Incidence of TCA Taint.

Incidence of TCA taint.

Over a month ago, I wrote about a small experiment aimed to determine the incidence of TCA taint in a real-world setting. I created a survey on FreeOnlineSurveys.com to gather data from volunteer contributors. The aim of the survey was to gather real-life data of the incidence of TCA taint in wines finished with natural closures. The survey was prompted by discussion of the true incidence of cork taint on the OpenWine Consortium (OWC), initiated by Remy Charest.

The participant cohort was comprised of 12 individuals (including myself): at least two winemakers and other wine professionals who describe themselves as writers, public relations professionals, wine education professionals and wine importers.

The survey consisted of 6 questions. Each entry consisted of participant identity validation (Q1 & Q2), the number of bottles of wine opened since last visiting the survey (Q3), number of bottles opened that were sealed with a natural cork (Q4), the number of bottles sealed with natural cork perceived by the participant to be definitely tainted (Q5) and the number of bottles sealed with natural cork which may possibly have been tainted, by the participant’s perception.

A total of 30 entries were collected in the course of a month and a half (see tcataint1.xls). A total of 208 bottles of wine were opened by participants with 158 of those being sealed with a natural cork. Of those, 9 bottles were reported to be definitely tainted (5.7%) and 4 bottles were reported to be possibly tainted (2.5%).

Contributor 6 (reporting 20 bottles opened, 18 with natural cork closures, none tainted) provided a fictitious name and an invalid email address. When this contributor is removed from the cohort, the data is as follows (see tcataint2.xls): A total of 188 bottles of wine were opened by participants with 140 of those being sealed with a natural cork. Of those, 9 bottles were reported to be definitely tainted (6.4%) and 4 bottles were reported to be possibly tainted (2.9%).

The results of this short and informal survey indicate that the incidence of definitely tainted wine is in the range of 5.7% to 6.4% and that of possibly tainted wine is in the 2.5% to 2.9%. These numbers appear to fall in the range previously reported in wine literature, indicated to be as high as 7%.

This survey was limited in its scope and size. Furthermore, variability in individual TCA sensitivity may confound these results. Laboratory analysis of suspect wines (and non-suspect wines) as a verification of findings would have illucidated the true nature of TCA taint incidence but was outside of this scope.

I welcome all readers and participants to contribute to the discussion of this survey.

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This entry was posted on Friday, September 26th, 2008 at 2:10 pm and is filed under Wine Research. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

6 Responses to “Incidence of TCA Taint.”

1. Survey finds 5.7% to 6.4% incidence of TCA Taint. « Wine Surveys Says:
   September 26th, 2008 at 2:23 pm

   [...] To discuss this survey, visit winesooth.com. [...]

2. Jerry D. Murray Says:
   September 27th, 2008 at 10:02 am

   Arthur,

   Was there any attempt to sort out the price points of these wines? Corks come in a great variety of grades and prices. I would assume that few $10 bottles are closed with $.75 corks and that few $50 bottles closed with $.25 corks. I would postulate that incidence of cork taint is inverse to bottle price. Of course this is only up to a point; I am sure that DRC isn’t paying $30 a cork. Interesting work I will keep my eye of this post and future posts. Of course as an advocate for screwcaps I do assume a ‘told you so’ position. However the renewable and biodegradabel nature of cork as well as its ease of application make it a potentially attractive closure.

3. Arthur Says:
   September 27th, 2008 at 10:09 am

   Hi Jerry.

   I had proposed that participants track the wines (and presumably prices). This would have allowed us to see if certain cork producers had greater incidences of taint. The group was reluctant to do this so I am afraid we did not collect this information.

   What do you think of the DIAM closure?

4. Jerry D. Murray Says:
   September 29th, 2008 at 7:51 pm

   Arthur,

   I haven’t had any experience with them, either as a consumer or producer. Many of my peers have thier doubts. These are obviously ‘glued’ together somehow and since the cork are ‘composite’ I tend to think that they have traded one ill for another. You might be able to remove TCA ( and I emphasize MIGHT ) but how well will the cork stand up to time and will the adhesive impart any negative characteristics? I don’t know but similiar efforts, glueing in particular, have been tried before and I have known producers that have had serious problems with them. I would certainly be interested in hearing some testimonials from producers that have used them.

5. Arthur Says:
   September 29th, 2008 at 8:26 pm

   Thanks Jerry

   I believe Nathan Carlson was running some trials and he showed me some preliminary results in the past. I can put you in touch with him. He may have even posted his results in the thread on the OWC. See here: http://tinyurl.com/43ymet

6. winesooth.com » Blog Archive » Made in forests, spoiled in processing? Says:
   October 23rd, 2009 at 10:30 am

   [...] down when I open a highly-anticipated wine only to find TCA gushing out of the bottle. That happens only in a small portion of [...]