Coopering Process

The coopering process has an almost age-old history. From the earliest days of preserving and transporting liquids—first in leather, then in amphorae (earthenware), and finally around 225 BC, wooden containers.

Casks provided numerous solutions, as the shape stood up to pressure, traveled easily, and allowed for aging. In the 9th century, coopers in France began to form corporations, and in 1268, statutes were filed with the high court for approval.

SEGUIN MOREAU pays homage to the ancestral art of coopering, balancing the traditional hands-on touch with the strictest quality controls and modern technology—all aimed at a barrel of the highest consistency and highest quality.

Each barrel, tank and foudre is hand-toasted and hand-finished with the skill and experience of our master coopers.

From the forest to the timber yard and wood yard

Our selected timber is transformed into rough staves in Vélines (Dordogne). The number assigned by our logger in the forest identifies each batch of logs unloaded to our stave mill.

The batch is then processed as a whole and continuously monitored in the workshop, as well as on each pallet containing staves from the same log.

From the timber to the barrels, each stage of manufacture is tracked and coded. The characteristics of the wood making up the barrel can be tracked at every phase of its life, thanks to the unique code given to each barrel: the species, type of grain, thickness, geographical origin, supplier, maturation time, and date of preparation of staves.

SEGUIN MOREAU is the biggest user of French oak for barrel making and its requirements exceed the production capacity of our own stave mill. As such, we source as well from other stave mills we have done business with for a number of years.

The oak logs arrive at the timber yard, where they are cut into short bolts, using a cut-off saw that optimizes the staves’ length.

A forklift immediately carries the short logs to one of the two stave manufacturing lines.

There the short log is placed vertically underneath an enormous hydraulic steel wedge for splitting. When the wedge is driven into the wood, it splits lengthwise naturally along the grain of the wood. French oak needs to be split to respect the natural grain – sawing it would make it porous and affect its water tightness.

The first split produces two half-short bolts. Next, the quarters are split into a series of triangular sections, which are worked into staves by following the rift and the grain of the wood.

Optifente®, a laser guided plotting computer, offers the operator various splitting points in order to use the most of the oak, though the experienced splitters also make their own readings of the wood.

The squared timber is sawn to a thin length so that its face is perfectly flat and parallel to the grain. It is then re-sawn to obtain staves with a thickness of 25 or 31 mm.

At the final sorting and grading, the staves first undergo visual conformity inspection before being put away on trolleys – they are then sorted by thickness and length.

Staves, unloaded, then sent to timber reception building, with a with a natural adjustable ventilation system, ensuring ideal hygrometry for the conservation of the stave wood, regardless of seasonal variations.

They are sorted, and then proceed to the oak wood yard, which is divided into homogeneous rows by oak type, by grain, by origin, and by age.

We have ISO 22000 certification, which is meant to ensure safe food products are produced, guaranteeing the safety of the products delivered to the industrial customer or distributor. This involves inspections of the wood yard and cooperage, carried out by Bureau Veritas, a worldwide private-sector organization that certifies, inspects and audits businesses. Sampling for quality, as well as chemical controls and non-contamination analyses, take place throughout the coopering process. Our stave mill is also certified by Bureau Veritas for natural air drying. This third-party audit verifies the length of our wood seasoning.

Proactive maturation in the wood yard

French, American, Eastern European, and Russian staves undergo the proprietary proactive maturation process, with controlled successive periods of watering and drying out, in our seasoning yards in France and Missouri.

The process, developed in conjunction with the Institut d’Oenolgie de Bordeaux, reduces the moisture content of the wood to between 12 and 15 percent and helps develop the wood’s quality.

In the yards, each pallet is coded and identified with a unique number and bar code. New and aged rows alternate, in a set of 30,000 pallets.

The oak spends least two years in the open air, exposed to the elements. SEGUIN MOREAU has five weather stations situated in the wood yard, relaying meteorological data and allowing researchers to set different spraying cycles and adjust the length of aging depending on the origin of the wood, its thickness, its structure and the oenological guidelines.

This even and consistent seasoning is key for the wood to develop its full organoleptic potential.

First, the pallets are rinsed, which allows for phenolic extraction.

The rain-like irrigation then provides for gentle, yet fast and homogeneous water disbursement over the staves. The pure potable spring water is filtered and UV sterilized, as well as chemically tested once a month, with real-time pH monitoring.

Favorable conditions are created and maintained for beneficial fungal colonization, or biofilming.

The wood pores begin to open, and the rough surfaces are refined, through micro-laceration. Oxygen is able to penetrate deeply, allowing for deep oxidation of the ellagic tannins, which reduces greenness and bitterness while refining the aromas and tannins.

Canvas covers on the wood protect against direct sunlight and wind damage.

In the cooperage

The aged staves (from 24 to 36 months) are sorted, and any damaged ones are culled. The rough staves are cut to size, and then planed on the outside, where they are slightly hollowed, and they are tapered at each end. They are jointed by the EDJ Stave Jointer, ensuring they will fit together perfectly and remain water-tight.

Food safety and risk prevention are naturally at the heart of SEGUIN MOREAU’s concerns. Its system of control of the manufacturing process is recognized: Bureau Veritas granted the cooperage the ISO 22000 certification in December 2007. This standard ensures that safe products are put on the market and that they meet the demands of European regulations in terms of hygiene. It also ensures that measures are enforced to prevent the particular risks that are associated with barrel making.

On the cooperage floor, first comes “mise en rose,” or the raising of the barrel. The cooper arranges the staves on the inside of a mounting hoop, making sure to alternate between wide and narrow staves.

The widest stave becomes the bung stave. Metal toasting hoops hold the barrel together through the process until they are swapped for the galvanized steel hoops.


The barrel is heated over an open fire, in a charcoal pan or brazier. The fire is fed from scraps left over from the cutting of the barrel heads, maintaining an aromatic consistency.

The staves maintain some humidity from the seasoning process, and as they heat, water in the oak begins to steam, and is assisted by light sprays of water from the cooper. This all allows the staves to be bent without cracks.

The cooper then places a steel cable, set with a winch, in a half rigging key knot around the bottom of the barrel. After the barrel reaches an optimum tightness, it is removed from the knot and placed over a toasting fire. It begins to toast for aroma, as the toasting unlocks aromatic compounds from oak and caramelizes sugars.

Toasting regimens have been developed with precision and regularity, leading to consistent results.


The toasted barrel gets an initial press of toasting hoops, before cooling down some. The end toasting hoops are removed, and the ends are notched in the crozing machine. The bung hole is drilled, and then the next cooper begins to remove the toasting hoops, while replacing with galvanized steel hoops.

The head is inserted, and the toasting hoops are hammered further. A secondary hoop press ensures tightness, before a pressurized water test, to confirm the barrel’s integrity and detect any leaks.

The barrel is then planed, and the final hoops are added on and pressed. The heads are sanded, and the body is sanded, and the barrel is ready for its final lasering of logo.