The Difference Between Oak Barrels

Even in well-versed wine circles, oak will often boil down to one question: new or old? But in the last few centuries, oak barrels have evolved.

These days winemakers and other industry pros dig into the nitty gritty details. Is it thick or thin grain? Lightly toasted or heavily charred? Is it larger or smaller than the typical 225-liter barrique? And, maybe most importantly, where does the wood come from—the United States, France or further afield, like Slovenia, Hungary or Austria?

McGrail Vineyards, in the Livermore Valley, bottles different Cabernet Sauvignon expressions: Hungarian (A Jo Elet), American (The Patriot) and French (James Vincent). Sip them side by side and the differences imparted by the barrels are remarkable. The American is powerful, earthy and slightly spicy, while the French boasts more supple tannins and floral fruit. The Hungarian lends notes of cedar and vanilla to offset the bright blueberry.

Winemaker Manfred Ing of Querciabella mainly works with one grape for his Chianti Classico: Sangiovese. And while terroir does most of the talking, Ing also leans on hand-selected oak from Burgundy and Austria to usher his wines to the finish line.

But how, precisely, does the provenance of the wood impact the final outcome? Below, winemakers break it all down.

What’s the Benefit of Oak?

“Oak tannins are difficult to pick up, but they’re very important to how the palate receives the wine,” says Reed Skupny, winemaker at Lang & Reed Napa Valley and Rockhound Wines in St. Helena, California. He compares the subtleties of oak tannin to listening to a rock band without bass. “You know the song and it sounds good, but add some bass and the music is almost three-dimensional.”

But not all oak is the same. Matt Crafton, winemaker at Chateau Montelena, approaches oak as a chef does seasoning. “Oak should complement the natural character of the wine, not overshadow it or fundamentally change it,” he says

It’s like spice in cooking, explains Kevin Holt, director of winemaking at California’s Bartholomew Estate Winery. “Some pairings work while others don’t,” he says. “I have used oak from France, Hungary and the U.S., and each has its own place.”

For example, he’s never come across an American barrel that works with light varietals, like Pinot Noir, but he wouldn’t dream of making Zinfandel without it. The density of American oak helps to slowly extract and fill out the body of wines made from bold grapes, like Zinfandel, which is often (but not always) aged in oak barrels.

“And even within oak, Zinfandel finds different but complementary things depending on where it’s from,” he says. “Zinfandel gains caramel and smoke from American oak, toast and vanilla from French and spice from Hungarian.”

Ing similarly likes to explore the varied nuances. He stocks different types of oak barrels from various coopers, matching up each wine to a barrel that, he says, “allows the fruit to speak without giving it too much makeup.”

But using oak isn’t as easy as marrying a wine with a specific regional wood. “Even in a single location—a specific forest—and a single species, there will be variation in each tree,” says Crafton. “There’s a lot to unpack here.”

Hungarian Oak Barrels

“Hungarian oak lies somewhere between French and American,” says Holt. “There’s a spice aspect that is more intense than French barrels and the impact is less subtle, but it still works well in wines that would be overpowered by American wood.”

The wood hails from the hillsides of Hungary, alongside Slovakia and Romania. Research from StaVin, an oak supplier, has found that medium-toast Hungarian oak shows notes of roasted coffee, bittersweet chocolate and black pepper.

Experts agree it shares similarities to French—but for “60% to 70% of the price,” says Crafton.

McGrail adds, “it’s more spicy: I think baking spice notes like clove, nutmeg and cinnamon.”

She also notes that European oak—French and Hungarian—both add length to the palate, while the tannins imparted by American oak are more abrupt.

American Oak Barrels

McGrail says that American oak, which is denser than its European counterparts, adds “more vanilla notes and toasty aromas and flavors” to her estate Cabernet.

StaVin research cites that American oak lends aromatic sweetness and campfire and roasted coffee attributes and notes of cooked fruit, alongside fullness and mouthfeel.

It’s by far the most polarizing oak. “It’s the most different, stylistically,” says Holt. “American wood tends to be bolder in flavor, and it has more impact on the wine.”

Chateau Montelena’s Crafton finds American oak “gives a more overt flavor impact—coconut, vanilla and occasionally dill, plus it integrates faster compared to French oak.”

One of the downsides, however, is that since American oak has become the darling of spirits producers, it’s not particularly cost-efficient for wineries. “The value isn’t there any more,” he says.

Austrian Oak Barrels

Skupny uses Austrian oak on his Chenin Blanc because it aids in the light touch the grape requires. “We find the subtleties of the cooler-climate Austrian oak lends itself to restraint and slower extraction,” he says.

The most famous of the Austrian oaks is Stockinger, which Jancis Robinson dubbed “the winemaker’s Stradivarius.”

Because of the artisanal nature of the cooperage—it’s run by a father-son team—Stockinger barrels aren’t widely available, but are renowned for their preservation of fruit and discrete expression of oak. Instead of exclusively being used for finishing, they’re often used for fermentation.

Slavonian Oak Barrels

Slavonian oak barrels—hailing from Croatia—are less common, but still highly regarded. The highest concentration is along the country’s borders—Northern Italy down through Tuscany, with specific pockets found amongst Piedmont (with Nebbiolo producers).

Barrels sourced from Slavonia tend to be larger, offering more subtle tannins. “I find they’re less tannic, so they have less oak influence on the palate,” says Ing. “Austrian, and Burgundian, casks are all about elegance, and lifting up the fruit.”

French Oak

French Oak can hail from a range of forests within the country, and largely sets the standard for oak production.

There’s the Allier forest, outside of Beaune in the Cote d’Or, which produces tight-grained wood that often gets a lighter toast in the barrel. Within the northern section of the forest is Troncais, known for a more coveted fine grain. There’s also Alsace’s Vosges oak forest; Nièvre, northeast of Allier; and Limousin, in western France.

Skupny likes French barrels—from Burgundy’s Louis Latour and François Frères cooperages specifically—because they have “a more hedonistic influence on Chenin,” says Skupny. “They bring a sweetness and opulence otherwise lacking in the Austrian.”

Joe Harden from Nickel & Nickel, in Napa Valley, swears by French oak. “They introduce subtle notes of baking spices, cinnamon and dark chocolate, are less harsh on the nose and deliver a delicately structured, elegant wine.”

Many pros agree that French barrels with these delicate but more complex flavors and mouthfeel are ideal for lighter wines made from grapes such as Chardonnay, Sauvignon Blanc and Pinot Noir, as well as classic bedfellows like Cabernet Sauvignon and Merlot.

“They tend to be more elegant and less heavy-handed than their American counterparts,” says Holt. “Classic French barrels are the most versatile. Almost any wine can find a home in them.”