In an
interview with Wein-Plus, the wine merchant Rolf Cordes claimed that the corks of the
French closure manufacturer
Diam Bouchage were not sensorially neutral and caused an "atypical
bitter tone". In addition, he reported about a series of tests he had designed himself, which, according to him, proved the problem. Now Dominique Tourneix, CEO of
Diam Bouchage, has faced the accusations and our questions.
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| Dominique Tourneix% CEO of DIAM (Image: DIAM) |
Mr. Tourneix, wine consultant and merchant Rolf Cordes said in our interview that he found a wine fault that he directly linked to
Diam corks. How did you learn about this?
Tourneix:
A customer informed us about the issue a few weeks before the interview was published. My staff then contacted the author of the interview to find out more about his
test procedure and its results. We cordially invited him to visit
Diam Bouchage so that he could gain a better understanding of our production processes. This is very important to us because otherwise you are missing the point. We were quite surprised about the interim publication of the interview. Incidentally, Mr Cordes let us know that he had behaved so offensively because he feared he would otherwise not be taken seriously by us.
How often do you hear about reports of wine faults - from winemakers, traders and sommeliers, for example - that are said to be caused by one of your closures?
Tourneix:
So far, we have not become aware of any negative comments about allegedly detrimental sensory effects of
Diam corks. On the contrary, we have always received a very positive or even enthusiastic response to our products. By the way, our customers often think that the quality of
Diam products causes a certain envy.
Attack attempts and criticism are the price
Diam seems to have to pay for its success.
How do you and your team deal with such references?
Tourneix:
Diam takes criticism very seriously. We try to understand the background and in this context we examine very closely the circumstances, facts and procedures underlying such statements.
Can you and your experts understand the
lack of tone described by Rolf Cordes?
Tourneix:
We have carried out numerous sensory wine tastings for comparison purposes, in which experts, consultants and wine scientists have also participated. We have never heard any comments about an alleged untypical
bitter tone that is supposed to emanate necessarily from our corks.
So why do you find Rolf Cordes' observation incomprehensible?
Tourneix:
In response to our enquiry, wine scientists have confirmed to us without reservation that the tests in question here were carried out under conditions that do not correspond to the factual circumstances of the usual use of a cork. Therefore, in the opinion of these experts, the
test result in question cannot be recognised. In the context of a correctly developed sensory study, it would be necessary, among other things, to establish the correct conditions of use and handling of the packaging of the wine, such as, in particular, a correct and proper closure of the wine from the outset, without constant opening and reclosing of the bottle.
However, the possible problems of closure alone cannot be a reason not to take the observation seriously.
Tourneix:
Many studies have been carried out all over the world by
Diam itself, by independent universities and wine scientists and even on the initiative of our competitors. Not a single one of these studies has so far observed an "atypical
bitter tone", which is now, astonishingly, supposed to be the result of the tests in question. The scientists of the universities we have approached in this context - as, by the way, have long-time customers including renowned oenologists - are all, without exception, of the opinion that the
test results brought about under the said circumstances must necessarily be distorted and, contrary to the claims made in the interview, have no significance or evidential value whatsoever.
Tourneix:
For many years, we have been working with the
AWRI to
test the preservation of wines that have been sealed with various corks from our existing product range as well as from the range of new corks developed by
Diam that are not yet available on the market. The aim of these studies is to determine the optimal
OTR (oxygen transfer ratio; ed.) for each grape variety and for each storage period. We use many different versions of our corks in order to be able to follow the development of the wine. For not a single one of these corks has the issue of an "atypical
bitter tone" ever arisen, which has allegedly been found as a result of the tests discussed here.
Diam corks are said to exclude
TCA in particular. Is it possible that by focusing on
TCA, other sensory aspects have not played as big a
role in the development?
Tourneix:
The best thing to do is to read the scientific publication in the "Revue des Oenologues" No. 120 of July 2006, which deals with a very comprehensive study of components and in particular molecules extracted from the cork material during its purification with a treatment of supercritical CO2.
Diam has developed and patented this extraction and purification process under the name "Diamond". Not only
TCA, but also some other so-called "volatile substances" are extracted and removed, because some of them can cause sensory deviations when coming into contact with wine. This study also contains a comparison between the sensory effects that cork can have in each case in its original state or after its purification with supercritical CO2. Here, the technical background for the fact that a sensory neutrality of the cork material can be achieved to a large extent with a cork cleaning using supercritical
CO2 becomes understandable.
Do you have wines sealed with
Diam corks stored for longer periods and sensory tested by trained experts?
Tourneix:
We work with numerous universities on studies about the long-term storage and preservation of wines sealed with
Diam corks. Some of our clients keep samples for several years; we are regularly invited by them to participate in blind and comparative wine tastings. No "atypical
bitter tint" has ever been systematically observed in any of these samples.
How often are the corks produced normally tested for causing off-flavours?
Tourneix:
The batches of cleaned cork are systematically analysed; all raw materials used by
Diam are also regularly tested for sensory effects. When we visit our customers, we take several cork samples from our production lines and carry out sensory tests with them to check the efficiency of our cork cleaning process. The result is clear: cork cleaned with supercritical
CO2 has no negative sensory effects on the wine.
