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Stakvat excels for wine maturation

The Stakvat™ wine storage system of Ausvat Pty Ltd, with its associated oak technologies, provides an ideal means for winemakers to control oxygenation and maturation of wine, at a time when over supply in the industry means that rapid oxygenation is likely to be avoided in favour of more prolonged and controlled development.

The STAKVAT barrel alternative wine storage system of AUSVAT PTY LTD, combined with the innovative Ausvat oak technologies, is recognised by many leading winemakers as the ideal system for the fermentation, storage and maturation of wine.

STAKVAT is a barrel alternative and is a composite stainless steel and oak construction regularly used by the wine industry for the storage and maturation of wines. It is approximately one cubic metre in size and is housed in a robust stainless steel frame and this allows stacking of single units up to 5 high. Each unit stores 900 litres of wine and has inbuilt cooling for fermentation and storage temperature control. More detail can be found on Ausvat’s web page www.ausvat.com.au.

STAKVAT is an Australian invention, Patent No 617673, Registered Design No 1545/95 and is a Registered Trade Mark No A574931. There are many other associated Patents and Registered Designs.

The first prototype of the STAKVAT invention was launched by Dr Bryce Rankine in August 1988 at a winemakers forum in Mclaren Vale South Australia.

Ausvat has exported STAKVAT to various countries including South Africa, Germany, Canada, and the United States of America. We believe with the recent changes in European wine law, the STAKVAT invention will be more easily accepted by the various wine communities.

We have seen this invention gradually evolve into a very useful winemaking tool. This of course has come with winemakers involvement and industry input over 20 years or so. Wine made in the STAKVAT invention has won many awards.

It is our opinion that an article published by Flextank Pty Ltd director Mr Anthony Fleknoe-Brown in the August 2006 edition of the Australian and New Zealand Grapegrower and Winemaker viz: “Diffusive methods of oxygenating wine:simpler, better, lower-cost barrel replacement” makes incorrect statements, and gives a very misleading impression, about the capacity of the STAKVAT system to mature wine.

The article by Mr Flecknoe-Brown contains a discussion of factors affecting levels of dissolved oxygen (DO) in wine. The article contains a bar chart (Fig. 2) which purports to compare “Oxygen uptake rates in various winery processes/packaging”, including “Stackvat (2–3 years old)”, and goes on to say that, “from the graph … ‘Stakvat’ steel and wood composite cube containers, with two oak faces do not have enough permeable surface area to effectively mature wine”.

The source of information and statements shown in Figure 2, the bar chart regarding DO uptake rates, is said to be The Australian Wine Research Institute (AWRI) and Flextank Pty. Ltd. In our opinion the reference to AWRI is incorrect and misleading. As can simply be found by reading the article, referenced as note 1, by Jones et al (2004) “Exposure of red wine to oxygen, post fermentation”, STAKVAT was never involved in this research, and there is no mention of STAKVAT in the article, which deals primarily with the effects of oxygen levels at bottling, and microoxygenation (MOX).

Our company Ausvat Pty Ltd and many wineries involved in joint oak research and development utilise the AWRI’s commercial analytical service to measure oak volatiles and other compounds contained in wine development at various stages. Results are, for example, recorded measurements of oak flavouring and other compounds, and these results are generally inconclusive without a parallel sensory analysis.

Statements in the Flecknoe-Brown article appear, erroneously, to equate maturation of wine simply with oxygenation. It is clear that many other factors influence maturation. One of the great advantages of the STAKVAT system is its ability to enable the winemaker to vary and control factors, such as oxygenation.

STAKVAT cube containers are not used alone for wine maturation, in the manner inferred in the Flecknoe-Brown article. The STAKVAT system uses oak walls and internal oak insert “battens” which can be adjusted up or down or equal to oak barrel regimes.

The oak walls are reclaimed to then become the internal battens and so on. We know from actual oak/wine analysis, which is done on a frequent basis, that the desirable compounds extracted from this oak are at various levels as required by the winemakers.

For complete and finished wine, stainless steel inserts (membranes) are applied between oak and wine to give a totally inert environment as required by the winemaker. Oxygen would be detrimental to wine at this point. Particularly in the current climate of over-supply, winemakers are not likely to require rapid oxygenation of wine, and STAKVAT provides an ideal means to control and prolong maturation.

We feel the STAKVAT development has pioneered a change in thinking away from “barrel mindset” to a change in culture and gradual acceptance by the wine industry of other effective alternatives in oaking and maturing wine in larger volumes.

“Barrel Reclaim” and “Heating of Oakwood” are other patented inventions being “spin off” technology from the STAKVAT invention and allow the recovery of high quality oak from decommissioned barrels processing and application of this oak to wine.

Winemakers using this system have experienced barrel like results in stainless steel tanks at very low cost with rapid oak extraction, excellent integration of the oak compounds and with definite and distinct maturation characteristics.

In closing it is very important to realise stainless steel tanks and vats are a very versatile means for the storage and maturation of all wines.

Stainless steel tanks and vats will retain their purchase value for life as an asset and this is particularly important if a wine production business incorporating stainless steel storage as a major part of its infrastructure is sold.

In this circumstance also oak barrels are still very valuable as an oak source even after decommissioning as they can now be reclaimed using Ausvat’s reclaim technology to oak wines. One reclaimed 225-litre barrique will oak 2000 litres of wine using the same oak. Ausvat has always encouraged traditional coopering input into the barrel reclaim function as we feel it is just a natural progression on from the initial barrel produced by the artisan cooper.

As said above, these important industry advancements and progression forward would not be possible without the evolvement of the “STAKVAT” invention.

By Peter Warren, CEO Stakvat Pty Ltd, Ausvat Pty Ltd, Westbridge Pty Ltd.



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