Has anyone ever encountered a geosmin flaw?

Hi all. I'm a rare poster from the former iteration of the WLDG. I'm posting because I ran across something I've never seen before.

The wine in question is a 2002 Pascal Janvier Coteaux du Loir. It reeks of beets; like, it smells precisely and overwhelmingly like roasted beets. The smell is so overwhelming that it renders the wine completely unpalatable. At first I thought of a mercaptan fault, but I've run into that before and this smelled subtly different. Next, I suspected a malolactic fault; but this is an aggressively acidic Loire wine; it sure doesn't taste like it went under malo. So I checked my copy of Harold McGee, and he said that beet aroma was a result of a molecule called "geosmin". Google revealed a few studies claiming that geosmin is produced in rotten grapes, and that tests have found various levels of geosmin in wine.

So my question is: did I encounter a wine with a geosmin fault? I've never heard of this fault before.

There's been quite a bit of discussion on the subject in the last few years. See the wine fault discussion on Wikipedia and

http://www.decanter.com/news/60674.html

A young Bordeaux scientist has discovered the cause of geosmin, a compound that gives a musty flavour that has bedevilled winemaking for several years.

The smell is often described as 'turnip', 'musty', 'rotten', or like wet earth warmed by the sun. It differs from the classic musty flavour of TCA or cork taint, which does not have a vegetal edge.

Geosmin has been known about for decades, but was not common knowledge amongst winemakers when it seriously infested Beaujolais in the 2000 and 2002 vintages. It had also affected red wines from various regions including Bordeaux, Burgundy and the Loire since at least 2000. ....

http://www.springerlink.com/content/3ca6ektlntgt1l5h/


Authors
Philippe Darriet, Sophie Lamy, Stephane La Guerche, Monique Pons, Denis Dubourdieu, Dominique Blancard, Panagiotis Steliopoulos, Armin Mosandl

1Faculté d' Oenologie, Université Victor Segalen Bordeaux 2, 351 cours de la libération, 33405 Talence, France
2Institut National de la Recherche Agronomique, Unité de Santé des Plantes, 33881 Villenave d' Ornon cedex, France
3Institut für Lebensmittelchemie, Biozentrum, Johann Wolfgang Goethe-Universität, Marie-Curie-Straße 9, 60439, Frankfurt am Main, Germany
Abstract

Geosmin (trans-1,10-dimethyl-trans-9-decalol), a well-known, highly odorous compound, has recently been identified and quantified in red and sweet white wines, as well as in grape juice before alcoholic fermentation. Geosmin is a chiral compound and the (-) form is much more odoriferous than the (+) form. Enantioselective multidimensional gas chromatography analysis of a purified Cabernet Sauvignon wine extract revealed the presence of only one enantiomer: (-) geosmin. In grape juices obtained from rotten grapes and in wines this compound can be found at concentrations much higher than its olfactory perception threshold, indicating that it contributes to their earthy aroma. (-) Geosmin is also the only enantiomer to have been identified in pure cultures of Streptomyces sp. and Penicillium sp. strains isolated from rotten grapes.

Your description is very similar to what I tasetd a couple of years ago in a Beaujolais -- I thought it was corked at first, but the odor was more "rooty" than "musty".

yes, several times - including two weeks ago at the finger lakes wine competition. there was one wine that reeked of it; but i forgot the name and had to ask two other judges before they came up with the name. one, a master of wine, said 'oh, i know it well, what is it'. every beaujolais i had from 2002 had it; and many sweet loire whites from that same era had it. cooked beets is right; warm humous earth also. hadn't come across since 2002. hard to love. btw - most people's sensitivity is much lower than yours. many people refuse to believe there is a fault with these wines.

Thank you both for your replies...very helpful.

Thank you, Bob, for that reference.

Tom Stevenson's "aromas & flavours guide" has geosmin as the the main component of the beetroot flavour one might find in Pinot Noirs, and also something that might be repsonsible for corkiness in a wine.

well, if things do come in three's i've now had all the geosmin i need for awhile. after not having smelled it for 6 years, i got the third shot of it in as many weeks at yesterdays loire tasting in chicago. one red and three whites had it - all from the wet 2006 vintage - shoulda known to expect it there i guess. only one bretty wine, so all in all a fine day. more cab franc in one place that i've ever seen - most of it really good. i'll post later about the chenins.