Reprinted with permission:
The Australian & New Zealand Grapegrower & Winemaker
August 2008 - Issue 535 • www.winebiz.com.au

Table 1 (click here for larger view)

Oak purchases comprise a large proportion of a winemaker's budget (Table 1) with Australian winemakers buying anywhere from 30 to 100 percent new oak for premium, high price-point wines annually, depending on oak budgets and desired wine styles.

In recent years more research and investment has gone into methods of extending the life of oak barrels, including reusing barrels through shaving and retoasting and reclaiming oak barrels for ongoing use. Barrels are being used well into their fifth vintage, sometimes more, along with the use of staves or other oak alternatives to add fresh oak tannins and flavors as the barrels age. By this stage (third to fifth year since purchase), barrels are being used in medium to lower price-point wines, helped along with judicious use of oak alternatives.

The need to reclaim and reuse oak is not a choice driven purely by dollars. There is an environmental argument to consider as reusing wine barrels saves forest and energy resources spent transporting new barrels around the world (and as one supplier puts it, just how many half-barrel flower pots do we really need?). A third and vital influence on an oak purchase decision is the price-point and wine style to be produced.

In the USA, barrel reconditioning (shaving and retoasting) is coming back into vogue (Ecker); but one Australian supplier, Peter Warren of Ausvat, believes Australian winemakers have stolen the march on countries such as the U.S. and France when it comes to extending the life of oak.

Barrel reclaim: quadrupling oak surface

"The main difference with what we are doing with barrel reclaim in Australia and what is being done overseas is that we are not reclaiming the barrels to make back into barrels again as they are doing in France and the U.S. With our development, it's about the amount of oak contact surface area you can get out of one decommissioned barrel. As an industry I think we are a lot further down the track with barrel reclaim applied oak products than they are in the U.S. or Europe," Warren said.

"The barrel reclaim development in Australia by Ausvat and industry is about turning the available existing wine oak contact surface area of each used barrel (a barrique barrel about 2m2 per barrel) into 8m2 of contact surface area of reclaimed oak (excluding the barrel heads). So you quadruple the existing oak contact surface area. This brings the oaking costs down dramatically from $1 per litre over three vintages in a barrel regime to 7 cents per litre in a tank regime.

"The method is about pulling each barrel down into individual staves, band-sawing the wine-affected oak off each stave, then splitting the remaining sound oak into two thin 'battens.' These battens are then shaved each side to expose wood fibers and grain structure. The battens are straightened (from barrel curvature) using heat (toasting) and pressure, drilled each end, then put back into wine tanks on stainless steel rings.

"We have now extended the barrel reclaim process to include the barrel heads. Similar to barrel staves, the barrel heads are pulled down into individual staves, wine-affected oak taken off, staves split into battens then toasted. The main difference here is the resultant oak battens reclaimed from barrel heads are crushed into oak chips after toasting. These oak chips are weighed and put into infusion bags for wine immersion in tanks. In this form, the oak chips have a huge surface area. So now the whole barrel is reclaimed," Warren said.

There is an ongoing argument that reconditioned, re-used or reclaimed barrels can never replace the characters of fresh new oak. On the other hand, proponents of shaved or reclaimed barrels say "the re-used barrels can impart a soft oak character with less of the hard tannins found in new barrels, particularly with American oak" (Ecker).

Samples of the Ausvat oak reclaimed product

According to Barossa-based wine consultant John Weeks of Wine sans Frontieres, one of the issues with reshaving barrels and toasting them again is caramelized flavors from residual wine. "I know the technology has improved a lot in recent years but in my mind caramelized flavors are still a potential issue. One of the other alternatives that I think has some depth to it is to replace the barrel heads without shaving the barrel--and this way you can also have French and American oak in the same barrel," Weeks said. "I do feel that oak barrel usage in general is reducing but the use of alternatives like chips, staves and powders are increasing globally. Globally speaking, most wines sell at entry-level pricepoints so while winemakers are trying to over-deliver wine styles, they can markedly increase flavor profile with some integrated alternative oak treatment," he said.

"Use of oak alternatives has improved markedly as well with other winemaking tools like micro-oxygenation and also the timings of usage as well (primary ferment, MLF). Most wineries that I see around the world are using more and more oak alternatives to barrels in some form or another," Weeks said.

Director/winemaker of Shingleback John Davey, who utilizes the Ausvat barrel reclamation system at his McLaren Vale winery, agrees with Weeks about the possibility of caramelized flavors from shaved barrels. "My experience has been that not all of the wine-soaked wood is removed in the shaving process and when toasting the remaining wine cooks and caramelizes creating these burnt-toffee characters that can be detrimental to the next fill of wine," he said.

"Wine in new oak will develop slightly faster than wine in older oak and the oak influence (flavor and tannin) will be much more pronounced. Barrel-maturing wine influences style and obviously the cost matrix of the wine. Filling, storage, rack and returning wine, emptying and washing barrels involves considerable labor and specialized warehouse space and, therefore, cost. We produce a number of labels at different pricepoints and with distinct styles. Red blends can be made from all barrel-matured wine, generally from barrels of various ages and types, or from a combination of barrel and tank-matured wine," Davey said.

Value-adding to the new oak purchase

West Australian wine industry consultant Cathy Howard has trialed and used shaved and retoasted barrels over the years and found a downgrade of quality when using these options. She doesn't recommend using shaved or retoasted barrels to her clients but has recommended the use of oak alternatives, both in barrel and in tank.

Howard lives and works in the Margaret River region where she and her husband own a vineyard and she makes wine for their own wine label, Whicher Ridge, as well as providing consultancy services.

As may be expected from a premium wine region such as Margaret River, many winemakers there continue to use a higher percentage of new oak barrels for their premium ranges, but Howard says they commonly use oak alternatives combined with wine maturation techniques in tank, such as micro-oxygenation, for medium to lower price-point red wines. "The cost of new barrels for smaller makers is quite significant and many simply can't afford the outlay for significant numbers of new barrels, and using good quality oak alternatives in older barrels is a very good option offering significant savings without loss in wine quality," Howard said.

"Another option for small makers is to mature their medium to lower pricepoint wines in tank along with oak staves. Consistently better quality wine is produced, using good quality commercially available oak alternatives, compared with using a higher proportion of older oak barrels in the blending mix.

"There are also labor savings in the winery as a spin-off of using fewer barrels and maturing reds in tank with tank staves. Far less time is spent on barrel management such as topping," Howard said. Reclaimed barrels are not part of the 'bag of tricks' used by Cathy Howard's clients in Margaret River. She said none of her clients currently use reclaimed oak.

"The strong Aussie dollar has had some effect on the decision to continue purchasing new barrels but there are other pressures, such as increasing freight costs, a major concern for West Australian wineries, and the need to reduce input costs in the production of medium to lower price-point wines that leads to the decision to purchase fewer new barrels. This is where the use of and demand for oak alternatives has increased dramatically over the past few years.

"Commercially available oak alternatives now provide a range of various toasting options to enhance and improve tannin and flavor profiles. I always conduct bench trials with various alternatives on the wine to be treated, to find which best suits and improves the wine structure, before recommending particular alternatives for my client to purchase.

"I have advised my clients to use barrel staves in older barrels for smaller volume batches and for larger volume medium to lower price-pointed red wines, I have advised retiring the old barrels and changing to maturing the wine in tank with tank staves and utilizing micro-oxygenation or a similar maturation treatment such as TankMate.

"With shaved barrels (shaved, then retoasted or left untoasted), my personal experience is this results in lesser-quality wine and I don't advise my clients to do this. If winemakers were going down the path of shaving barrels to extend their useful life, I'd recommend to only shave barrels they know the history of, that have been well maintained and are known to be Brettanomyces and taint-free.

"In regards to barrel reclaim as a source of oak alternatives for my clients, I would recommend trialing this first, using some of their barrels and comparing against commercially available oak alternatives. If the outcome of the trial was improved wine quality using the barrel reclaim process, I would not hesitate in recommending this option.

"I would recommend to winemakers considering barrel reclaim to only select barrels they know the full history of, made from high quality oak and known to be Brettanomyces and taint-free. Barrels constructed with thin staves would not be suitable, as the shaving down to fresh oak may leave the staves too thin," Howard said. While having no direct experience with using reclaimed oak, Howard said opinions of West Australian winemakers she'd spoken with about the products remained mixed.

"A local cooper in Margaret River offers this type of work, and very good results have been obtained by one winery here. With the reclaimed barrel staves, flavor profiles are better and tannins are more delicate (which suits the wine styles being made) when trialed against commercially available oak alternatives. High quality French oak barrels are pulled apart at their winery, shaved back to fresh, uncolored oak and left to air dry for two to three weeks. The staves are cut down into blocks, then toasted, placed into infusion bags and used for maturation of reds. The benefits for the winery have been a cheaper alternative option compared with commercially available oak alternatives, and provide a viable alternative to further utilizing stocks of older barrels that would otherwise be destined for flower pots.

"For two other winemakers, results have been less positive. For one winemaker, the results of trials were inconsistent, and they have obtained much better wine quality results and consistent wine quality improvements when using commercially available oak alternatives. For the other winemaker, the results of their trials gave lesser quality wines and, as a result, they do not use reclaimed barrel staves. I would certainly consider using reclaimed barrels, if the results of the trials on the barrel reclaim products showed positive benefits to wine quality. As well as solving the annual issue of the disposal of old barrels, it is also a way of value-adding further onto the original high quality oak barrel purchase, with the added benefit of a cost saving down the line by substituting the reclaimed barrel products for purchased oak alternatives," Howard said.

Ecker, Bob. How companies are rejuvenating barrel life and saving trees in the process. Wine Business Monthly, May 2004.