AU2008101172A4 - Maturation Container - Google Patents

Description

01/12 2008 17:08 +61 3 9543 8822 Morcom Pernat #0417 P.007/026 1

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION INNOVATION PATENT "Maturation Container" The following statement is a full description of this invention, including the best method of performing it known to me: COMS ID No: ARCS-215439 Received by IP Australia: Time 16:13 Date 2008-12-01 01/12 2008 17:08 ±61 3 9543 8822 Morcom Pernat Morcm Penat#0417 P.008/026 00 2 o MATURATION

CONTAINER

Field of the Invention This invention relates particularly but not exclusively to containers for the maturation 2 of table wine and other beverages by control of oxygenation.

00 Background of the Invention Many red and some white table wine varieties are matured in bulk quantities in oak barrels, according to the wine variety, quality and desired character. Many other liquid beverages such as whiskey also benefit from similar maturation in oak by oxygenation.

The general aim of wine aging in Oak barrels, is to develop a desired aged wine bouquet and character, by: Controlled and slow oxidation of various wine substances especially the phenolic compounds. This slow oxidation, followed by polymerization, results from limited and gradual exposure to air oxygen diffusing through the walls of the barrel over months.

Extraction of Oak flavour components, including Oak phenolics to enhance and expand the wine's complexity.

However Oak barrels are expensive to fashion, cumbersome to store and handle, often inconsistent in wood properties, subject to leakage and limited in usefUl life.

COMS ID No: ARCS-215439 Received by IP Australia: Time 16:13 Date 2008-12-01 01/12 2008 17:09 -v6l 3 9543 8822 Norcom Pernat Morcm Penat#0417 P.009/026 003 0 Oak barrels also require a voluminous storage facility with a controlled temperature o and humidity environment to minimize evaporative loss due to transpiration through 0 their porous walls.

Accordingly there have been many attempts to replicate the effects of barrel aging on table wine in bulk quantities, without the actual use of oak barrels. For example: -The addition of Oak sawdust, chips or staves into metal hulk storage 0 tanks, to expose the wine to Oak characters. However this only achieves o0 10 the Oak flavour extraction function of barrel aging, not the oxidative one.

0 This can be mitigated to some extent by regularly "Pumping over" the wine in the tank, in order to re-aerate it. However this often introduces too much dissolved oxygen all at once, allowing aerobic bacteria such as Acetobacter to become established and begin oxidizing the ethanol in the wine into acetaldehyde, ethyl acetate and ultimately acetic acid, with consequent loss of wine quality. These oxidation products are termed "volatile acidity" in the wine industry.

-The development of composite bulk containers made of metal (stainless steel) and fitted with flat Oak panels or ends which can be more easily fashioned and which may be reversed to expose fresh Oak to the wine contents. Such containers usually don't have the optimum ratio of surface area of Oak to volume of wine contained and are usually inadequate both in the extractive and oxidative functions.

More recent developments include the use of "micro-oxygenation" wherein air or pure oxygen is introduced directly into bulk-tanked table wine with added Oak chips or planks, by generating very fine bubbles through the wine by means of a microporous (ic. sintered) dispersion element on the end of a submerged gas line or lines.

This is a difficult process to adequately control and can possibly lead to excess levels of dissolved oxygen at the bubble interfaces, again promoting ethanol oxidation and other degradative side-effects through fast oxidation of table wine. The equipment COMS ID No: ARCS-215439 Received by IP Australia: Time 16:13 Date 2008-12-01 01/12 2008 17:09 +61 3 9543 8822 Morcom Pernat #0417 P.010/026 00 4

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Cl required to contain and feed fixed volumes of oxygen or to accurately meter a continuous flow over set time periods at very low flow rates, is normally expensive Sand difficult to operate. That cost also means the resource has to be shared over a O number of tanks, which militates against long, slow maturation times in individual tanks.

Recent studies such as reported in "Gaseous Exchange in Wine Stored in Barrels", SMoutounet, Mazauric et al, J. Sci. Tech. Tonnellerie, 1998 (herein incorporated by Sreference) have explained the mechanism by which barrels add oxygen to wine and 00 promote "correct" maturation. The oak walls of wine barrels act as semi-permeable C1 "membranes", allowing oxygen gas in the atmosphere outside the barrel to permeate through the barrel walls and diffuse into the wine. This osmotic exchange is driven by the partial pressure difference of the atmospheric oxygen outside the barrel (0.18 atm) and the effectively zero partial pressure of oxygen inside. This absence of oxygen in the barrel arises because wine continuously consumes all available oxygen in the slow-oxidation reactions that occur in the reductive environment that exists when the rate of oxygen addition occurs at very low rates over long periods, due to slow diffusion.

Furthermore, it has been shown that it is this slow permeation (diffusion) of atmospheric oxygen that contributes most to "barrel softening or maturation".

Moutounet et. al. (referred to above) showed that a typical new oak barrique allows 02 permeation through its walls, in the range of 2 0 -30mg/l.yr. Kelly and Wollan reported an estimated "highest diffusion" (ie. permeation) rate into a typical barrique as 2.2ml 02/litre wine/month or 26.4 ml/1/yr (34.6mg/l./gr) in their paper "Microoxygenation of Wine in Barrels", Wine Network Technology, www.winenet.com.au, incorporating International Patent Application PCT/AU02/01250 (both herein incorporated by reference).

It has been found that the oxygen permeability of an oak barrel typically decreases by approximately 20% for each year filled. Thus the permeation rate of a typical barrel after 5 years of use may be as lows as 7 milligrams/1/yr ie. thus the oxygen COMS ID No: ARCS-215439 Received by IP Australia: Time 16:13 Date 2008-12-01 01/12 2008 17:09 +61 3 9543 8822MocmPna#41 P01/2 Morcom Pernat #0417 P-011/026 005 0 0 permeation rate for normal barrels during the typical 5 years of barrel life lies o between 7 and 35 mg/l/yr.

It is well known that older barrels transmit less oxygen than new barrels, as the wood clogs over time with absorbed wine solids. The useful life of a typical barrel is also well known to be limited to 5 years. After that time they are too impermeable to properly mature wine within the usual maturation time frame and are either discarded or retained for use with wine types that do not require much oxygen exposure, such as some of the white varieties.

00 o 0 Any free surface arising from head-space in a table wine storage vessel is undesirable, if it contains oxygen. At that surface the levels of dissolved oxygen increase in concentration, to near saturated (9 ppm at 20 Celsius and I atm). In this oxygen rich surface layer aerobic bacteria will propagate, generating volatile acidity and acetaldehyde at a rate dependent usually on the surface area of the free surface and the oxygen content of the surface gas. The lesser the free surface area, the longer that wine can be safely kept in bulk storage.

This approach compares with the approach required for maturing a sherry style wine which typically requires a partially empty vessel with a head space open, or partially open to the atmosphere, such as occurs in a part-filled barrel, which continuously draws in air to replace the evaporative volume lost, as well as permeating it through the walls. Enough oxygen needs to be made available within the vessel to support the growth of certain yeasts at the surface, which help oxidize some of the wine ethanol into acetaldehyde, giving sherry its basic character. By contrast, in table wines, formation of acetaldehyde needs to be suppressed as its presence gives an undesirable spoiled taint ie. volatile acidity to the wine. Thus the rate of oxygenation needs to be controlled at levels substantially below that applicable for sherry and any significant free surface avoided or rendered inert.

COMS ID No: ARCS-215439 Received by IP Australia: Time 16:13 Date 2008-12-01 01/12 2008 17:09 +61 3 9543 8822 Morcom Pernat Morcm Penat#0417 P.012/026 00 6 Cl Disclosure of the Invention 0 The invention provides in one aspect a bulk polymeric container for controlling rate of oxygen transfer from the atmosphere into a liquid stored in the container wherein, the bulk polymeric container has self supporting walls, the walls having a Cl thickness chosen to permit sufficient oxygen to permeate the walls from the atmosphere into the liquid at a rate sufficient to promote controlled maturation of the 2 liquid over a prolonged period, the bulk polymeric container has a capacity of at least 225 litres, and the oxygen permeation rate is less than 55 milligram/litre per year.

00 01 Cl The liquid may be a beverage such as table wine. The table wine may be stored for a period between 4 months and 36 months.

The polymer forming the container may be a wine-safe polymer.

By wine-safe polymer, we mean a polymer which is suitable for contact with wine, does not impart an undesirable taste to the wine and does not leach dangerous levels of chemicals toxic to humans into the wine. Polyethylene is a particular example of a suitable polymer.

By self- supporting polymeric walls we mean that the thickness and configuration of the walls and the strength and rigidity of the polymer are such that the container can maintain its own shape without support when it is empty. The walls may include the base, sides and top of the container, It may be moulded in one piece from polymer by a conventional process, such as rotational moulding.

The relationship between the various factors governing Oxygen transmission into liquid in the container is described by the following equations where: OTR (mg/I/day) P(matl. permeability, mgQ2/sqmlday for 1mm) divided by t(mm thickness) all multiplied by A (area sqm) divided by V (volume litres) i.e. OTR =P/t x(AMV COMS ID No: ARCS-215439 Received by IP Australia: Time 16:13 Date 2008-12-01 01/12 2008 17:10 +61 3 9543 8822 1) ernat#0417 P.013/026 007 o or OTR x =Pit o or V/A =1I/(t xOTR) Or rt= (PXA) -(OTR xV) The applicants have found by experiment that simplified relationships of volume range versus surface area versus thickness can be used to define the characteristics of 1 a suitable plastic container provided a plastic with a particular range of physical properties and thickness range can be used.

o0 20 The thickness of the container walls (eg. Polyethylene) may then be adjusted having 0 regards to the desired volume and surface area of the container to ensure that the rate of oxygen transmission is maintained at levels suitable for the maturation of table wines or other liquids, ic. at rates similar to conventional oak barrels.

From the foregoing equations it can be seen the permeation of oxygen through the walls of a polyethylene container reduces in inverse proportion to the increase in wall thickness. The oxygen permeability of polyethylene depends on its solid density and varies (increases) with temperature. Oxygen from the atmosphere (ic. at 0.18 atmn partial pressure) typically permeates through polyethylene at rates from 13mg to 6 Smg of oxygen per square metre per day at room temperature, ic. at about 20-25 degrees C. the applicants have found that a container volume ranging from 5 to hectolitres per square metre of container surface area for a wall thickness of 1mm will allow oxygen permeation to proceed at rates similar to barrels of various ages.

To illustrate the application of' this three-way ratio, a typical example of a polyethylene container of 1,000 litres (10 hecto litres) and a nominal 6 square metre wall surface area is considered.

The broad thickness range is: At 5hl.mm/sqmn t= 5 x6/10 3n, At 30 hLmm/sqm t =30 x 6/10 =18mm COMS ID No: ARCS-215439 Received by IP Australia: lime 16:13 Date 2008-12-01 01/12 2008 17:10 +61 3 9543 8822 Norcom Pernat #0417 P.014/026 00 8 0 0Depending on the polyethylene permeability chosen, the oxygen transmission rate (OTR) ranges are: At 3mm: Min. OTR: 13/3 x 6 x 365/1000 9.5 mg/1./yr Max. OTR: 65/3 x 6 x 365/1000 47.5 mg/I/yr At 18mm: Min. OTR: 13/18 x 6 x 365/1000 1.6 mg/l./yr Max. OTR: 65/18 x 6 x 365/1000 7.9 mg/l./yr 0 For a container of this layout, the atmospheric oxygen permeation range thus lies 0 between 1.6 mg/I/yr and 47.5 mg/l/yr.

Of course, because the broad transmission range quoted above exceeds that for normal table wine, the parameters of the container can be adjusted so that the OTR is less than 80mg/l/yr and preferably lies within the typical range for wine barrels, namely 7 to The properties of polyethylene are fortunately such that it is sufficiently rigid within a 3mram to 18mm thickness range as to provide a self supporting bulk container according to the invention. The container may even be up to 10 hectolitres or more.

Furthermore, the oxygen transmission characteristics of polyethylene are such that it is suitable for constructing bulk containers capable of performing maturation of liquids, especially wine maturation similar to that achievable with oak barrels.

In order to limit the transfer of oxygen into the surface of the wine, a barrier member may be floated on the wine surface. Suitably, the barrier member has a peripheral portion which is in sliding contact with the container walls to separate the liquid surface from the head space in the container.

Oak staves may optionally be suspended in the wine during the storage period.

In another aspect, the invention provides a container for controlling rate of oxygen transfer from the atmosphere into a table wine stored in the container comprising, COMS ID No: ARCS-215439 Received by IP Australia: Time 16:13 Date 2008-12-01 01/12 2008 17:10 ±61 3 9543 8822 MroiPra 01 .1/2 Morcom Pernat #0417 P-015/026 00 9 Cl a bulk polymeric container having self supporting walls, the walls having a thickness chosen to permit oxygen to permeate the walls from the atmosphere into the 0 table wine at a rate sufficient to promote controlled maturation of the table wine over o a prolonged period.

Cl The rate of permeation is suitably less than 55mg/L/yr. The rate of permeation is suitably comparable with permeation rates typically associated with maturation of 2 bulk table wines in oak barrels.

00 The container may comprise a barrier member for providing a barrier to limit oxygen Cl access from head space in the container to a surface of the wine the barrier member having a construction which causes it to float on the wine surface.

A peripheral flange may surround the barrier member so that it makes slidable contact with the walls of the container, In another aspect the invention provides a barrier member as described herein.

The method and apparatus of the invention can be used to achieve the simultaneous extractive and slow-oxidative effects of Oak barrel aging without the need to use such barrels or to add extra oxygen gas or air into the wine.

Furthermore the method of our invention can allow the independent adjustment of both the degree of Oak extraction and the degree of slow-oxidation. In this way it is possible to replicate the different extractive and oxidative effects of Oak casks of different ages (the oxygen perneability of a barrel decreases by about 20% for each year it is used) and of different surface area to volume ratios. Common Oak cask sizes are Barriques (225 litres), Hogsheads (300 litres) and Puncheons (500 litres).

Preferred aspects of the invention will now be described with reference with to the accompanying drawings.

Brief Description of the Drawings COMS ID No: ARCS-215439 Received by IP Australia: Time (I-tm) 16:13 Date 2008-12-01 01/12 2008 17:10 +61 3 9543 8822 Morcom Pernat #0417 P.016/026 00 0 SFigure 1 shows a cut away isometric view of a container constructed in accordance with the invention; SFigure 2 shows an enlarged view of the circled area at the top of Figure 1; Figure 3 shows an enlarged view of the circled area shown at the bottom of Figure 1; C Figure 4 shows an alternative tank construction; Figure 5 shows an enlarged cross sectional view of part of the circled region of Figure 4; and Figure 6 shows an isometric view of a barrier member for use with the 00 o 10 invention.

0 Detailed Description of the Preferred Embodiments The various elements identified by numerals in the drawings are listed in the following integer list.

Integer List 1 Cover 2 Water trap 3 Level 4 Plastic tank Staves 6 Hole 7 Rod 8 Base valve 9 Cylinder Outer cylinder 11 Disc 12 Lip 14 Top panel Skirt Plastic tank COMS ID No: ARCS-215439 Received by IP Australia: Time 16:13 Date 2008-12-01 01/12 2008 17:10 +61 3 9543 8822 MroiPra Morcom Pernat #0417 P.017/026 0 021 Neck o22 Closure 023 Skirt 24 Water trap 25 Circumferential wall 26 Tap 28 Wine Barrier member 31 Foamned plastic core 00 32 Polyurethane film overwrap 034 Peripheral flange wall 36 Tag 37 Hole/loop Whilst the following aspects of the invention are described with particular reference to table wine it is to be appreciated that they may also be applicable to other liquid beverages.

Referring to Figures 1 to 3, there is shown an optionally thermally insulated plastic tank with an opening in the lop defined by a neck form-ed as a cylinder 9 forming part of the tank, to which any closure can be fitted.

In this embodiment an optional circumferential wall in the form of an outer cylinder 10 is welded to or molded as part of the tank 4 and an optional base valve 8 is fitted through the side wall, above the base of the tank so as to enable bottom filling or discharge of the tank contents without disturbing sediment that may have settled to the bottom of the tank.

The tank 4 is sealed by means of a closure comprising an inverted domne-shaped cover 1 having a top panel 14 and depending skirt 15. The skirt is partially submerged in a water trap 2 formed by adding water to the space between the two concentric cylinders 9 and 10. Whilst the specific embodiment shown uses a water trap it is to COMS ID No: ARCS-215439 Received by IP Australia: Time 16:13 Date 2008-12-01 01/12 2008 17:11 +61 3 9543 8822MocmPrt#01 P.8/2 Morcom Pernat #0417 P.018/026 00 12 0 be appreciated that a simple closure such as a wide mouth screw cap can be used. It o is preferable that the closure and container neck be wide enough to allow a person to 0 have hand access to all internal surfaces for cleaning.

The tank 4 and top cylinders 9 and 10 are made from polyethylene with an oxygen N permeability in the range between 13mg to 65mg of atmospheric oxygen per sqm of tank surface per 24hr for each 1mm of tank wall thickness at typical storage 2 temperatures of 20-25 degr C.

00 The ratio of contained volume to surface area of the container falls within the range 0 to 30 hectolitres per square metre of surface for a inim thick container wall exposed to atmospheric oxygen, to ensure that an adequate rate of permeation of oxygen is maintained. Thus for example, for a 4mm thick wall the contained volume range becomes 1.25 to 7.5 hectolitres per square metre of surface.

Suspended within the wine-filled tank are an optional number of oak-wood staves of the desired variety and degree of toast (ie. charring). At the lower end of each stave a hole 6 is drilled to enable that stave to be threaded onto or otherwise attached to a solid rod 7 usually made of stainless steel, which is sufficiently heavy to keep all of the wooden staves attached to it from floating to the surface. The total surface area of oak-wood presented to the wine will depend on the variety of wine, the degree to which the winemaker wants to impart oak character to it and the number of times the oak staves have already been used in wine.

In this embodiment, the stainless steel rod 7 is bent into a shape, so that the ends hang downwards and the staves float upwards. By this simple means the staves are prevented from floating off the ends of the rod 7.

Alternatively, the oak planks may be pre-assembled into a pack, not requiring a hole or rod to fit them onto. The pack may be inserted preassembled through the mouth of the tank and removed for replacement, cleaning or sterilization as and when required.

COMS ID No: ARCS-215439 Received by IP Australia: Time 16:13 Date 2008-12-01 01/12 2008 17:11 +61 3 9543 8822MocmPnt#01 P01/2 Morcom Pernat #0417 P.019/026 00 13 Cl The level of wine 3 in the tank will normally lie within the top cylindrical chamber U formed by the cylinder 9. Resting or floating on the wine surface is a barrier member 0 compri sing a buoyant disc 11I made of wine-safe polymer such as polyethylene. It o may comprise an upside down dish shape. Alternatively it may be a composite structure comprising a disc of plastic foam overwrapped and sealed within a wine- Cl safe film of predetermined oxygen barrier properties. The outer perimeter of the buoyant disc may optionally be thrnished with a flexible lip 12 which forms a "Wiper 2 seal" with the inner face of the chamber cylinder 9. The purpose of the buoyant disc is to lie in and block the free wine surface from access to the head space air or gas in 00 the chamber 9. The disc minimizes the rate at which particular gases in the head Cl space, such as oxygen, can dissolve into the wine via the free surface.

The buoyant disc acts as a barrier member which can also have tailored gas permeability suitably at the levels already described to enable controlled oxygen permeation into a tank made from impermeable material, such as Stainless Steel.

Thus, the barrier member and poly tanks can be used together or separately, to passively "meter" the addition of atmospheric oxygen into wine, without allowing conditions to develop where a significant free surface area of wine is directly exposed to the atmosphere.

The upper rate limit of mass transfer of oxygen into wine by permeation is typically about 80mg/I/year. At rates higher than that wine is not capable of using up all the available oxygen in typical maturation reactions and a measurable concentration of dissolved oxygen results. In those conditions, aerobic bacteria such as acetobactor, and gluconobacter, which are always present in low populations in all wine that hasn't been sterile-filtered will propagate and damage the wine.

When used in the main body of a tank as is shown in Figure 4 CO 2 or another inert gas can be added into the head space to protect the small area of exposed wine around the perimeter of the added barrier member. As gas dissolves into liquid at a rate directly proportional to the exposed surface area, re-charging the head space with C0 2 only needs to be done very infrequently when a barrier member is used, ie. once COMS ID No: ARCS-215439 Received by IP Australia: Time 16:13 Date 2008-12-01 01/12 2008 17:11 +61 3 9543 8822 MroiPra Morcom Pernat #0417 P.020/026 00 14 0 per month rather than every couple of days, due to the 50 to 100 fold typical o reduction in exposed surface area. The exposed annulus is typically about 5mm wide.

0 If the tank body has a diameter of in meters, the exposed surface without barrier x D 2 /4 and with a barrier it is 0.005 x ni x D. For a tank of 3m diameter, the exposed surface with a barrier is proportionally 0. 005 x 4/1) or just 2% of that without a hatrer member.

The edge flap helps to centralize the disc, keep out contamination and contain SQ gas that is coming out of solution from the wine so that mould cannot grow there.

00 1 o Referring to Figures 4 to 6, there is shown a plastic tank 20 for wine with a neck construction generally designated 21. The illustrated tank uses any typical closure that seals the opening.

is A closure 22 having a depending circumferential skirt 23 closes off the neck.

As in the case of the previously described container, a circumferential wall surrounds the neck and provides a water trap 24 between the neck and circumferential wall and the skirt 23 of the closure fits into this water trap to seal off the neck.

A tap 26 is provided at the bottom of the container to drain off the wine 28 as and when needed.

A barrier member 30 having a foamed plastic core 31 floats on top of the wine in the body of the container. The foamed plastic core 31 of the barrier member is ovcrwrapped with a polyurethane film overwrap 32 which comprises two separate layers covering the top and bottom of the foamed plastic core. These two separate layers are laminated together at their edges to form the peripheral flange 34. The Peripheral flange provides a slidable seal with the wall 35 of the container so as to substantially reduce the rate of oxygen transfer from the head space of the container through the surface of the wine and hence limits the growth of undesirable aerobic bacteria.

COMS ID No: ARCS-215439 Received by IP Australia: Time 16:13 Date 2008-12-01 01/12 2008 17:11 +61 3 9543 8822 MroiPra 01 .2/2 Morcom Pernat #0417 P.021/026 00 0 The baffler member is provided with three tags 36 distributed around its upper surface, each of the tags being formed with a hole or loop 37. The tags assist wit 0 allowing the barrier member to be correctly located in the container in contact with the wine initially and to be removed after the container has been emptied. In this regard, it is noted that the barrier member comprising the foamed plastic core and polyurethane film overlap may suitably be formed of flexible materials in order to allow it to be folded so that it may be inserted through the neck of the container 2 during initial setup and to be removed through toe neck when the container is emptied.

00 ot 0 Whilst the above description includes the preferred embodiments of the invention, it is to be understood that many variations, alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the essential features or the spirit or anmbit of the invention.

It will be also understood that where the word "comprise", arnd variations such as "comprises" and "comprising", are used in -this specification, unless the context requires otherwise such use is intended to imply the inclusion of a stated feature or features but is not to be taken as excluding the presence of other feature or features.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that such prior art forms part of the common general knowledge in Australia.

COMS ID No: ARCS-215439 Received by IP Australia: Time 16:13 Date 2008-12-401

Claims (3)

1. 2. The container according to claim 1 wherein oak is provided in the container in an arrangement which prevents the oak floating to the surface of the liquid in the container.
2. 3. The container according to claim 1 or claim 2 wherein the container is configured so that the rate of oxygen permeation from the atmosphere is maintained within a range typically associated with maturation of bulk table wines in oak barrels,
3. 4. The container according to any one of the preceding claims wherein the container comprises polyethylene, the liquid is table wine and the container contains a quantity of the table wine for maturation. The container according to any one of the preceding claims wherein the ratio of contained volume to surface area of the container can be calculated to fall within the range 5 to 30 hectolitres of wine capacity per square metre of surface for a millimetre of thickness, when the container is exposed to the atmosphere. Dated this 1 st day of December 2008 Flextank International Ltd by their patent attorneys Morcom Penat COMS ID No: ARCS-215439 Received by IP Australia: Time 16:13 Date 2008-12-01