Let’s Get Barreled! A simple explanation of oak in wine

The Facts

One standard wine barrel holds 60 gallons of liquid. This equates to about 25 cases of wine or... hold on let me do some math.... (25 cases) x (12 bottles/case) x (5 glasses/bottle) beep boop beep beep boop = 1,500 glasses of delicious, mouth puckering vino.

Indeed, Mr. Barrel.  Indeed. 

Indeed, Mr. Barrel.  Indeed. 

Wine barrels are almost always made from oak and have two main purposes/functions besides containing our prized liquid: Flavors and Aging.  Why is oak so special you ask? Not only is the wood extremely dense, tight grained, and sturdy, Oak provides flavor compounds that can improve and enhance wines when used correctly.

This wine tastes…oaky?

Wines aged properly in oak barrels take on another dimension of flavors and aromas. These can be as simple as vanilla, caramel, coffee, cedar, chocolate and cinnamon. Or we can get real fancy, lift our chins a bit and start speaking about nuances of redwood bark, worn leather, cigar box and forest floor.

A wine barrel will add flavor character to wines for roughly four or five years. The most dramatic flavor influence will be perceived after the first year the barrel is used, which is why new oak barrels are highly sought after for certain styles of wine.  After the fourth year a barrel is considered ‘neutral’ or ‘mature’ and no longer contributes oak flavor. These older barrels can still be used for aging.

Barrel Science

Each barrel is shaped, fitted, and toasted by hand over an open flame by an artisan called a ‘cooper’. The result is a liquid tight, savory masterpiece. Since oak wood is porous and breathes, the barrel is not actually ‘air tight’. As a wine ages in barrel, it is exposed to tiny amounts of oxygen that soften the harsh, astringent characteristics of the wine. Over time, tannins mellow and sharp freshness eases into a richer, more focused fruit character. Barrel aged chardonnay is a perfect example. The wine shows flavors of crisp green apple before barrel aging commences, and after a year in barrel becomes an opulent baked apple pie with cinnamon spice and a decadent creaminess.  Dark, angular reds require longer time in barrel to curve their rugged edges and soften the mouth feel.

A bottle of Eight Sides Zinfandel in the cellar with its friends, the barrels. 

A bottle of Eight Sides Zinfandel in the cellar with its friends, the barrels. 

If a wine is aged too long it is susceptible to oxidation and eventually, god forbid, turns to vinegar. Wines in barrel must continually be monitored and “topped” or refilled every month to minimize the head-space and reduce risk of oxidation. Minimal amounts of sulfur are often used to reduce the rate of oxidation and keep wines free of microbial spoilage.


Winemakers create barrel aging programs or formulas to create a wine with the perfect amount of oak influence. The amount of oak flavor and the time a wine spends in barrel is somewhat of a balancing act.  For example, a Cabernet Sauvignon will stay in barrel for 18 months but only 1/3 of the barrels will be new. This results in a mature wine with the optimal amount of oak flavor.

Oak barrels are expensive and a new French oak will run you about $1000 dollars a pop on average. American barrels will be about $400. What’s the difference, you ask? Ya gotta pay for that French finesse. American oak is notorious for big, powerful flavors that in unskilled hands can result in awkward flavor profiles and the infamous 'wood shed' effect.  French oak is pricey yet delivers subtleties that integrate more harmoniously with the wine.  However, when done right, wine aged in either barrel variety can result in a balanced and enjoyable wine.

With wine, there is no greater learning tool than tasting. On your next trip to the local wine shop, ask the sommelier for a wine with little oak influence and for one with big powerful oak flavors to see which style you prefer.  Then educate him on how much you know about wine barrels from reading this blog. Cheers :)

- Grant