Bordeaux - It has to be one of the most serendipitous accidents of history.
France's towering oak forests, first cultivated generations ago for Louis XIV's warships, today provide the raw material for the barrels that help produce the best wines of Bordeaux, perhaps the finest expression of the heady alchemy between oak and wine.
“We are lucky in our business, because these trees were initially meant for naval construction, not barrels,” admits Jean-Luc Sylvain, a third-generation barrel-maker, or cooper, and CEO of Tonnellerie Sylvain in the south west of France.
“But the fact that we selected and cultivated a variety of oak and forced it to grow in height not girth, has a chemical effect, which has a consequence for wine.
“There is something that happens between the oak tannins and the wine tannins, you have a marriage, an alchemy that takes place in the barrel.”
With an annual production of 500,000 barrels, France's coopers dominate the global trade, relying on the forests first cultivated on the orders of Jean-Baptiste Colbert, minister under Louis XIV in the 17th century, in his effort to produce tall, perfect oaks to build a navy capable of challenging England's maritime dominance.
“We are the only country in the world to cultivate oak,” said Sylvain, with each generation tending saplings that won't reach their prime for another 200 years.
“These trees are more appropriate for making wine barrels than what you can find naturally in the forest.”
The French forests are managed to encourage tall, exceptional trees without branches or knots. The result is timber with a tight grain and the quality of tannins and aromas that improve wine, says Sylvain.
But that is a recent discovery. The humble barrel has spent most of its long relationship with wine serving two mundane purposes - storage and transportation.
Winemakers discovered the barrel's true calling at a point when many were abandoning it due to its bad reputation for harbouring mould, and ruining the wine. Only when cement and stainless steel became available did its true worth reveal itself.
“They noticed something was missing in the wine not aged in the barrel,” said Sylvain.
Research in the 1970s and 80s showed that a clean oak barrel was an invaluable multi-tasker.
“The tannins in the wood balance with the tannins in the wine, and it helps develop aromas,” said Charles Chevallier, director of Domaines Barons de Rothschild, including Chateau Lafite, one of Bordeaux's elite properties.
Lafite is one of the few estates to run its own cooperage, crafting 2,400 bespoke barrels a year and providing in-house R&D on the marriage between wine and oak.
“For us, above all the barrel is a physical phenomenon. It allows for fining the wine with the racking of the lees every three months. When we put the wine in a small container, the sedimentation happens naturally,” said Chevallier.
“And the micro oxygenation that happens through the wood is necessary for aging fine wine.”
The barrel, as it turns out, excels as a discreet two-way escape route.
“During the barrel aging, water and alcohol evaporate, concentrating the wine, little by little, this is the angel's share,” said Dominique de Beauregard, director of research and development at Chene and Company.
“There's also a tiny amount of oxygen that enters. Only a barrel can do that. It's terrific.”
Unfortunately for wine lovers, only a tiny splash of the world's wine sees barrel time - around two percent according to the French federation of coopers, whose 50 members supply 80 percent of the world's wine barrels.
This is where oak chips and staves come in. An anathema to a grand cru classé producer, they are an economical option for wine that can't justify the 600 euro price tag for a 225-litre barrel, say experts.
“Oenological wood is used for two main reasons: to imitate barrels or to augment the fruitiness in wine. For example, if you want to enhance the fruitiness, you can add granulated oak chips during fermentation. If you want to add barrel aromas, you can add staves to the finished wine. These are both used all over the world for ordinary wines,” said de Beauregard.
Adding aromas to the wine is one of oak's more noticeable tasks.
Some aromas develop during cultivation, with different forests producing subtle differences, then the drying stage encourages sweet notes like vanilla while banishing bitterness, says de Beauregard.
Toasting the inside of the barrel unleashes a sensory cornucopia that de Beauregard articulates as: “Fresh wood, vanilla, coconut, cloves, grilled almonds, toast, mocha, chocolate, dark chocolate, caramel, coffee, toasted coffee and smoke.”
Winemakers pinpoint their preferred forest and the intensity of the toast, as well as the percentage of new barrels, according to the style of wine they make.
“The barrel must not dominate the wine. You put the wine in the barrel, not the barrel in the wine,” said Chevallier.
Alternative oak products may have their role, but nothing quite matches the barrel.
“If you talk to a winegrower, his dream is to age his wine in barrels,” said Sylvain. “If he doesn't, it's because he can't afford it, due to the price of his wine.” - Sapa-AFP