Oak's Impact on Wine

Oak isn't a bad thing.
by Erin Henderson
Years ago I attended a tasting for Frescobaldi, the centuries-old Italian winery that's the creator of some of the world's most recognizable and longest lived wines. The current president, Lamberto Frescobaldi, the 30th generation to take the helm, was discussing the wines and the company's view of using restraint in the oak aging of their wines.
"In the 80's it was the fashion to have lots of oak," he told the crowd. "It was preferred to taste oak, not the wine."
Now, fashion has changed – and has for years – as winemakers the world over work to dial back the oak influence, instead of dominating, working more in a symphony.
Still, as the saying goes, it takes years to build a reputation, and minutes to destroy it.
And such is the blip in time with heavily oaked wines. Decades later, I, and I know many of my colleagues, continue to encounter wine drinkers who claim they, "don't like oaky wines."
My suspicion, when people tell me this, is they remember the wines of yesteryear (and the handful that still exist) that taste closer to a butterscotch sundae than that of a lively and fresh wine. And these wine drinkers use "oaky wines" as a pseudonym for Chardonnay.
So, before we get into the meat (the wood?) of today's topic, let address ...
The Elephant in the Cellar: Chardonnay and Oak
When I was in sommelier school, an instructor told us, "Chardonnay is like chicken; it will take on whatever flavour you give to it."
So, if you choose to use a brand new, American oak barrel with loads of charring to age your Chardonnay, the wine will come out deeply golden, and smelling of vanilla, butterscotch, and coconut. The flavour will be similar, with the unctuous texture of butter and cream.
However, if you choose to age your Chardonnay in stainless steel, as is often the case in Chablis, your wine will taste bright and crisp, with lip smacking notes of green apple, lime, and flinty minerality.
So we can't always assume Chardonnay is an oak bomb.
You may also like: A Chardonnay for Every Taste
So, What's the Point of Oak?
Oak plays many crucial roles in winemaking beyond giving flavour and aroma.
The wood itself is porous (on a very micro level, of course), which allows for the slow entry of oxygen and evaporation of alcohol (wines kept in barrel for years will inevitably lose volume which is known as, "the angels' share") This breathing process allows for a wine to soften and develop complexity. This also helps with a wine's longevity after it goes in the bottle. (Most wines that can age for decades have spent a good amount of time in oak barrels.)
Oak also, believe it or not, has tannins, the astringent compounds found in grape skins and black tea. But with oak these tannins leave a subtle imprint on the wine, more of a supporting character rather than the star, and creates a balanced and interesting wine.
Finally, the barrel helps provide a creamier, richer texture to the mouthfeel of the wine.
Where Does Oak Come From?
Oak is sourced from many places including Canada, Hungary, and Croatia.
But by a large margin the most popular countries to supply quality oak are France and America.
American oak tends to leave more baking spice notes: toffee, vanilla, and coconut in white wines; clove, coffee, and mocha in red wines.
French oak leaves more woodsy character: saw dust, smoke, and, well ... wood.
Barrel Size
Like many things in life, size matters. Smaller means more wood impact on the wine, large means less so. The most common size that you will have likely seen during a tour of a winery is the Bordeaux barrique, which holds about 225 litres of wine (59 gallons.)
New Oak Versus Old
A barrel can typically be used up to seven times if so desired. And just like reusing a teabag, the impact of the barrel weakens with each use. But it still helps with the micro-oxygenation of the wine, allowing complexities to develop and the wine to mellow, without a significant impact on flavour.
Toasting
Barrels will have a certain amount of toasting before being used. How much depends on what the winery wants to achieve. Some barrels can be charred completely black for intense flavours and aromas, some barrels barely touched for a more delicate impact.
Can Only Oak Be Used for Barrels?
Oak is by far the most popular wood for wine barrels because it is durable, water-tight but still porous enough for micro-oxygenation, and flavour impact is controllable.
Chestnut is used in some wineries in Italy, and Acacia has been occasionally used for a floral note. Pine had been used in Greece for Retsina, which is a resinous wine of acquired taste, but it's that distinct note that makes it unappealing for modern winemaking.
Chips, Staves, and Powder
Some wineries might look to produce a wine with oak influence but at a lower cost, as is often done with large-scale, or bulk, wine production. Wines will be aged in stainless steel tanks but have wood chips or planks added to the aging wine. This is only used to add flavour and aroma, but ignores the benefits of micro-oxygenation, so wines will not develop the same complexity or aging potential.
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