Barrel-Chested

BBE (Before Barrel Era) 

As Caesar’s empire stormed its way into Gaul during the first century BCE, the Ancient Romans made a discovery that would change the course of wine-history. These armies, like all armies, were often in need of refreshment. And, having lugged their wine in heavy clay amphorae for hundreds of miles across future-Europe, they were intrigued to find the Gauls storing (and rolling) their beer in wooden barrels, bound together with metal hoops.

Unimpressed by the beer itself, but fascinated by its convenient, lightweight method of transportation, Roman merchants were soon fermenting and shipping their wine in barrels throughout the Mediterranean. After a time, they noticed that their cargo was often improved by the journey; somehow, the barrels were imparting mysterious but pleasing qualities to the wine.

Already abundant throughout the forests of continental Europe, oak was the clear choice of wood – its softness made barrel staves easier to bend and shape, while a tight grain-structure provided natural waterproofing.  What’s more, both Romans and Gauls could likely sense that oak’s chemical compounds, (what we now know as lignin, lactones, tannins and vanillins) were contributing interesting flavours, and smoothing any bitterness in their contents.  

Over two millennia later, not much has changed. Most wines in Bordeaux are still aged in barrels crafted from French wood; at Domaines Barons de Rothschild Lafite, we are unusual if not unique in making our own casks at the Château Lafite Rothschild ‘tonnellerie’. As vintages mature, the interaction between oak and grape is integral to the development of body, contributes structure and finesse, adds subtle flavour, reduces astringency and softens tannins in our wines – factors too important to be left to chance. 

We spoke to DBR Lafite’s Merrandier (or stave-maker) Guillaume Gauthier, co-founder of the famed Merranderie-Tonnellerie ‘Gauthier Freres’, and DBR Lafite’s cooperage manager Sylvain Guiet, to better understand the complex dance of nature, science and artistry that goes into a barrel’s journey from forest to cellar.

Gauthier explains that far from arriving fully formed, barrel staves undergo a metamorphosis that includes many stages.  From the live tree comes what’s known as a ‘grume’ – the straightest (lower) part of the trunk from a felled oak. From grume, we proceed to ‘billon’ – metre-long portions from trunk, usually 5-10 per tree. To ‘deligner’ means to cut the billons, with the help of a band saw, into rough sections of approximately equal length. These are cut from the central portion of the trunk – poetically known as the ‘heartwood’ – which is generally stronger, more watertight, and resistant to decay than the surrounding sapwood. 

An ageing period of 1-3 years now ensues – we aim for about 18-24 months – initially in the open air, allowing the elements to extract tannins and moisture which matures and ‘seasons’ the wood to ensure the right balance of chemical compounds.

Ideal seasoning requires a method of stacking which lets the air circulate freely between each piece, with cycles of rainfall and sun-drying gently leaching out the harshest tannins and aromas.

These will appear as dark splotches or stains over time, along with a greyish fungus – evidence of the very real transformation at work within.

After a long period of exposure, the staves – now known as ‘douelles’ – will be moved indoors at Lafite for 6 months dry-ageing, another cut (into what’s called a ‘douve’), before making their way into the cooperage workshop. But first, let’s return to the oak itself, long before it begins its transformation into a DBR Lafite barrel. Long, long before.

Into the Woods 

In central France, surrounded by over ten thousand acres of verdant forest, there is an unusual historic monument. Within a grove of close-growing oaks, their thick canopy filtering the sunlight into long green shafts, stands The Sentinel. This ancient tree, 21 feet in diameter, has stood watch over the Foret de Tronçais for over 400 years. It might be among the oldest specimens in the forest, but even its relatively ‘young’ neighbours have stood for centuries. 

Strangely, we have war – and France’s most flamboyant ruler –  to thank for this peaceful refuge in the Auvergne. Jean-Baptiste Colbert, First Minister of State to King Louis XIV, was charged with building a fleet of ships to satisfy the Sun King’s vaulting aims for French military dominance; in 1670, Colbert established the Tronçais and Limousin forests to supply materials for hypothetical ships – 200 years into the future. The vast oak groves were interplanted with beech and larch, encouraging straight, high growth free from knots – ideal for ship masts. 

But by the time these trees were reaching maturity, the French Navy had outgrown its own supply. The shift to steam power was… under full steam. By the late 18th century, iron forges fuelled by wood-charcoal were making the greatest demand, followed by a flurry of felling during the French Revolution and Napoleonic era.

Not until the 19th century were the forests permitted to regenerate, with orders issued to manage their growth more sympathetically – and their essential role in barrel-making firmly established.

Today, the forests are maintained by the ONF (Office National de Forêts), a French Government Agency who plant, gently cultivate, preserve and fell trees with great precision, in a process known as ‘futaie regulière’.  But precision doesn’t equal pace. Timelines, instead, are on an epic scale. 

From acorn to axe, it goes something like this: silviculturists plant several hundred oak saplings simultaneously in each ‘plot’ of the forest – Tronçais, for example, is made up of over 400 plots of Quercus petraea, otherwise known as ‘sessile’ or French oak. This species is favoured as it flourishes in drier, densely-planted environments, with high competition among the young trees leading to slow, straight, knot-free growth; the straighter the grain, the better the barrel. A few beech and acacia trees have been added, interspersed with some pine, hornbeam, checker and cherry, to encourage species diversity.

About twice over the first 60 years of growth, ONF workers will go in to thin the planting; only when trees reach 120 years of age do they (several generations hence) begin to cut every 15 to 20 years. But how does a forestier know when the time is right? Growth rate varies from tree to tree, and not every oak will reach the right height or diameter at the first evaluation. It’s a decision that relies in large part on intuition, along with extensive study, and a few centuries of inherited savoir-faire.  

The trees Guillaume selects are usually between 150 and 250 years old – is it a case of the older the tree, the better? Not exactly. While a mere century might be too young in tree terms, it seems there’s an upper age limit too: «By 300 years, the wood can be too old,» he says, «and it begins to change in ways that make it less interesting for winemaking».

Trees that are ready to be felled – not necessarily the ‘best’ trees in each parcel, but rather those whose removal will lead to the overall health of the plot itself – are marked, catalogued, and inspected by merrandiers or suppliers to determine their value. When the wood is sent to auction, bidders have the chance to make an offer for trees from particular plots, usually about 100 at a time. The catch? Bids must be placed in a tight 20-second window – by the time the gavel is raised, there’s no room for doubt in a merrandier’s mind.  

Wood for DBR Lafite barrels often hail from the Foret de Tronçais, but might also include oak from Fontainebleau, Chateauroux, Blois, and St Palais; each barrel will be numbered and recorded to identify the source of its wood for future provenance, and to ensure continuity from one year to the next.

Barrelling Ahead: The Tonnelier

As we begin our tour of the Lafite cooperage, Sylvain Guiet explains that the art of the tonnellier goes beyond savoir-faire – it’s also deeply rooted in the barrel-maker’s own body. The particular strength required to lift, shape, and move the barrels is a kind of muscle-memory that comes only with practice, and the unique physical structure of each piece of wood must be approached with attention and sensitivity; apprenticeship, therefore, is essential.  

The Lafite Tonnellerie was built in 1987; broadly speaking, says Sylvain Guiet, procedures are similar from one tonnellerie to the next, but each will have individual, sometimes even top-secret ways of doing things. Stave shape, toasting heat and length, and the machinery used can all vary for desired effect.

There are three preliminary steps: cutting to equal length in ‘mise en taille’, smoothing the outer surface in ‘dolage’, and splicing along the grain during ‘jointage’. The ‘bouge’ or bilge is the widest, rounded part of the barrel – allowing for easy rolling and manoeuvring. To create this shape, the douelles must be spliced into a slightly convex shape – wider at the centre, tapered at the ends, following the grain. From here, they are uniform in length but not necessarily in width; a variety of sizes allows skilled coopers to form tighter joins and more perfect shape, in a process known affectionately as ‘montage de la tulipe’ or ‘building the tulip’.  

After this, assembly or ‘montage’ begins in earnest. Several steel hoops known as ‘batissures’ are fitted to the upper section where the staves are joined, to fix the mouth of the barrel into circular shape. A first heating softens the wood, warming the fibres to improve flexibility – think of it as a warm-up before exercise, to prevent injury. Then, a device known as a ‘cabestan’ is used to gently bend and draw the lower part of the staves together into their final shape.

The subsequent toasting or ‘chauffage’ takes place over an open flame fed by oak scraps, carefully tended. The toast is a signature of each tonnellerie, and requires the collaboration of both winemaker and expert cooper to determine the time and temperature for each estate, which will lead to the expression of different qualities in the wood.

Vanillin, for instance, is a molecule responsible for more sweetness and smooth, vanilla-like flavours in the oak. The longer it is heated, the stronger the aromas expressed. These can vary from toasted bread to coffee (preferred in cognac, Guiet tells us) or lean into spicier, caramelised, even burnt notes. Heat also softens the wood’s tannins, creating a more mellow or ‘rounded’ structure, and tames any greener notes remaining.

For Chateau Lafite Rothschild barrels, Sylvain says, there are very strict instructions that the flavour of the grapes must remain the star turn – only short and intense toasting is permitted, to prevent any heavy aromas emerging in the wood. For the barrels destined to contain Rieussec Sauternes, a longer, lower toasting is applied, allowing deeper penetration and the expression of richer qualities. The application for Château Duhart-Milon, meanwhile, sits somewhere in the middle for a medium (Goldilocks-style) finish. 

After toasting is complete, steel truss-hoops are pressed on, to hold the barrel in shape; as the wood cools, a groove called a ‘jable’ or ‘croze’ is cut into each end of the cask, and the rim of the barrel is gently refined. Several douelles are then shaped and cut with diagonal edges into a rounded shape, to form the head and base circles – the shape of their edges designed to fit snugly into the croze groove, along with a flour-and-water paste to create a watertight seal. 

After an initial tightness test, we proceed to ‘proving’, when waterproofing is ascertained by forcing hot water and pressurised air inside through an opening cut into the head known as a ‘bung’ – if any moisture escapes, it’s essential to avoid future leaks by changing the staves and perfecting the joins. It’s not an outcome any cooper relishes; deconstructing and rebuilding takes time, and the hope is always that not even a drop emerges.

During these steps, the barrel is supported by six metal truss-hoops or ‘batissures’ – three at either end, four of which are now removed to be replaced by new hoops. The ‘bouge’ or bilge hoop is closest to the widest central band on the barrel, with the outer band known as the ‘colle’.

Finally, for Lafite barrels, a bung hole or ‘esquive’ is cut into the head, and a small plaque engraved with the Château Lafite Rothschild crest is affixed. A ‘barre de fond’ or pine reinforcing bar is fixed to the base of the barrel – the only piece of non-oak wood used in the entire process, as it will have no contact whatsoever with the wine. 

A final metal truss-hoop is added to the head of the barrel, and two chestnut finishing-hoops, held together by a thin wicker branch, are placed at the outer edge or ‘chime’ (the rim where the staves overlap the head), bound and closed with a neat section of wicker-work.

The last step? There’s only one thing missing…

Barrel-chested

The body of wine is a much-discussed concept, but its meaning is often oversimplified.  It’s a broad term, covering everything from mouth-feel to alcohol content, ‘weight’, texture, richness, acidity, tannins, softness, even sweetness. While oak ageing is commonly assumed to add body – making wines fuller or heavier regardless of grape variety or vintage – the truth is a bit more subtle than that.

An oak barrel isn’t just a container or home for the wine as it matures, but rather an essential character in the living, breathing exchange taking place within: part chemistry, part artistry, part mystery.

As the wine takes on qualities (hundreds that we know of, and probably some we don’t) from the wood, it changes forever. Most components that define body and flavour are altered in some delicate and complex way, blending to create a vintage that’s always more than the sum of its parts. In a word? It’s alchemical. 

When a wine is first tasted, there’s always an evocation of the year it was bottled – 12 months of clement or difficult weather, the growth of the vines, the hands that performed the harvest, even cultural or political events of the day. A time capsule, if you will, uncorked to transport us through the senses, memory, emotion, to a different era. But what if we could factor in the influence of the barrel’s wood to this time-travelling melange? The oak itself may have been planted two centuries before a single grape was pressed… imagine what might have been happening then.

In closing, we asked Guillame Gauthier if he had an affinity for any particular tree. «In the Foret de Berce» he told us, «near a little village called Jupille, there is a parcel of trees that’s been conserved, where the oaks are over 300 years old. I love going there. It’s incredibly peaceful… when you look up, it’s like being inside a cathedral».

Bon-dieu: Carved wooden contraption, to hold staves in places during the first stages of assembly

Chasse: Small device tapped with a hammer, to push the truss hoops into place

Racloir de fond: Literally a ‘bottom scraper’ – similar to a sander, used by hand to smooth any snags or burrs from the wood 

Plane: hand-held blade that cuts and smooths at a shallow angle

Le Chien: Oddly translating as ‘the dog’, this tool unique to barrel-making aligns and holds the stave ends during assembly, before and during the ‘pas d’asse’ (when the croze is cut around the mouth of the barrel).  

Compass: used to determine and align the barrel’s circumference – to calibrate machinery and coordinate the dimensions of croze, base, and head (so the bottom and top of the barrel fit!)