is cork-taint not cork-taint?
suspect there's something wrong with the glass in front of you, but
you aren't quite sure. In this detailed review, Nick Alabaster
discusses some of the problems quality issues facing wine that often
get confused for cork taint.
With such a title youíd be excused for thinking Iím going
to start off with a joke. However,
neither do I have a joke, nor do I think cork-taint is a laughing
matter. Too much is at
stake: on the one hand millions of bottles are being damaged yearly by
faulty closures, and on the other, a multi-billion pound industry is
trying to convince everyone that natural cork is still the only choice
for sealing wine bottles.
Lots has been written on cork taint. However, the purpose of
this piece is to separate cork taint from other quality issues
affecting wine, where possible, and identify where this just isnít
The umbrella declaration of Ďcork-taintí has too long
been assigned to any bottle that performs below expectations. This has
not helped. People still
think of cork particles floating in their wine as corked; oxidised
wine as corked; heat or light spoilt bottles as corked.
This has blurred the real issue, and there is a real issue:
that is the genuine taint that is derived through cork, and spoils a
wine irredeemably. There are a number of compounds associated with
cork-taint: TCA (the primary taint Ė 2,4,6-trichloroanisole), TceA,
TBA, PCA, DCA and others (and Iím not just making them up!).
Also, other chemicals present in wine can also be associated
with corks, as I shall mention later.
But is the cork the sole mechanism by which the spoilage
compounds can enter a wine? No; there are the winemaking barrels and
other oak-based wine products too and these also harbour an
environment in which the same pungent compounds that taint our wine
And can you be absolutely sure that when you think you smell
taint, it is TCA? Again, no; not without knowing more about the wine
youíre drinking, and without discounting other potential issues
At the mass wine sales end of the market, the cork-taint
issue has been conveniently hidden from the consumer. But why should the mass-market consumer care anyway? If a
wine doesnít perform, or is not liked for any reason, the
supermarkets and high-street merchants take back or exchange wine for
any reason you care to give. And how often does the retailer actually
hear of people correctly using cork-taint as the issue? Well, on the
supermarket side of things, my experience tells me itís not often:
most consumers simply arenít aware of the problem.
Even if they think they are, as often as not theyíll confuse
it with something else sub-standard about a wine. However, the
retailers do care: they care that products are either being returned
or not repurchased. Hence we are seeing a big drive in the
screw-capping of wines at the lower end, with the supermarkets doing
their best to deliver fresh, taint free products to the mass market.
At this end of the scale, I simply donít see any reason in a quality
sense, why all ready-to-drink wines arenít packaged this way.
Why take the risk of taint when you use natural cork for such a
short period? But image
is also key to a productís success, and unfortunately natural cork
still has an image that implies quality.
If only everyone knew the true price they are paying for that
On the other end of the scale, avid wine collectors and
drinkers are painfully aware that a £1000 prized bottle is in no way
immune to the damaging effect of cork-taint. Added to that, if the
wine isnít opened until years or even decades after it was bought,
how can anyone expect any fair exchange of goods should it be tainted?
And it is for the more interested consumer that I think a
discussion about the many guises of cork-taint and other possible
Ďtaintsí is worthwhile.
Cork-taint is not only extremely variable between cases, but
so is our sensitivity to it. As
important as our innate ability to detect certain compounds Ė which
can vary enormously - is that recognition of compounds in wines can be
drastically improved with experience.
I believe Iím fairly well tuned into the TCA aroma and its
effect on wine, however, frustrating as it is, there are still cases
in which I just canít be sure.
Here is a list of the aromas and effects of cork-taint, as
lack of aroma
lack of fruit
Effects of oak and cork-taint
The impact of oak and cork-taint is closer than some people give
it credit for, yet why should they not be Ė they are both from the
same source! There is a
particular chemical which would be considered positive in oak, but not
so in cork. In one case guaiacol
impacts a smokiness which is precisely what some oak treatment is
designed to do. However,
if it randomly comes out through the cork, then this is more likely to
be frowned upon. Itís
entirely likely that if this chemical does come about through cork,
then other less appealing flavours will also be introduced.
So, do I think cork taint and the effects of oak can sometimes
be confused? Yes: not often, but I do. It may be that the source of my
confusion is actually the same source, TCA or related compound, but
Iíve found a certain type of barrel toasting characteristic to prick
my senses to the potential presence of cork taint.
Itís happened on a number of occasions, but as Iíve found
other people not to be convinced by a call of taint, it makes me think
that it isnít TCA, but perhaps some other shared or similar
chemical. However, sometimes the only true test in this case is to
refer to another bottle, and see if variation between them clearly
puts in the likely cork-taint bracket. Of course, if TCA is recognised
in numerous bottles, then the source is quite likely to be the barrel,
and the cork can be forgiven. (But in this case, not the winemaker.)
Effects of yeast and cork-taint
No this is were I hold up my hand and say, youíve got me
confused here. A number of times when I detect the yeasty, leesy or
similar aromas in a wine and I start to wonder about possible cork
taint. Sometimes that thought has been well warranted: cases at
tastings where Iíve asked for another bottle and been given a
cleaner wine, but other times another bottle comes back the same. If
only these incidences were getting rarer:unfortunately not. Maybe this
is where an innate ability is letting me down, or maybe that mushroomy,
yeasty/mouldy element is just so close to being one of the same? The
wines I find particularly troublesome are Burgundies and Champagnes,
where the yeasty, leesy characteristics are now highly sought after,
but there are other white wines too. In one recent case, I thought an
element of taint was there (it seemed to get worse with time), but
then gone: not even a yeast/lees character left Ė what caused that I
wonder? (TCA is not usually volatile enough to dissipate with air,
although we do assimilate it very quickly with the net result we think
itís gone, when it hasnít really).
Effects of unclean glasses and cork-taint
Although itís easy to discern the effect of detergent or mould
in the glass by comparing the wine in a perfectly clean vessel, I
wonder how many bottles have been returned without considering the
glasses to be the cause of the off taint? I know I had an issue with a
water filter that must have developed mould within the carbon element.
However, it only came to light after several bottles seemed affected,
and I realised the wine was releasing the dried aroma which clung to
the glass. (It could be detected by breathing into the glass also Ė
a good method for releasing potential taint material.)
Brett and cork-taint
Brettanomyces is a yeast taint which can impact a wine widely,
from a gentle earthy/spicy edge, through to medicinal, leathery and
animal to farmyard and stables. Now this is a relatively recent
comparison for me, yet I know several people who swear theyíve
always had a problem separating the two at some levels. But recently
Iíve come to find that the spicy/earthy side to brett is indeed
something which cork could have imparted, or vice versa.
When testing for brett, one of the chemical fingerprints is
Am I clutching at straws here, or is that in no small way
related to the chemical found in oak and cork? One
thing Iíve found is that some wines which have been called corked
have not got any worse, over many hours or even days.
And that, based on my experience with TCA, doesnít add up: it
just about always gets worse with air. Now I suspect that it could be
an element of brett which gives a more consistent profile. I recall a
dinner many yearsí ago where some around the table said TCA, but I
said I couldnít get to the TCA for the brett.
Now, either the wine was unlucky and had both (definitely a
possibility, it was a Burgundy after all!), or we were in fact
smelling the same thing. Iím
not sure how much bearing it has, but both TCA and brett have the
effect of subduing fruit, and so once again given rise to the
possibility of confusion. Although I personally find the medicinal
smell of phenol compounds quite distinct from TCA, there are others
that put medicinal in the possible TCA bracket, and so here is another
potential source of confusion.
Overall, the last thing I want to do is downplay the cork issue;
in fact, quite the opposite: I
think the cork issue is wider than just about taint, but the whole
issue of irregular seal and bottle variation.
However, it is equally unhelpful to misdiagnose TCA and be
misled into thinking that cork-taint is the only issue affecting wine
quality today, so Iíve laid out my thoughts on what you might like
to consider just before you next think about declaring a wine
also: special section on the closure
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