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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