Riesling's Petrol Flavours are a Fault -- Peter Barry

In particular its a viticultural fault; petrol flavours are caused by sunburned grapes, says Peter Barry...

http://www.wine.co.za/news/news.aspx?NEWSID=29944

Interesting!

[David M. Bueker]

Ah yes, another "study" (aka the opinion of a winemaker who wants you to buy his stuff versus someone else's) that ties petrol to faulty grape growing/winemaking.

Plenty of Rieslings with petrol that never got sunburned. The character is too widespread to be caused by that. His assertions about the grapes getting sunburned is just his opinion, nothing more.

Also, the notion of wine having 'faults' tries to make the whole thing sound more objective than it really is. A wine's purpose is to be drunk and enjoyed. If someone enjoys certain things (brett, oak, petrol) then the wine was not faulty for them!

Oh dear...Yawn.

Bring me your flawed petrolly Prums, Grunhausers, and Knolls
I'll take your flawed bretty Cordier Gruauds and Meyneys from the 80s, too.
If you can't take a little VA in your LdHs and Unicos, I'm your man.

Oh dear...Yawn.

Was that the same yawn that started over on the UK Wine Forum version of this thread?

Sure was but I will feel better Saturday as I have a Port tasting .

Bring me your flawed petrolly Prums, Grunhausers, and Knolls
I'll take your flawed bretty Cordier Gruauds and Meyneys from the 80s, too.
If you can't take a little VA in your LdHs and Unicos, I'm your man.

Ditto.

Michel Chapoutier said much the same as Barry when he burst into Alsace. I took it then partly as arrogance and partly as an effort to differentiate his product for marketing purposes.

[Jenise]

Bring me your flawed petrolly Prums, Grunhausers, and Knolls
I'll take your flawed bretty Cordier Gruauds and Meyneys from the 80s, too.
If you can't take a little VA in your LdHs and Unicos, I'm your man.

Me three. Riesling without petrol is boring.

[David M. Bueker]

I would not go that far!

Indeed. I don't particularly like petrol in riesling, or brett or VA in other wines. But it's just the concept of claiming 'fault' that rubs me the wrong way.

Nothing like a little hint of petrol to liven things up!

Thanks for sharing Peter, I think learning and grasping some understanding of the mechanism that results in the formation of chemical compounds found in wine is very interesting.

David, as far as the Riesling stored in your “Glacier cellar” the conversion or transformation of TDN precursors into actual TDN might take longer to occur (than say “warmer” storage conditions). . Researchers now suggest that the TDN precursor concentration could very well be dependant on a photochemical (how much sunlight and the actual timing of exposure during the berries ripening stage, thus “sunburned” grapes may have a higher concentration of TDN precursors) and/or enzymatic reaction within the ripening grape berry themselves as they hang on the vine in the vineyard. Researchers say if the grape clusters get a lot of sun exposure prior to color change TDN concentration could increase by 2X, if the grape clusters get a lot of sun exposure after color change TDN concentration could increase by 4X. (So canopy management and timing will assist in managing TDN). The conversion or transformation of the TDN precursors into actual TDN might be an acid catalyst hydrolysis reaction, which occurs as the wine ages in storage. Riesling wine generally has a high Total Acidity (TA) and low pH so researches tell us Riesling (not to mean the only wine grape, TDN is found in lots of wines, red and white) is a prime candidate for a “petrol aroma”. Try storing two identical Riesling wines from a very “sunny vintage”, one in your “Glacier cellar” the other one in a “warmer” location; see which one develops a “petrol aroma” (if any).

Whether or not the TDN (or any other compound for that matter) becomes a fault, I totally agree with Rahsaan, if the concentration of TDN plays nicely with the other components of the wine it could be “delicious”. But than again I wouldn’t want to drink a glass of kerosene or petrol.

Salute

The writer has a follow-up to their original article including reposnses from Cape winemakers

http://www.wine.co.za/news/news.aspx?NEWSID=30109