TCA

My anecdotal evidence (a mess of bottles opened for various events every year) would also indicate that the incidence of TCA is way down in the cork world. It still exists, but is probably around 1-2% on recently-released wines. Certain regions and eras still have issues - I've given up buying mid-1980s wines from Henri Jayer because he seemed to be sourcing corks from the same batches otherwise destined for Australia, another region where sometimes there seemed to be more corked bottles than sound ones.

I think that in general, quality winemakers (at least those who haven't moved on to Stelvin or Vino-lok are paying more for corks and that enables the cork industry to spend more for QC, even while their advertising budgets increase. The introduction of DIAM closures (http://www.diam-cork.com/) has also been a good thing for they who prefer the romance of cork-finished wine to the alternatives.

-Eden (Kay, the concept of decaf coffee is indeed criminal. It's sort of like Jerry Lee Lewis' cousin just being his cousin, y'know?
 
originally posted by Arjun Mendiratta:
The Swiss Water Process is distinct from supercriticial CO2 extraction:

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en.wikipedia.org
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Yes, since posting that I've been made aware of the distinction. Years ago, another chemist of my acquaintance claimed that coffee marketed as SWP decaf was decaffeinated using the residual water in supercritical CO2. That was in the early '80s and I'd never thought to question my source, but I see now that true SWP dates from the '30s and is entirely distinct. Maybe I missed my colleague's point, or maybe he was blowing smoke. Anyway, thanks for the information, Arjun.

Mark Lipton
 
The serious players in the natural cork business have enormously reduced TCA in their finished products by: improved harvesting and storage of the raw cork, major investment in cleaning and sterilisation facilities and continuous testing using state-of-the-art gas chromatography-mass spectrometry [GC-MS] equipment.

But it hasn't been sudden and has taken way too long bearing in mind that TCA was identified in cork 3 decades ago. Without the success of the screwcap and more recently the DIAM cork et al these improvement may well have taken even longer to materialise.

Perhaps the DIAM cork for still wines and the DIAM Mytik for sparkling wines [many Champagne producers/houses are now using them for at least some of their production] is a good example of a company that was a major natural cork producer but now treats cork fragments with a super-critical CO2 process to remove TCA and many other potential contaminants and and also removes other natural constituents before reforming the [very different] cork particles with synthetic spheres using food-grade glue. These 'corks' are now being made with claimed controlled oxygen-transfer rates and are guaranteed free of detectable TCA.

However the remaining major [fully natural] cork producers have their own much improved and increasingly sophisticated sterilisation and removal processes and facilities which have been fully operative for the past few years although the processes were being upgraded and quality management systems put in place before that.

Indicative of the general effort the Cork Quality Council [made up of the major cork companies in the US] have involved Scott Labs [and ETS I think] in routine testing of cork bales imported for the production of corks for the US market. I have not seen more recent data but IIRC average figures for TCA in 2001 were 4 parts per trillion but by 2008 this figure had fallen to 0.8 ppt. Given the enormous range in individual sensitivity to TCA this would logically mean that, even at the 'sharp' end, TCA would be experienced by a diminishing number of people on a diminishing number of occasions.

Other evidence for the long overdue reduction in cork-induced TCA in wine has come form the 'fault clinics' established at major wine competitions which have seen the incidence also reduce very substantially in the last decade.
 
originally posted by Eden Mylunsch:
Certain regions and eras still have issues - I've given up buying mid-1980s wines from Henri Jayer because he seemed to be sourcing corks from the same batches otherwise destined for Australia, another region where sometimes there seemed to be more corked bottles than sound ones.
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the 85s are fucked. but 83, 86 and 87 are ok in my experience. (in fact, i can't recall a corked 86, and i've burned through several doz of the cp alone.)

fb.
 
originally posted by SFJoe:
How is the estrogen receptor agonism of the DIAM glue, I wonder?
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??? Most glues that I can think of show little resemblance to known estogens. Do you know something of the nature of the DIAM glue? Intriguingly, mussle glue, which is formed by the Fe(III)-induced crosslinking of DOPA residues, might be the most likely estrongen I can think of among adhesives.

Mark Lipton
 
originally posted by SFJoe:
How is the estrogen receptor agonism of the DIAM glue, I wonder?
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I'm sure there's an immense witticism in there for initiates. But if Mark doesn't get it, I doubt anyone else will.
 
originally posted by MLipton:
originally posted by SFJoe:
How is the estrogen receptor agonism of the DIAM glue, I wonder?
Click to expand...

??? Most glues that I can think of show little resemblance to known estogens. Do you know something of the nature of the DIAM glue? Intriguingly, mussle glue, which is formed by the Fe(III)-induced crosslinking of DOPA residues, might be the most likely estrongen I can think of among adhesives.

Mark Lipton
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Oh, I don't presume to know the SAR, I just wonder what they use to maintain elastic properties & etc.
 
originally posted by Oswaldo Costa:
originally posted by SFJoe:
How is the estrogen receptor agonism of the DIAM glue, I wonder?
Click to expand...

I'm sure there's an immense witticism in there for initiates. But if Mark doesn't get it, I doubt anyone else will.
Click to expand...
Never a Yaniger around when you need one.
 
originally posted by fatboy:
originally posted by Eden Mylunsch:
Certain regions and eras still have issues - I've given up buying mid-1980s wines from Henri Jayer because he seemed to be sourcing corks from the same batches otherwise destined for Australia, another region where sometimes there seemed to be more corked bottles than sound ones.
Click to expand...

the 85s are fucked. but 83, 86 and 87 are ok in my experience. (in fact, i can't recall a corked 86, and i've burned through several doz of the cp alone.)

fb.
Click to expand...

News to me on the 85s. Must have been very, very lucky. But I've only had a dozen altogether, I am guessing.
 
originally posted by .sasha:
originally posted by fatboy:
originally posted by Eden Mylunsch:
Certain regions and eras still have issues - I've given up buying mid-1980s wines from Henri Jayer because he seemed to be sourcing corks from the same batches otherwise destined for Australia, another region where sometimes there seemed to be more corked bottles than sound ones.
Click to expand...

the 85s are fucked. but 83, 86 and 87 are ok in my experience. (in fact, i can't recall a corked 86, and i've burned through several doz of the cp alone.)

fb.
Click to expand...

News to me on the 85s. Must have been very, very lucky. But I've only had a dozen altogether, I am guessing.
Click to expand...

The three of you are making me sick. Have we become eBob all of a sudden?
 
Nigel, I would love to see the test results from CQC if possible. A (cursory) look at their site didn't yield any leads.

I know quite a few growers who have or are seriously considering switching to DIAM closures.

I also wonder whether I'm less sensitive than I used to be - there was a suspect bottle last week (2009 l'Ecu Orthogneiss) but no one else picked up on it, and the bottle was drained too quickly.
 
I don't know if the Diam is intended for any kind of aging, but otherwise I've had very good luck with it in both still and sparkling wines.
 
originally posted by Yixin:
Nigel, I would love to see the test results from CQC if possible. A (cursory) look at their site didn't yield any leads.

I know quite a few growers who have or are seriously considering switching to DIAM closures.

I also wonder whether I'm less sensitive than I used to be - there was a suspect bottle last week (2009 l'Ecu Orthogneiss) but no one else picked up on it, and the bottle was drained too quickly.
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Yixin I was going from memory and simply re-telling an account I have given in the closure debates over many years.

I have no access to the detailed figures but am simply recalling CQC/Scott Labs reports from some years ago. However I have found this with a Google Search which I hope is of some use: http://corkqc.com/S-mat/TCA-Bro-Final.pdf

If you look at the DIAM site you will see that there are e.g. some big hitters in Burgundy and Champagne that are using DIAM.

When companies like William Fevre start putting all but their Grand Cru wines under DIAM it suggests that the closure has gained major credibility and it seems likely that the decision could be related to more than just TCA. I believe de Montille wines are now also under DIAM [and this may include their GCs]

Unproven ageing capability may be why Fevre's Grand Cru wines remained under [top] natural cork although there may be perceived residual marketing concerns behind that hold-out too.

IIRC DIAM are 'proving' their ageing capabilities empirically on a year by year basis i.e. each year that passes adds to their claims which now include different specified oxygen transfer [oxtrans] rates as well as a TCA guarantee.
 
1-2% here for young wines that I sample recently, which is waaay down. But when it hits, most recently with a 2008 Bouchard P&F Vosne-Suchots, it hurts.

Back in the 1990s, Pascal Delbeck, then at Ausone, told me that the cork companies taught how to test batches for a 5% corked rate. I wonder if now their instructions are for testing at a lower rate? I'll have to ask around.

OTOH, I've had no problems with screwcaps. :)
 
originally posted by Oswaldo Costa:
originally posted by SFJoe:
How is the estrogen receptor agonism of the DIAM glue, I wonder?
Click to expand...

I'm sure there's an immense witticism in there for initiates. But if Mark doesn't get it, I doubt anyone else will.
Click to expand...

I was struggling to come up with something for mussle glue, but it's just too late in the day.
 
I opened no corked bottles at all for the first seven months of this year. Then I opened five in a row,all quite grand wines,annoyingly.
 
originally posted by Tom Blach:
I opened no corked bottles at all for the first seven months of this year. Then I opened five in a row,all quite grand wines,annoyingly.
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Tom,should I assume these were all wines from an era when a 'corked' bottle was a more likely event than in more recent years? An indication of the 5 vintages would be much appreciated?
 
I just talked to a Diam rep and asked him about aging under the closure. He said that Diam makes a variety of corks, with names like Diam 3 or Diam 5, and that the number indicates the minimum number of years that wine should age properly under the closure. His customers have mostly been using the '5', and he says he's tasted wines aged successfully for 8-9 years under it.

He said that they guarantee less than 0.5 ppt TCA for every cork, and that the curve of SO2 change under the Diam 5 is about the same as the average for bark corks.
 
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