Does Whisky Age in a Bottle?

by Oliver Klimek on March 21, 2010

Just like the issue of whisky with vs. without ice, this question is one that is continuously popping up among whisky lovers. Much has been written about that topic, but still there is much uncertainty and confusion about it. Let me try to shed some light on this.

The Old Commonplace: It doesn’t!

One of the things any aspiring whisky afficionado learns first, is that whisky does not change after it has been bottled, under the condition that it has been properly stored. A 10yo bottled in 1970 will still be a 10yo today. Unlike wine, which does change after bottling quite a bit, the high alcohol concentration forbids anything to happen inside the liquid. So they say.

Or does It?

But nevertheless many have reported that they had found differences in taste between to bottles of the same whisky opened within a period of many years. Can this be explained only by psychology?

And then there is also the strange phenomenon that many ancient bottles containing whisky bottled at a young age seem to get much better marks than their contemporary cousins. Is this just because “they don’t make it like that anymore”? So much research has been done around whisky making that it is hard to believe that just using Golden Promise barley instead of the modern varieties and heating the stills with a direct fire could powderize all progress in whisky making in the last fifty years.

So It Does Then?

Meanwhile, more and more whisky lovers recognize the fact that their favourite tipple does indeed change over time, even in a sealed bottle. The high alcohol content may work against it, but if you look at it with a bit of common sense, it should be clear that something just must happen in the bottle after the cork has been sealed.

And What Exactly Does Happen?

The key in understanding whisky bottle ageing lies in understanding the change that red wine undergoes during bottle ageing. The two key elements here are air and tannins.

1. Just underneath the cork, there is always a bit of air in the bottle that can react with the wine. And furthermore, no cork can seal a bottle tightly enough to disallow any exchange of air with the outside. The exchange may be only minimal but it is there.

The interaction of wine with air is commonly called oxidation. This is a bit of a misconception because wine is not a homogenuous material like iron that can rust. It is a very complex mixture of many chemicals, some of which actually do oxidise and some of which are inert to the influence of oxygen.

2. The tannins contained in the wine – resulting from the stems and pips of the grapes as well as from the cask wood – slowly react with other substances to form new aromatic compounds.

In bottled whisky, exactly the same things happen. The process is much slower though because the alcohol forms a kind of coating around the reactive molecules that first has to be overcome by the reactants. And then, whisky has less tannins than red wine because the spirit itself does not contain any. All tannins present in whisky have been leeched out of the cask wood. This might also explain why especially old bourbon whiskey seem to beneftit drastically from bottle ageing. I remember one of the Malt Maniacs e-pistles where there is an amazing report about a tasting of some very old American whiskeys. Due to their maturation in fresh oak casks there should be more tannins present in those than in your average scotch.

So in my opionion it would be foolish to believe that all of the hundreds of chemical substances that are present in whisky would become totally inert right after bottling.

Time for an Experiment

The only way to really pin down changes in a bottle of whisky over time can be a long-term experiment. 20 bottles of the same whisky batch have to be stored together in a controlled environment. Every year, a bottle is opened and analysed by gas chromatography. Any volunteers?

Changing vs. Ageing

There are people who admit changes taking place in bottled whisky, but they refuse to call it ageing or maturation because these terms were legally restricted to the period the whisky rests casked in the warehouse. Let’s see what the 1990 Scotch Whisky Order has to say about that (Section 3 c):

“Scotch whisky” […] means whisky 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.

This is the only mention of maturation in the order, the 1988 Scotch Whisky Act say the same in a slightly diferent wording.  And the term “ageing” is not mentioned in either of the documents, so I think it is fair to indeed use the term “bottle ageing” for the things that happen in a whisky bottle.

{ 26 comments… read them below or add one }

Johannes Krause March 21, 2010 at 4:25 pm

Very interesting topic as I mentioned earlier.
And yes, I think your’re right. There is something like ‘bottle ageing’ and probably this explains the uncommon behaviors of some aged bottles of whisky. But on the other hand there is another reason which also has its influence in quality.
In former times the industry didn’t set its focus so much on quantity concerning whisky production than it does it these days.
And I think a growing quantity rarely does not influence the quality of a product.



Rick Mentry January 2, 2011 at 4:21 am

A small question my father bought a bottle of jim beam in 1965 in maryland and brought it home and has never been opened and still has the paper seal on the top he’s gone now and i was wondering about the whiskey could u tell me anything about it please


Oliver Klimek January 2, 2011 at 11:54 am

Hi Rick, if the filling level is still up at the neck, it should be perfectly drinkable Jim Beam. It might be interesting to compare it to today’s version but it will also have changed a bit durint the long time in the bottle. But there are also collectors who might be interested in an old bottle like this. I can’t tell you anything about its value, though.


Jeff Ausen February 21, 2015 at 8:19 pm

It is interesting. I have recently acquired Jim Beam bottles from the late 50’s and early 60’s with the seals still intact. It would be impossible to adequately compare the current Beam which I just so happened to have with these as it is akin to comparing baseball teams of the 60’s with those current. All I know for sure is the one I have opened is tenfold smoother than the newbie. It rivals some of my very pricey bourbons. So….. I’m not going to look for a market. The market is going to be right in my house.


jon clements September 10, 2011 at 6:49 pm

my wife inherited two quart size “bowling pin” bottles of jim beam. i would like any comments on these collectibles…not sure of age but from the 1950 ish era i would guess.


Jeff Ausen February 21, 2015 at 8:20 pm

Go to eBay and you will find a zillion of them. I too had though I had hit the motherlode but reality sets in quickly.


Colin January 6, 2014 at 3:03 am

To say that whiskey doesn’t change after bottling, you’d have to argue that it is chemically stable and inert, which it isn’t.

Old whiskey DEFINITELY has a distinct taste that I’ve never tasted in contemporary whiskey. I never liked whiskey generally, until I tried a 20+ year old bottle. Now I look for it at estate sales, and that’s the only whiskey I’ll drink. I don’t know what it does after many years, but it does something.


Clifton L Sikes July 6, 2016 at 4:21 am

Have multiple bottles and decanters from the 60 so to the 70s


Drinker March 9, 2014 at 5:26 pm

There are probably a few more factors:
1 the recipe of yesteryear – how has the recipe changed? You mention ingredients, but the recipe may have evolved as well.
2 the maker – did the process change?
3 angels share – when I open bottles that have been sealed with a cork for more than 20 years they are inevitably 3/4 full or less. The concentration seems to produce a longer lasting finish and smoother taste. It took a little longer to open up on the nose. I actually decantered it (had to filter out cork pieces).

I just opened some 15 yr aged in barrel from 1969 (45 years in bottle!). Total age 60 years. I don’t typically drink beam, but I suspect back then this came from single barrels and I really enjoyed it! The bourbon was clear and looked like it was bottled yesterday.

I found three sealed beam’s from the late 60’s early 70’s and intend to work my way through them.


Eric April 30, 2014 at 3:05 am

In terms of a long term test, one would want to analyze all 20 bottles at the beginning. Best would be to do gas chromatography and mass spectrometry on them. I suspect there may be slight differences between the set of 20. That is, the tests should be sensitive enough to show slight variations. Once done, the bottles can be resealed and stored in a controlled environment. This creates a baseline for all twenty bottles.

The amount of sample needed each year is rather small for both GC and MS. Of course, one would want to take a shot each year for tasting. In the first year, one shot from bottle one. In year two, one from bottle one and one from bottle two, and so on. Until, year twenty when you need carefully taste twenty shots! This allows for bottle one to have twenty shots of air in it at year twenty vs the other bottles which have less air. A wee bit of control in the science.


Andrew July 26, 2014 at 3:08 am

I think there are several other factors that lead to old-fashioned whiskies being better. The fermentation times were much longer than they are now, and the yeast wasn’t as powerful. Distillation times were also longer and slower, both of these are factors which allow for the creation of much more complex and deep whiskies.


Mark October 11, 2014 at 11:34 pm

I just picked up a Jim Beam decanter (1963 corvette) bottled in 1987..still sealed.. I am now torn as to drink it or hold on to it thinking it may become more valuable…


Jeff Ausen February 21, 2015 at 8:23 pm

Drink it. It is not all that valuable. Take a look at eBay at the empties. A comparable bottle of Bourbon would cost you close to $75 – 100 and you will not get that much for it because you have no place to sell the alcohol. Best bet to sell would either be at a wine auction or estate sale.


tom October 17, 2014 at 3:51 pm

I have a bottle of Jim Beam that opened about 5 years ago. Bottle is about 1/2 full. My question is it still drinkable


Oliver Klimek October 17, 2014 at 3:55 pm

It will never go bad, even when the bottle is not full anymore. It will only lose flavour over time.


ramesh December 31, 2014 at 2:29 pm

i have a 1/2 bottel of scotland wishky/it was open in 1984.can we can use this opened bottel after 30 was close tightly in 1984.


Oliver Klimek January 1, 2015 at 4:19 pm

No problem here.


Mark January 25, 2015 at 7:28 am

I have been reading a bit lately about batch ageing or (bottle ageing)
Its more to do with the molecular structure of the spirit rather than the flavour from the barrell.
As the spirit oxidizes the molecular structure of the spirit changes,I guess mellowing it out and making it more desirable.
Heres a good video about it on youtube.


Kevin April 22, 2015 at 1:52 am

My Dad past away recently and left a half full bottle of JD black lable he opened in about 1990…my brother and I hoisted a shot to him thinking it would not be very good, but to our surprise, the harshness was gone and it was quite smooth… Bottle aged with a little extra o2 in a dark closet….


Matt September 7, 2015 at 12:08 pm

I have a 4.5L bottle of White Label Jim Beam I bought way back in between 2004 and 2006. It has remained unopened for that entire time and kept in somewhat of temperate climates. I’m very interested to hear anyone else’s opinion on whether or not there may have been some type of ‘change’ taking place?

I am intending on saving it for another 16 years for my son’s 21st birthday.


Mark September 8, 2015 at 12:24 am

I had payed this previously it might help.
I think the flavour possibly won’t change but the spirit in it might mellow in time when exposed to the air making it a bit smoother.
But at the end of the day Jim beam white label will always taste like kerosene.


Gray September 12, 2015 at 6:08 am

I have a bottle of Makers Mark in the cupboard that has been there for 20 years. Is it improving with age or am I kidding myself and need to crack it open


Eileen February 26, 2016 at 11:15 am

I ended up with a dozen or so unopened miniatures of various bourbon, scotch and liqueur. My husband’s grandmother received from her brother whenever he got to fly for work back in the 60s. She and her husband weren’t drinkers, so they lived in a shed in Georgia until her death last year. The liqueurs have weird scum floating in them, but for the majority the whiskeys are clear as the day they were bottled. I opened a Jack Daniel’s from around 1965 and tasted it… After the burning ended, the taste was surprisingly not bad. 🙂


Keith March 6, 2016 at 6:39 pm

My grand parents died and in the cellar he over 100 bottles of variety of boze like 3 bottles of scotch from the 40s, he has 40 yr old bottles of burbinthat are 35 yrs old , calua just a lot of bottles . There is a few open the whisky ones .
I’m not a drinker of Alchole .are they worth any thing .
Thanks Keith


Dave June 3, 2016 at 4:16 pm

I believe so! All you include here are real, and will be following your post from now on.


Frank July 16, 2016 at 12:39 am

I recently was given some old bottles of liquor I got one from the tennis and racquet club which I’m sure it’s about 45 to 50 years old it’s a blend scotch whiskey made exclusively for the tennis and racquet club I got some wild turkey from the 60s early 60s some Canadian Schenley Canadian clubwhiskey from the 60s wild turkey from the 60 bonded being Kentucky bourbon from believe the 60s also a bottle of QT American like whiskey I believe that’s also old Canadian club from 1971 can anyone tell me the value of these bottles


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