|
A Technical Guide for Wine Producers
|
|
RECENT ARTICLES | WYNBOER HOME
WINE IN WOOD AND WOOD IN WINE
Innovative technology and oak products
With the international emphasis on sustainability, the focus remains on oak barrels. The limited penetration of the inside of barrel staves by wine means that a very low percentage of the wood is actually utilised. The convex shape of the staves, which results from the heating and subsequent bending of the oak staves, gives the barrel its characteristic shape, but also makes it impossible to turn the unused oak inside out so that it may be used inside another barrel. Many flower tubs therefore contain a high percentage of unutilised oak that had been purchased at a high price.
A report about barrels and oak usage in North America is compiled annually to identify certain trends in the market. The findings of the 2008 report may be summarised as follows:
Recent developments involve various new oak products and related technology.
Radoux cooperage has developed an infrared system that instantly determines the extractable tannins in oak staves. Known as Radoux Oak Scan it will scan more than 50 000 French barrels in their French cooperage this year. The process is executed by moving oak staves on a conveyor belt past an infrared spectroscope, where the extractable tannins are determined. The tannin strength of each stave is documented and identified with a bar code, according to which similar staves can be grouped together for use in barrels with specific tannin potential. The technique can also be used to ensure a greater degree of consistency in quality characteristics when purchasing raw oak from plantations. Barrels that have been sorted using this technique are not expected to be more expensive.
Rennaissance cooperage has developed an ecologically friendly barrel, known as Barrikit, which is easily constructed. The patent halves the use of quality oak in the composition of a barrel. Oak staves with a fine grain are used on the inside of the barrel and standard oak staves on the outside. The different layers are affixed and the shape adjusted by thermal treatment. Oak from the same tree may therefore be used, while oak that is usually rejected by coopers can be used for the outside of the barrel. Seeing that only 3 millimetres on the inside of a barrel is penetrated by wine, the same effect can be achieved using the new design. Barrels of different shapes and sizes can be obtained and assembled by wineries themselves at a final cost that is approximately 40% cheaper than standard barrels.
Various cooperages offer staves and oak segments that are able to reproduce the style of specific French wine regions. Oak Solutions offer oak staves known as Latitude 44° Bordeaux, 45° Rhone and 46° Burgundy, that have been developed for specific cultivar wines and impart extra complexity to the wine within a 4 to 6 month maturation period. Boise France on the other hand combines oak segments with different degrees of toasting that imparts a specific French regional character to the wine.
In recent years there has been an increase in the occurrence of a mouldy character in wines caused by new barrels. Excell Laboratory, a French company which has facilities in four winemaking countries, has developed the Check List Barrique method to determine the occurrence of trichloro anisol (TCA) and tribromo anisol (TBA) in barrels. This is based on the analysis of water samples of new barrels, first taking a random sample and then individual barrels, if necessary. For many years ETS Laboratories have offered analytical services to determine the TCA and TBA content in new barrels. Their analyses are based on oak samples that are taken from the barrels and subsequently soaked in acqueous solutions.
The Californian biotechnology company, Z-Wine Co, has developed a quick method to monitor the occurrence of Brettanomyces in barrels. Known as Z-Brett Assay, the company claims it is the quickest, easiest and cheapest method for this purpose. More information about this method can be obtained from the website www.unitechscientific.com (Anonymous, 2009).
References
Anonymous. 2009. Oak Round-up. Wine Business Monthly, May 2009: 32 - 35. |
|
Wynboer is incorporated in WineLand, magazine of the SA wine producers.
Visit our sister sites:
|
| UP |
COPYRIGHT (C) 2000 WineLand |