Wine Talk

Snooth User: napagirl68

Corks, TCA, Taint, research... my old post re: research....

Posted by napagirl68, Sep 24, 2012.

I found the old post re: cork taint (TCA).  It includes information from my communication with a leading UC Davis researcher.  Internet links require cut/paste:

Reply by napagirl68, Sep 17, 2010. Edit

    Well... biology is not my current field-nanotech/semiconductor is.  if you ask me about silicon, I can answer, but not the mold spore realm.  Sooo, I emailed a scientist who has done actual research on this matter, Dr. Christian Butzke.  He was very kind to get back to me with some info, which I am paraphrasing, not quoting.  He said some interesting things.. one of his grad students was involved in the cork vs. screwcap comparison in the ~$150 Plumpjack wine and found no difference.  He also mentioned that there really isn't money designated for university research in the US on this subject, and the winemakers/ cork suppliers both blame each other.  He also mentioned that most people are not super sensitive to TCA, so it is of little consequence to them.  He gave a link of a book he co-authored, that is meant to educate those in the wine field about cork properties:

    He also attached an Italian research paper called "The Volitile Components of Cork Used for Production of Wine Stoppers".  I don't know how to attach PDFs here.. if someone tells me how, I will post it.  Interesting read.

Reply by napagirl68, Sep 18, 2010. Edit

    Here is a link for the abstract of the paper i previously mentioned: Volatile Components of Cork used for Production of Wine Stoppers-

    I also found another very interesting abstract:

    Effects of electron beam irradiation on cork volatile compounds by gas chromatography-mass spectrometry

    If I log in at work, I can read the articles for free, otherwise I think you have to have a membership to read the whole paper.  The irradiation concept intrigues me...




Reply by GregT, Sep 25, 2012.

Too bad we can't read the entire articles.  Now to figure out how to do so w/out getting yet another subscription.

Looked thru the preview of the book and there are a few wineries in Napa that do the sampling like he describes - Neal for example, told me that's what they do.

As far as money dedicated to research - the EU has finally devoted a little bit because cork is a big deal to Portugal and Spain, and in Bordeaux they have labs dedicated to detecting taint, but their approach is to "fix" the problem, not to solve it. He's sure right about most people not being able to detect it.  Or perhaps detecting it and having no idea what it is they're detecting, instead attributing it to "terroir" or the wine.

If I'm not mistaken, the Australians have done the most research and for the longest time, except their approach was not to fix a problem with cork - they solved the problem of taint by using alternative stoppers.

Interesting articles tho - from what we can read!  And you're right - the idea of irradiating the corks is really intriguing. Seems like it should be almost foolproof, no?  I wonder if that's acceptable to "natural", much less biodynamic, winemakers!


Reply by napagirl68, Sep 25, 2012.


Let me see if I can read these at work...... I will ck today.

Reply by napagirl68, Oct 3, 2012.


I was able to read one article at work, albeit it is from 1998:

Effects of Electron Beam Irradiation on Cork Volatile
Compounds by Gas Chromatography-Mass Spectrometry
M. Careri 1 / V. Mazzoleni2/M. Muscil*/R. Molteni 2
1Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica, Universitfi di Parma, Viale
delle Scienze, 43100 Parma, Italy
2Istituto di Enologia, Universitfi Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29100 Piacenza, Italy

Granted, it is an older study (1998), but it was interesting reading. Some background cited:  Cork undergoes a natural growth of mold/bacteria during processing and storage. Wineries typically use chlorine or peroxide based cleaning methods to take care of this problem.  Both byproducts from cleaning substances, and remaining volatile components in corks can remain in "cleaned" corks, some present in a concentration that will cause a wine to taste "off".  

In this study, a total of 74 volatile components were identified in unused, untreated cork samples via gas chromatography/mass spec.  Irradiation studies were done using ebeam rad to look at results at varying dose.  The basic result was that a lower dose of 25kGy was successful in lowering most of the volatile components, while maintaining cork structural integrity.  Larger doses actually INCREASED some volatile components, thought to be the result of liberating these existing components from the matrix of the cork itself.  

As to what has become of this research, I do not know.  I will have to do more of my own research to see what current technologies are being utilized.   IMO, I think many have just moved to alternative stoppers.  I, too, like a glass stopper.  Whitehall Lane in Napa uses them on their higher end cabs.

Reply by GregT, Oct 4, 2012.

Thanks NG.  Interesting about the dosage of radiation producing different effects. It's actually pretty hard to find a lot of information about corks - I guess it's because it's not a hot topic in the academic world so little pure research is done.  Most of the info is probably in the labs that are doing real-world work and they're not inclined to publish for purely academic reasons.  

I have in front of me right now an article about headspace pressure in bottled wine but after a dozen 2004s it's hard to focus. That's why I opened a 2008.


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