Different Wood Casks

[robs42]

I was on a tour of the Speyside cooperage and remember them mentioning how oak is better suited to maturing whisky then any other wood. I also recall it had something to do with how the grain forms.

My basic question is, does anybody have any more information on experiments done with other types of wood?

Robby

[Paul A Jellis]

I seem to remember reading somewhere that oak is the only wood not affected by alcohol. Other timbers would rot very quickly if filled with whisky.

Cheers

Paul

[Deactivated Member]

My vague recollection is otherwise--that there are indeed odd casks of other wood, but the peculiar flavor of oak is best suited to the task. Do I recall correctly that Scotch whisky must be aged in oak?

[Virginia Gentleman]

My vague recollection is otherwise--that there are indeed odd casks of other wood, but the peculiar flavor of oak is best suited to the task. Do I recall correctly that Scotch whisky must be aged in oak?

I don't think Scotch must be aged in oak but bourbon does have that rule.

[kallaskander]

Hi there,

different types of oak have different properties, most important the density or graininess of the wood. Some wood types are not usable for making barrels, pines for example because of to much resin and the wood is not durable enough. Chestnut can be used but spirits matured in chestnut are too sweet because the wood itself sweetens the liquid stored in it. Therefore most barrels for a long term storage purpose are made from oak because of the durability and the properties.
Law requires scotch to be matured for three years in oak.

Interesting read: http://www.thescotchblog.com/2006/02/into_the_wood.html

http://www.findarticles.com/p/articles/ ... _115036817


Greetings
kallaskander

[Mr Ellen]

Law requires scotch to be matured for three years in oak.

Greetings
kallaskander

That's true...just found an updated version of The Scotch Whisky Act from 1988.

This is the Scotch Whisky Order 1990 No.998

Definition of Scotch whisky

3. For the purpose of the Act "Scotch whisky" means whisky—
(a) which has been produced at a distillery in Scotland from water and malted barley (to which only whole grains of other cereals may be added) all of which have been—
(i) processed at that distillery into a mash;
(ii) converted to a fermentable substrate only by endogenous enzyme systems; and
(iii) fermented only by the addition of yeast;
(b) which has been distilled at an alcoholic strength by volume of less than 94.8 per cent so that the distillate has an aroma and taste derived from the raw materials used in, and the method of, its production;
(c) which has been matured in an excise warehouse in Scotland in oak casks of a capacity not exceeding 700 litres, the period of that maturation being not less than 3 years;
(d) which retains the colour, aroma and taste derived from the raw materials used in, and the method of, its production and maturation; and
(e) to which no substance other than water and spirit caramel has been added.

However, before these adjustments were made the following applied for "Scotch Whisky" (Scotch Whisky Act 1988), Here it states nothing about oak:

"whisky" means spirits—
(a) which have been produced by the distillation of a mash of cereals which has been—
(i) saccharified by the diastase of the malt contained therein, with or without other natural enzymes; and
(ii) fermented by the action of yeast,
to an alcoholic strength of less than 94.8 per cent by volume so that the distillate has an aroma and taste derived from the raw materials used; and
(b) which have matured for at least three years in wooden casks of a capacity not exceeding 700 litres.

I understand this as other types of wood were allowed in whisky maturation prior to the change of law in 1990...

Cheers
______________________
Anders

[kallaskander]

Hi there,

as of 1988 the Whisky Act clarifies which kind of wood is obligatory for maturing scotch whisky. That does only mean that you have no scotch whisky if you use other woods.
Besides the question what other wood you could use, who would want to do that?

I just learned recently that some fruit brandies which are the German-Swiss-Austrian-French tradition of distilling are matured in barrels made of wood from ashes -because that wood does neither give flavours nor colour to the spirit.
Fruit brandies are drunk clear most of the time, only recently the barrique barrel is used to give maturity and colour. If they are matured in the normal way glass ballons or huge casks of stoneware are used for that.

Greetings
kallaskander

[Deactivated Member]

I wish I could remember where I read about the existence of various odd old barrels of different types found in warehouses--an article in WM or Malt Advocate, some time ago. And of course, there is the mythical "Glenmorangie Cherrywood" that crops up from time to time!

[Jan]

On the subject of wood, does anybody know what the difference is between different kinds of european oak ?

I mean spanish oak is the standard, but more than one distillery has launched french oak finished/matured whiskies and I think it was glengoyne that at some point launched a scottish oak finished whisky.

Does these other sorts contribute something substantially different to the whisky or are this done mostly for marketing purposes ?

Cheers
Jan

[Paul A Jellis]

To quote Charles MacLean, in his book MacLean's Miscellany of Whisky: 'Wine barrels, rum puncheons, port pipes, beer barrels, brandy casks and sherry butts . . . all were cheerfully filled with whisky, whatever wood they were made from. However, most will have been made from oak grown in the great forests of central Europe, in Limousin or in Galicia (Quercus robur). English and Scottish oak, although also Q. robur, does not cooper well, so it was rarely used for making barrels. Today, 95% of the casks coming into the system arrive from the US and are made from American White Oak (Q. alba)'.

He also says ' - although I am told that there may still be the occasional chestnut cask lurking in the murky depths of remote warehouses . . .'

If you want to know more, you'll have to buy the book. I've probably infringed the copyright already . . .

Cheers

Paul

[kallaskander]

Hi there,

some reading.

http://www.maltmadness.com/guide-05.html

http://www.thewhiskystore.de/experts/casks.htm

http://www.thewhiskystore.de/experts/fassmake.htm

http://www.edringtongroup.com/media/pre ... sspack.pdf

http://www.undiscoveredscotland.co.uk/u ... house.html

The one from Edrington is interesting in itself, even if you do not learn much about barrels probably.

Greetings
kallaskander

[robs42]

Thanks guys for the info. I actually found something interesting in my hunt.

In an Irish parliamentary debate from 1980 on a new spirit law the subject partially came up and in passing this was mentioned:

When whiskey comes out of a traditional type cask after three years the experience is that it has not had time to extract the colouring from the cask and there is need for an additive. It will obtain the colouring during that three-year period if it is put into a cask made of either cedarwood or chestnut, but if it is put into one of these casks there is a problem where the aroma is concerned.

Here's the link to the debate - http://historical-debates.oireachtas.ie ... 30005.html
It actually makes quite interesting reading for those interested in the history of Irish whiskey.

[Deactivated Member]

As I recall, Jackson addresses the various species of oak in the %th edition of the Companion.

I believe the designations "Spanish oak", "French oak", and "Scottish oak" have more to do with what has been in the cask than the species--i.e. sherry, wine, and of course Irn Bru.

[kallaskander]

Hi there,

I copy the very good article from the Scotchblog here.

Most Questions are answered in it.

Into the Wood

The interaction between wood and whisky is one of the most interesting, if not completely understood components of the whisky production process.

The following article is based primarily on a presentation entitled “A Wood Primer” that John Glaser of Compass Box Whisky created and was kind enough to share with me - much of the content of that presentation was based on the work of Dr. Jim Swan who is well known for his work as a consultant in the whisky industry and who is currently working with the Welsh Whisky Company in the production of Penderyn. Additional information came from a recent article by Ian Wisniewski entitled America - the Stave in issue 52 of Whisky Magazine; the work of Dr. Masaharu Minabe of Suntory; Graeme Richardson of William Grant & Sons; and Dave "Robbo" Robertson of the JMR Easy Drinking Whisky Company. Enjoy!

---------------------------------

Why Oak?

One of the most frequently asked questions is “Why do whisky makers use Oak?”

The reason that Oak is utilized is its unique physical and chemical nature. Oak has strength - physically, its wide radial rays give strength when shaped for a cask; Oak is also a "pure wood" as opposed to pine or rubber trees which contain resin canals that can pass strong flavors to maturing whisky.

But it’s not just the Oak itself, it’s the transformation that happens to the Oak as a result of the seasoning and heating treatments during the coopering process - these result in the production of pleasant-tasting Oak lactones.

Oak has three broad effects on the spirit:

1. Additive - Adds organoleptically (a $0.50 word meaning the taste and aroma properties of a food or chemical) desirable elements from the cask. For example: vanillin, Oak lactone (coconut, bourbon character), toastiness, wood sugars and color.
2. Subtractive - Removes undesirable elements from new make spirit. For example: sulphur compounds and immaturity.
3. Interactive - Adds extractive wood elements from the cask and converts them to organoleptically desirable elements. For example: change tannins to acetals; change acetic acid to fruity esthers.

Dr. Swan defines 5 specific constituents of Oak and identifies how they influence maturing spirit:

* Cellulose - Which has virtually no effect other than to hold the wood together.
* Hemicellulose - Which consists of simple sugars that break down when heated and provide:
o Body: through the addition of wood sugars
o "Toasty & carmelised aromas & flavors"
o Color (unaged or "new make" whisky is a clear liquid)
* Lignin - The binding agent that hold the cellulose in wood together which, when heated yield:
o Vanillin
o Sweet, smoky and spice aromas
* Oak Tannins* - Which play an essential role in maturation by enabling oxidation and the creation of delicate fragrance in spirits. Tannins combine with oxygen and other compounds in the spirit to form acetals over time. According to Dr. Swan, acetals:

Have a strongly ethereal influence on the product giving it delicacy and top-note…without it, spirits are dull and flat.

*Naturally occurring preservative compounds with a slightly puckery, astringent taste in the mouth, similar to the effect of strong black tea or fresh walnuts.

* Oak Lactones - Resulting from lipids in the Oak, they increase dramatically during toasting and charring and can pass on a strong woody and perhaps coconut character; lactones give bourbon its distinctive character; and occur in higher concentrations in American Oak than in European varieties.

Will any Oak do?
So any Oak tree can be used when making a whisky barrel? No. Of the hundreds of Oak species, just three species are used for wine and whisky cooperage:

Quercus Alba, “White Oak” (America)

* Commonly referred to as “American Oak”
* The most commonly used variety in whisky cooperage
* More vanillin than European varieties
* Fast growth
* High in lactones, which when toasted, provide woody, vanilla, and coconut flavors

Quercus Petraea, “Sessile Oak” (Europe)

* Found across Europe, notably in France
* Most commonly used for wine cooperage
* Slow growth, fine tannins and more vanilla (compared to Pedunculate)
* Most common species in Tronçais forest

Quercus Robur, “Pedunculate Oak” (Europe)

* Found across Europe
* Spanish Oak generates more raisin, prune-like flavors
* Most commonly used for cognac and sherry cooperage
* Fast growth, more tannins, thus more oxidative characteristics in the matured products (compared to Sessile)
* Most common species in Limousin forest

Whoak Now that that's out of the way, there are a number of other factors in how wood affects whisky. Chief among them are:
- Growth rate of the "donor trees";
- Method and length of time to dry the wood;
- Toasting and charring during cooperage.

Impact of Oak Growth Rate: Slower is Better
Winemakers are convinced of the relationship between Oak growth rates and the flavor and quality of their wines; while in whisky, this factor is not widely considered. It is known that slow growth Oak has more of the “good stuff” - especially vanillins and Oak lactones. White Oak is "fast-growth."

Tis' the season
Once the wood is cut, the method used to season (dry) the wood has a huge impact. The wood MUST be dried before being used to make barrels - the drying process converts chemical compounds in the wood to more desirable types. How the wood is dried and for how long has a direct impact on the quality of the spirit.

It's accepted that air seasoning is better than kiln drying (it reduces tannic astringency as well as releases more vanillin), yet, while the barrels used to age wine may be made of staves which have been air dried for as much as 24 months - most bourbon barrels are made from wood which has been kiln dried in a matter of weeks.

Why? Some distillers think that the method for drying the wood is only important for the first-fill of a spirit aged in a new cask, (e.g., wine or bourbon) and has little or no impact when maturing spirits in previously used casks - and of course, Scotch is aged in previously used casks.

The Heat is On
The application of heat is integral to the process of making the barrel - wood fibers behave much like plastic polymers - they want to be straight. In order to bend the staves, they need to be heated. The straight staves are arranged inside a metal hoop and heated. I have heard that either an open flame or steam may be used. As they are heated they become more pliable and are shaped - hoops of various diameters are added to each end - six in total - which are hammered down, towards the middle. Each hoop is held in place by the pressure exerted by the staves as they try to straighten themselves. The casks are then toasted which caramelizes the wood sugars.

This is where the construction of bourbon casks and sherry casks diverge.

Bourbon Vs. Sherry

Bourbon Casks

The barrels, once formed, are charred - the inside of the cask is set on fire for a short period of time, which creates a black charred layer. There are various levels of charring which will have different affects on the spectrum of compounds and flavors the Oak will impart to the maturing spirit: more vanillins, lactones, "toastiness," spice characters, and tannins.

Charring casks causes further transformation. Char (carbon) removes sulphur compounds and immaturity from new spirit. Bourbon casks are typically charred for 40 seconds to 1 minute, but some distilleries have experimented with charring times of up to 3-4 minutes. The result of charring is dramatic changes on the surface - for example, wood sugars are caramelized, which will leech into the maturing spirit.

Sherry Casks

Sherry casks are only toasted and not charred. The casks used to mature Oloroso are the most popular with the Scotch industry. Sherry casks can be made of American Oak, but this is usually for Fino Sherries and are generally not used by the Scotch industry. It's accepted that European Oak adds more flavor than American Oak - sherry cask matured whiskies tend to be more full-bodied than bourbon cask matured ones, and this is likely the result of the type of wood, just as much as the type previous liquid occupant.

More History

The wide-spread use of bourbon barrels is a fairly recent occurrence - a result of the difficulty in sourcing sherry casks during the Spanish civil war in the late 1930's. Currently any where from 300,000 - 400,000 bourbon casks are acquired for use in the maturation of Scotch whisky - in contrast to only about 18,000 sherry casks.

Contrary to popular belief, very few whiskies are aged exclusively in bourbon barrels - most ex-bourbon aged malts are vatted with a (varying) percentage of whisky which was aged in ex-sherry barrels. Laphroaig, Glemorangie 10, Ardbeg 10, Glenlivet 12, are among those few "pure" ex-bourbon matured whiskies.

It's not the size of the cask (or is it?)

There are three cask commonly used by the Scotch whisky industry:

* Barrels - 190 liters/50 gallons
* Hogsheads - 250 liters/66 gallons
* Butts - 500 liters/132 gallons

Butts come from the sherry industry while the majority of barrels and hogsheads originate in the bourbon industry. All things being equal, the larger the cask the slower the maturation. Conversely, a smaller cask means that the maturing whisky is exposed to more wood and maturation is quicker - the Laphroaig quarter cask is an example of this.

One last thing
Once a bourbon cask has completed its "first life" that is, it has been used to age bourbon, it is ready for its second life as a whisky aging vessel. It is broken back down into separate staves and shipped to Scotland. In Scotland, coopers reassemble the staves into casks which will be used to age the whisky that you will enjoy in a few years. Some bourbon casks and all sherry casks are generally shipped whole - not broken down into separate staves.

It's not common, but some companies re-char ex-bourbon casks before use.

Casks may be used for as many as four fills, i.e., filled with four separate batches of new make spirit. Generally, though, casks are retired after their second, or third re-fills. Sometimes when a cask has reached the end of it's their useful life - after it has been filled and re-filled so many times that the spirit has taken out all the "good stuff" from the wood, some distillers will shave down the the inside of the cask to reach fresh wood and then the cask will be re-charred.

Below are pictures of this being done at a Diageo Cooperage in Carsebridge. The first picture shows the machine that shaves down the inside of the cask. The second picture shows the recharring - which lasts 30-45 seconds at this cooperage.
Carsebridgeshave

Carsebridgechar




How ex-sherry casks are treated, once whisky distillers get their hands on them, differs by distiller. Most will empty the cask of any residual sherry, nose the cask (to ensure the casks smells fresh, and then fill with new spirit. Dave Robertson doesn't believe any one would char fresh sherry casks unless the sherry cask does not smell "right", in which case they might char, or may simply reject the cask.
------------------------

I'm sure that in the future I'll delve more into the nuances of maturation, bottling, etc. But for now, I suggest that you pick up issue 52 of Whisky Magazine. In his article, Ian discusses the various charring techniques - focusing on "how the bourbon barrel influences the taste of whisky." A thoroughly interesting article.

As a matter of fact, if you live in the US and you don't currently subscribe to Whisky Magazine, you may want to consider a subscription; especially since Paragraph publishing offers readers of The Scotch Blog a 22% discount off a new subscription. Simply go to Whisky Magazine and use the code BLOG1205 when placing your order.

From: http://www.thescotchblog.com/2006/02/into_the_wood.html

Greetings
kallaskander

[Mr Fjeld]

Nice Kallaskander - the most informative article I've seen so far!

Christian

[ScotchBlog]

Well thank you Mr. Fjeld.

Thanks for posting Kallaskander. Though I prefer people read my work on my site (Gets the tracking statistics up, you know )

-Kevin

[ScotchBlog]

I don't think Scotch must be aged in oak but bourbon does have that rule.

Until The Scotch Whisky Act, there was no legal dictate that it had to be oak, so though it's pretty recently in the world of whisky, it legally must be aged in oak, though before 1990, any wood would do.

[Mr Fjeld]

Well thank you Mr. Fjeld.

You're welcome!

Though I prefer people read my work on my site (Gets the tracking statistics up, you know )

-Kevin

I've added your site to my favourites. Looks good!

[kallaskander]

Hi there,

before Kevin beat me to it I was about to reply to you Christian that I merely found the article. I had posted the link somewhere above but the ongoing questions seemed to suggest that the link was overread. I thought that Kevin would mention that he had something on that topic on Scotchblog but as that article really is very comprehensive I saw no harm in foregoing him.

Greetings
kallaskander

[Scout]

Contrary to popular belief, very few whiskies are aged exclusively in bourbon barrels - most ex-bourbon aged malts are vatted with a (varying) percentage of whisky which was aged in ex-sherry barrels. Laphroaig, Glemorangie 10, Ardbeg 10, Glenlivet 12, are among those few "pure" ex-bourbon matured whiskies.

From: http://www.thescotchblog.com/2006/02/into_the_wood.html

I strongly prefer these "'pure' ex-bourbon matured whiskies".
I would be very interested in a more complete list.

I would also be interested in an online source of scotch reviews by someone for whom this is an important issue. Sherrying irritates me, much as perfumes and cigarettes do.

Thanks a lot.

[Di Blasi]

Great info there, thanks! Speaking of "different wood casks," Mackmyra Swedish Single Malt Whisky uses new Swedish Oak for some of their whiskies. And for those not familiar with them, they do sell 30 liter casks, and yes, the Swedish Oak too. For more info:
http://www.mackmyra.com/
The Arran Malt uses lots of different ex-casks for finishing. I have their Marsala finish, very nice! And a Grand Cru Champagne, and a Chateau Margaux are among others that may be firsts for finishes:
http://www.arranwhisky.com/lmenu/splash.asp

[Lawrence]

Don't forget Glenmorangie 10 and An Cnoc 12 and I think the current BenRiach are all ex bourbon.

All excellent whiskies.

[Wendy]

At the risk of asking a dumb question, I was wondering if someone could clarify what the term "fine oak" means. I have been wondering if it is supposed to mean the selection of the finest sherry/bourbon casks or does it relate to a particular characteristic found in the oak tree.

Cheers,
Wendy

[Aidan]

At the risk of asking a dumb question, I was wondering if someone could clarify what the term "fine oak" means. I have been wondering if it is supposed to mean the selection of the finest sherry/bourbon casks or does it relate to a particular characteristic found in the oak tree.

Cheers,
Wendy

Wendy, it's probably just wood passed through the marketing filter.

[hpulley]

At the risk of asking a dumb question, I was wondering if someone could clarify what the term "fine oak" means. I have been wondering if it is supposed to mean the selection of the finest sherry/bourbon casks or does it relate to a particular characteristic found in the oak tree.

Cheers,
Wendy

It is the finest they could get without staying with all sherry like they used to do for years and years, bourbon casks being much cheaper! Not very fine at all, I'd say. Pure marketing, as Aidan says. Not that a bourbon casked Macallan is necessarily a bad thing but it is a bit of a bait and switch, IMO. They got rid of true vintages on their 18yo even earlier.

Harry

[Wendy]

Thank you Aidan and Harry for helping me discern fact from fiction. I think the effect of wood on whisky is a really interesting subject so it is just one more question off my list! I must add, the phrase "Fine Oak" is certainly catchy!
Kind regards,
Wendy

[hpulley]

Thank you Aidan and Harry for helping me discern fact from fiction. I think the effect of wood on whisky is a really interesting subject so it is just one more question off my list! I must add, the phrase "Fine Oak" is certainly catchy!
Kind regards,
Wendy

That's why they pay well for good marketing people. Most like to think that marketing is unnecessary but more lead has been turned into gold by good marketing than by good product research & development (sad but true).

Harry

[Di Blasi]

I don't think Scotch must be aged in oak but bourbon does have that rule.

Until The Scotch Whisky Act, there was no legal dictate that it had to be oak, so though it's pretty recently in the world of whisky, it legally must be aged in oak, though before 1990, any wood would do.

So we can assume any whisky we may be drinking pre-1990 legally could be not oak aged? Anyone out there drinking or have something like this?

[kallaskander]

Hi there,

there is no big chance of drinking a malt pre 1990 which was not matured in oak. Statistics and the experiences made with oak centuries ago are against it.
The mass of casks that were around were made of oak for centuries because other kinds of wood do not keep for decades as well as oak does. The first barrels that were available in bigger numbers in the UK were sherry casks and wine casks and most probably rum casks. Then bourbon casks turned up in huge numbers after the Straight Bourbon rule in the USA.

No I do not think Di Blasi that you will find a malt which was not matured in a oak cask.

Greetings
kallaskander

[Di Blasi]

Thanks! But it sure would be interesting if back then someone, (like today, folks finishing whisky in ex-Grand Cru Champagne, ex-Tokaj, ex-Marsala, etc.), thought about ageing in other wood, as a one-off, single cask, "never to be re-peated" kind of deal? Come on, someone out there has a very special bottle of pre-1990 whisk(e)y not aged in oak?!! Might not be good to drink, but collectable anyway.

[Deactivated Member]

I seem to recall an article on this subject somewhere some time ago, that said that there were indeed very rare experiments with odd woods. But this is a very hazy recollection, and I cannot swear to it. And kk is most likely correct--your chance of ever seeing such product is pretty much nil.

Thank you Aidan and Harry for helping me discern fact from fiction. I think the effect of wood on whisky is a really interesting subject so it is just one more question off my list! I must add, the phrase "Fine Oak" is certainly catchy!
Kind regards,
Wendy

That's why they pay well for good marketing people. Most like to think that marketing is unnecessary but more lead has been turned into gold by good marketing than by good product research & development (sad but true).

Harry

I don't think marketing is unnecessary, just that a very large proportion of it is complete malarkey, and it's amazing how much of it many people will swallow. You are right, Harry, but good marketing without good product is an empty, if pretty, package.

[bamber]

The world is nuts.

[kallaskander]

Hi there,

not a exotic kind of wood but a BenRiach which spent 26 years in virgin oak.

http://www.benriachdistillery.co.uk/tme ... sItemId=40

Greetings
kallaskander

[Deactivated Member]

I'd like to try that, kk. In fact, I was just thinking that I'd like to see more virgin oak used in Scotch whisky--use the new barrel three years for blend fodder, and then as normal for single malts. An "all-malt" barrel, as it were. But it won't happen as long as used bourbon barrels are readily available.