Scientific(ish) whisky storage

That's a fun experiment . I would have thought that heat would affect it more negatively

@Alexsweden Yeah, surprising aye. It would have been interesting to have a bottle laying on it's side too. No real surprise with the light. Beer get's 'skunked' in the light, and the effect of light on anything left outside is pretty obvious. Cool and dark still seems like the safest bet for those precious bottles.

@Hewie, thanks for posting this very interesting article. This is a subject very dear to me because I inadvertently ran an experiment on my, at that time, 175 open bottle collection, by not cooling the house over the very hot (here) summer of 2011.

From what I read of this article the heat experiment and variable-heat experiment were run with full (sample) bottles. I would be interested to know whether an effort was made to make the air contents of the experimental bottles nearly devoid of air. It is important to note whether they are speaking in this article about unopened bottles or opened bottles. It appears that they are attempting to duplicate with small bottles unopened bottles of whisky. Any significant air in a sample bottle renders it the equivalent of a 2/3rds full larger bottle...so I do have questions about the techniques used in their study.

What I found was that several months of high heat, 90 F/32 C temperatures for most of the day, will have strong effects on many open bottles. I had about 20 bottles which I considered ruined after that summer, and at least 80-100 more which I considered slightly to somewhat damaged. I am certain that it was the combination of heat plus oxygen that was the cause of the damage. More delicately flavoured whiskies fared the worst. The guys in this study did not even attempt to replicate the effects of "half-full bottle plus high heat". They are killer, I can tell you.

People like to talk about chemical oxidation, and ignore the other big effect of oxygen exposure in an opened bottle, which is secondary fermentation. If you leave an opened bottle (opened here defined as at least 10-20% of the contents removed and replaced with air) with significant heat and air for a period of many months I allege that what you get is refermentation of the sugars in the whisky, yielding a far more sour and bitter product than what was bottled at the distillery. The sweet/dry balance is destroyed in these damaged bottles. Basically the sweet component is eventually removed via refermentation by ambient organisms in the air in contact with the whisky.

Heavily peated whiskies, briny whiskies, and high ABV whiskies hold up much better under conditions of heat and air stress than do more delicate whiskies. I think that it would be even more instructive to see this experiment performed with whiskies like Hazelburn, Cardhu, Pappy Van Winkle 20 yo (on the delicate side), and any world whisk(e)y made from corn, than for a Cask Strength peated whisky like Laimrig.

My experience has taught me to be quick to decant and/or gas any delicately flavoured whiskies in the first 6 months the bottles are open. Decanting into low-air-space glass sample bottles I find more effective than using inert gas, but the gas is a great help too, and I do use gas with almost every open bottle I own which has not yet been decanted.

@Victor In a nutshell; cool, dark and full, and if not full, emptied tout de suite?

@BlueNote, YES.

@BlueNote - That's certainly my approach. I don't use gas but I would think that leaving a bottle even for a few weeks with, say, less than 100 ml would not be a good idea. When I get down to say 1/5 or 1/6 of a bottle I tend to focus my attentions on it . . .

As a general rule, how long would folk keep a bottle if not gassing it? I like to drain in under six months (if they last that long).

@RianC I agree, six months without gassing or decanting is probably the limit. My problem is, I just lose interest in certain single malts after I get half way through them and then tend to forget about them. I've had some for several years that still have a third or so left. If they are good ones that get down to the last 100ml or so, I decant them into my collection of 50ml miniature bottles. I've never gassed, but probably should.

@Hewie, a fascinating topic!

I'm a firm believer in allowing the fill level of a bottle to decline without intervention. I've had 100+ bottles open at one time, currently hovering at 78. Not all of my bottles have been without some form of intervention. I have experimented with inert gas on a select few bottles and failed to notice any difference in those bottles when compared to the same (same batch) whisky without gas...yes, identical open bottles with similar declining balances.

Not all whisky bottle-ages gracefully. Heavily peated varieties tend to experience a decline in smoke and phenols (and fill level lol). Laphroaig Quarter Cask comes to mind immediately, and there are many more, but the point I aim to make is for the case of some delicate, some low proof, and some delicate & low proof whiskies.

There is a surprising group of whiskies, some gentle, some elegant, that have sat for periods of a year or more and maintained a high level of integrity: Century 25 YO 100th Anniversary Calgary Stampede 40% abv (3+ years, @Victor can attest to this), Danfield's 21 YO 40% abv (1 year+), Gibson's Finest Rare 18 YO 40% abv (1 year+), Forty Creek Confederation Oak 40% abv (4+ years open and scored 95 by @Jason Hambrey), Alberta Premium 25 YO (2+ years), Macallan 18 YO 43% abv (4+ years), Crown Royal Ltd Ed 1975 40% abv (opened almost one year, @talexander scored this 95 and @Victor scored this 93). W.L. Weller 12 YO is known for its ability to age well in an open bottle. I open Weller 12 in pairs and sometimes split a bottle upon opening to ensure exposure. This is only a small sample from the "delicate" whisky style, yet it confirms the ability of "soft" whiskies to bottle-age well.

The climate in which these bottles were aged was not temperature controlled, with the exception of Macallan 18 (1993). My whisky cabinet has been in a climate controlled room (15C - 24C) since 2013, before that time the bottles were subjected to temperatures in the 15C - 34C range, away from direct sunlight.

@Victor @paddockjudge thanks to you both for your valuable input - gained at your own expense! It's always good to hear from those who have a decent sample size to speak from. You're right @Victor, that it woud have been interesting to see how the combination of factors affected the outcome. As I eluded to in the title, this was partially scientific. As scientific investigations are typically taught in school (fair testing), only one variable was changed at a time rather than multiple variables. That is an interesting theory around secondary fermentation, and I remember the thread discussing residual sugar in whisky. I'm not personally convinced this is the reason for the apparent souring over time. Have you ever tasted the last drips of whisky in the bottom of a glass the next morning? We're familiar with smelling the glass, but if you taste any liquid left over it is nasty! It becomes very bitter. I don't think there was sufficient time for a secondary ferment. I suggest the souring over time (in an open bottle) is due to the loss (or change in composition) of the much more volatile sweet flavoured compounds such as esters. This, as you would expect, would be accelerated with increased air exposure (lower bottle level). It sounds like you've identified those bottles most at risk and have a suitable strategy to protect their integrity. @paddockjudge I agree, in my much more limited experience, that heavily peated whiskies experience a significant decline in their phenolic profile, or at least a change in their profile. Your observations on the group of more delicate (gentle, elegant) whiskies whose integrity is maintained is interesting. I wonder what the actual basis for the difference is? Most of this knowledge is clearly only learned by experience! @RianC I also have never used any gas to preserve. I rely on cool, dark conditions (yes, I still store my bottles in their tubes), and relatively fast turnover of bottles (less than 1 year). Thanks for all your valuable thoughts and experiences.

If a bottle is something special, I pour off a sample early in the bottle's life to be enjoyed by Future Me. Beyond that, I've regretted every instance where I've poured off the final portions of a bottle into some rando little bottle.

Given that I'm not trying to stretch out a bottle's life past 6-12 months max, the decanting thing just seems like a solution to a problem I don't have.

More importantly to me, the whisky loses some of its caché when it's no longer in the original bottle. The last third of my only-ever bottle of Octomore, for example, went into a smaller bottle last summer "to preserve it." And now I feel like I don't really even have it anymore. I'd rather take my chances with potential degradation (or at least change) and keep drinking down the original bottle.

@BlueNote - I'm starting to have that problem myself. I've got about 1/6 left of Superstition and the Laga 8 but I'm struggling to finish them off, especially the former. I'm also generally drinking less at the minute.

I have a 'rule' that I have no more than 6 whiskys and a couple of bourbons/rye open at one time; and it's a one in, one out policy. It's hard to keep to that at the minute as I've so many new ones I want to try. Worse problems to be had it must be said

@Hewie - I keep them in the box too! But maybe get a few out and put on the shelf for over the weekend.

@Hewie, the primary reason that I believe that secondary fermentation is the reason for the souring and bittering of very-long-aired bottles is that I see no sweet component left in these whiskies. If there is any sweetness in a whisky it can generally be detected no matter how much bitterness, or sourness, is also present. The only way I can account for this is that the sugars have been transformed and removed.

I would also go so far as to suggest that, logically speaking, if you wait long enough, secondary fermentation is an inevitable phenomenon. The only way to prevent or retard it is by providing conditions inimitable to any ambient organisms, viz. high ABV, brine, or chemicals like the phenols from peat. It is no accident that whiskies with high ABV, brine, and/or peat are the ones which do NOT deteriourate in the same way as less protected whiskies do.

I also do not rule out that secondary fermentation can occur in the space of one day with a glass left out completely uncovered. It is completely radical what happens to a glass of whisky left out for 12+ hours. How do you account for that? No I personally don't think that the evapouration of esters does a good job of explaining that phenomenon. There isn't a lot of sugar in most whiskies. It would not take much re-fermentation to throw off the sweet-dry-bitter balance in them. Can I prove any of this by chemical analysis? No. It is just the best way I know to make sense of these experiences.

@Victor: "It is no accident that whiskies with high ABV, brine, and/or peat are the ones which do NOT deteriourate in the same way as less protected whiskies do."

It sounds like you're talking about actual brine here, not just a briney character. Care to expound?

@MadSingleMalt That's a very good point vis a vis the attraction of the original bottle.

@MadSingleMalt, I am not at all sure what the difference is between 'actual brine' and a 'briny character'. Any amount of brine/salt will have some effect on the organisms which can live in its environment. No doubt larger quantities of brine/salt will have a more inhibitory effect on a larger number of microorganisms than will lesser concentrations of brine in the drink . I meant my comments in a general sense, which is to say, salt in the whisky from whatever influence, maturation-environment air, water, peating, etc.

@RianC After five weeks of serious over indulgence in Mexico, my wife and I are on the program. At least to the extent that we are not drinking on weeknights and being much more moderate on weekends. So many of the open bottles in my cabinet are languishing. I have 67 bottles at last count, 38 of which are open. It's a modest cabinet compared to some (I'm looking at you @Victor @paddockjudge @Nozinan @MadSingleMalt @talexander to name a few) but I do worry about some very expensive malts going off. I might just have to quit buying until I can reduce my current inventory of open bottles. If I buy them I can't resist trying them.

@Victor: A "briney character" would be something like Old Pulteney or Springbank that tastes kinda salty.

"Actual brine" would mean salt. Actual salt. Yes? Especially if you're talking about a chemical composition capable of preventing fermentation.

From what I've read, whisky normally has zero actual salt content. Is Serge the one who often writes a self-aware comment like "blah, blah, blah, salt—er, a salty character—blah, blah, blah" is his review of "salty" whiskies?

@BlueNote, don't paint me with your glorious broad brush! I only keep about five bottles open at a time.

@MadSingleMalt You, sir, are an example to us all

@BlueNote I hear you....the problem isn't the drinking, it's the buying...

@Victor I don't think anything at 40% or higher will be subject to secondary fermentation. No yeast or bacteria can thrive in that.

@BlueNote - I'm trying hard to decrease my number of open bottles. But I'm VERY flattered to be considered among the high rollers on this site.

@MadSingleMalt yeah, this is my understanding too. @Victor This is all just part of the mysterious and somewhat unpredictable nature of whisky - how and why it changes over time. I googled some images of mass spectroscopy spectra of whisky - essentially a graph showing all the components in a sample. Suffice to say, whisky, in it's various forms, is an extremely complex liquid! It's no wonder that it experiences changes over time and under different environmental conditions. a = Scotch, b = American, c = a counterfeit whisky

Gotta love that delicious counterfeit whisky!

@BlueNote - Up to now I'ts not been too hard to show restraint as I worry I'd have 20+ bottles open before I knew what was happening if I broke 'the rule!'

One plus of having fewer open is that I tend to focus on one malt for a week or so, so I can really get to know it and then do it again down the line. Obviously, that's easier when they're tasty

Speaking of counterfeit whisky, when I was in grade 8 we were doing a unit on "the pioneers" and we had to prepare a meal (for class) that a pioneer would have eaten.

Ever lazy, a friend of mine and I decided that dried fruits and nuts would be appropriate to eat, and to drink, what other than whisky. So we took an empty whisky bottle of my dad's and filled it up with water. We didn't know about e150a, but we used food colouring to make it look like whisky.

The teacher confiscated it...

@Nozinan, when I was in Grade Eight, we got to keep our whisky providing we had brought enough to share with everyone.

Lightning strikes twice in one month, March Madness! I actually agree with @MadSingleMalt.

I lament the pouring of samples (knowing they will be delegated to the back of the cabinet to languish in obscurity for eternity).

I have become accustomed to pouring a 60 ml serving from newly opened bottles. This allows me to archive each bottle for future reference. The upside to this is the portability of the two ounce mini. The convenience of toting 10, 20, or 30 mini bottles to a gathering has proven to be worth the effort of harvesting the samples.

...and yes @MadSingleMalt,

"the whisky loses some of its cache when it is no longer in the original bottle...I'd rather take my chances with potential degradation (or at least change) and keep drinking down the original bottle" oh so true!

I have managed to preserve some of the cache by attempting to harvest labels from the original bottles and applying them to the mini bottles. I enjoy drinking down the 700/750 ml bottles to get to the label harvesting portion of the experience and it also helps to create shelf space.

@paddockjudge You do understand that this is not a porn site don't you?

@paddockjudge - that is impressive dedication. Love the shelving as well. Beats my back of the wardrobe and cupboard under the stairs methods of storage! I basically store my whisky in Harry Potter's bedroom