The Auswine Forum

On Thursday a thread appeared on the Mark Squires Wine Bulletin Board under the title Worrying research on oxidation ? The initial post contains material from a “science research site” which describes A recent study by the research arm of l’Union de Maisons de Bordeaux headed by Dr. Jean-Pierre Varoni, as yet unpublished, appears to have established that high alcohol wines may be at risk of rapidly turning sour in the latter stages of cellar development.

The study, prompted in part by the tendency toward higher alcohol levels in New World red wines, concluded that the results were, “alarming,” and calls into question the suitability of this wine style for medium- or long- term cellaring.

Unfortunately no link was provided to the “science research site” and the thread originator has not (at this time) returned to provide any additional information. But this is a sufficiently interesting topic to follow up so……..

A little checking reveals that the l’Union de Maisons de Bordeaux site is here. Their Partners, presumably including their "research arm", are here. The study could come from the Oenology Dept of Université Victor Segalen Bordeaux 2. But my French is not good enough to figure out if the work comes from there or if Dr. Jean-Pierre Varoni is a member of the Faculty.

OK, so letÂ’s look in the research literature databases to see where Dr Varoni does publish as this will help locate him. So far I have searched PubMed which is excellent for biomedical literature searches, but its fairly limited when it comes to non-medical related vinous topics, as the original post seems to be. There are other databases that can be searched via Ovid Tech. The most relevant databases are probably Agricola (Index to materials acquired by the National Agricultural Library and cooperating institutions.) and Biological Abstracts (Indexes life science research reported in nearly 5,500 journals. Coverage is international and includes biological and medical research findings, clinical studies, discoveries of new organisms, biotechnology, pharmacology and botany.)

J-P Varoni does not appear in any of these databases. So either Varoni has yet to publish, publishes only in obscure French journals that are not indexed in major library data bases, or the wrong name was given. Googling VaroniÂ’s name or phrases from the text of the original post does not pull up anything.

Is this whole thing a hoaxÂ…Â….?

Mike

I had to look at the date to make sure it wasn't April 1.

For me, the "latter stages of cellar development" is 10-15 years of age and the only high alcohol wines I've noticed turning sour are those left open in the bottle for a day or so on the odd occasion that we failed to finish a bottle. The last time I tried a 91 Bullers Calliope Shiraz (16+%a/v) about 4 months ago I failed to detect any signs of sourness after 14 years and it still has a few years ahead of it by my estimation.

KMP,
Mark is a good guy on the most parts
while his board is a Dogville (I asume you've seen the movie). I take 90% of BS posted there with a grain of salt....from the Dead Sea.
http://www.winetalk.com/forum/showthread.php?t=778

High alcohol wines rapidly turn to vinegar.

Is this New world wine bashing of the first degree!

My 92 reds (well over 16% ) showed no sign of vinegar when tasted last year.

This is just utter utter utter BS.

Cheers
Smithy

Logistically there is a possibility, however it is also very possible for the same thing to be observed in lower alcohlol wines. The following are few cases (which may explain, confuse, prove or disprove these theories) where I have focused on acetaldehyde production, due to its role in oxidised characteristics.

Fermentation is the conversion of primarily glucose and fructose into ethanol and carbon dioxide. However through glycolysis carbon sources can be diverted to other important metabolites, such as acetaldehyde and glycerol (remembering there are numerous cascade effects from here). Consequently, yeast used in production which have high acetaldehyde producing properties may lead to the development of oxidised properties earlier on in the development process, especially if under poor seal (be it cork or screwcap). However, yeast which have high acetaldehyde production theoretically would also produce less ethanol as there is defined quantinty of carbon which travels through the glycolytic pathway for production of metabolites.

Another theory could be that wines with high alcohol may lead to the degredation of bonds between anthocyanins and acetaldehyde or sulphur and acetaldehyde (as an example), therefore increasing the perception of oxidised characteristics.

All of this however, rests intrinsically on so many other attributes, tannin, acid, wine style to name but a few. I will keep my eye out for the article if it is printed, but it is quite an aspertion to make.

FYI PUBMED is a great resource, but it is very rare that wine research makes it as far as the impact of the journals that are listed, Science Direct is also a good resource as is Scirus.

Cheers
Colin.

smithy wrote:8)

High alcohol wines rapidly turn to vinegar.

Is this New world wine bashing of the first degree!

My 92 reds (well over 16% ) showed no sign of vinegar when tasted last year.

This is just utter utter utter BS.

Cheers
Smithy

Smithy,
New World wines don't have to even think about, they are consumed...
it's an old world problem who don't know what to do with their juice

Another desperate attempt by the Frogs to bash new world wines. As if they've got high alcohol wines going back far enough to do meaningful research.

From my experience, if they look good as young wines they'll probably be good as mature wines. If they look alcoholic young then they probably might not look that good later.

I've had plenty of Bordeaux that looked like vinegar at supposed maturity!

(Looks like this thread is turning into vinegar going by the last 2 posts.) Ignore as the moderator gave em the chop they deserved, Davo

However, on a more serious note, I thought the production of vinegar required the presence of vinegar cultures containing acetobacter, and that the higher the alcohol level the less productive the culture.

Otherwise, and to go with the argument put forward, surely all brandy would turn instantly into vinegar and definitely would not last the time that it does, says he sucking on a 30YO XO to follow the sensational Clos Clare 2002 Shiraz.

Oh and, Smithy I love you, will you have my baby?