Thursday, May 24, 2018

Cognac Barrels


There are plenty of resources on the web about whisky barrels, but when it comes to cognac barrels, I couldn’t find a one-stop shop that provided all of the information I was looking for – even the BNIC website had some informational gaps. A lot of sites were pretty helpful, though, and this post is the result of cobbling together information from various sites and creating that one-stop shop for your cognac barrel information needs. I hope this post is an evolving piece since I don’t know everything about cognac barrels and more knowledgeable people will (hopefully) chime in to keep us informed and honest.

The Law
The AOC regulations and law regarding cognac can be found in the Decree n ° 2009-1146 of September 21st, 2009 relating to the controlled label of origin "Cognac" or "Brandy of Cognac" or "Brandy of the Charentes" (the link is provided below).

Article 3, Paragraph D, Subparagraph 9 of the regulations state that "spirits intended for direct human consumption shall be aged in an oak container for a minimum period of two years."

  • The use of the term “oak” is a generic term. Article 3, Paragraph E, Subparagraph 4 ("Ageing") states that "the Tronçais or Limousin type oak ("oak" or "pedunculate" according to the uses) was chosen because of its capacity to allow for long periods the exchanges between brandy, the external environment and the wood. . The numerous cooperage companies that have developed in the geographical area have been able, in close relationship with Cognac winemakers, to build know-how in the development of the most suitable housing for the aging of Cognac. It is up to the cellar masters to select the most suitable dwellings, according to the initial characteristics of the new brandies, the aging stage and its qualitative objectives". When the regulations discuss Tronçais or Limousin type oak (along with some online articles), they indicate that cognac casks have traditionally made from French oak, but there is also no outright prohibition on using any type of oak, really, and the primary use of French oak appears to be more of a general trade practice. As proof, Bache Gabrielsen released a cognac aged in virgin Tennessee oak, which was allowed to be called cognac.
  • In the past, the law may have prevented aging cognac in re-use casks, or at least it was frowned upon (?). Currently, the regulations do not address using re-use oak casks, and it appears that cognac can be aged in oak casks that previously held grape-based wines and spirits. On the web, there are several sites addressing Pierre Ferrand’s discovery of an early 20th century document showing cognac can be aged in wine casks (or at least that the practice used to be allowed). There are now several wine cask finished cognacs on the market, such as the Pierre Ferrand Renegade Barrel No. 1 which is finished in a Sauternes wine cask, as well as the Courvoisier’s Sherry Cask Finish Cognac, which was finished in a sherry wine cask.
  • An oak cask that previously held non-grape based wine or spirit, such as bourbon or scotch, cannot be used to age cognac. Again, there are no regulations addressing this and it appears to be a trade practice or tacit understanding among cognac makers. Martel recently released Blue Swift, which is a VSOP cognac that was finished in bourbon casks. If you look at the very bottom of the front label it states “Eau de Vie de Vin,” which is intended to mean it’s not technically cognac (even though it says cognac on the upper part of the label…I know). Deceptively clever labels aside, if a cognac is aged in a cask that contained non-grape aged wine or spirits, it cannot be called cognac.

I guess to distill down the law of cognac casks into one sentence, “cognac must be aged in oak casks, either new oak casks or oak casks previously containing only grape-based wine or spirits” (yes, I’m quoting myself here).

One takeaway regarding the law is that if there isn't a direct statement prohibiting a particular practice, it seems like trade norms dictate whether a practice is allowable (such as using re-use wine casks) or impermissible (such as using re-use bourbon/scotch casks). I think the use of re-use wine casks was able to sneak into permissible usage because (1) cognac is aged in both virgin oak and re-use barrels that previously held cognac, (2) a prohibition on all re-use casks would prevent cognac from being aged in second fill cognac casks, and (3) being a grape distillate, cognac and wine are in the same family, and I think some clever producers used similarities and semantics to their advantage.   

The Main Types of Oak
This is an area that has tripped me up for a while because people refer to geographical regions as if they are tree varietals, different scientific names are used for the same types of trees, etc. So hopefully this provides some clarity…

Even though the law allows for cognac to be aged in any variety of oak cask(s), cognac is traditionally a tale of two oaks: Tronçais and Limousin. When people talk about Tronçais and Limousin, they are technically not referring to a type of oak, but rather, the region from where the oak trees were sourced.

Region: Tronçais (pronounced “tron-say”)
The forest of Tronçais is a French national forest which is located in Allier - practically the center of France. In regard to oak trees, 73% of the forest is comprised of Sessile oak (Quercus Sessiliflora / Quercus Petraea) and 8% is comprised of Pedunculated oak (Quercus robur). The Office Nationale des Forets (“ONF”) manages the forest of Tronçais and also handles the sale of oak within the forest (along with replanting trees and addressing sustainability issues). The oak trees sold to coopers (both wine and cognac barrel coopers) tend to be very old, easily over 100 years in age. Coopers can bid on particular trees and usually purchase the oak trees several years before use. The ONF cuts and processes the oak trees and retains the timber on behalf of the coopers for several years to allow for sufficient air seasoning time (up to 3 years).



Region: Limousin (pronunciation “lee-mo-sen”)
The forests from several regions of western France are generally considered the Limousin region, to include the eastern part of the departments of Deux-Sevres, Vienne, Hautes de Vienne, the northern part of the Correze, the Creuze, the eastern part of the Charente and the southern part of the Indre; the area is pretty close in proximity to the Cognac region. A majority of the oak trees in this region are Pedunculated Oak (Quercus Robur) and many of the woods in this region are also managed by the ONF.


Actual types of oak used for cognac cask making

• Sessile Oak (Quercus Sessiliflora / Quercus petraea / Quercus Rouvre) – wood from this tree is generally tightly-grained and softer for an oak.


• Pedunculated Oak (Quercus Robur) - wood from this tree tends to have wider grain than Sessile Oak and it imparts more tannin into the spirit. According to some sites, these oak trees impart vanilla notes into the cognac.


Do the differences in species matter? That depends. What I’ve found is that coopers do not usually distinguish the two species of wood in their workshops and instead pay more attention to forest location and grain size than oak species. However; the forests of Tronçais and Limousin generally contain different types oak trees, so species overlap in cask making is likely not an issue. Further, most cognac producers prefer the use Limousin oak due to the heavier tannins imparted from the oak (it also probably helps, or at least plays a role, that Limousin is close to the Cognac region).

To summarize, Tronçais and Limousin are not oak types but regions where specific types of oak trees grow; Sessile Oak is the predominate oak in Tronçais and Pedunculated Oak is the predominate oak in Limousin. Sessile Oak is tight-grained and Pedunculated Oak is wide-grained and imparts more tannin into the spirit.

Cooperages and Barrel Details



Called the “tonnellerie” in French, there are a lot of cooperages that produce barrels for cognac producers. Wine and the use of French oak is big business so there is no shortage of barrel makers in France (some even have a footprint in the USA!). There are plenty of small and mid-size cooperages, and some of the big houses have their own cooperages, too. For example, Hennessy has a “barrel-making factory.” There are also barrel brokers where producers can purchase barrels made by different coopers.

There are no restrictions on barrel size for cognac, and the norms seem to be 350 liters or 500 liters. However, don’t be surprised by other barrel sizes if you come across them (unlike scotch, they don’t have goofy names for the different barrel sizes)…some cognacs spend time in gigantic vats, tuns, or whatever the producer decides to call it.

One of the big differences between cognac barrels and whisky barrels is that cognac barrels are “toasted” rather than charred. Just like charring, toasting is a process that burns the inside of a barrel to a desired point to mellow the wood tannins and raw oak flavors. Toasting is on the lighter end of the burning spectrum and helps release vanillin from the cellulose in the wood and imparts spicy, vanilla notes. There are degrees of toasting, from light to heavy, and the stronger the toast the more the barrel flavors are present. Separate from barrel charring, which further mellows interaction between tannins and the spirit, barrel toasting allows for more interaction between the wood tannin and spirit. Not all cognac producers use a toast; Daniel Bouju uses a char and it’s easy to see that use in the dark color of his cognac. If you’re more interesting in the science of toasting check out some of the cooperage sites I listed below (like Vicard Tonnelleries).

 (radiation toasting)

 (toasting vs. charring)

Effect of Wood on Cognac
Below is a chart on the coloring of cognac. Obviously it’s just a generalization because toast (or char) level as well as cask type are going to play a role in how quickly the cask affects the spirit. Surprisingly, it does not take very long to gain color which is mainly due to new oak casks being used for the first few years of cognac aging (I’ll dive into that topic on another post about aging).


Summary
This post is just about cognac barrels and I’ll write another piece about ageing in the future. The main takeaways that I think are important are: (1) cognac casks must be made from oak, (2) re-use casks can be used only if they held wine or grape-based spirits, (3) Tronçais and Limousin are regions where oak trees are sourced for cognac casks, (4) cognac casks are generally 350 or 500 liters in size, and (5) cognac barrels are generally toasted but not always.

There are some interesting topics of discussion (like the Blue Swift label) that I’ll leave for the discussion groups (like Serious Brandy on Facebook).

UPDATE: A buddy provided me with the link with the actual AOC law and regulations for cognac. The link is provided below and I've updated the law section of this post.

Sources

AOC Regs for cognac (google translate): https://translate.googleusercontent.com/translate_c?depth=1&hl=en&prev=search&rurl=translate.google.com&sl=fr&sp=nmt4&u=https://www.legifrance.gouv.fr/eli/decret/2009/9/21/AGRT0916772D/jo/texte/fr&xid=25657,15700022,15700124,15700149,15700168,15700186,15700189,15700190,15700201,15700205&usg=ALkJrhiwbtaibTcRKjLqxSsCohvBZJ_62w

The Law: http://www.cognac.fr/cognac/_ru/2_cognac/index.aspx?page=appellation

The Law: www.pediacognac.com

The Law (use of casks holding grape-based wines/spirits): https://troymedia.com/2018/05/07/understanding-cognac-global-market/

The Law (Blue Swift issue): https://blog.cognac-expert.com/martell-releases-blue-swift-vsop-bourbon-cask-finish/

Forrest of Tronçais: https://en.wikipedia.org/wiki/Forest_of_Tron%C3%A7ais

ONF Website: http://www.onf.fr/filiere_bois/@@index.html

Troncais Timber: http://seguinmoreaunapa.com/innovation/best-of-oak/

Limousin Oak (Germain-Robin): https://youtu.be/1xHWD45E6S4

More on wood: https://blog.cognac-expert.com/oak-barrel-cask-cognac-age-limousin/

More on wood: http://www.knoxbarrels.com/FAQ.html

Cooperages: http://www.alcademics.com/2009/10/a-cooperage-in-cognac.html

Cooperages (list of Coopers): http://www.bouchardcooperages.com/usa/products/products_intro.html

Cooperages: https://www.hennessy.com/en-gb/news/7842-barrel-making-factory

Toasting: http://seguinmoreaunapa.com/products/barrels/toast/

Toasting: http://www.bouchardcooperages.com/usa/products/vicard/vicard_intro.html

Toasting vs. Charring: http://www.winespectator.com/drvinny/show/id/52130

Charring: https://vinepair.com/wine-blog/what-are-barrel-char-levels-and-how-do-they-affect-the-way-my-whiskey-tastes/

BNIC Press Pack: http://www.cognac.fr/cognac/pdf/publications/dossier_en_07.pdf





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