The impact of oak

Oak in wine is like salt for cooking: in some cases it’s an essential seasoning that adds to the depth and flavor of the wine, but in other cases, oak, like salt, can be overdone, drowning the flavors of the wine with flavors and aromas of vanilla and wood. But it’s a lot easier in theory to understand what oak is and how it impacts wine than it is to be able to determine the impact it has on the flavors when you’re actually tasting a wine and not just talking about it. But luckily, you can train your palate. Here’s how:

One of the easiest ways to see the dramatic night and day effect oak can have on a wine is by drinking an oaked and an unoaked Chardonnay. When a Chardonnay sees no oak, the fruit shines through, delivering a crisp acidity that isn’t often seen in Chardonnay. The quintessential vanilla and cream flavors one gets from a Chardonnay spending time in oak are absent, and often the buttery flavors are gone as well, since many unoaked Chardonnays are not allowed to go through malolactic fermentation, whereas almost all oaked Chardonnays are – but let’s save malolactic fermentation for another article.

In tasting the two styles side by side, you’ll also be able to notice how oak can impact a white wine’s color. When a white wine spends time in oak, the pale yellow, almost translucent color you see in your glass of unoaked Chardonnay morphs into a deep dark yellow, resembling straw. That color change is the oak at work, imparting a bit of the wood’s tone to the lighter wine – just like how a charred oak barrel turns white whiskey golden brown.

But what wines should you try if you’re looking to understand oak’s impact on red wines? For that, you need to turn to Rioja. The reds of Rioja are made from the Tempranillo grape and they can vary in the amount of oak they see, from none at all, to two years or more in an oak barrel.
Rioja color levels When Rioja is young and spends no time in oak at all the wines have the classification of Cosecha Rioja – you can easily identify these bottles because there will be a small green square on the back of the bottle. In these wines you’ll experience the unadulterated flavors of Tempranillo – bright red fruit and high acidity – which may taste “fresh.”

But as Rioja moves up the classification scale from Cosecha to Crianza, the wine starts to spend a bit of time in oak – it actually must spend at least a year by law. Now you can start to taste the vanilla and spice the oak can impart, especially when tasting the Crianza alongside the Cosecha.

Finally, it’s time to try a Reserva or Gran Reserva. These bottles are required to spend one to two years in oak, and it’s here that you’ll observe how oak can dramatically influence a wine’s tannins, since, like a grape’s skin, seeds and stems, oak has tannin as well that seeps into the wine as it sits in the barrel. You’ll notice how much more dramatically your palate is dried out than when you had your original glass of Cosecha, plus you’ll pick up on the richer, rounder flavors thanks to the wine spending a good amount of time in wood. It’s these wines that will age a long time, and much of that is thanks to them spending a bit of time in oak.