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March 2022
The newsletter from ProCork
​ProCork Products Protect Wine from Oxygen, Cork Tannin, Glues and Cork Taints





In May this year we were alerted to a significant difference found in a Chablis 1er cru Fourchaume 2018, which was bottled with two different micro-granulated technical corks. One had the ProCork semi-crystalline polymer membrane protecting the wine from contact with the cork and glue materials and the other used the leading brand of technical cork in the market which was unprotected.

The taster was Jean-Marc Quarin, a well known, independent and influential wine critic in Bordeaux. He has a reputation for publishing exactly what is in the bottle the consumer buys. Jean-Marc Quarin is the only critic in the world who publishes wine comments that identify who produced the cork that was so intimate with the wine for so long. For over 25 years he has been regularly bringing up the enormous problem of the difference from one bottle to another in the most famous and most expensive Bordeaux wines. Since 2004 he has also been writing comments under the title he coined “The cork, wine’s ultimate dimension”. In addition, Jean-Marc Quarin has written a tasting method called "Palate over nose". He teaches how to recognize the mouth descriptors responsible for the quality and the style of wine. 


Jean-Marc Quarin came across the wine, which was bottled 6 months prior, so out of interest he did a number of professional blind tastings over various time periods. In his findings, Quarin noted a loss of "Ripe Fruit Character" in the wine without the ProCork Oxygen Control Technology. We commissioned SENSENET, an independent perfume sensory laboratory in Paris, to undertake an analysis of the molecular differences in the two wines.

SENSENET confirmed Jean-Marc Quarin's observation showing a very different ester profile in the two wines caused by more oxidation in the wine without the ProCork membrane. As well as a significant increase in ethyl acetate in the oxidised wine there was a loss of the long chained esters.


Dr Christie from ProCork said "The terroir driven fruit characters come from long chained esters that are produced by yeasts during fermentation from precursors in the grapes. They create the unique ester profile that distinguishes the fruit character of the wine and make it individual.

Dr Christie from ProCork said " We are not the first to measure the loss of long chained esters due to excessive oxidation loads and we won't be the last. Unrecoverable damage to the inherent fruit character results from short but high bursts of oxygen which overrun the anti-oxidant sulphur dioxide and long carbon chains of the fruit esters are an easy target for the oxidation that follows. The overall effect is a conversion of the unique fruit characters of a wine to more generic oxidised fruit characters like cooked fruits or bruised apple. This independent study supports our opinion that ProCork's Oxygen Control Membrane is the best solution to this problem"

You can read the report here.

Contact: Dr Gregor Christie


83 Avenida Santiago

Rio Meao Portugal                            email:

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