Settle a Bet

[chelms11]

If I leave a bottle of bourbon whiskey out over night WITHOUT the top on, what happens to the whiskey? My friend seems to think nothing happens, I think he's stupid.

[peergynt323]

It will change, but it won't necessarily go bad. I've left drams overnight that were still drinkable in the morning--definitely changed, but still good.

If a bottle has 15 drams in it, it will oxidize at 1/15 the rate of one dram.

[Deactivated Member]

Leaving the cap off overnight doesn't really do much. Once opened, there's already air in the bottle (it's not really half-empty, it's just half-full of air). With the cap off, there's just more air on top of the air in contact with the surface of the whiskey in the bottle.
If you were to leave it uncapped for an extended period -- say, weeks or months -- especially if regularly shaking the bottle to bring additional whiskey in contact with the air, you'll suffer some oxidation eventually. But it's a looonnggg-term process. High-proof spirit is remarkably stable.

[TheLaddie]

Someone will probably drink it.

Otherwise I think the guys above have it. It appears your friend is not stupid.

[Deactivated Member]

I agree that nothing much will happen to an open bottle overnight. This does not necessarily contradict your assessment of your friend, however.

As TN said, that cushion of air isn't going anywhere in that scenario. I've left a dram out overnight, though, and the change is drastic and catastrophic. And I've had drams poured from bottles with pourers permanently affixed, and thus open (even if only through a narrow tube), that were definitely off. Alcohol evaporates much more easily and quickly than water.

If the event was an accident, and the whiskey tastes okay, count yourself lucky. I'd be peeved if someone carelessly left my bottle open overnight, anyway.

[peergynt323]

Alcohol evaporates much more easily and quickly than water.

Ay ay ay, TH. Again with the evaporation. Your observation about how quickly alcohol evaporates in its pure form has nothing to do with how fast it evaporates in a 50% solution of water.

First off, alcohol's boiling point is slightly above room temperature.

Secondly, if you put a bottle of spirit in the freezer, does the water half freeze while the alcohol half doesn't?

State change has to do with energy and pressure and only indirectly with temperature.

As with wine, the change in your whisky is a result of oxidation, not evaporation. If you're going to state your opinion as fact, at least provide some thought experiments or net resources.

[Di Blasi]

I was luckily stopped once when I went to pour out a first growth red Bordeaux after it had been left out over night. It was just as good, perhaps better than the night before! Bourbon I'm sure will be fine.

[Deactivated Member]

Here is a very interesting article about nosing alcoholic beverages that says, in part:

"In a solution of alcohol, the ethanol starts to evaporate when it comes into contact with air," says Taylor. He speculates that in solutions over 12 per cent alcohol, the rate of ethanol evaporation at the surface is enough to cool this layer, causing it to sink down the sides of the glass. This pushes warmer liquid at the bottom up to the surface, creating a self-stirring effect.

Here is another about alcohol used as a surfactant in printer's ink:

Of course, there are other disadvantages to using alcohol, namely evaporation, which has precipitated environmental regulations designed to reduce or eliminate its use in the pressroom altogether. Since alcohol is a volatile organic compound (VOC), it releases toxic and flammable fumes into the air creating health and safety concerns.

And here, from our very own forum, a discussion of "legs" and the Gibbs-Marangoni effect, which is dependent on differential rates of evaporation of water and alcohol.

Oxidation is a specific chemical process. My opinion is that whisky does not oxidize overnight--it does not undergo a chemical change. The vast majority of the time, the word is used inappropriately here.

As with wine, the change in your whisky is a result of oxidation, not evaporation.

If you're going to state your opinion as fact....

[Muskrat Portage]

Peergynt & Mr Tattieheid:
I'm find this discussion about the evaporation rates of alcohol very illuminating. I had "Googled" Ethyl Alcohol evaporation rates, earlier this evening, to see what I could discover and many of the MSDS sheets merely stated the information was N/A. Interesting that you found the references to evaporation and posted them for our information. Thank you Bruce.

I had noticed at University, when ingesting higher ABV alcohols, that there was a definite affinity for displacement of oxygen by the alcohol. In other words, after you had a shot of Everclear, if you wanted to be able to breath, close your mouth and inhale through your nose! From this personal experience I would confirm that the alcohol with a higher ABV would not only be attracted to water in the atmosphere, but it would also evaporate at a higher rate than, say a bottle of Single Malt would.

Oh yeah, and you got inebriated faster.

Muskrat

[Deactivated Member]

Here is another brief discussion of Gibbs-Marangoni effect.

[peergynt323]

Here is a very interesting article about nosing alcoholic beverages that says, in part:

"In a solution of alcohol, the ethanol starts to evaporate when it comes into contact with air," says Taylor. He speculates that in solutions over 12 per cent alcohol, the rate of ethanol evaporation at the surface is enough to cool this layer, causing it to sink down the sides of the glass. This pushes warmer liquid at the bottom up to the surface, creating a self-stirring effect.

Using the word speculate and 12 percent isn't very scientific--but that's not really the issue. All of these statements are true, however, the alcohol evaporates at a slow rate just like the aromatic molecules in your beverage. It doesn't take very many organic molecules to set off your nose. If you leave a piece of fruit out overnight, will it lose its smell? If you leave the cap off the pine sol, will it have any noticeable change in the smell?

Here is another about alcohol used as a surfactant in printer's ink:

Of course, there are other disadvantages to using alcohol, namely evaporation, which has precipitated environmental regulations designed to reduce or eliminate its use in the pressroom altogether. Since alcohol is a volatile organic compound (VOC), it releases toxic and flammable fumes into the air creating health and safety concerns.

Printer ink that is constantly agitated, exposed to heat, and being exposed to air over a very large surface area, namely the newspaper. Now those are conditions for evaporation.

And here, from our very own forum, a discussion of "legs" and the Gibbs-Marangoni effect, which is dependent on differential rates of evaporation of water and alcohol.

If you spread any liquid over a large surface area, the rate of evaporation will increase, but even so, what evidence is there that the rate of evaporation will make a difference in the ABV?

Oxidation is a specific chemical process. My opinion is that whisky does not oxidize overnight--it does not undergo a chemical change. The vast majority of the time, the word is used inappropriately here.

Again, you state your opinion as fact. I'm quite sure that your not a chemist and neither am I. But I do have a bachelor's in physics and a stint of five years experience in the sciences.

This is a quote from the Wikipedia article on Ethyl Alcohol:

During the fermentation process, it is important to prevent oxygen getting to the ethanol, since otherwise the ethanol would be oxidised to acetic acid (vinegar).

There is no mention of the danger of the alcohol evaporating.

As further support for the cold hard fact that it doesn't evaporate that fast, I had the priviledge of witnessing experiments with liquid helium, the coldest liquid on earth--a superfluid. That means that this liquid evaporates faster than any other liquid known to man. From first hand experience, it didn't evaporate all that fast.

As with wine, the change in your whisky is a result of oxidation, not evaporation.

If you're going to state your opinion as fact....

I guess you didn't bother to read my previous supporting fact and thought experiment, so I provided a few more. I also linked to some great articles on the oxidation of wine last time we had this debate. I can't help but make a guess that you're a Capricorn, TH.

[Deactivated Member]

First off, alcohol's boiling point is slightly above room temperature.

What does this have to do with it?

Secondly, if you put a bottle of spirit in the freezer, does the water half freeze while the alcohol half doesn't?

Huh? Well, it will, if you get it cold enough, but that's entirely irrelevant.

"In a solution of alcohol, the ethanol starts to evaporate when it comes into contact with air," says Taylor. He speculates that in solutions over 12 per cent alcohol, the rate of ethanol evaporation at the surface is enough to cool this layer, causing it to sink down the sides of the glass.

Using the word speculate and 12 percent isn't very scientific

The speculation is about the convection effect, which isn't relevant here. Relevant part in bold. Don't know what's unscientific about "12%".

Of course, there are other disadvantages to using alcohol, namely evaporation, which has precipitated environmental regulations designed to reduce or eliminate its use in the pressroom altogether. Since alcohol is a volatile organic compound (VOC), it releases toxic and flammable fumes into the air creating health and safety concerns.

Printer ink that is constantly agitated, exposed to heat, and being exposed to air over a very large surface area, namely the newspaper. Now those are conditions for evaporation.

Relevant part in bold.

And here, from our very own forum, a discussion of "legs" and the Gibbs-Marangoni effect, which is dependent on differential rates of evaporation of water and alcohol.

If you spread any liquid over a large surface area, the rate of evaporation will increase, but even so, what evidence is there that the rate of evaporation will make a difference in the ABV?

Gibbs-Marangoni effect is all about differing rates of evaporation of alcohol and water. Read the cited article.

Oxidation is a specific chemical process. My opinion is that whisky does not oxidize overnight--it does not undergo a chemical change. The vast majority of the time, the word is used inappropriately here.

Again, you state your opinion as fact.

Which?

This is a quote from the Wikipedia article on Ethyl Alcohol:

During the fermentation process, it is important to prevent oxygen getting to the ethanol, since otherwise the ethanol would be oxidised to acetic acid (vinegar).

There is no mention of the danger of the alcohol evaporating.

There's a lot going on during fermentation. It's a very different situation from a dram sitting on a table. The "spoiled" drams I've had taste nothing like vinegar--they have merely been flat, weak, and flavorless. It's very obviously an entirely different scenario to spoiled wine.

As further support for the cold hard fact that it doesn't evaporate that fast, I had the priviledge of witnessing experiments with liquid helium, the coldest liquid on earth--a superfluid. That means that this liquid evaporates faster than any other liquid known to man. From first hand experience, it didn't evaporate all that fast.

No? Did you leave some out on the table overnight? If you did, I bet it was gone the next day. This is completely irrelevant, anyway.

You say yourself that oxidation of wine results in the production of vinegar-like compounds. I've never heard that discussed here when "oxidation" comes up, and I've never tasted vinegar in even a really old sample of whisky. It strikes me as far more implausible that this could happen to a dram left out overnight, than that a significant amount of alcohol (and perhaps other volatile compounds important to the flavor of whisky--I've only ever speculated about such) might evaporate.

I can't help but make a guess that you're a Capricorn, TH.

Now there's a scientific mind. Wrong again.

[peergynt323]

First off, alcohol's boiling point is slightly above room temperature.

What does this have to do with it?

The alcohol needs extra energy to evaporate.

Secondly, if you put a bottle of spirit in the freezer, does the water half freeze while the alcohol half doesn't?

Huh? Well, it will, if you get it cold enough, but that's entirely irrelevant.

Yes, state change is entirely irrelevant to evaporation. Brilliant.

"In a solution of alcohol, the ethanol starts to evaporate when it comes into contact with air," says Taylor. He speculates that in solutions over 12 per cent alcohol, the rate of ethanol evaporation at the surface is enough to cool this layer, causing it to sink down the sides of the glass.

Using the word speculate and 12 percent isn't very scientific

The speculation is about the convection effect, which isn't relevant here. Relevant part in bold. Don't know what's unscientific about "12%".

The question that you never address is how much alcohol evaporates. You also didn't address the surface area issue. I speculate that 98.5% of what you say is uninformed. Is that scientific?

Of course, there are other disadvantages to using alcohol, namely evaporation, which has precipitated environmental regulations designed to reduce or eliminate its use in the pressroom altogether. Since alcohol is a volatile organic compound (VOC), it releases toxic and flammable fumes into the air creating health and safety concerns.

Printer ink that is constantly agitated, exposed to heat, and being exposed to air over a very large surface area, namely the newspaper. Now those are conditions for evaporation.

Relevant part in bold.

How is evaporated alcohol dangerous? The volatile chemicals that are dissolved in it are the problem.

And here, from our very own forum, a discussion of "legs" and the Gibbs-Marangoni effect, which is dependent on differential rates of evaporation of water and alcohol.

If you spread any liquid over a large surface area, the rate of evaporation will increase, but even so, what evidence is there that the rate of evaporation will make a difference in the ABV?

Gibbs-Marangoni effect is all about differing rates of evaporation of alcohol and water. Read the cited article.

I read it the first time. Are you trying to prove that alcohol evaporates again?

Oxidation is a specific chemical process. My opinion is that whisky does not oxidize overnight--it does not undergo a chemical change. The vast majority of the time, the word is used inappropriately here.

Again, you state your opinion as fact.

Which?

This is a quote from the Wikipedia article on Ethyl Alcohol:

During the fermentation process, it is important to prevent oxygen getting to the ethanol, since otherwise the ethanol would be oxidised to acetic acid (vinegar).

There is no mention of the danger of the alcohol evaporating.

There's a lot going on during fermentation. It's a very different situation from a dram sitting on a table. The "spoiled" drams I've had taste nothing like vinegar--they have merely been flat, weak, and flavorless. It's very obviously an entirely different scenario to spoiled wine.

Again, alcohol is completely flavorless. If evaporation were the only thing that changed, it wouldn't taste any different. The lower alcohol content might let you taste more.

As further support for the cold hard fact that it doesn't evaporate that fast, I had the priviledge of witnessing experiments with liquid helium, the coldest liquid on earth--a superfluid. That means that this liquid evaporates faster than any other liquid known to man. From first hand experience, it didn't evaporate all that fast.

No? Did you leave some out on the table overnight? If you did, I bet it was gone the next day. This is completely irrelevant, anyway.

Endpoint thought experiments are essential to proofs. The fact that liquid helium evaporates so slowly in an environment 300 degrees celsius above its boiling point proves that pure alcohol in an environment 5 degrees BELOW it's boiling point will not evaporate nearly as quickly. And a 50% water/alcohol solution will evaporate even slower still.

You say yourself that oxidation of wine results in the production of vinegar-like compounds. I've never heard that discussed here when "oxidation" comes up, and I've never tasted vinegar in even a really old sample of whisky. It strikes me as far more implausible that this could happen to a dram left out overnight, than that a significant amount of alcohol (and perhaps other volatile compounds important to the flavor of whisky--I've only ever speculated about such) might evaporate.

Again, alcohol is scentless and flavorless. I have tasted a nasty kind of acidity in very old whisky samples, along with just a general rotting flavor that is probably the esters having oxidized as well.

I can't help but make a guess that you're a Capricorn, TH.

Now there's a scientific mind. Wrong again.

At least when I make a guess I admit it.

[les taylor]

You guys really get up to some stuff whilst we are fast a sleep in our beds. Phew.

[Deactivated Member]

First off, alcohol's boiling point is slightly above room temperature.

What does this have to do with it?

The alcohol needs extra energy to evaporate.

More than the water? Obviously not. Sorry, I don't see your point.

Secondly, if you put a bottle of spirit in the freezer, does the water half freeze while the alcohol half doesn't?

Huh? Well, it will, if you get it cold enough, but that's entirely irrelevant.

Yes, state change is entirely irrelevant to evaporation. Brilliant.

No, freezing a bottle of whisky is entirely irrelevant to the issue at hand.

The question that you never address is how much alcohol evaporates.

That's true, because I don't have any idea. I don't think it would have to be too much to have quite an effect. I never said it all evaporates overnight, or after the bottle has been open for some months; just that enough did to be noticeable.

You also didn't address the surface area issue.

So? What about it?

How is evaporated alcohol dangerous? The volatile chemicals that are dissolved in it are the problem.

Yes, of course. Again you are missing the point by focusing on irrelevant parts of the quote.

I read it the first time. Are you trying to prove that alcohol evaporates again?

No, that it evaporates at a faster rate than the water in the solution, a point you seem to wish to deny.

Again, alcohol is completely flavorless. If evaporation were the only thing that changed, it wouldn't taste any different. The lower alcohol content might let you taste more.

Anyone who has tried nonalcoholic beer or wine will tell you different. Such beverages are almost impossible to make palatable, never mind feinschmeckin' good. Alcohol may be flavorless, but it clearly affects the way we taste. And I don't think (yes, I'm speculating) that alcohol is the only thing evaporating; there are other volatile compounds important to the flavor of whisky. In one of the discussions we've had on this topic, someoned cited a few of these. Sorry I can't find the reference just now.

Endpoint thought experiments are essential to proofs. The fact that liquid helium evaporates so slowly in an environment 300 degrees celsius above its boiling point proves that pure alcohol in an environment 5 degrees BELOW it's boiling point will not evaporate nearly as quickly. And a 50% water/alcohol solution will evaporate even slower still.

So what? Sure, slower, but still it evaporates, and quite a lot will, at varying rates, in a bottle that has been open a long time. I don't think you'd have to change the balance very much to be quite noticeable on the palate.

Again, alcohol is scentless and flavorless. I have tasted a nasty kind of acidity in very old whisky samples, along with just a general rotting flavor that is probably the esters having oxidized as well.

That may very well be oxidation, and if that's what was being described, I'd be inclined to agree with you. But it's not. When people here describe a whisky that has gone off due to the bottle having been open too long, they usually say it is weak, flat, and flavorless. One poster said it was though it had been overwatered. This isn't whisky chemically transformed by oxidation, or even aeration (although the latter seems far more likely than the former). It has lost its oomph due to evaporation of alcohol and other volatile components.

At least when I make a guess I admit it.

Do you now? You've presented your "oxidation" theory as fact, without the least shred of evidence, other than to try to refute the effects of evaporation. Why you think it's impossible for enough evaporation to occur in a standing sample to upset the balance of a whisky, and yet are so sure that oxygen can be introduced into the same sample, causing chemical alteration, I do not understand. If you have a case, please make it.

[vitara7]

looks like its going to be a long one......

[peergynt323]

More than the water? Obviously not. Sorry, I don't see your point.

Should I take this as an admission that it does need extra energy?

No, freezing a bottle of whisky is entirely irrelevant to the issue at hand.

I think this will be my last post. You're making no effort to follow my arguments. If an alcohol/water solution has a lower freezing point than water, an alcohol/water solution will have a higher boiling point than alcohol.

The question that you never address is how much alcohol evaporates.

That's true, because I don't have any idea. I don't think it would have to be too much to have quite an effect. I never said it all evaporates overnight, or after the bottle has been open for some months; just that enough did to be noticeable.

Again, alcohol is scentless and tasteless. I would do the experiment myself if I had an inkling that you would believe my results. Materials needed: a graduated cylinder, a dram of whisky, a dram of water, 12 hours. Are you the kind of person who performs experiments or do you just blindly believe?

You also didn't address the surface area issue.

So? What about it?

How much faster will liquid nitrogen evaporate if spilled on the floor as opposed to in an open steel container? Your argument that alcohol evaporates fast when agitated and spread over a large surface area is not congruent to leaving a bottle of whisky open overnight.

How is evaporated alcohol dangerous? The volatile chemicals that are dissolved in it are the problem.

Yes, of course. Again you are missing the point by focusing on irrelevant parts of the quote.

What was the point? That alcohol evaporates again? I was gratuitously pointing out that your source was suspect. Evaporated alcohol is not dangerous.

No, that it evaporates at a faster rate than the water in the solution, a point you seem to wish to deny.

Show me where I denied that?

Again, alcohol is completely flavorless. If evaporation were the only thing that changed, it wouldn't taste any different. The lower alcohol content might let you taste more.

Anyone who has tried nonalcoholic beer or wine will tell you different. Such beverages are almost impossible to make palatable, never mind feinschmeckin' good. Alcohol may be flavorless, but it clearly affects the way we taste. And I don't think (yes, I'm speculating) that alcohol is the only thing evaporating; there are other volatile compounds important to the flavor of whisky. In one of the discussions we've had on this topic, someoned cited a few of these. Sorry I can't find the reference just now.

Well, one way to test your theory is to add everclear to a bunch of different stuff and see if it tastes different. The "alcohol taste" is actually biproducts of fermentation, not the alcohol itself.

They use flash evaporation to create non-alcoholic beer and wine to reduce the effects that oxidation will have on the flavor. If oxidation didn't occur, they could just boil the alcohol out.

Also, I'm giving no regard to the marketability of non-alcoholic beer and wine. I know some alcoholic beer and wine that is also undrinkable.

Endpoint thought experiments are essential to proofs. The fact that liquid helium evaporates so slowly in an environment 300 degrees celsius above its boiling point proves that pure alcohol in an environment 5 degrees BELOW it's boiling point will not evaporate nearly as quickly. And a 50% water/alcohol solution will evaporate even slower still.

So what? Sure, slower, but still it evaporates, and quite a lot will, at varying rates, in a bottle that has been open a long time. I don't think you'd have to change the balance very much to be quite noticeable on the palate.

Again, I would do the experiment with everclear, but you wouldn't believe me. The reason it is so popular among kids is that it is scentless and tasteless.

That may very well be oxidation, and if that's what was being described, I'd be inclined to agree with you. But it's not. When people here describe a whisky that has gone off due to the bottle having been open too long, they usually say it is weak, flat, and flavorless. One poster said it was though it had been overwatered. This isn't whisky chemically transformed by oxidation, or even aeration (although the latter seems far more likely than the former). It has lost its oomph due to evaporation of alcohol and other volatile components.

Definition of aeration given on Wikipedia:

In chemistry, to oxidise a compound dissolved or suspended in water.

Do you now? You've presented your "oxidation" theory as fact, without the least shred of evidence, other than to try to refute the effects of evaporation. Why you think it's impossible for enough evaporation to occur in a standing sample to upset the balance of a whisky, and yet are so sure that oxygen can be introduced into the same sample, causing chemical alteration, I do not understand. If you have a case, please make it.

I made my case for oxidation last time we did this. The Wikipedia quote above pretty much sums it up. You have to keep fermented beverages away from oxygen to prevent oxidation. There are tons of resources for the oxidation of wine on the internet.

I offer an experiment to you. Blind taste test a dram against the same dram with three or four drops of everclear in it. If you can taste the difference three times in a row, you're right and I'm wrong.

You often talk of warming your drams in your hand, facilitating the evaporation of alcohol and flavor compounds. Does your dram taste weak and off by the time you reach the end?

[Muskrat Portage]

I propose to deal with the original query...

If I leave a bottle of bourbon whiskey out over night WITHOUT the top on, what happens to the whiskey? My friend seems to think nothing happens, I think he's stupid.

...with a simple experiment. At 2:15 pm today I set up a simple experiment:

1) I have placed six identical tasting glasses in the same location where the temperature will remain consistent, in my whisky room downstairs.

2) I have filled two glasses with one ounce of Connemara Peated Single malt at 40% abv, sealing one with plastic wrap and leaving one open to the air.

3) I have filled two glasses with one ounce of Connemara Peated Single malt CS at 58.6% abv, sealing one with plastic wrap and leaving one open to the air.

4) As a control, I have filled two glasses with one ounce of Lake of the Woods tap water, sealing one with plastic wrap and leaving one open to the air.

5) I have marked with a line on the glass, the level that the liquid is at in each subject container.

At 2: 15 pm Saturday afternoon, I will check the glasses to see if there has been any appreciable evaporation in the 24 hours. I will then taste the whiskies to see if there is an appreciable change in flavours. Yeah, I'll check the control too!

At the expense of sacrificing four ounces of delightful whisk(e)y and two of indifferent water, I'll let you know what happens so Chelms11 can get his query answered. Sorry, I don't have any bourbon to run the study with, so in honour of the Welsh patron Saint of Ireland , St. Patrick, I have substituted Connemara.

Muskrat

[mithril]

First off, alcohol's boiling point is slightly above room temperature.

What does this have to do with it?

Absolutely nothing. Evaporation is a surface state change from liquid to gaseous which is pressure independant. Boiling is a rapid phase change which can occur on all levels of the solution and is influenced by pressure. They are different phenomena altogether. Even were they not, the boiling point of pure ethanol is 78.5° C (173° F) which is a bit more than "slightly above room temperature".

The amount of energy required to force the change from liquid to gas (ie: standard enthalpy change of vaporization) is calculated at the boiling point of the given substance. That does not mean the standard enthalpy change of vaporization for the substance is the boiling point. Liquids evaporate as molecules at the surface level of the liquid obtain standard enthalpy change of vaporization. This can happen above, below, or at the boiling point. The further below the boiling point however the more energy the surface molecules need to acquire and the slower the rate of evaporation. Conversely the closer to the boiling point the less additional energy that's required and the faster the rate of evaporation.

I think this will be my last post. You're making no effort to follow my arguments. If an alcohol/water solution has a lower freezing point than water, an alcohol/water solution will have a higher boiling point than alcohol.

See above. The boiling point is merely the arbitrary temperature point chosen to measure the amount of energy required for 1 mole of liquid to transition from liquid to gas. The boiling point has no effect whether evaporation happens or not. The rate of evaporation does increase however as liquids approach their boiling point.

The boiling point of pure ethanol is 78.5° C (173° F) and water is of course 100.0° C (212° F). A 40%ABV ethanol-water mix will have a net boiling point somewhere in the middle of those 2 values. Mixing ethanol and water in solution doesn't alter the chemical structure of either substance though. Surface ethanol will still evaporate faster than surface water therefore more ethanol will evaporate than water thereby diluting the solution and removing the alcohol soluble aromatics and volatile chemicals that are responsible for whisky's scent and taste.

What did you think the "angel's share" was? Why do you think raw spirit is casked at roughly 70% ABV and 10+ years on is bottled a 60% and lower for cask strength expressions?

[WestVanDave]

Here I was - reading along trying to figure out who was winning this battle when I started to feel the dizzying effects of my whisky - poised below my nose - evaporating in my warmed glass. Fearing the worst I drank it back quickly - but couldn't stop reading as the arguments to and fro'd. Had this been a paperback I would have been blistered at the pace of page-turning. I was blurry-eyed for fear of blinking and missing a jab or a left hook... and then - out of left field came a voice of reason - a voice of science - a Tolkien-inspired presence with such clarity it resonated resolute - and put the matter to bed (I hope) ... 'cause I wanted to get back to drinking!!! Thanks Mithril.

[mithril]

LOL. Thanks, I needed that laugh Dave. I hate wading into the middle of post battles like these, especially when both sides are for the most part essentially saying the same thing and just getting caught up on the phrasings. I tell you what though...... it's been a long time since I looked at the first year university chemistry textbook I had to drag out to clarify the differences myself. Wouldn't want to muddy the waters any further.

I also have to admit that I realised the 2nd half of my post was a bit unfair after posting it I saw that he'd already agreed with all the points I made in it. Apologies for that peergynt323. (I've left it in place though because I feel it's wrong to edit posts to cover up your own errors).

On that note, I feel a dram of Bowmore Dusk calling my name. Cheers all!

[Muskrat Portage]

If I leave a bottle of bourbon whiskey out over night WITHOUT the top on, what happens to the whiskey? My friend seems to think nothing happens, I think he's stupid.

I had set out Connemara CS, 40% and tap water, as a control, in open and sealed identical glasses. At 2: 15 pm this afternoon, I checked the experiment.
Evaporation:
The evaporation noted was as follows:
There was no appreciable change in the level of the three sealed containers, however there was evaporation in the open glasses:
Water: 1/8 inches evaporated below the marked line
Connemara CS evaporation 3/16 "
Connemara 40% evaporation 3/16"
This confirms Mithrils' assertation:

Surface ethanol will still evaporate faster than surface water therefore more ethanol will evaporate than water thereby diluting the solution and removing the alcohol soluble aromatics and volatile chemicals that are responsible for whisky's scent and taste.

the alcohol evaporated at a faster rate than water in the 24 hours of the experiment.

2) I then nosed and tasted the whiskies to see if there was an appreciable change in flavours. I also sampled the water
There was no appreciable change in the water. There was a change in the whisky;
The CS Connemara:
Open
Nose was lovely with a pronounced sweetness
Taste was bitter with no finish all the impact was at the beginning and all on the tip of the tongue.
Sealed
Nose was sweet and not as pronounced as the open glass
The taste was sweet on the tongue tip with a long finish in the back of the throat.

The 40% Connemara:
Open:
Nose was very pale with a light scent of clover or heather notes.
Taste was ni, there was no taste it was like drinking water over overwatered whisky. No foretaste, with a slight mouth side and back of throat finish.
Sealed:
Nose was mild with clover notes, stronger than the open sample.
Taste was velvety but delayed with a slight warming mouthfeel in the finish. Pleasant but not exceptional.

Based on this simple 24 hour study, there are both quantitative and qualitative changes to whisky when it is left out open overnight. The lighter, flavourful aspects evaporated away to the Angels, leaving a poorer tasting watery remnant. Whether the impact will be as pronounced if left in a bottle with a smaller neck and a greater quantity of liquid than in a tasting glass is something to be left for someone who wishes to risk a greater amount of alcohol.
I concluded that there was a negative impact on leaving a glass or bottle of Connemara open for 24 hours, although the Cask Strength sample appeared to retain more flavour than the diluted sample. By extension, the impact should be similar on any alcohol left out to the depredations of open air. This confirms the second aspect of Mithrils' assertion:

...thereby diluting the solution and removing the alcohol soluble aromatics and volatile chemicals that are responsible for whisky's scent and taste.

Mithril, you have "hit the nail on the head" and, Chelms11, it would appear that your friend is incorrect in stating that "nothing happens" and may deserve the nomenclature you have chosen to hang on him.

Muskrat

[peergynt323]

It's quite obvious that I am in the minority opinion on this subject and that my comments are probably not welcome. Nonetheless, I'll give my comments for the perhaps silent members of this minority who don't like to lock horns as much as me.

First off, your unit of measurement was 1/16" and the difference between the two samples was 1/16". I would hesitate to make any calculations from this. If you had measured it in a graduated cylinder, we could at least make some assumptions about the change in ABV in the whisky sample.

There was a 1/16" difference between the evaporated water and the evaporated whisky. Because of this I don't know how you could conclude that there was an appreciable change in the ABV of the whisky. Obviously a good amount of water evaporated along with the alcohol.

Also, you noted that there was not much change in the noses. This doesn't bode well for the theory that the aromatics evaporated overnight.

The finish of the whisky, however, has a lot to with the amount of tannins imparted by the barrel. It is well-known that tannins soften when exposed to oxygen. This is my interpretation of what happened.

Also, the original question posed had to do with an entire bottle of whisky, where the ratio of surface area to volume is much lower and will have much less exposure to air at all. I wouldn't draw any conclusions about what happens to a whole bottle from what happens to a dram.

I'm not trying to contradict your interpretation. Just present an alternate.