Monday, March 7, 2011

Bourbon and Sherry casks

Scotch, unlike wine, does not mature or age once it is bottled.  It matures when placed in oak casks.  The quality of the casks where the scotch was aged is very important.  According to experts, the nature and quality of the casks, together with the quality of the barley, the making process can make up for 95% of the final quality of a malt whisky.

Naturally, wood, in the form of the casks, plays a very important role in the production of whisky.  Only oak casks are used, as they are flexible yet solid enough to be constructed into the shape of a cask.  Oak also adds very distinct character and flavor profile to the spirit as well.  Only specific oak species are used for whisky casks: White American Oak, and European Oak.


In the process of making scotch, second-hand casks are used almost exclusively.  A virgin oak wood cask, with its fresh "woody" elements" could potentially overpower the subtleties that we appreciate in a fine glass of scotch. 

The second-hand cask used for the maturation of scotch, almost always, has been used before in the production of bourbon or sherry to absorb some of the harshness of the new wood. 

But why bourbon?  Well, that is because American law (bourbon is mostly produced in Kentucky) states that a bourbon cask can only be used once for the production of bourbon.  The cask become of little use to the bourbon distillers, and the Scots can then pick it up for a nice price. 

Bourbon casks, generally speaking, import a characteristic vanilla flavor to the whisky.

In olden times, when alcoholism was more socially-acceptable and rampant, sherry (fortified Spanish wine) used to be shipped to Britain from Spain in casks rather than bottles.  It was expensive to ship the sherry casks back to Spain when the alcohol was drained from the cask, and so empty and discarded sherry casks were scattered all over the 19th century Scottish landscape.  In what is quite possibly one of the world's earliest recycling initiatives, the Scots started gathering these second-hand sherry casks and re-used them for the maturation of their scotch.

Sherry casks are more expensive than bourbon casks, and account for only 7% of all casks imported for whisky maturation.  In addition to transferring flavors from their former contents, sherry casks also lend maturing spirit a heavier body and a deep amber color.  For this reason, single malt scotches that have been matured in sherry casks are prized by blenders and usually fetch a price premium. 

These days, it is not uncommon to see both bourbon and sherry casks being used more than once.  A sherry cask that has seen four or five fillings is not unusual.  Naturally, with each filling, lesser and lesser of the wood's character is transferred to the whisky, which just goes to give scotch their uniqueness in the sense that one bottle can quite easily differ from the next bottle, based on the cask they were in.

Till the next time, bottoms up my friend.

57 comments:

  1. very informative, nice to know about those casks. :)

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  2. I didn't know that about casks, thanks

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  3. And I thought it all came from the Scotch Fairy, this makes much more sense...

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  4. I never knew that law about bourbon. Interesting.

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  5. "Scotch, unlike wine, does not mature or age once it is bottled."
    Another knowledge gained.
    Thanks!

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  6. That is actually very interesting. I had no idea about the processes or history of all those alcohols

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  7. So that's where that vanilla taste comes from :D. I learn something new everyday about scotch :D

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  8. I had no idea of the symbiotic relationship that existed between bourbon producers and scotch producers, nor did the importance of the specific would in the cask ever enter my mind either.

    It's nice to learn something new, man, thanks!

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  9. I didn't have any clue as to the relationship of the cask to the final product - very insightful!

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  10. Another great post. I've found that you can really taste both the bourbon and especially the sherry in the Balvenie Double Wood.

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  11. Very interesting.. Great post, as always..

    -Koal0r

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  12. Awesome post, I saw casks when I went to the Guinness Storehouse in Dublin, it's quite a sight to see all the work that goes into producing those delicious flavors.

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  13. Education about alchohol. Not good for my healh, but good for my knowledge :D

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  14. is a Sherry casks related to making the drink sherry? how does sherry differ from port? may have missed something.

    check out my latest restaurant reviews @

    famishedstudent.blogspot.com

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  15. nice work.. good information man!

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  16. this is really interesting i', learning alot i didn't know before

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  17. good post. i learned some of that stuff in bartending school but not all of it. pretty cool info.

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  18. Great post. Very informative. I learned something.

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  19. thanks didnt knew that much about bourbon and sherry b4

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  20. Information I didn't know, I like that.

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  21. im a bartender, this sounds cool enough to sa it to impress people haha, so thank you <.<

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  22. Well researched and written post! I'd have never guessed that secondhand casks were so important to the flavors in good scotch.

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  23. I had no idea the cask was that important.

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  24. Hold up. When did alcoholism stopped being socially acceptable and rampant? lol

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  25. Wow very informative and interesting!

    It felt like I was reading National Geographic or something.

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  26. I didn't know that about sherry casks...everyday is a school day

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  27. I actually learned something from this.

    Now I'm tempted to try a glass one day. :P

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  28. I don't know but I love that wooden flavor on my drink, they should be more considerate about reusing too much times the caskets

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  29. Random side note: My taiko group in college made our own taiko drums from a used barrel that used to contain some wine of some type. It was a nice smell hah.

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  30. This is something I didn't know... I learn something new everyday! :)

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  31. very interesting, i learned something new today!

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  32. So, in short, there may be a little Jack Daniels in my Cutty Sark?

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  33. Amazing piece of knowledge. I have a friend who is obsessed with bourbon and is a cartographer/mapmaker. He once made a map of the history of Kentucky bourbon. I'm sure he would get a kick out of this.

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  34. Sherry <3

    This was very informative. Thanks!

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  35. cheers for sharing this info man! a good friend of mine is amazing on how to make alcoholic drinks in general. Although his speciality is wine

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  36. First cask makes bourbon, then goes on to make scotch. I love learning knew things and as a writer, I have to start my alcoholism somewhere.
    +

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  37. I'd like to get my hands on one of those casks hehe

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  38. amazing, didn't know about this

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  39. nothing like a nice, aged, oaky tasting scotch i must agree. thanks for detailing the process this is very interesting!

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  40. Thanks for the info, more cool knowledge.

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  41. That's crazy. I was under the impression that it matured past that point.

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  42. MMM nice, I want to drink something now

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  43. very interesting, thanks man

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  44. Very educational. Thanks!

    I follow and support those who do likewise.
    toastburnt.blogspot.com

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  45. The reason sherry casks became more expensive was due to legal changes that prohibited the sale of filled barrels of sherry (in other words sherry had to be put in glass bottles before they could be sold). Thus the Scotch distilleries had to start buying empty sherry casks to use for aging whisky. Unfortunately an empty sherry barrel picks up bacteria and mold if they aren't reused immediately (since bourbon has a much higher alcohol content those barrels are effectively sterilized and don't have this issue). One method of cleaning a sherry cask is to burn a sulfur candle inside the barrel. If not properly rinsed after this treatment, the whisky that is added later may pick up a noticeable sulfur character. People who are sensitive to sulfur tend to notice a matchstick note on the nose.

    Woah, didn't mean to write that much but I wanted to mention sulfur because it's going to be something most of us encounter eventually.

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