By James Atkinson

Wine critic Tyson Stelzer's claim that about 5 per cent of Champagne is affected by cork taint drew fire from cork devotees over the weekend.

Patrick Spencer, of the Cork Forest Conservation Alliance, said Stelzer's claim "should be considered an opinion and in no way factual".

"Suggesting that there's 'fair agreement' among wine writers is not scientific or quantifiable," he said.

"Until figures from the wineries themselves are presented showing these percentages, the 'accepted' numbers are no more real than the Yeti and are a disservice to consumers and the cork industry."

One reader claimed "rigorous studies" have found the rate of cork taint is actually about 1 per cent.

Another questioned whether Stelzer had any of his 'corked' Champagne tested to confirm what the real problem was with the bottle.

"There are a tonne of things that can make any wine taste off, but of course the cork always gets the blame," he said.

But Stelzer (pictured) was standing firm today, telling TheShout he encountered 5.5 per cent taint directly attributable to natural cork in tastings he conducted to compile the last two editions of his award-winning Champagne Guide.

"This is from across more than 800 bottles of Champagne – not a huge sample, but sufficient to be representative," he said.

"As an experienced wine show judge and wine critic, I can reliably identify cork taint and corky flavour/aroma and distinguish this from other faults. In almost all cases I was able to open another bottle to confirm the fault in the first."

Stelzer said his findings were backed up by Fréderic Panaïotis, chef de cave at Champagne producer Ruinart, who spent years working in the technical department of the CIVC, Champagne's regulatory, supervisory and promotional body.

"The figure that he reported to me from the CIVC last year was 4 per cent cork taint in natural champagne corks. Hence my suggestion of between 4 and 6 per cent," Stelzer said.

Readers also queried the suggestion that cork taint could be costing the industry as much as $2 billion.

In response, Stelzer said the average price of the more than 400 champagnes that he reviewed in The Champagne Guide 2012-2013 was AUD$100.

"Using this figure, of the 320 million bottles of champagne sold every year, 4 per cent spoilage equates to $1.28 billion and 6 per cent equates to $1.92 billion."

"Hence my reckoning that it must be at least a billion dollars and possibly as much as two billion."

Stelzer completely rejected one reader's suggestion that he was being paid by De Bortoli to promote their new screw-capped sparkling wines.

"As a fully independent wine critic I have certainly never been on the payroll of any wine company," he said.

The Shout Team

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  1. The problem with cork taint is that the majority of consumers rarely detect the fault in their wine.(Unless the taint is very strong) Screwcaps have virtualy eliminated quality issues except in a few cases where the cap has not been applied correctly ie. mechanical failure.

  2. Go easy guys, I don’t know Tyson but I’m sure he hasn’t made this up. We all know still wine had significant issues with cork (if not why is it now all under screw) so it’s only natural that it would happen in the sparkling category.

  3. John most wine is still corked only Australian and some other new world wine is mostly under screw caps and the reason is people like Tyson I guess the rest of the world don’t know what they are doing even though they have been doing it for hundreds of years

  4. Stelzer is independent and is passionate about his wine. Spencer is paid by the cork company, passionate about saving a dying industry. I know who I would trust in this debate.
    I’ve had more than a few corked bubbles, and the stuff ain’t cheap!

  5. Stelzer is being attacked so strongly because he is exposing the reality that is the very poor reliability of this highly-priced, luxury product – due to cork taint, random oxidation, light exposure, etc. The majority of sparkling wines would be far better preserved under crown seals – if you do a little research you’ll find that even some important players in Champagne admit this. I hope De Bortoli’s new closure is a great success. Let the change come, as it has with table wines.

  6. In standing by my previous statements, I would also like to add that as Mr.Stelzer is “an experienced wine show judge and wine critic” he must know that there are many different chemical agents that can affect the smell and taste of wine and that these agents are, to a large degree, highly variant in their perceptibility to any person and are not the direct affect of the cork. No two people have that same level of smell or taste awareness. With his heightened sensory ability to suggest that everyone who drinks Champagne would have the same experience is indefensible. Adding to these questionable percentages is the fact that many bottles of wine are returned because the customer didn’t like the taste and the way to not be embarrassed is to say, “it’s corked”

    When wineries produce the numbers from their accounting departments that show distributor “bill backs” in the 4-6% range. I’ll send Mr. Stelzer a written apology.

    P.S. I went to the CIVC site and could find no data on closure failure.
    I’d also be happy to open the discussion with Mr. Stelzer on the economic and environmental impact mining for Bauxite, (from which aluminum is made) has to the peoples of the world, (well above $2 billion)

  7. Mr. Stelzer based his article on wine tastings “using more than 800 bottles of Champagne – not a huge sample, but sufficient to be representative.” Actually, it’s not sufficient.

    Wine tastings are anything but objective, and the sample size is dwarfed by much larger studies that show significantly lower rates of TCA. Tastings rely on the variable nature of an individual’s olfactory system and inherent biases. That’s why a recent study of 3,000 wine drinkers found that one in 20 complained that their wine was “corked” when in fact it had come from a bottle with a screw‐cap. And when someone accurately does detect TCA, they have no way of knowing the source of the compound.

    By contrast, many of the studies cited below include actual analyses of the cork closures and wine. The combined sample size: more than 10 million bottles of wine and/or cork closures. The conclusion: The TCA was often below 1% and never above 2%.

    Granted, some of these studies also rely on tastings, so they, too, should be discounted. But even without those studies, the sample sizes and methodology of the remaining studies utterly discredit the study cited by Mr. Stelzer.

    I have no reason to question Mr. Stelzer’s integrity. However, it’s clear he relied on highly flawed evidence to support his conclusion. But that seems to be standard operating procedure when it comes to the issue of TCA.

    • In 1999, before the introduction of numerous improvements to cork processing,
    wine chemist John Casey estimated the likely incidence of TCA at below 2
    percent of all wines made in Australia. Casey based his analysis of the results of
    19 studies involving over 35,000 wine samples. (John Casey, ‘Taint necessarily so’,
    Aust. Wine Industry Journal, Nov‐Dec 1999, Vol 14 No 6, 49‐56)
    • In 2002, a survey of 5,735 bottled wines conducted by the UK Wine and Spirit
    Association verified that only 0.6 percent had TCA contamination. (Wine Business
    • In a trial by Southcorp in Australia involving 150,000 corks over nine years, the overall incidence of different types of cork taint was just 1.84 percent. Of this, 1.5 percent was due to TCA. (Simpson, RF, DL Capone, BC Duncan and MA Sefton, ‘Incidence and nature of “fungal must” taint in winecorks’, Aust. & NZ Wine Industry Journal, Jan‐Feb 2005)
    • TCA levels are now 81% lower compared to levels found in 2001, according to the
    testing of more than 10 million corks by the Cork Quality Council. (CQC Audit
    Results, July 2010)
    • Christian Butzke, Ph.D., one of the leading wine experts in the U.S. and a vocal critic
    of cork taint, stated: “TCA is no longer a major problem for the U.S. wine industry.”
    His findings at the Indy Wine Competition found cork taint to occur at levels at or
    below 1%. (May/June 2009 edition of Vineyard & Winery Management)
    • In a test of 500 bottles of wine, some of which included older vintages that would
    presumably have a higher incidence of TCA contamination, the French Wine Society
    found that four bottles – or 0.8 percent – were affected by TCA. The Society
    declared TCA a “non‐issue.”
    • Internationally renowned wine critic Robert Parker conducted a grenache tasting in
    late 2009 for almost 600 guests at Spain’s WineFuture. Less than 1 percent of the
    wine was affected by TCA.

    Please see for links to all of the above citations.

  8. I’ve been in the wine business for 28 years and for as long as I’ve been in it, cork producers have been claiming that their stopper is near perfect. If they spent more time and money fixing the problem than paying for PR magic then their consumers would be better off. When you add the incidence of random oxidation to cork taint anyone can work out that it isn’t. Given that it is just packaging, it should be assessed in the same light as a tin can for beans or a carton for milk. If you had to take back even 1% of these you would be pretty pissed. I don’t know why cork should get any special dispensation when considering its failure rate. And for what it’s worth I believe that around 3-5% of wines are corked and the failure rate is even higher for sparkling wine as the cork is made up of various parts.

  9. Im not sure if anybody pointed this out after the last article but the screw cap in question is not suitable for Champagne or other bottle fermented products. So its an argument over nothing at this stage.

  10. Love all this cork rhetoric from paid cork ambassadors, all carefully citing stats that mostly come to the same conclusion – that we’re still looking at a 1-2% failure rate (at a minimum) for TCA alone. Add in the other issues (particularly random oxidation) and cork is still a less than optimal seal for wine. Period.

    Nice one Tyson for standing up and defending yourself.

  11. My experience has been around about 1 in 20 for champagne and table wines.
    Of all synthetic corks i’ve come across the rate of faulty wine has been as high as 4 in 5.
    (not cork taint but usually oxidised or microbial issues)

    As a winemaker there is no question that screw caps at least for wines consumed within 10yrs is the only way to go.
    I would prefer sparkling wines in crown seals but they do not sell.. hence champagne is all but the last frontier for cork.

    Most consumers and certainly ‘on Premise’ trade want screw caps for practical reasons.

  12. As this is about sparkling wine, I’ll keep my observations purely on that varietal. More importantly on sparkling Shiraz. We all should know that champagne & other method champagne wines are matured under crown seals. When the wine is disgorged of it’s yeast plug, then the finished closure is applied. I know of one favourite sparkling shiraz of mine which sells out of crown seal closures way before the cork closed bottles. I’ve had many disappointments with corked sparkles & sent some back when ordering by the glass from outfits that should know better.

  13. As editor of Winewise magazine I taste my fair share of champagne. Tyson’s figure for TCA (cork taint)is probably conservative. Even worse is the variation brought about by the inconsistency of corks. Some shrink more than others, allowing gas to escape and oxygen to enter. Why is champagne tiraged on reliable crown seals and sold with unreliable corks?

  14. Thank you Tyson for being a lone voice of reality and truth in this discussion. Its the same discussion now firmly resolved in Australia – persons with vested interests using fancy figures and fancy language to confuse the real issue.And dont kid yourself, it’s really not 1 or 2 per cent, it’s much higher but many of the casual drinkers don’t even pick up on it.Looks like a duck, waddles like a duck – what is it??

  15. So-called “Random Oxidation” is a hoax perpertrated by wine bottles to exculpate themselves. Post-bottling oxidation is caused by the incorporation of extra oxygen and oxidants at bottling and often with inadequate or marginallly adequate levels of SO2; it is not caused by the cork.
    The rates of TCA taint are difficult to pin down because of differencesn wine styles, tasters and ambience. Moreover, the intensity of the the taint is mostly below the ‘recognition threshold’, and this probably accounts for the relatively high level of false positives, i.e., around 10%.

  16. If you have ever done the standard test when choosing batches of cork whereby 20 corks from a batch are put in XL5’s with 50 ml of pure water in them and seen the variation in colour of the water with a few hours, then you will understand that it is just random, rather than random oxidation!! There will be avariation in colour from totally unaffected to something a bit like Cognac. This is the very real problem with corks. They are a natural product and every single one is different and eventually every single bottle of cork closed wine will be different as a result of the differing amounts of wood material absorbed from the corks. I do not like this level of unpredicable and totally unavoidable level of variation in the same wine. Then there is the cork taint issue. I am sure the cork producers are happy to defend cork taint as it may be preventable the variation in absorbtion of varying levels of colour and tannin and “wood” flavour from the cork is indefendable. They can do nothing about it.

  17. DIAM corks for sparkling have pretty much 0% cork taint, and hold CO2 in better than any closure (stat: Vinpac Angaston) – so a win/win there. That said, I believe National Wine shows have a much much higher rate than 5% of wines under cork rejected.
    Oxidation – Huon Hooke wrote an article some time ago (quoting research from Southcorp) stating that corks can have 1000% difference in how much oxygen is allowed in from one bottle to another.
    BUT – the issue never brought up in these debates – is that of all the older wines I’ve had, most have neither been oxidised or TCA, but had a CORK FLAVOUR. That, if no other reason, is why we use screwcaps on our wine. And I’m sure someone from the cork industry could verify that only 5% of cork goes into wine.

  18. Tyson is on the money- anyone with half a palate and a good cellar will confirm the disappointment and financial cost with cork.

    Roll on screw cap or crown seals for champagne, not to mention burgundy etc.

  19. As a wine scribe with 32 years experience, and a formal education in wine prior to that, I support Tyson 100%. His findings accord with mine. Neither of us has any reason to criticise cork, as far as I’m aware, other than that we love good wine and hate to see it ruined by corks. The only reason cork is still being used in sparkling wines and the reason companies like Penfolds have given in and gone back to offering a choice between cork and screwcap is marketing. People who don’t know better don’t want screwcapped bottles. What’s needed is education in countries like China to show them what they stand to lose by supporting cork. And the point about almost all Champagne being aged on tirage under crown seal has already been well made. Crown seal is the best answer but Diam also seems a good clean seal.

  20. If TCA contaminated as much wine as its detractors claim, no one would buy wine closed with cork. Instead, consumers, at least in the U.S., overwhelmingly prefer wine sealed with cork.

  21. I am also in agreement with Tyson. I also taste ‘regularly’. The incidence of anisole taint with sparkling wines seem to be enhanced by the CO2. How many bottles of faulty Champagne/spk wines are ever returned? I think the statistics could be rather different if consumers actually did not forgive bottles that are, in general, used on a joyous occasion. I also query the comment on Wine Futures Grenache tasting. I was one of the backroom tasters. We tasted every single wine except the 1945 Riscal; too fragile for all the bottles to be opened in advance. Robert Parker wanted ‘warts and all’ on the wines, including a whole dozen wines that were refermenting (to the horror of the winemaker). The only wines rejected were any with foul and obvious taint; we served quite a number with low level taint so I certainly refute the statement of less than 1 percent.

  22. Cork Taint is another one of those thresh-hold things like Residual Sugar, Tannin, acid and many other such things. The difference between when TCA is detectable and when it mutes a wines flavors is pretty vast. I believe humans detect between 7-9 parts per trillion, while it effects the fruit and character of wine down to something like 4 parts per trillion.

  23. A short reply to Andrew and anyone else who might suggest that the Cork Forest Conservation Alliance, (CFCA) is a “paid cork ambassador”, that is clearly not the case

    We are a 501c3 forest conservation NGO. The CFCA is a member of the FSC, United Nations FAO and the European Forestry Institute. Our mission is to preserve and protect the cork forests of the Mediterranean basin. Our financial statements are open to the public and would answer any questions regarding our complete financial neutrality regarding the sale, marketing or manufacture of cork products.

  24. I’ve been producing wines and bottling them under bark cork for 25 years. I’ve also been a paid researcher and worked on testing and validation of every sort of bottle closure. I have been involved in insurance cases where the rate of quantifiable cork taint in particular bottlings approached 100%.

    And I still use natural bark closures. I am not a cork apologist or a paid shill for the cork industry. I am an enthusiastic proponent of the benefits of cork – not the least of which is the positive contribution they make to the aroma, flavor and evolution of wines bottled under them.

    My sensitivity to TCA has been tested at less than 1 ppt. I pick it up as an intolerable flaw in bottles that others blithely consume without complaint.

    I open over 50 bottles a week in our tasting room, and I can say unequivocally that the rate of TCA taint we encounter in our wines is less than 1 in 200. We can go months without opening a single tainted bottle.

    I don’t have any complaint about screwcaps, but I won’t purchase any wine under screwcap other than something I plan to consume immediately.

  25. My experience (about 30 years in various parts of the wine business) would tend to support Tyson Stelzer’s figures. I recently judged at a major international competition in Portugal (one of whose sponsirs is Amorim !!!)and our panel had a 5.8% bad cork taint rate on a series of 153 wines. This is a bit higher than my usual percentage of about 3% for the 150 plus bottles I open per week for wine clubs I manage and my work as a wine journalist. But we are just talking about high level of cork taint here, whereas the real problem with solid cork lies with various levels of oxidisation that these engender. And here we are looking at a “failure” rate of maybe 30/50% !

  26. Diam corks seem to be TCA free.
    Maybe they should be adapted to all sparkling wine corks.

  27. Why we, as an industry, are willing to accept any significant percentage of faulty product is beyond me. Beyond that, the inherent variability of the cork and how it impacts the wine should be reason enough to steer clear. I want my customers to have full confidence in purchasing my wines, knowing that each bottle will be the same as the last. This is achievable with screwcaps, and never will be with corks.

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