At a GuildSomm workshop at New York City’s Corkbuzz in 2013, Master Sommelier Laura Maniec led a blind tasting with seasoned and fledgling sommeliers. At one point, after pointing out our confusion of American and French oak once again, Maniec commented, “I find that sommeliers are so used to smelling ripe fruit and oak together that it is hard for them to distinguish a wine that has ripe fruit and no oak from one with oak.” My interest was piqued. Why didn’t we, the wine-learned, know our oak better?
After the workshop was over, I began several honest conversations with my peers about oak—not only about tasting but also about our knowledge of oak’s history and role. Time and again, Maniec’s point was substantiated: our knowledge of oak did not match its importance in winemaking. As the number of these conversations grew, so did the level of my inspiration.
I decided to head to France, taking the principles I’d learned about the role of grapes in wine—provenance, terroir, cultivar, the characteristics and families of grape varieties—and applying them to a study of oak. Perhaps it appears ancillary to wine’s higher pleasures, but what I uncovered was a world rich in knowledge and history, and a network of people for whom oak has been as central to their experience of wine as wine itself.
In the small Burgundian village of Bouilland, a short distance north of Beaune, I met Becky Wasserman at the 14th-century farmhouse where she’s lived since moving to France with her then-husband, an artist, in 1968. “Oak is a wonderful thing,” she told me. “Everything used to be shipped in oak, you know—flour, salt.” She looked purposefully at the oak beams overhead. Wasserman is a pillar of the Burgundy wine trade after 35 years as the proprietor of Le Serbet, but few people know that her first job in France was selling barrels to small California and Oregon estates, aggregating orders to reduce shipping costs.
Nostalgia shone through everything she shared. Oak, it seems, is a key part of a life well lived in Burgundy. It is fitting that the lauded dinners that Wasserman and her husband, Russell Hone, are known to host convene at their massive oak dining table. “People built this area with the natural resources they had. It’s all made of stone and oak, oak and stone,” she said. “Even in a tiny village like this, all the residents had the right called affouage.” Residents could cut an allocation of firewood from communal land every year. “You go into the forest, the trees are marked—and this dates from the time when people had fireplaces and wood-burning stoves.”
Oak played an important role in early maritime trade as well. In fact, the Tronçais and Limousin forests were planted by Jean-Baptiste Colbert, minister of Louis XIV, in the late 1600s so that the French would have sufficient material for building ships as they sought maritime dominance.
Certainly, the demand for lumber for both ships and stoves has diminished, but local and national French forests remain, especially oak forests. The Institut National de la Recherche Agronomique (INRA) reported in 2014 that 32% of France’s 16,400,000 hectares of forest are oak. The trees look wild and natural, but they are planted deliberately. Over time, the Office National de Forêts clears slower-growing oaks, until only the fastest-growing, straightest, and, therefore, healthiest remain. In this system of management, called futaie régulière, the competition among young trees encourages upward growth free of knots. The straighter the grain, the better the wood.
Before I left Wasserman, she connected me to Mel Knox of the California-based Mel Knox Barrel Broker, so that I could learn more about futaie régulière. Knox and Wasserman were early business partners, until Knox took charge of the oak company in the mid-1980s. Today, he represents some of France’s finest cooperages and sells to a diverse global clientele of winemakers.
France has a long and well-respected history of managing its forests, especially since World War II. Knox stressed the concept, explaining, “It’s important to note that these forests are managed.” But he soon dispelled my notions of top-down, highly regimented management. Describing futaie régulière, he told me that employees of the Office National de Forêts go in about twice in the first 50 or 60 years of the forest’s existence to thin the crop. Then, at 120 years of age, they begin to cut every 15 to 20 years. “Is it 15 years or 20 between evaluations?” I asked; in answer, he laughed. When I asked the minimum size an oak must be before it is cut down, he responded, “That’s an interesting question. As a whole, you want to find a tree 25 inches in diameter. The French will sell you a tree that is 120 years old, which is plenty big.” Yet while age and girth are related, the growth rate differs from tree to tree. I pressed him to see whether the law specifies a minimum age or diameter, and Knox responded. “Is it a practice or a law? Well, I don’t know, but perhaps the law codifies the practice.”
Emerging from the haze was the notion that forest management isn’t top down but, literally, ground up. The tree determines its own age for cutting. Since not all oaks have reached the required size at the time of the 120-year evaluation, some are left until the next one 15 or more years later.
To understand the key species of oak, I spoke with Thierry Lamant, a forest geneticist at the Conservatoire Génétique des Arbres Forestiers in Orléans and co-author of Guide illustré des chênes (Illustrated Guide to the Oaks). He explained that of the world’s more than 430 species of oak, only 10 grow in France in significant numbers. Of those, only two are considered prime for barrels: Quercus robur, also known pedunculate or English oak, and its close relative Quercus petraea, the sessile oak. Both species grow in the six main French forests known for oak: Limousin, Vosges, Nevers, Bertranges, Allier, and Tronçais (a sub-section of Allier).
Through reading François Feuillat, a colleague of Lamant, I learned more about the nature of English and sessile oak. In the article Characterization of French Oak Cooperage (Quercus robur L., Quercus petraea Liebl.), Feuillat says that English oak craves sunlight and thrives in low-competition environments. The Limousin forest in southwest France has historically been optimal for it. English oak grows faster than sessile and more trees are cut out, so it has less competition for water, light, and soil nutrients, and the spaces between growth rings are wider, resulting in a coarser grain. In contrast, sessile oak flourishes in higher-density plantings where there is greater competition, such as in the more centrally located Tronçais Forest. The trees grow slowly, and the space between the growth rings is compact, yielding a tighter, smoother grain. Grain size is one component that explains oak’s flavor transfer to wine. The looser the grain, the more easily liquid can penetrate the wood. Tighter grain yields opposite results.
On the surface, Feuillat’s writing seemed to confirm an assumption of mine. Just as one can try to pin the origin of a particular Chardonnay to Montrachet, or a Pinot Noir to Chambertin, I thought it should be possible to link a single oak species with a particular forest. But oak is not so straightforward. Due to weather variations from year to year and to climate change, Lamant told me, sessile is now planted more frequently regardless of location. “Because of several dry years, like 1976, 2003, and 2006, a lot of Quercus robur [English oak] forests have disappeared.” Sessile withstands the new conditions better.
Since all coopers start with the same raw material, they begin by looking for very similar criteria. Only the straightest section near the bottom of the tree is suitable for cask production, and it must be segmented into roughly one-meter logs. French oak is split to follow the wood’s natural vertical sap channels, called medullary rays. The medullary rays are not the same as grain; rather, they are what make French oak resistant to leakage. As the most central “heartwood” hardens, these longitudinal fibers—which run perpendicular to the tree’s circular growth rings, from the roots to the branches—are filled with enough tylose lignin that they become plugged. If the fibers are crooked, the barrel will leak. By contrast, American oak (Quercus alba) has a higher amount of tylose, which allows coopers to saw across the face of the log, breaking sap channels without fear of wine leaking. As such, American oak has a high yield of over 50% for making barrel staves. French oak maxes out at a meager 20%, with the remaining wood used to kindle the fires that toast the barrels. French wood also requires more skill later on, as the initial process creates staves of more uneven sizes. A cooper will work with a 30-stave jigsaw puzzle for one barrel—though most can select the right pieces by sight. After these initial steps, each cooperage has its own formula and way of doing business.
Among Burgundy’s tonnelleries, or cooperages, Wasserman had cited François Frères in Saint-Romain as a major influence on her during her time as a barrel broker. “I used to go to the forests and taste oak wood. I approached it with the same curiosity that I now do wine.”
François Frères is located just outside the small village of Saint-Romain, at the end of a winding road. This cooperage prioritizes consistency, paying little attention to the shift to sessile so long as there are trees to fell. The company labels nothing by forest. It sorts incoming wood purely according to grain and sells barrels as very tight, tight, medium tight, noble, very special, and open. François Frères takes the view that winemakers are concerned only with how the grain affects a maturing wine, not where the wood comes from. Further, no matter the species, not all oak from the same forest grows and matures at the same rate nor has the same grain. Thus the tonnellerie, rather than put the forest on a pedestal, chooses to be fastidious about the grain and the toast. The latter comes from the fire applied to the inside of the barrel before the barrelheads are put in place, a process that originated as a way of make the staves more flexible in order to position them correctly.
Other cooperages promote both the grain and the origin of the oak they use. That’s the case 20 kilometers north at Tonnellerie Remond in Ladoix-Serrigny. Founded in 1964, it was purchased in 1988 by Catherine Desbois and is run today by her eminently hospitable stepson, Clément Desbois. On the topic of grain versus provenance, he told me, “We favor tradition.” This means that Remond classifies oak by forest and marks each barrel accordingly, while still using the tightness of the grain as the base for production. Unlike François Frères, most Remond barrels are not made of a mix oak from different forests. With Tronçais, Desbois told me there is a general expectation that the grain will be rather tight, and when Remond purchases it, they select accordingly. Oak from the Vosges is known to be coarser, so they select Vosges oak that meets that criterion. However, Remond also honors today’s market, so they make barrels labeled “Centre,” combining wood from forests around Paris, Orléans, Normandy, and the greater Loire Valley. That allows the company to use oak from lesser-pedigreed forests as well as any surplus from more famous areas.
Each tonnellerie has its own standards for toasting barrels as well. The information as to how long and at what temperature the cooperages fire their barrels is proprietary, but one thing is clear: cooperages make their own rules, and one cooperage’s medium toast might be another’s light toast. The toast is the signature of each tonnellerie, and the task is reserved for the most tenured employees. Many say that medium toast gives the best expression of the wood, taming the harsh greenness while not adding any overt caramelized, burnt, sweeter flavors or aromas. At Remond, the process lasts nearly an hour and seems a bit like a medieval sport, as the barrels are moved every five minutes across 11 different wood scrap fires, flipped each time so that the opposite side is near the fire.
In the outdoor merrain yard at Frères, Max Gigondat, the company’s sales director, showed me the wooden merrains (unfinished staves), which most tonnelleries stack and age outdoors. A finished stave is a douelle or douve and is made after the merrains have aged. Gigondat praises their situation. “Our higher elevation is ideal for resting the stave wood,” he comments, citing how the particularly cool nights promote slower maturation. Exposed to the elements, especially rain, the oak leaches out the harshest and strongest of its tannins and flavors. These appear as black splotches staining the wood—the more senior exhibit the most. The industry standard is a couple years, but it is not uncommon for domaines to request extended aging. In this case, they must commit and prepay for the wood before it becomes a barrel. Laurent Vaillé of Grange des Pères has wood aging for five years, as this cult wine producer from Languedoc’s l’Hérault prefers the increased mellowed character of the oak. The famed Burgundian Domaine de la Romanée-Conti’s wood sits for four years.
Three hundred miles north of Burgundy in Champagne is one of the staunchest examples of oak stewardship in all of France. At Maison Henri Giraud in Aÿ, Claude Giraud is looking to the history books and taking a united stance with winemaking and oak.
After Giraud became production manager in 1982, he set out to celebrate his burgeoning interest in fermenting and aging Champagne in oak barrels. He looked back to the period before World War I, when Champagne’s houses, large and small, were served by over 80 cooperages. Today, only two tonnelleries remain in Champagne.
In 1998, Giraud was introduced to Camille Gauthier, one of the last in France holding title as merrandier, or stave-maker. Gauthier, now in his late 70s, is part of a dwindled profession of people who split, shape, and plane the staves by hand, a process now almost always accomplished by machine. Gauthier worked originally with his father, scouring forests around France for wood and learning how oak trees grow—fôret to fût, as it were. “He further initiated our traceability notions and the importance of the oak’s origins,” explained Giraud.
Proving a perfect partner for Maison Giraud, Gauthier helped isolate four lieux-dits in the Argonne where the best trees grew and, with Giraud, developed an understanding of their terroir. Châtrices trees grow on gaize (a base of silicate sponges) in a rift with green clay, with a southern/southwestern exposure and protection from the heavy rains. In contrast, Beaulieu is situated on deep green clay with southern exposure and is not protected from rain. La Contrôlerie is also on gaize but faces west and gently slopes towards a river. Bois des Hauts-Bâtis is atop a plateau with deep soils, faces due west, and gets the fullest onslaught of rains coming from the English Channel. It seemed radical to think in terms of oak as many do with vines.
After processing the wood into the crude merrain, Gauthier ages it for three years to leech out a generous amount of tannins. Then, after the barrels are fabricated, lieux-dits names are proudly stamped on barrelheads, just as vineyard names appear on bottles. Even Gauthier’s name is branded onto the barrelheads above the names of the land that he manages.
Wine writer Michael Edwards wrote in his book The Finest Wines of Champagne that Argonne oak is “gentle” and “flattering” to the delicacy of Champagne. I tested his proposition with the 2002 Argonne bottling of Maison Henri Giraud, released in 2013. The wine was aged in new oak from Châtrices (described by Giraud as demanding a powerful wine with notes of pear, clementine, and candied orange peel) and Beaulieu (which he says gives some gentle flavors of chocolate and clementine). To me, the Argonne 2002 has an incredible richness. It tastes of a lot of yellow apple and a bit of sunflower honey, with a surprising precision and freshness underneath the richness.
The total isolation and understanding of these lieux-dits and their individual effect on Champagne is yet to be fully understood. However, the project is filled with unique promise and offers a great window into how oak can be as important to the winemaker as grapes.
Throughout my travel, one name popped up over and over again: Aubert de Villaine, co-owner and co-director of Domaine de la Romanée-Conti in Burgundy, one of the world’s most hallowed wine properties.
De Villaine offered a view of the relationship between grain and provenance similar to what I’d heard before: “What is the most important is the grain, more than the origin.” But he brought additional insight as well, citing Tronçais, Bertrange, and Jupilles as his preferred forests. He goes into the forest with his team to select still-living trees that are for sale, which he bids on at auction, then carefully pairs merrains with his wines each vintage. “The merrain aged for four years will preferably go to Romanée-Conti and La Tâche,” he explained, though there is no precise formula. I had recently tasted the domain’s 2009 Romanée-Saint-Vivant and found concentrated fruit (evidence of the warm vintage), firm structure, and, in truth, no overt oak flavor. De Villaine made this observation: “[Oak] is also a factor of purity for the wine and it brings tannins which, if the vinification and élevage have been correct, gives to the wine something that is not detectable by tasting but [adds] to the finesse.”
The smell of oak now generates greater narrative—Becky Wasserman’s farmhouse, the Argonne forest, the many cooperages. There is a whole world of oak that seems to run parallel to winemaking, with few intersections.
In the sommelier community today, conversations about yeasts are nearly commonplace and the language of terpenes, geosmin, and lactones has entered normal discourse. We ought to embrace oak in the same way, exploring the history and science behind it and asking questions to better understand its role. How long was the merrain aged? Where is the oak from? How long is your medium toast? Through these questions, we can create more conversations around oak, deepening our relationship to wine.
We can take inspiration from Frédéric Drouhin of the Burgundy négociant Maison Joseph Drouhin. In his dimly lit Beaune cellar, he explained, “When I serve a reasonably old wine, that is, say, 50 years old, I ask the questions: where were you, what were you doing, who was president of your country when this wine was made?” He paused for me to consider that, and then his eyes lit up. “If you raise the same question with the barrel,” he said, “there is the emotion that the tree was planted 200 years ago. Think about what was going on then!”
Editing assistance from Trevor Weltman
Heather Curtis Thanks for catching this discrepancy! We rechecked our sources, and there are competing estimates but agreement that it's over 50%, with the key point being that the yield for French oak is so much lower. The article has been updated, and a revised illustration is coming soon.