I grow Pinot Noir in California and this last vintage I had about 5% of my fruit un-harvested when it rained 2.75 inches in the middle of October. This created a bloom of the usual suspects (Aspergillus and botrytis) and also something new, multiple strains of beautifully colored penicillium.
I am in a region that because of marine influence and latitudinal effect on daylength is very cool, where we are able to practice fairly extensive leaf removal and expose the fruiting zone to sun and air. Sun and air are better than any pesticide when it comes to controlling fungal disease, and this helped minimize problems. Affected clusters were handled the day before harvesting by going through and carefully sorting the fruit on the vine in daylight, examining each cluster and dropping any blemished or affected fruit to the ground. (Which I do not believe is a common practice, due to the expense.)
I was alarmed because I had never seen it rain like this before during harvest. I started reading as much as I could about these molds and their potential effects and discovered that there is quite a large body of research on a byproduct of botrytis and penicillium, a compound called “Geosmin” (trans-1,10-dimethyl-trans-9-decalol.)
The research appears to show that when wines are found to have earthy characteristics, this compound, Geosmin, is always(?) present.
The research shows that the compound has very low sensory thresholds and that it masks fruit aromatics and flavor. The compound is very common in certain wine growing regions and is possibly the predominant characteristic of numerous vintages?!
The materials I read went on to explain that the characterics produced by this compound are typically explained as being created by or as showing terroir…
I have been ruminating the last several months over my recent understanding of Geosmin and noting that there are many who criticize fruit characteristics in wines, while praising the earthy (non fruit character) wines as the archetype.
I throw this information out because it appears that there are many wines whose primary character is in fact driven by what many, including myself would call a flaw(?) that is created by mold?!!!
I’ve heard geosmin discussed, but no one has ever pointed me to a particular wine where it exists. Rovani for one vintage in Burgundy (I recall that it was 2002, but I may be wrong) said sometime after harvest that it was going to be a big problem, but then I don’t recall his ever pointing to a wine where it occurred (but I only saw his comments on the internet, not in WA).
If someone can identify specific Burgundies (or Northern Rhônes) where they think it exists, I’d be most interested.
Of course, it’s possible that it’s neither terroir nor a fault. Small amounts of brett can make a wine more interesting for me and some other people, yet I would not call it terroir and, if in small enough quantities, not a fault.
I’d love to hear the Oregon folk’s take on this since their wines often have that earthy quality to me. Sometimes its hard for me to tell whether it is an attribute of the wine or a sign of reduction though.
This is certainly a very interesting post. But if it has existed for a long time, maybe it is a normal part of winemaking(and if it’s not bad for you then why is it necessarily bad). I like wines that exhibit terroir, but often times i find that in wines that are less overtly ripe and lower in alcohol. I always assumed it was partly based on microclimate and partly due to lower brix levels at harvest. I’m not sure if you are suggesting that places like Carneros that tend to have earthier wines simply have this fungal compound and warmer places less influenced by maritime to the north don’t? Either way, my issue with many Central coast, warm napa, warm sonoma, and definitely aussie wines is that if they are so ripe and sweet maybe you wouldn’t even notice if these compounds are present.
Long story short, if geosmin is what it takes to have more balanced and complex wines that aren’t like grape juice and vodka, i might just like fungus. Anyway, I’d appreciate your thoughts and appreciate the insight, but I don’t think its a good defense for fruit bombs.
i don’t recall if you make any of your own wine or only grow the grapes, but barrels with that last 5% if separately barreled would sure make an interesting case study of sorts if they are otherwise similar blocks to some other barrels harvested earlier. Obviously it would be tough to isolate that one factor if acidity, sugars, etc were vastly different. Just a thought.
Thanks for the link, Peter. I just skimmed it, but I didn’t see any identification of individual wines. Did I miss something or is this a non-responsive answer?
I remember that WA issue. It was his report on the 2002 vintage. He stated that it was a widespread problem and that he did not recommend any wines that exhibited that characteristic. Of course, per the usual WA policy the wines that were not recommended were not named.
One point: I think there is a bit of misconception about the phrase “shows terroir”. Terroir is the phsyical characteristics of a site that influences how a grape developes as opposed to the actual taste of dirt in wine.
I agree that this is an excellent, thought provoking thread. Thanks Peter.
I think the relationship of geosmin to ripeness is also interesting, since I could see it cutting different ways. On the one hand, maybe geosmin laced wines really are less ripe; it’s easy to see how rain and the onset of rot could force the grower’s hand and cause picking to occur earlier than would otherwise have been the case. Alternatively, grapes become more susceptible to rot the riper they get. I can imagine geosmin knocking back the fruit in even very ripe vintages and making them appear more restrained. As another alternative, consider that grapes with rot will usually induce early fining of the must as a countermeasure – at some cost to the fruitiness of the wine; raising the possibility that geosmin and fruit diminution covary as a function of botrytis rather than being directly causally related.
It doesn’t make me like fruit driven wines any more than before, but it does make me wonder about the origins of the things I admire. Makes me want to make a barrel of rot affected wine.
I’m with Rich Graham on this one. Historically, many pinots would show flavors of earth, forest floor, and sometimes barnyard. These flavors, if done in proportion, would often add complexity, character, and distinctive flavors to the wine. Now, it appears as if someone is wanting to call all of this a flaw!
Not buying into it. Let the super-ripe, fruit bomb, boys do as they may, but these flavors, in proper proportions, imo, are not flaws in the wine.
This story reminds me of a young Cal-Davis winemaker in the St. Lucia HIghlands a few years ago. He declared that if a wine was not ready to be drank upon bottling and needed cellar time, it meant it came from unripe fruit! Here someone is trying to tell us that the flavors mentioned above are flaws!
There seems to be a view among many people that any attribute in wine that you can trace to a particular chemical compound is a “flaw.” “Ah-ha, it has brettanomyces!! Flaw!!!” As if that settles the question, as if flaws are matters of chemistry rather than aesthetics. Don’t tell these people that their favorite wine certainly contains dihydrogen monoxide!
Sort of like what people did when they discovered we have bacteria in our digestive systems. They freaked out. Did everything they could think of to purge them, ignorant of the consequences. Generations later, with better understanding, we are intentionally introducing “good” bacteria to our systems.
I’m reading an oral history interview with Paul Draper right now. http://digitalassets.lib.berkeley.edu/roho/ucb/text/draper_paul__w.pdf" onclick="window.open(this.href);return false;
He thinks something similar happened with wine in the post-Prohibition era. Some of the old timers went back to their old ways and made great wines in the '30s (but soon retired). The newbies bought up old equipment that had been sitting around all that time and ended up with contaminated wine. They over-reacted and incorporated the newest technology, and made flawless, clean, industrial wine. Then it took several decades to pull back to the best of the old ways, and the best of the new, and start making great wines again.
So, of course you want to sort out any mold you can see or smell, but you don’t want a sterile boring wine.
If “earthy” means what I think it means, then I don’t mind some “earthy” notes at the table-wine price point [$9.99 and below] - in that market segment, “earthy” can be a nice counterpoint to the sterileness [or hygienicity or whatever] of mass-produced industrial wines.
But somewhere after about the $19.99 price point, my wines had darned better be clean.
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