Oxidation

@HeartlessNinny We've discussed this in some depth over the last year or more (keeps coming up as a topic), I suggest a quick search through the old discussions to see what we've all had to say so far.

In short though - the sequence of oxidation events goes something like:

1) Open bottle. Might be a little "closed up" - give it a week (or several weeks in the extreme cases) and it will generally open up beautifully - this is beneficial oxidation and I've not had a whisky yet that didn't benefit from being open a week or two.

2) For Islay malts, smoke will noticeably dissipate over the first few to several weeks. Peat remains, but that volatile smoke goes pretty quickly in most cases.

3) At some point (say 3 months+ but as much as 6 to 12 months later) you will hit the tipping point where your whisky will stop improving - this varies a lot between whisk(e)y styles and where you are, and how you store your whisky. From there, you generally don't want any excessive air contact with your whisky. Either drink quickly, decant and seal or gas it for long term storage.

Frequent air exchange (opening and pouring a dram) will hasten oxidation, and anecdotal evidence would suggest that in warmer or more humid climes, the oxidation process is also enhanced. In short - air is your friend initially, but then quickly becomes your enemy.

Some people (like myself) notice adverse oxidation quite quickly. Others on this site seem to still be able to enjoy their open whiskies 1 to 2 (or more) years later without experiencing much if any dissatisfaction at the results of oxidation - like nosing or tasting, your affinity (or lack thereof) to a whisky's oxidation will be a personal experience but generally speaking, adverse oxidation is not something you want, especially in a whisky who's character you greatly enjoy while it's "fresh" because excessive oxidation will turn it into a mere shadow of its former self.

@systemdown pretty much nailed it with his reply. I would put less of a positive spin on the first few months than he does, as I think whisky tends to just flatten out over time. Here's a blog post I really enjoy that pertains to this topic: scotchandicecream.com/2012/04/…

Thank you for the replies, gentlemen... Sorry for not doing a search on the topic first. Bit of a newbie mistake there.

Either way I'll heed your words and start opening new bottles more cautiously. I must say, though, that I decided to pour myself a dram of Laphroaig Quarter Cask earlier tonight, and though it's been open a year (or close to it), I find that it still tastes pretty great to me.

It's true that I keep it in a cool dark place, and I didn't pop the cork all willy-nilly every five minutes... But given that I'm down to that last inch and it's still going strong, well, that bodes at least somewhat well to me. Or maybe I just don't have that sophisticated a palate yet. :)

@HeartlessNinny Glad your Laphroaig QC is holding up - it's a pretty robust dram at a decent bottling strength so I would not necessarily expect it to degrade as quickly as some. If you had a mild, fruity Speysider that was opened about the same time I suspect you might notice the difference with that one.

Do you remember what the smoke was like when you first opened the QC? How does it compare now?

@systemdown You know, I'm really not sure... I can say this, though. I've been sharing another bottle of QC with some friends recently (we have a nascent whisky club) and I haven't noticed much difference between that and the dram I poured tonight. As I said in another thread, when a dram is different when I come back to it, I used to think that it was me that changed, not the whisky. Now I'm guessing it's both! As if life wasn't complicated enough already. :)

@systemdown You know what, contrary to what I just said, now that you mention it I do think the QC might be a bit less smoky than it used to be. I still find it to be quite peaty, though. I'm not usually the kind of person who finds himself wracked with doubt, but I have to admit that delving into the nuances of a good dram is making me wonder about my very senses. Not that I have any less enjoyment of it, mind you.

@HeartlessNinny my advice is don't start worrying about it. This kind of thing saps the fun out of whisky (I can tell you from experience).

I would add that different styles of whisk(e)y react differently. For example, bourbons appear to have more variation/volitility than non-smoky Scotch.

One thing I am curious about, for the chemists (or otherwise scientifically inclined on Connosr) in our midst. I was under the impression that the phenomenon discussed here is actually effects of evaporation, rather than an oxidative process. Clarification/discussion about this would be appreciated.

@Pudge72 I was under the impression that no one, scientists included, really understands why a whisky's taste might change after the bottle has been opened.

And by the way, I find that I have pretty much the same number of opened bottles... Some are done with, but for the most part I'd say everything has held up pretty well. I don't think I have anything that's been open more than 6-8 months, though.

A nice place to start with SCIENCE! and whisky is, well, the Whisky Science blog :) There is, of course, a post about bottle maturation (both with oxygen and without): whiskyscience.blogspot.co.uk/2013/02/…

It's mainly about sealed bottled, but gives some insights.

As far as I know, there are a lot of different effects going on once you open a bottle: oxidation, evaporation, light triggered reactions, general 'ageing' (increasingly so as the bottle loses alcohol), reaction with the glass, reactions thanks to the agitation of the bottle...

@cowfish...thank you for the great link! SCIENCE!