Focus on oak

Focus on oak – survey on factors considered in selecting oak barrels for wines

Larry Walker

When it comes to oak, what do winemakers really want, anyway? Coopers must ask that question from time to time, both of winemakers and of themselves as well.

After a long lunch of dim sum with barrel broker Mel Knox – he wrote the entry on oak for Jancis Robinson’s “The Oxford Companion to Wine” so presumably has some thoughts on the subject – I returned to my office and devised a short and simple questionnaire which was faxed to a small group of key winemakers, coopers and barrel suppliers.

The question asked was “What is the most important single element in your selection of an oak barrel: The species or variety of oak? Where the tree was grown? The cooper?”

(One could ask a parallel question about wine. Is it the varietal, the terroir or the winemaker? Another time, perhaps, we’ll venture into that debate.)

Knox, being on the spot, said he believed that species was the most important element. “The key to selecting a cooper is finding out how the wood is milled and how and where it is dried,” he said. Expanding on the species theme, Knox gave the example of wood now coming out of central Europe, which is the same species (Quercus sessiliflora and Quercus robur) as the oak found in France.

“If the wood from eastern Europe is treated properly and the forests are maintained properly, eastern Europe could be a major factor for a long time,” Knox said.

Questions and Answers

Questionnaires were sent to 24 winemakers and 11 coopers or barrel suppliers. Responses came from 19 winemakers (79%) and eight suppliers (about 73%).

Of the winemakers, 11 felt coopers were the most important, three opted for terroir, three for oak variety and two didn’t make a clear choice. Of suppliers, four said it was impossible to make such a choice, two believed the cooper most important, one the species and one the terroir.

Most of the answers were highly-qualified. For example, Alan Sullivan of Sta Vin answered, “I do not believe there is only one single element in selecting a high-quality oak wine barrel. A reputable cooperage produces a wine barrel that exhibits their own distinct, inherent character. This unique wine barrel will enhance wine through a blend of workmanship, oak selection, seasoning and toasting. An important element in selecting a wine barrel is the cooper’s detail in piecing all the necessary variables to create a high quality barrel. With this qualifying statement, leaving the cooperage aside, the most important element in selecting an oak wine barrel is twofold: 1. Selecting trees which develop in a climate and terrain that produce relatively slow growing, straight, tight grained mature oak; 2. The length of time, location, and methods of seasoning the staves”

Phil Burton of Barrel Builders responded, “I don’t know how to separate the elements of barrel selection. First, the species of oak is most important, but the care and consistency of the cooper is also of paramount importance. A poorly-coopered barrel of poorly-aged wood will be junk regardless of the species. Where the tree comes from is probably of the least importance, especially since there are micro terroirs and highly-varied growing conditions even in the same stand of trees.”

Todd Stanfield of Tonnellerie Remond replied, “The cooper is everything! For the last couple of years, Tonnellerie Remond has been part of an experiment comparing cooper techniques on the same wood. The wood was independently purchased, air-dried together at one location and then split evenly between two coopers. The wood also represented many forests.”

On the question of species or varietal, Stanfield said that in dealing with French oak, “I have been told that sessiliflora and robur cannot be told apart by oak experts except when the tree still has its leaves.” On the question of where the tree is grown, he added, “I associate the major differences with grain tightness first and then the subtle differences in flavor profiles.”

Bob Rogers of Innerstave pointed out that the choice of barrels was personal, especially in selecting origin (French or American.) “This is a subjective decision based upon style of wine or most often price coupled with the need to have containers made of oak in which to age the wine. All sub-species of white oak will differ depending on the species, the growing area, the climate, the drainage,

the aspect, the slope, the growing year, etc. There are numerous variables that must be taken into consideration which only the cooper can manage. Therefore, the most important link in oak selection after geographical location, is the cooper rather than the species.”

Rogers also said, “The cooper is very important stylistically – each cooper manages the oak aging regime differently and toasts with his own style.”

At Radoux USA, Max Gasiewicz replied, “There are many concerns to think about in picking a barrel but you will find most winemaker’s main concern is the cooper’s reputation and track record. All winemakers taste at other wineries and taste a myriad of barrels, so to see consistency from one varietal to another is a key factor.”

Raymond Willmers of Mendocino Cooperage was short and to the point with his listing of the three most important elements of an oak barrel:

“How the oak was aged, length of time and was it watered the first 90 days; Is it tight grained?; Did the cooper toast it slowly over an open flame?”

Winemakers’ Response

Winemakers, as you might expect, had fairly strong opinions. Here are a few highlights from the men and women in the cellar:

Don Blackburn, Bernardus: (Blackburn trumped my question with what is undoubtedly the single most important requirement for a wine barrel – that it not leak.) After that, he thought the source of the wood, the species and the cooper were most important in that order. His comment was short and provocative: “American oak is like margarine. It has improved since it hit the market, but it’s still not butter”

Marco Cappelli, Swanson Vineyards: “Air dry time is the most important element, assuming that you can trust your cooper to give you what you want.”

Daryl Groom, Geyser Peak: “Most important is the species of oak; American oak gives quite different flavors than French oak. The second most important is the cooper, due to house techniques for processing barrels. Some coopers are consistent year after year, others have variations.”

Paul Hobbs, Paul Hobbs Winery: “At first, I wanted to say species but in the end its the ‘hand of the cooper,’ whose knowledge at crafting barrels is the defining element.”

Richard Arrowood, Arrowood Winery: “More and more we rely on the track record of a particular cooper. Consistency of supply and consistency of quality are first and foremost on our minds before we decide which oak to request. Where the tree was grown is important, but not so much as the reputation of the cooper.”

Marketta Fourmeaux, Chateau Potelle: “If the cooper is good and quality oriented – same thing as with a winemaker I trust that he would put out only quality barrels, same with quality wine.”

Dan Gehrs, Daniel Gehrs Wines: Gehrs also stepped in with the obvious point I missed in my mini-survey: “Barrel tightness is number one,” he replied. No leakers, please. As for the variety of oak, Gehrs said, “Depends on the wine. American oak has been getting a lot better. French oak can be excellent, but is overpriced. Eastern European oak can be exciting. Naturally, the tighter grains are more desirable, wherever it was grown. There are lots of choices for lots of wine that will keep us busy for years. I see American oak as ascendant, eastern European oak somewhat so and French oak as the high end choice for bragging rights.”

Linda Trotta, Gundlach-Bundschu: “At the risk of sounding simplistic, because so many factors go into choosing barrels, I would liken choosing an oak barrel to choosing a wine. Consider the variety of oak and where the tree was grown as the equivalents of the variety and appellation of a wine. Just as the winemaker influences the transformation from raw material to finished product, so does the cooper. Each gives their own unique signature to their work. So while species of oak, where it was grown, my intended application and price all are important considerations, I’d say that the cooper is the most important single element.”

Daniel Baron, Silver Oak Cellars: Baron listed variety of oak as of first importance, followed by how long it was seasoned, where the tree was grown, the cooper and toast level. The seasoning and toast level are elements of coopering, so overall he seemed to see coopering as very critical. “Ultimately” Baron replied, “The single most importune element in our choice of barrels is how they make our wine taste. We never buy large quantities from a cooper or new region without prior tasting of small lots with our wine. This is purely a question of style and taste; there are no absolutes in this kind of judgment. We search for the barrels that complement our flavor and aroma goal.”

Dan Karlsen, Chalone Vineyards: “When buying oak, trust and integrity are important. You develop a relationship with cooperages so that when you specify a variety or location of oak, you get the flavor profile desired.”

Elias Fernandez, Shafer Vineyards: “For us it is the tightness of grain that is the most important element which is determined primarily by where the tree is grown. But this only becomes a priority after it is determined by experiments if the cooper is able to bring out the sweet flavors and vanilla aromas without green harsh tannins.”

Judy Matulich-Weitz, Buena Vista: “I use different types of oak from many places, but the single factor that makes the biggest difference is the cooper.”

Jim Clendenen, Au Bon Climat: “There are only two coopers who use a government certification agency to prove by bond the provenance of their wood and the length of time of natural air drying, Taransaud and Francois Freres. These guarantees, a long business relationship and the trust about which forest is supplying the best wood at any given auction in France, seem to be the only refuge that a cynical American winemaker can find.”

The results clearly show that winemakers come to rely on coopers and feel that it is important to find a cooper they can rely on and trust to deliver. The winemakers’ comments also show that the relationship with the cooper is one of the key elements in making wine.

We want to thank all the suppliers who took the time to answer our questions and also the winemakers who provided many thoughtful comments during a time that they were up to their hips in wine grapes.

We would be glad to hear from other winemakers and barrel suppliers on this subject. Send comments to Larry Walker at Wines & Vines or directly to

Resources: For an up to date list of the most important barrel suppliers, please consult the Wines & Vines 1998 Buyer’s Guide.

COPYRIGHT 1998 Hiaring Company

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