Volatile Acidity in wine

[ufo]

Just reading the topic about Skillogalee Gewurz with too much (according to some) volatile acidity (VA) and wondering how one detects too much VA or any VA in wine. Can some please explain what the sensory description of VA in wine is ?

[Sean]

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[ChrisV]

Ah so it's a fancy name for acetic acid/ethyl acetate? I fancy I can detect both of those. Interesting.

Doesn't make me any less confused about the Skillogalee wine though. I haven't opened my bottle so maybe I'll make a report when I do.

[cuttlefish]

I thought that if you smelled promonent "nail polish remover" aromas that that was a sign of VA, also ??

[KMP]

Here is a note on VA from UC Davis and another from an Aussie company. Note that VA and ethyl acetate (EA, nail polish remover) are not the same but that EA is produced from acetic acid and ethyl alcohol, and has a lower detection threshold than VA.

There is also a very good (but lengthy) discussion of Volatile Acidity in Prof Bruce Zoecklein's Enology Notes from Virginia Tech.

Mike

[ufo]

Well, after reading all responses and provided links, I am more confused. Nobody gives a clear explanation of how VA or VAs supposed smell!?!? I thought it was nail polish remover smell too but according to some it is not.
Come on guys (those experts in this panel) give us not-so-experienced drinkers a hand to how we pick up/detect VA in wine and this is an honest request, I am not insinuating anything.

[Sean]

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[Red Bigot]

VA (acetic acid) presents itself when it is above a certain threshold as a sour or vinegary taste.

And often a vinegary smell - if it's high enough some people want to sneeze on smelling an affected wine.

Pour a little wine into a glass and leave it on the bench, or leave some wine in a bottle the same way. Smell it the next day and again the day after, the vinegar-like aromas should appear and increase in that time.
A wine which has been deliberately handled oxidatively to some extent will have a (low) level of VA designed to complement (lift) the other characters of the wine. Penfolds Grange often has a level of VA higher than many other red wines, or used to, haven't tried recent vintages.
A wine which has been mis-handled during fermentation/maturation/bottling or had a cork allowing oxygen ingress will likely have a level of VA and/or EA that is offensive to many drinkers.

[KMP]

Well, after reading all responses and provided links, I am more confused. Nobody gives a clear explanation of how VA or VAs supposed smell!?!? I thought it was nail polish remover smell too but according to some it is not.
Come on guys (those experts in this panel) give us not-so-experienced drinkers a hand to how we pick up/detect VA in wine and this is an honest request, I am not insinuating anything.

Va is what it is - volatile acidity and its most easily detected as the smell of acetic acid which is what gives vinegar its smell. As red Bigot says sitting a glass of wine out to spoil will result in a vinegar smell, or just dilute some vinegar in water (a drop in a glass would be more than enough). However VA has a high threshold for detection and so its not easily noticed. In contrast EA (ethyl acetate) which is the product of acetic acid and ethanol is more easily detected and so it has been suggested that deteting EA can be a substitute.

To be honest I don't mind a little EA in a wine, it can give a lift to the flavor profile. And in recent years I can only remember one wine where I was confident that there was definite VA. VA is an indicator of spoilage and with modern winemaking it should not be a problem.

Mike

[n4sir]

VA can be evident in a wine a number of ways, depending on what the wine is and how it's made. After the vinegar/varnish descriptors, about the next most common one would be in reference to Grange and other reds with heavy vanillin/American oak - crushed ants/formic acid. With heavy use of new French oak it can appear as a powerful flytox/insecticide-like character too. In white wines (and young Sauternes) it can combine with the banana like esters to become something like model airplane glue - in "James & Oz Big Wine Adventure" I remember Oz Clarke & Christian Seeley's simultaneous looks of horror when James May described the 2001 Suiduraut smelling like "dope" (the glue, not the other stuff).

As has been mentioned EA smells like nail polish remover, similar but different, and pretty consistent. What they do have in common is the element of "lift" they add to the bouquet, it really does have an edge and "bite" when it hits the nostrils.

Cheers,
Ian

[KMP]

Just to add a little more to the confusion. There is a 1984 study showing that aging Cabernet Sauvignon in French versus American oak leads to more VA in the wine from French oak barrels esp past 300 days of aging. However the level of VA is less than half the legal limit. At that level its questionable as to whether most could smell the presence of VA.

Mike