Alternative oak additives have been used in the wine industry for approximately 30 years. The price of new barrels was the initial motivation for its development, but the image of alternative products was previously negative and especially traditional wine purists were also negative about their use. The suppliers of the products became very innovative, however, which led to different forms of alternatives. Winemakers also experienced over the course of time that alternative products can comply with certain requirements that cannot be met by barrels. The magnitude of the market consequently increased considerably and their use has become a standard practice for specific aims at the most cellars. This is also confirmed by the increase in the number of local and international suppliers of the products.
One of the main advantages of the manufacturing of alternative additives for cooperages, is the better utilisation of timber in comparison with barrels. The physical specifications of alternative wood additives ensure that different sizes thereof can be used, but this advantage for cooperages can be an important disadvantage for cellars, because the quality of the wood used for the products cannot be verified easily and the integrity of the cooperage is crucial. Contrary to the variation of individual barrels, the specifications of alternative wood additives can be maintained easier, which improve the consistency of their use.
Seeing that the contact between wood and wine ought to be better with alternative wood additives than barrels, their physical measurements are important to ensure optimal wine contact with subsequent extraction from the wood. It is illustrated by the specifications data in Table 1.
Although alternative wood additives will most probably never replace traditional barrels, the suppliers’ goal is to get as close as they can. It must rather be seen as an alternative wood treatment than a barrel alternative. The suppliers consequently reacted innovatively in different ways. Most suppliers of both French and American oak products, due to the quality of timber used, is much closer to barrels than 10 years ago. Except for the wood quality being better, cutting technology is also used to ensure that optimal wood contact is obtained. The spectrum of flavour profiles which can be obtained, was also extended considerably by the better understanding of toasting techniques and development of new ones. The required extraction period was also shortened in order to obtain the required wood flavours quicker. These innovations went with a product price that is still considerably cheaper than barrels. As result of the lower price, it is consequently also possible to create a required wood character in cheaper wines, which are sold at a younger stage. Many of the changes were initiated by winemakers. The younger generation of winemakers are not so tradition-bound and are consequently willing to experiment with new products like alternative wood additives (Siegel, 2016).
The changed use and perception of these products are also confirmed by winemakers:
Although its price remains a significant factor, the influence of alternative wood additives on the style and quality of wine has also become a determining factor in its choice. Winemakers realise that specific products and variations thereof can impart required specific wood characters to wine. It can range from a subtle wood character in Chardonnay to a sweet, outspoken vanilla character in red wines.
Different products like staves, smaller products or chips are used during the different stages of winemaking like prior to or during alcoholic fermentation or during malolactic fermentation (MLF) or maturation.
Both French and American oak are used.
Alternative wood products are also used for premium wines, especially if wood contact is required during MLF or prior to maturation.
More expensive alternative wood additives are also acceptable, if the required results are obtained with them.
Certain wood brands or types suit specific cultivars or wine styles and it is important to evaluate it or request the experience of other winemakers, before it is used commercially.
The use of alternative wood additives has different advantages. Commercial red wines can be marketed sooner, more structure can be added to wines, colour stabilisation can be improved and more oak flavours, but less tannins are extracted over a shorter period.
Staves must be at least 9 mm thick, but preferably 12 mm or more to impart sufficient structure to wines.
The duration of wine contact must be managed cautiously, seeing that results occur much faster than with barrels. Wine balance is a critical issue of wine quality and it is consequently important to prevent excessive wood character.
Winemakers are willing to talk about the use of alternative wood additives, because the stigma attached to them has decreased.
It will be welcomed if alternative wood additives can be connected to specific wood origins.
Roundtable: Oak alternatives. Australian & New Zealand Grapegrower & Winemaker, September 2015: 82 – 84.