OAK AND SUSTAINABILITY
Transportation and storage in barrels is a very old technique, already used 2 000 years ago. It's more solid and lighter than terracotta and it can roll. It also has an influence on the wine itself as it allows small oxygen ingress, smoothening tannins, improving colour stability in red wines, reducing the need of sulphur dioxide to protect the wine, helping wine clarification and stabilisation, improving its ageing ability. It also brings flavours (vanilla, coconut, cloves, coffee...). Oak vessels vary a lot in size, from big foudres to smaller barrels.
Oak tends to be used on red varieties and neutral white varieties (chardonnay, pinot blanc). Aromatic white varieties will usually not benefit from the oxygen exposure and oak flavours (riesling, sauvignon blanc, muscat).
In the 1980s, the demand for oak barrels increased significantly, when the very influent American wine critic Robert Parker rewarded the influence of oak flavours on wine.
More recently, the rapid development of new wine markets (like in China) and spirits production also had an influence on this rising demand. Wine barrels demand is now expected to rise at about 5% yearly in upcoming years (source), and this doesn't include competition from other industries (furniture and coffins for instance).
Types and producers
There are three major types of oak used for barrels production. The European oak, finely-grained, which adds subtle flavours to the wines (spices); American oak, with coarser grain and stronger flavours (vanilla, coconut); and Eastern European oak, that sits in-between. Famous producers include François Frères, Séguin Moreau, Canton and Nadalié.
Choosing the right producers is crucial for winemakers. It will impact the provenance, type, size, toasting level (level of fire to which the barrel is exposed when it is shaped), quality and marking of the barrels.
What about sustainability?
It's not new, forest degradation and deforestation are strong threats and impact biodiversity and life balance. It takes about 60 years for American oak and 150 years for French oak to grow an oak tree for barrel production... Additionally, only half of American oak can be used for barrel making, and it's reduced to 30% for French oak (unlike American oak, it can't be sawn and has to be slipped, leaving more wood on the side). So one tree can only produce between 2 and 5 barrels. One barrel loses its flavours in 2 to 3 years, so producers have to invest in new barrels quite regularly.
As the demand increase, there won't be enough trees and enough time for them to grow to satisfy everyone.
Organisation like PEFC (based in Switzerland) promote the sustainable management of forests, so winemakers can buy only certified vessels, sourced from a conscious management of oak trees. It implies higher costs, but consumers are getting more knowledgeable, they know where to get the information. They already expect full transparency and environmentally-friendly practices from brands they buy. And naturally, beyond the marketing asset, it's just about doing the right thing and preserving forests.
Yet, the majority of winemakers can't get oak vessels from certified sustainable forests: the quantity is limited and prices can be too expensive, from few hundreds to a thousand euros.
Some winemakers only buy used oak vessels, which is cheaper. Their wines still benefit from the low oxygen ingress but don't get oak flavours anymore.
Others use oak alternatives: chips, staves, powder, that they add to the wine during fermentation and/or maturation (even for premium wines). This is cheaper, can come from oak that would otherwise be wasted, has a lower carbon footprint because it's easier to transport, and allows a more precise control of oak effects on the wine. It is however difficult for winemakers to be transparent about it, as this practice is synonymous with bad quality wines for consumers. Additionally, there are also questionable practices, like adding oak extract in the wine.
Another alternative is to use other species of trees. Acacia and chestnut show great results for some producers. But regarding forests' sustainability, it just moves the problem to other tree species.
In parallel, more and more winemakers (from inexpensive to super premium wines) now prefer to reduce the use of new oak, to enhance the purity of their fruits and the expression of their terroir. This trend is backed by a rising consumer preference for oakless wines. Will this trend be confirmed in the upcoming years?