AU2008100042C4 - Maturation of Wine - Google Patents

Description

2008 01/16 14:10 FAX +61 3 9543 2711 MORCOM PERNAT 1007/023 1

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION INNOVATION PATENT "Maturation of Wine" The following statement is a full description of this invention, including the best method of performing it known to me: COMS ID No: ARCS-175464 Received by IP Australia: Time 14:22 Date 2008-01-16

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2008 01/101 14:10 FAX +61 3 9543 2711 MOCMPRAIj00/3 NORCON PERNAT Q008/023 00 2 MATURATION OF WINE

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Field of the Invention o This invention relates to methods and apparatus for the maturation of wine by the o control of oxygenation of the wine.

00 oio Background of the Invention Many red and some white wine varieties are matured in oak barrels, according to the wine variety, quality and desired character.

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.

Oak barrels also require a voluminous storage facility with a controlled temperature and humidity environment to minimize evaporative loss due to transpiration through their porous walls.

COMS ID No: ARCS-175464 Received by IP Australia: Time 14:22 Date 2008-01-16 2008 01/1 6 14:10 FAX +61 3 9543 2711 MOCMPRALj09/3 MORCOM PERNAT Q009/023 00 3 Accordingly there have been many attempts to replicate the effects of bande aging on wine, without the actual use of oak barrels. For example:

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The addition of Oak sawdust, chips or staves into metal bulk storage tanks, to expose the wine to Oak characters. However this only achieves the Oak flavour extraction function of barrel aging, not the oxidative one.

This can be mitigated to some extent by regularly "pumnping over' the o wine in the tank, in order to re-aerate it. However this often introduces too 00 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 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 wine with added Oak chips or planks, by generating very fine bubbles through the wine by means of a micro-porous (ie. 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 ethaol oxidation and other degradative side-effects through fast oxidation of wine. The equipment 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 and difficult to operate. That cost also means the resource has to be shared over a COMS ID No: ARCS-175464 Received by IP Australia: Time 14:22 Date 2008-01-16 2008 01/16 14:11 FAX +61 3 9543 2711 MORCOM PERNAT [a010/023 00 4 0 0 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", Moutounet, Mazauric et al, J. Sci. Tech. Tonmellerie, 1998 (herein incorporated by reference) have explained the mechanism by which barrels add oxygen to wine and o promote "correct" maturation. The oak walls of wine barrels act as semi-perneable o "membranes", allowing oxygen gas in the atmosphere outside the barrel to permeate 00 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 20-30mg/l.yr. Kelly and Wollan report an estimated "highest diffusion" (ie. permeation) rate" into a typical barrique as 2.2ml O2/litre wine/month or 26.4 mil/yr (34.6mg/lJgr) 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).

Any free surface arising from head-space in a 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 1 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.

COMS ID No: ARCS-175464 Received by IP Australia: Time 14:22 Date 2008-01-16 2008 01/16 14:11 FAX +61 3 9543 2711 MRO ENT!j1/2 MORCOM PERNAT [A 011/023 00 Disclosure of the Invention

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The invention provides in one aspect a method of maturing wine in a container over a period of time by storing the wine in a closed container having walls exposed to an oxygen containing atmosphere wherein the walls of the container comprise a plastics material which allows oxygen to permeate the walls directly from the oxygen o containing atmosphere into the wine in contact with the walls and the plastics 00 material has an oxygen transmission rate of 13mg to 65mg of oxygen per square metre of the wall area per 24 hour period at room temperature as measured for a wall thickness of one millimetre.

The appropriate wall thickness of the container wall can be varied to vary the rate of oxygen transmission.

In order to liit the transfer of oxygen into the surface of the wine, a barrier member may be floated on the 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.

Typically, the wine may be stored in the container for a period ranging between 4 months and 36 months with the total rate of Oxygen transmission into the wine being maintained at less than 55mg/litre of wine/year.

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

in another aspect, the invention provides a container for carrying out the method of the invention having oxygen permeation characteristics as herein defined.

The container may comprise polyethylene. it may comprise a rigid form of polyethylene. It may be self supporting.

COMS ID No: ARCS-i 75464 Received by IP3 Australia: Time 14:22 Date 2008-01-16 2008 01/1 6 14:11 FAX +61 3 9543 2711 MRO ENT111/2 MORCOM PERNAT Z012/023 00 6 The method and apparatus of the invention can 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 allows 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 o different ages (the oxygen penneability of a barrel decreases by about 20% for each 00 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 Figure 1 shows a cut away isometric view of a wine container constructed in accordance with the invention; Figure 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; 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 invention.

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

COMS ID No: ARCS-i 75464 Received by IP Australia: lime 14:22 Date 2008-01 -16

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2008 01/16 14:12 FAX +61 3 9543 2711 MORCOM PERNAT [a013/023 00 7 0 0 c Integer List 1 Cover 2 Water trap 3 Level S4 Plastic tank Staves S6 Hole 00 7 Rod 0 8 Base valve 9 Cylinder Outer cylinder 11 Disc 12 Lip 14 Top panel Skirt Plastic tank 21 Neck 22 Closure 23 Skirt 24 Water trap Circumferential wall 26 Tap 28 Wine 30 Barrier member 31 Foamed plastic core 32 Polyurethane film overwrap 34 Peripheral flange Wall 36 Tag 37 Hole/loop COMS ID No: ARCS-175464 Received by IP Australia: Time 14:22 Date 2008-01-16 8 00

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

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In this embodiment an optional circumferential wall in the form of an outer cylinder 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 00 0the bottom of the tank.

The tank 4 is sealed by means of a closure comprising an inverted dome-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 be appreciated that a simple closure such as a wide mouth screw cap can be used. It is preferable that the closure and container neck be wide enough to allow a person to 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 permeability in the range between 13mg to 65mg of atmospheric oxygen per sqm of tank surface per 24hr as measured for each 1mm of tank wall thickness at typical storage temperatures of 20-25 degr C ie. oxygen transmission reduces proportionally with increasing tank wall thickness.

The ratio of contained volume to surface area of the container falls within the range to 30 litres per square metre of surface per atmosphere of oxygen for each 1mm of thickness, to ensure that an adequate rate of permeation of oxygen is maintained.

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 2008 01/16 14:12 FAX -i6S 3 9543 2711 MRCMPNAIj01/2 MORCOM PERNAT [a 015/023 00 9 (N 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.

VaO 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 o prevented from floating off the ends of the rod 7.

00 Alternatively, the oak planks may be pre-assembled into a pack, not requiring a hole o 1 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.

The level of wine 3 in the tank will normally lie within the top cylindrical chamber formed by the cylinder 9. Resting or floating on the wine surface is a barrier member comprising a buoyant disc 11 made of wine-safe polymer such as polyethylene. It 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 winesafe film of predetermined oxygen barrier properties. The outer perimeter of the buoyant disc may optionally be furnished with a flexible lip 12 which forns a "wiper 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 the chamber 9. The disc minimizes the rate at which particular gases in the head 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 ISteel.

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.

COMS ID No: ARCS-175464 Received by IP Australia: Time 14:22 Date 2008-01-16 2008 01/16 14:13 FAX +61 3 9543 2711 MRO ENT~ 1/2 MORCOM PERNAT (a 016/023 00 Cl The upper limit of mass transfer of oxygen into wine by permeation is typically about At rates higher than that wine is not capable of using up all the available oxygen in typical maturation reactions and a mcasurable 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.

o When used in the main body of a tank as is shown in Figure 4 CO 2 can be added into 00 the head space to protect the small area of exposed wine round the perimeter of the added barrier member. As gas dissolves into liquid at a rate directly proportional to Cl the exposed surface area, re-charging the head space with CO 2 only needs to be done very infrequently when a barrier member is used, ie. once per month rather than every couple of days, due to the 50 to 100 fold typical reduction in exposed surface area.

The exposed annulus is typically about Snun wide. If the tank body has a diameter of in meters, the exposed surface without baffler ni. x D 2 /4 and with a barrier it is 0.005 x ni x D. For a tank of hI diameter, the exposed surface with a barrier is proportionally 0. 005 x 4/D) or just 2% of that without a barrier member.

The edge flap helps to centralize the disc, keep out contamination and contain SO 2 gas that is coming out of solution from the wine so that mould cannot grow there.

Referring to Figures 4 to 6, there is shown a plastic tank 20 for wine with a neck construction generally designated 21.

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.

COMS ID No: ARCS-i 75464 Received by IP Australia: Time 14:22 Date 2008-01-16 2008 01/j6 14:13 FAX +61 3 9543 2711 MRO ENTI11/2 MORCOM PERNAT 191017/023 00 11 A baffler 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 baffler member is INO overwrapped. with a polyurethane film overwrap 32 which comprises two separate layers covering the lop and bottom of the foamed plastic core. These two separate layers arc 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 o substantially reduce the rate of oxygen transfer from the head space of the container o through the surface of the wine and hence limits the growth of undesirable aerobic 00 bacteria.

01 The barrier 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 with 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 during initial setup and to be removed through the neck when the container is emptied.

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 ambit of the invention.

It will be also understood that where the word "comprise", and 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.

COMS ID No: ARCS-175464 Received by IP Australia: Time 14:22 Date 2008-01-16 2008 01/16 14:14 FAX +61 3 9543 2711 MORCOM PERNAT 1018/023 00 12

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CN 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.

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0 0O 00 0 0 ci COMS ID No: ARCS-175464 Received by IP Australia: Time 14:22 Date 2008-01-16

Claims (3)

1. 2. A method according to claim 1 wherein the ratio of contained volume of wine to surface area of the walls of the container falls within the range 5 to 30 litres per atmosphere of oxygen per square metre of surface for each 1mm of thickness of the walls.
2. 3. A method according to claim 2 wherein the wine is stored in the container for a period ranging between 4 months and 36 months and the total rate of oxygen transmission into the wine is less than 55mg/litre of wine/year.
3. 4. A method according to any one of the preceding claims wherein the container comprises polyethylene. A container for maturing wine having the characteristics of the container defined in any one of claims 1 to 4. Dated this 23rd day of June 2008 Wychwood Estates Pty Ltd by their patent attorneys Morcom Pernat