be located adjacent to the fill port and configured to selectively close the fill port. A gas tube can be connected at the top of the hops vessel in selective fluid communication with a pressurized supply of inert gas, and in fluid communication with the interior space of the hops vessel. A branch pipe can extend from the bottom of the hops vessel and in fluid communication with the interior space, the branch pipe including a first opening, a second opening, and a third opening. A first valve intermediate the hops vessel and the first opening of the branch pipe can be configured to selectively open and close fluid communication between the interior space of the hops vessel and the first opening of the branch pipe. A supply hose can be in fluid communication with the second opening of the branch pipe and configured for connection to a vent arm in fluid communication with inert gas under pressure in the fermentation tank. A by-pass pipe can be connected at one end to the top of the hops vessel and in fluid communication with the interior space. A by-pass valve can be located intermediate another end of the by-pass pipe and the third opening of the branch pipe, the by-pass valve being configured to selectively open and close fluid communication between the interior space of the hops vessel and the third opening of the branch pipe. 
     Additional features, advantages, and embodiments of the disclosed subject matter may be set forth or apparent from consideration of the following detailed description, drawings, and claims. Moreover, it is to be understood that both the foregoing summary of the disclosed subject matter and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the disclosed subject matter as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other aspect of the presently disclosed subject matter will become clear from the following description with reference to the accompanying drawings, wherein: 
         FIG. 1  is a front view showing an exemplary embodiment of a hops cannon made in accordance with principles of the disclosed subject matter; 
         FIG. 2  is a front view showing an exemplary embodiment of a system for adding hops to a beverage made in accordance with principles of the disclosed subject matter; 
         FIG. 3  is a front view showing another exemplary embodiment of a system for adding hops to a beverage made in accordance with principles of the disclosed subject matter; and 
         FIG. 4  is a block diagram depicting an exemplary method in accordance with principles of the disclosed subject matter. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The presently disclosed subject matter will be described in detail hereinafter with reference to exemplary embodiments shown in the accompanying drawings. 
       FIG. 1  is a front view of an example of a hops dosing device or hops cannon  10  made in accordance with principles of the disclosed subject matter. The hops cannon  10  can include a main body  11  shaped as an upright cylinder which terminates at a cone shaped lower end section  12  to form an exit port  19 . Diametrically opposed sections of the wall of the cone shaped section  12  can be positioned substantially 60 degrees with respect to each other. The exit port  19  of the hops cannon  10  can be formed as, or connectable to, a material pipe  57 . The upper portion of the main body  11  can be sealed or releasably sealed with an upper cover portion which, in the embodiment depicted in  FIG. 1 , is a dome shaped portion welded to a cylindrical portion of the main body  11 . 
     A material port  20  can be located in the dome shaped portion of the main body  11  and can be sized to allow input of various ingredients (e.g., hops) into the hops cannon  10 . The port  20  can include a lid plate  22  that is rotatable about a hinge  21  to securely open and close the entryway to the port  20 . The lid plate  22  can include a clasp lock to secure the lid plate  22  when in the closed position to securely seal the port  20  of the hops cannon  10 . A gasket, o-ring or other sealing structure can be mounted to the lid plate  22  or to the rim of the material port  20  to effect a substantially (total or almost total) fluid tight seal between the lid plate  22  and the port  20 . A pressure sensor  24  can be provided in the lid plate  22  to provide an operator of the hops cannon  10  with a pressure reading related to pressure within main body  11  of the hops cannon  10 . A fluid connection  23  can also be provided in the lid plate  22  for connection to an outside fluid supply/source, such as a carbon dioxide reservoir  80 . A release valve  30  can be located in a top portion of the main body  11  to allow for release of excess fluid pressure that may build up in the main body  11  during operation. 
     As indicated above, an exit port  19  can be formed at the bottom of the cone section  12  of the hops cannon  10  such that ingredients located in the hops cannon  10  can be discharged via material pipe  57 . A material valve  51  located on the material pipe can be provided in order to regulate flow of material out of the hops cannon  10  in a manner described in more detail later. A “tee”  59   a  can be located immediately below the material valve  51  and include an exit branch connected to a sight glass  54  which, in turn, can be connected to an outlet line  53  formed as a hose or pipe or other type of discharge tube. A middle branch of the tee  59   a  can be connected to a bypass pipe  40  that extends from and is in fluid communication with a top portion of the main body  11 . In particular, the bypass pipe  40  can be formed as a pipe that extends from an opening in the upper cover portion of the main body  11  to the middle branch of the tee  59   a . A bypass valve  41  can be located between the middle branch of the tee  59   a  and the bypass pipe  40  to regulate the fluid connection between the upper portion of the main body  11  and the tee  59   a.    
       FIG. 2  shows a system for adding hops and other ingredients to a beverage including a hops cannon  10  connected to a fermentation tank  70  via a series of hoses and pipes. The hops cannon  10  as described above can have an outlet hose  53  connected thereto, for example, at an exit end of the sight glass  54 . The outlet hose  53  can terminate at a connector, which can be releasably connected to a mating connector located at an inlet end of an inlet pipe  55  which is ultimately connected to a top portion of the fermentation tank  70  via a top port  71 . The fermentation tank  70  can include a number of structures, including pressure gauges, temperature gauges, heaters, coolers, pressure relief valves, stirring structures, etc., for processing the final beverage. A vent arm  72  can be provided on the fermentation tank  70  to allow excess carbon dioxide that is produced during the fermentation process to escape from the fermentation tank  70 . In an alternate embodiment, the outlet hose  53  extending from the hops cannon  10  can be connected directly to this vent arm  72  for introduction of the hops and/or other ingredients to the fermentation tank  70  via the vent arm  72 . In this manner, a separate inlet hose  54  is not necessary for introducing the ingredients to the fermentation tank  70 . An exit port  77  can be located at a bottom cone shaped section of the fermentation tank  70  to allow for distribution of the beverage into barrels, bottles, growlers, etc. 
       FIG. 3  shows another embodiment of a hops cannon  10  and system for adding hops and other ingredients to a beverage. In this embodiment, the tee  59   a  is replaced with differently shaped tee  59   b  in which the portion extending between the bypass valve  41  and the connection to the sight glass  54  or outlet hose  40  is substantially straight and has an interior cross-section that is narrower at the location where the material pipe  57  connects via material valve  51  to the tee  59   a  than a cross section of the pipe, hose, or tube located at inlet and outlet portions extending to and from the location at which the material pipe  57  connects to the tee  59   a . Thus, a venturi effect can be created at the material pipe  57  inlet into the tee  59   b  that allows for increased discharge velocity of materials from the material pipe  57  into the tee  59   b  and ultimately increased discharge efficiency to the fermentation tank  70 . The reduced cross section of tee  59   b  can be accomplished in many different ways, including designing the tee  59   b  to have an interior cross-section that is narrower than both the inlet and outlet pipes/tubes to which the tee  59   b  is connected. Alternatively, the straight portion of the tee  59   b  can include a narrowing portion at the junction of the tee to create the venturi effect. Further, the straight portion of the tee  59   b  can be narrower in cross section than the tube or pipe to which each end of the straight portion of the tee  59   b  is connected. 
       FIG. 4  is a block diagram depicting an example of a method for introducing hops into a fermentation tank in accordance with principles of the disclosed subject matter. At the outset, the hops cannon  10  can be sterilized using a variety of different processes, including steam cleaning or using a steam jacket to clean by elevating the temperature of the hops cannon  10  without contacting the hops cannon  10  with water. Once the interior space of the hops cannon  10  is sterile and dry, a vacuum pack or packs of pelletized hops can be broken open and placed into the main body  11  via the material port  20 . The lid plate  22  can then be closed and sealed in an air tight manner. A gas line that is connected to the lid plate  22  can then be opened to purge the interior of the main body  11  of the hops cannon  10  of atmospheric gases, which will be replaced with the gas from the open gas line. The gas can be an inert gas that does not include oxygen, and can be, for example, carbon dioxide gas. The atmosphere can be vented from the hops cannon  10  via different ports, such as through the pressure relief valve  30 , or through the material pipe  57  and/or bypass pipe  40  and ultimately out of the system via hose  53 , until the only fluid remaining in the hops cannon  10  is carbon dioxide (i.e., until the only fluid being vented is carbon dioxide). Typically this purging process takes a few minutes, but can take longer or shorter depending on the amount of hops in the hops cannon  10 , the pressure of the gas line, the size of each of the fittings and tubes/pipes, etc. 
     Once the hops cannon  10  is sufficiently purged of atmosphere, all vent openings can be closed or sealed and the outlet hose  53  can be connected to the inlet pipe  55  of the fermentation tank  70 . The pressure inside the hops cannon  10  can then be allowed to increase to, for example, 0.3 MPa. 
     When the pressure inside the hops tank  10  reaches approximately 0.25-0.3 MPa, the material valve  51  (bottom body valve) can be opened to allow hops to move under pressure from main body  11  through valve  51  and into the sight glass  54 . The hops will then become viewable in the sight glass  54 , and will stop movement (i.e., become plugged). At that point in time, the operator can close the material valve  51  and allow the pressure to build again in the hops cannon  10 . The time from the opening to the closing of the material valve  57  can be a matter of a few seconds, e.g., 5 seconds. After closing the material valve  57 , when the pressure reaches approximately 0.25-0.3 MPa, the bypass valve  41  can be opened to introduce an unfiltered (i.e., undamped by hops) pressure of carbon dioxide to those hops that remain located in the area of the sight glass  54  (in the sight glass  54  and possibly in the adjacent outlet hose  53  and tee  59   a ). The unfiltered pressure will cause the hops located in the area of the sight glass  54  to move from the area of the sight glass  54  towards and through the outlet hose  53  and eventually into the fermentation tank  70  via the inlet pipe  55 . 
     Sometimes, the hops located around the sight glass  54  will not be fully discharged to the fermentation tank  70  when the bypass valve  41  is initially opened. In this case, an operator may be required to close the bypass  41  and allow the pressure in the main body  11  of the hops cannon  10  to again reach approximately 0.25-0.3 MPa. The bypass valve  41  can then be opened again to deliver a second wave of pressurized carbon dioxide to the hops located in the area of the sight glass  54 . Hopefully, the hops will then be moved along the outlet hose  53  and through the inlet pipe  55  into the fermentation tank  70 . This process of opening and closing the bypass valve  41  can be repeated until the hops located in the area of the sight glass  54  is finally discharged and moved into the fermentation tank  70 . 
     In accordance with another exemplary embodiment of the method, the material valve  51  can also be opened and closed multiple times in order to move hops from the main body  11  to the area of the sight glass  54 . The material valve  51  and the bypass valve  41  can also be opened and closed in an alternate fashion until the hops located in the area of the sight glass  54  is discharged into the fermentation tank  70 . Opening and closing the material valve  51  in between opening and closing the bypass valve  41  will allow the hops located in the area of the sight glass  54  to move or become redistributed in nature. Thus, when a subsequent opening of the bypass valve  41  occurs, the redistributed hops will be more likely to be fully transferred to the fermentation tank  70 . 
     The mobility of the hops through the system will depend on many different variables, including type, freshness, moisture content, and quantity of hops, as well as mechanical variables such as operating pressure of gas lines, size of lines, pipes and fittings, friction coefficients of surfaces, and environmental conditions such as heat, humidity, etc. 
     The disclosed subject matter can be accomplished using many structures and method processes that are different from those described above with respect to the exemplary and depicted embodiments. For example, any of the structures described as pipes can easily be refitted with a hose type structure, and vice versa. The term tube is intended to be a generic term referring to either a pipe or a hose. The pipes can be made from stainless steel, or any other known material for making and distributing beverages, such as aluminum, steel alloys, etc. The hops cannon  10  can form a 75 L containment body, but can be larger or smaller depending on particular application. The cross-sectional dimensions of each of the pipes and hoses can also vary depending on application and, for example, can be 3 inch diameter pipes and hoses. Each of the different portions of the hop cannon  10  can be welded together via, for example, an argon-arc welding process, or can be joined together using fittings, couplings and other mechanical attachment devices. Legs  13  with wheels at ends thereof can be provided on the main body  11  to allow the hops cannon  10  to be easily moved between different fermentation tanks. Alternatively, the hops cannon  10  can be permanently attached to a frame structure adjacent a fermentation tank. The fermentation tank  70  can be sized to create 120 barrel batches of beverage, but can be larger or smaller depending on a particular application. 
     The main body  11  of the hops cannon  10  is shown as a cylinder attached to a cone portion  12 . However, these shapes can be varied, and can include a spherical main body shape (with or without cone shaped bottom portion), polygonal main body shape, and others. 
     It is also contemplated that the specific location of each of the ports of the hops cannon  10  can vary without departing from the spirit or scope of the disclosed subject matter. For example, the inlet port  20  can be located at a center of the top portion of the main body  11  instead of being offset as shown in  FIG. 1 . In addition, the inlet port  20  could be located on a sidewall of the main body  11 . Likewise, the exit port  19  of the hops cannon  10  can be offset with respect to the central axis of the cone portion  12 , and can be an asymmetrically located port if the portion  12  is not formed as a symmetrical cone. 
     The opening and closing of each of the bypass valve  41  and material valve  51  can be accomplished by hand or by a control unit connected to a solenoid or other actuation device for actuating each of the valves. The valves themselves can be any known type of valve that will allow both fluid and dry materials to pass therethrough when in the open position, and preventing both fluid and dry materials from passing therethrough in the closed position. In addition, although a sight glass  54  is shown in  FIG. 1 , the hops cannon  10  can also function adequately without a sight glass  54 . 
     While there has been described what are at present considered to be preferred embodiments of the present invention, it will be understood that various modifications may be made thereto, and it is intended that the appended claims cover all such modifications as fall within the true spirit and scope of the invention.