I hear a lot of people in my region (Languedoc-Roussillon) saying that they don’t like the flavour of barrel-aged wine. This seems odd because nearly all the most famous wines of France are aged in barrels.
The close relationship between wine and oak goes back centuries. Originally chosen simply because it is watertight and easy to work, the effects that it has on wine have become increasingly appreciated, especially in high quality and highly-priced wines.
Barrel-ageing is the preferred method for making great, age-worthy wines from tannic grape varieties like Cabernet Sauvignon, Merlot and Syrah. Meanwhile in Burgundy, oak barrels help to bind the fragile colour of Pinot noir and add structure and body to the wine.
White wine, notably Chardonnay, is often fermented in barrels as well as aged in them, giving a buttered toast richness and glossy texture to the wine as well as clarifying the wine by removing the hazy grape proteins, which react with the oak tannins from the barrel.
The aromas and flavours that oak imparts, of toast, coffee, caramel and vanilla depend on the type of barrel used, how old it is and how long the wine remains in it.
Oak barrels are toasted, or fired, on the insides. The level of toasting and the way it is done will alter the flavour of the wine. A light toast will impart toasted bread, resin and wood. A high toast will give roast coffee or caramel. Barrel-makers, tonneliers, use either traditional fires, blowtorches or ovens to toast the wood and each method has subtly different effects on the wine.
The choice of the wood is also important. France has forests dedicated to the production of oak for barrels which are desired above all others, but Eastern European oak is now also used.
American oak is cheaper than French and, coming from a different species of oak, has a different character. American oak is regarded as preserving the fruitiness of wines and giving more vanilla flavours. It is very popular in the production of Rioja. French oak has a finer grain and more subtle flavour and is therefore the better choice for crafting the fine-structured red wines of Bordeaux and Burgundy.
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All these flavour differences are only really noticeable when the barrel is first used. In subsequent years it diminishes until after three to four years when there is little flavour imparted. These older barrels are referred to as neutral barrels.
However, the reason for ageing red wine in barrels is not primarily to give it additional flavours. It is to modify the structure of the tannin molecules to make them more suited to developing smoothness and perfumed aromas with time.
Oak is porous and the barrels need to be regularly topped up, meaning that the wine is subjected to micro-oxygenation, which combined with the extraction of oak tannins, helps to smooth out the texture of red wine and bind the colour without removing the preservative qualities of the tannins.
It seems counter-intuitive that oak tannins can improve the smoothness of tannic red wines. What is happening at a chemical level is that the oak tannins form long-chain molecules with the grape tannins and these long-chain tannins feel smoother in the mouth than short-chain molecules.
At first, the wine extracts a lot of flavour from the barrel but experiences little oxidation. Leaving the wine in barrel extracts more oak flavours as well as oxidising the tannins. So the winemaker has to decide what is the best length of time to keep a particular wine in barrel. In some regions this has been written into the rules of the appellation. In Spain, and Italy to a lesser extent, length of time in oak is used to differentiate wines into quality brackets such as Crianza, Reserva and Gran Reserva.
These advantages of oak and the association of oaky aromas with high-quality wine, has encouraged wineries to look for alternatives to the costly and laborious barrels. A new French barrel costs around €800 hors taxe. Adding toasted oak staves, chips or even oak-essences to large stainless-steel tanks of wine gives the impression of oak-ageing at a fraction of the cost.
Micro-oxygenation machines which bubble controlled doses of oxygen into a tank can emulate the effect of months in porous barrels. Today, vast amounts of smooth, oaky tasting wines are made without ever having touched an expensive barrel.
While impressive results can be achieved by combining quality oak products with micro-oxygenation, especially during the fermentation period of red wines, the results can often be clumsy and noticeably oaky. In particular, heavy doses of poor-quality oak chips to a poor-quality base wine in an attempt to add flavour or hide faults will usually result in a very obviously manipulated flavour.
A wine which smells strongly of vanilla, coconut or cinder toffee along with a caramelised sweetness on the palate are the hallmarks of oak chips.
Oak barrelsJonathan Hesford
It is probably too many bad experiences with these clumsy attempts that has led certain consumers to believe that they don’t like any barrel-aged wines. It is quite ironic really because the oak chips were used to convince the consumer that the wine was of higher quality than it is.
It is also true that the Languedoc-Roussillon does not have a long history of using barrels to age their dry red wines because they naturally had smoother tannins due to working with riper grapes. Therefore some producers lacked the experience of working with barrels and perhaps were putting powerful red wines in them which didn’t need the effects of the oak to help them soften and improve with age.
There are some wines which suit barrel-ageing, especially if they are designed to improve over time in bottle. There are some which don’t, be that a light but attractively-perfumed wine or a smooth but powerful one. The key point is that use of barrels, or of oak products, should be used to improve a wine, not to try to fool the consumer.
Jonathan Hesford holds a WSET Level 3 and a Postgraduate Diploma in Viticulture and Oenology from Lincoln University, New Zealand. He is the owner and winemaker of Domaine Treloar in Roussillon, www.domainetreloar.com.
