WineAdvisor: Corked?

[Robin Garr]

I introduced this topic in a forum thread, and thanks to all who responded there. This slightly more polished version goes out to the 30 Second Wine Advisor E-mail list today.

Corked?

One of the more frustrating experiences in wine appreciation is the discovery that the wine you've been looking forward to enjoying was the victim of a random drive-by slaying perpetrated by a tainted natural cork.

The musty, moldy, mushroomy, chlorine-scented damp-basement and wet-cardboard stench that cork taint imparts, even in homeopathic amounts, is sufficient to spoil the enjoyment of your wine and prompt pouring it out, or if you're willing to make the effort and have a cooperative wine merchant, taking it back for a refund or exchange.

Even if we grant that the incidence of cork-tainted wine has diminished somewhat in recent years, thanks to increased quality control efforts by some cork producers and wine makers, there's no question that a significant percentage of wines stoppered with natural cork will be spoiled.

But here's a twist, and I don't mean the twist of a screw cap: The other night I opened a bottle of decent Alsatian wine from a respected producer - specifically, <B>Trimbach 2002 Pinot Blanc</B> - only to be greeted by the telltale aroma. Tasting confirmed the first impression: Musty wet-cardboard and fruit that was muted at best left me in absolutely no doubt. I'll stake my reputation, such as it is, on my judgement that this wine was corked.

But here's where the story goes off the rails: The bottle was not fitted with a natural cork. It was closed with a slick-skinned, foam-filled <i>synthetic</i> stopper, a modern invention explicitly designed as a taint-free replacement for natural cork.

What's up with that? We've been kicking this topic around on our WineLovers Discussion Group, and the consensus is that the chemical malefactors involved in taint - trichloroanisole (TCA) and the less-familiar tribromoanisole (TBA) and others - is not limited to natural cork. These compounds may turn up in barrels, in wood used in winery building and other organic materials that may come in contact with wine.

It's for just this reason that the folks at Amorim - the major Portuguese cork producer that I had the pleasure of visiting last autumn - object to the term "corked" to describe tainted wine. Cork defenders argue that taint comes from many sources and that it's not fair to associate it with the bark of the Portuguese oak tree.

While I don't buy it completely - <i>most</i> tainted wine is affected by the cork - this tasting certainly offers a compelling wake-up call and demonstrates that alternative stoppers can't guarantee that a wine won't pick up taint from other sources.

I've E-mailed Trimbach asking for comment but at this point have had no reply. If and when the company responds, I'll pass it on.

TCA may arrive at a winery via cork, but TCA can also be "hosted" by wood, and can be carried by water, which means it can be found in winery domestic water pipes and drains. So there's no mystery, really. You can read all about it in "Bottle Closures In The Wine Industry" by Berenice Baker: It's in a pdf file, and the section on TCA is on page 11: http://www.capewineacademy.co.za/seminars/CWM_B_Barker.pdf

Robin, two questions:

1. Trimbach uses both corks and synthetic stoppers; is it possible the bottle was closed using a machine that also closes bottles with corks, and that the TCA was picked up from the bottling machine infected by the natural corks?

2. Trimbach audits Jancis's Purple Pages daily and responds to any question about Trimbach wines. Would you mind if I quoted your piece and asked him to comment there? I would, of course, post any response here.

Regards, Bob

[Robin Garr]

1. Trimbach uses both corks and synthetic stoppers; is it possible the bottle was closed using a machine that also closes bottles with corks, and that the TCA was picked up from the bottling machine infected by the natural corks?

Interesting question, Bob. I'm clueless - and not even certain whether the job of shifting a bottle-corking line from natural to Nomacork is trivial (just dump the appropriate closure into the feeder bin) or complicated (serious cleaning, or even a completely different corker). Just dunno. But certainly it doesn't take much TCA to contaminate a lot of volume.

2. Trimbach audits Jancis's Purple Pages daily and responds to any question about Trimbach wines. Would you mind if I quoted your piece and asked him to comment there? I would, of course, post any response here.

Jean Trimbach did send me a nice note today, albeit not particularly informative. (Summary: "Gee, I'm sorry, I wonder how that happened?") which I've asked his permission to publish. I certainly wouldn't object to your raising it on Jancis as well, but you should know that he has responded.

Thanks Robin.

1. High praise indeed from a tough reporter like yourself -- "interesting question" -- I'm beaming.

2. I'll revert. It's amazing the detail he goes into with Jancis.

Regards, Bob

PS: Still beaming.

Robin, here's Jancis' take -- dirty filter pads, not corked?

Jancis Robinson (Mission Control) (05:39 PM - Oct 7, 2006)


I have smelt TCA in a screwcapped wine, and Australian super-judge Ian McKenzie agreed with me. As you say, there are many sources of TCA and TCA-like compounds (such as TBA) other than corks. That said, I associate the smell of musty wet cardboard and muted fruit with dirty filter pads whereas TCA smells more obviously mouldy (no cardboard component) to me and is often accompanied by a very hard, fruit-less finish on the palate.

You might also like to scroll through Musty alphabet soup, Julia's survey of common wine faults.

[Robin Garr]

That said, I associate the smell of musty wet cardboard and muted fruit with dirty filter pads whereas TCA smells more obviously mouldy (no cardboard component) to me and is often accompanied by a very hard, fruit-less finish on the palate.

Bob, I have nothing but respect for Jancis, and I think I've said this again and again. But I'm startled by this, and I simply can't embrace it. "Wet cardboard and muted fruit" are the classic cork-taint descriptors to me, and this is based not only on personal observation but also on sniffing Jerry Mead's TCA vials way back in the '80s. I simply don't see "dirty filter pads" as being anything like as prevalent as cork taint. What's more, I in the event of a filter-pad problem, I would expect it to taint all wine in the affected batch, not merely random bottles as with cork taint. In short, I'm gobsmacked, as our British friends say.

Let's see what Trimbach says, Robin. I can hardly believe he'll like being told his filters were dirty. [I tried to see if the 2002 Pinot Blanc was filtered, but failed.]

I think I'll check the Oxford 2 to see how she defined "corked" there -- I was gobsmacked myself. :-)

***

This is really odd, Robin -- I've lent out my 3rd, but her definition for "corked" is out of the main stream in the 2nd:

Corked. Pejorative tasting term for a wine spoiled by a cork stopper contaminated with cork taint. This is one of the most serious wine faults (see faults in wines) as in most cases it irrevocably imbues the wine with such a powerfully offputting smell that it cannot be drunk with any enjoyment (although it can be used for the more vigorous methods of cooking with wine). The unpleasantly, almost mould-like, chemical smell is occasionally present in smaller doses that may initially be noticed only by noses particularly sensitive to it, but the odour usually intensifies with aeration and it is difficult for tasters to enjoy a wine once their attention has been drawn to its existence. A wine spoiled by cork taint may also be described as corky and the condition is known as corkiness.

The article on cork taint seems to put all the onus on chlorine:

Corks are normally bleached in a strong chlorine solution prior to washing and drying. Research work in the 1980s, particularly in Australia, demonstrated that this chlorine treatment could inadvertently produce chloroanisoles some of which, trichloranisole or TCA, for instance, can be smelt at concentrations of just a few parts per trillion. The chlorine reacts with phenolics in the cork to form trichlorophenol, which is converted to chloroanisoles by moulds growing on the cork, the germination and growth of these moulds being favoured by moist conditions. TCA appears to be at least part of the explanation for corked wines. The cork industry is therefore replacing chlorine bleaching with other processes (see corks).

This may not provide a complete solution to the problem, however, as moulds growing on unbleached corks can still generate a corked aroma and taste which may be due in part to compounds other than chloroanisoles. Corks, even though cut from boiled and probably sterile cork bark, can be recontaminated with mould spores at any point during the preparation process. Corks can furthermore pick up off-flavours that migrate from other surfaces, even the floorboards in shipping containers, or as a result of poor storage conditions at the winery.A new method of disinfecting corks with ozone seems to avoid cork taint.

T.Harriet Lembe

And the reference to faults in wines is even more odd:

Some wines smell so stale and unpleasant that the taster is unwilling even to taste them. The most likely explanation for this is a mouldy cork causing cork taint. Such a wine is said to be corked, but a wine served with small pieces of cork floating in it indicates a fault in the service of the wine (see service of wine) rather than a fault in the wine. Contact with fragments of sound cork does not harm wine.

I'll wait to respond further after I read the 3rd edition -- so far, Robinson seems quite insensitive to "corkiness" as I understand the word.

Regards, Bob

Hi Robin and Bob,
It should be noted, TCA taint is not limited to the wine industry, and traces have been found in baby food, soft drinks, bottled water and other foodstuff products. Basically they claim it’s a handling problem. I guess if you use chlorine based sanitizing solutions or chlorinated water and a certain mold is lurking about and you have any wood products around (this could be a wooden skid, pallet, cardboard box, or piece of paper) this is not a good combination- TCA can be formed.
As stated the drains of the winery, transfer hoses, bottling lines, barrels, a cardboard box that the bottles are stored, and even a humidifier can be a source of TCA taint. Because of this wineries have been “remodeling” (actually tearing off the roof and replacing it) their winemaking facilities. One winery in Sonoma Valley, California converted its old winery facility which had intricate tongue and groove woodwork into a museum.

Here’s an interesting article; http://www.winebusiness.com/ReferenceLi ... taId=29793

What are we actually saying here?
A corked wine is not the same as a TCA tainted wine?
A “corked wine” is one where the cork failed to do its job of sealing the bottle correctly?
TCA tainted wine is one that’s actually tainted with the chemical compound TCA?

Salute