Volatile Acidity Question

[ufo]

Some of the aged wines from my cellar had horrible volatile acidity (smelling like nail polish remover) when I opened them very recently, even very long decanting (up to a day) did not help at all so the wines ended up in the sink.
All of these wines were fine a few years back. A couple of examples are 2003 Spring flat Shiraz & 2002 St Hallett Blackwell Shiraz. To my knowledge, if a wine has volatile acidity issue would have it all the time and display excessive volatile acidity all the time not only when it is aged.
But then I read the following in a wine magazine “Esterification will occur when acid and alcohol react with each other and produce bottle aged esters with distinctive aromas, which at their most advanced and unattractive stage, smell like nail polish remover. “
Does this mean every aged wine will go through esterification at some stage as indicated above?
How long does this process take approximately ? (I suppose it will depend on the wine but I am trying to get a rough idea) Does wine go back to normal meaning loose nail polish remover smell once this process is over or once it goes in to esterification that’s it there is no going back, It should have been drunk earlier!?

[rens]

A very interesting question that I would like to know more about too.

[Wizz]

If your wine smells likenail polish remover, thats more likely to be ethyl acetate than VA. It can happen in young wines too, I saw a nasty case in a 2011 white this week!

That doesn't answer your question, but its not just bottle age that can produce this outcome,

[ufo]

If your wine smells likenail polish remover, thats more likely to be ethyl acetate than VA. It can happen in young wines too, I saw a nasty case in a 2011 white this week!

That doesn't answer your question, but its not just bottle age that can produce this outcome,

Even though it has more components, ethyl acetate and acetic acid(vinegar smell) are two major components of VA in wine. Because ethly acetate is the most prevalent one, it is the one that gets picked up/noticed most of the time if wine has VA issues. I know not just bottle age that can produce this outcome. The question here is that if it happens due to bottle age, does it go away with further aging or once it happens there is no going back, the wine is ruined!?! If it does go away with further aging, how long does it take roughly. I realize this will vary greatly depending on the wine but I want to get some idea about it and here other people's experiences with the issue. As I open aged bottles from my cellar and more and more wines are coming up with VA stink even though they were fine at their earlier ages and I suppose I don't have to mention how that makes one feel like .

[BigBob]

VA doesn't go away It's a permanent fault.

Acetic acid is present in far greater quantities than ethyl acetate. Ethyl acetate has a far lower sensory threshold than acetic acid, so just a little bit more will greatly increase the preception of volatility.

Allowing the wines to breathe will worsen the fault, as acetic acid is converted to ethyl acetate in the presence of oxygen.

I would suggest that the wines you have cellared had reasonably high levels of acetic acid to start with. As they have aged, this has been slowly converted to ethyl acetate and you are now starting to hit your sensory threshold for ethyl acetate.

Short of reverse osmosis (not practical for bottles), there is nothing you can do, the wines are shot - at least for your tastes, you may find someone else who has a higher tolerance who would still enjoy them.

[redstuff]

Allowing the wines to breathe will worsen the fault, as acetic acid is converted to ethyl acetate in the presence of oxygen.

I'm not sure this statement is entirely true. Perhaps if you let it breathe for days this may be a problem arising from acetobacter (which uses oxygen) converting the ethanol into acetic acid then condensation with another molecule of ethanol and thus forming some ethyl acetate - but this is a slow process isn't it? From an entirely chemical perspective acetic acid and ethanol do not need oxygen to condense to form ethyl acetate and I'm pretty sure oxygen doesn't catalyse the process.

[rens]

I'm not sure this statement is entirely true. Perhaps if you let it breathe for days this may be a problem arising from acetobacter (which uses oxygen) converting the ethanol into acetic acid then condensation with another molecule of ethanol and thus forming some ethyl acetate - but this is a slow process isn't it?

I'm not sure. On Friday with the Ch Muscar, I could not detect any VA when first opened at 4pm. Even at 8pm, it was fine. However close to the end of the night (say 9:30pm) the VA was at a point that I could not drink it. Nick said he could not detect it, but I know Michael could-and he even commented that it gave the wine a further dimension. The change from acitic acid to ethyl acetate probably is slow (I failed high school chemistry so know nothing about this), however I suspect the personal threshold at which an individual can detect it, once crossed, quickly becomes unbearable/drinkable.

[redstuff]

I got pretty big whiffs of ethyl acetate right from the beginning. Although it may appear the ethyl acetate is increasing in concentration is that what is really happening? Was the wine cooler when first poured? Ethyl acetate would be more easily lost with increasing temperature. Perhaps as the wine evolved in the glass other more volatile components were lost which at first masked the true ethyl acetate concentration.

[rens]

I got pretty big whiffs of ethyl acetate right from the beginning. Although it may appear the ethyl acetate is increasing in concentration is that what is really happening? Was the wine cooler when first poured? Ethyl acetate would be more easily lost with increasing temperature. Perhaps as the wine evolved in the glass other more volatile components were lost which at first masked the true ethyl acetate concentration.

When first opened the wine had been on my kitchen bench for 3 days. Perhaps you are right as the wine evolved in the glass other more volatile components were lost which at first masked the true ethyl acetate.

[Wizz]

If your wine smells likenail polish remover, thats more likely to be ethyl acetate than VA. It can happen in young wines too, I saw a nasty case in a 2011 white this week!

That doesn't answer your question, but its not just bottle age that can produce this outcome,

Even though it has more components, ethyl acetate and acetic acid(vinegar smell) are two major components of VA in wine. Because ethly acetate is the most prevalent one, it is the one that gets picked up/noticed most of the time if wine has VA issues. I know not just bottle age that can produce this outcome. The question here is that if it happens due to bottle age, does it go away with further aging or once it happens there is no going back, the wine is ruined!?! If it does go away with further aging, how long does it take roughly. I realize this will vary greatly depending on the wine but I want to get some idea about it and here other people's experiences with the issue. As I open aged bottles from my cellar and more and more wines are coming up with VA stink even though they were fine at their earlier ages and I suppose I don't have to mention how that makes one feel like .

Thats not correct - EA is not a volatile acid (and isn't an acid). You're right that it can be present at the same time and can in some cases have the same root cause.

VA should blow off as a wine warms, EA doesn't.

I'm not sure where the VA increase with ageing idea comes from, the most common cause is acetobacter in the winemaking process, which puts acetic acid into the wine in the beginning.

[redstuff]

I think the "cling wrap trick" might help with removing ethyl acetate through hydrophobic/hydrophobic interactions. I might have to give that a test someday.

[Thommo]

Delving into the musty corners of my memory back to highschool chemistry, I recal that ethyl acetate (EA) is formed by a reaction between ethanol and acetic acid (VA). So VA is probably a prerequisite for EA unless there are other chemical pathways along which it can form. As noted above however, threshold sensitivity is much lower for EA than VA and (I have noticed) varies considerably between individuals - some people (like myself) are quite sensitive to EA and can cannot enjoy a wine with even a hint of it that others seem perfectly happy to chug away at. The 09 Thorn-Clarke Shotfire Ridge Shiraz is one such wine for me - highly rated by many, but verging on undrinkable for me.