Barnyard and skunk are two unrelated things. Hydrogen sulfide (the main type of “reduction” that will lessen or be eliminated with aeration) doesn’t really smell like a skunk to me. When you’re saying it distinctly smells like driving by a dead skunk, I’m thinking mercaptans. A mercaptan compound is used to odorize natural gas. This will neither go away nor get worse with aeration, though, so it’s a bit confusing. I’ve never known brettanomyces to get worse with air.
From this post and from reading numerous articles on wine faults I think you are right about mercaptans. Thanks.
If you’re using “skunk” broadly enough to mean TCA, it frequently (always?) gets worse with air. Most of the time where cork tain is initially undetectable (but suspected due to the wine showing very little fruit and having very little nose), I’ll set the wine aside and within 30 minutes to an hour the smell of TCA is quite strong.
I see no resemblance between the smell of TCA and a skunk however, and would instead always describe the TCA smell as being moldy (or just as the smell of corked wine). Some describe it as “musty” (which is an imprecise description, as a “musty” basement might smell mouldy, but could also be musty due to the smells of mildew, dust, stale air, etc., each of which is a bit different from the others).
Definitely not TCA. I am fairly sensitive to that.
Sounds like a reduction issue and /or mercaptans. I try to carry a penny with me to tastings to see if throwing one in will clean up such a wine. Can work wonders, but if the reduction has gone so far as to create disulfide bonds, then nothing will get rid of it.
Just to reiterate what I said above, there is no way to know that we are using the same terms to mean the same thing. Even the concept of what a skunk smells like is not universal.
And the appearance of mercaptans in wine is not that common. When it does appear, the most widely used descriptors are garlic, onions, and cabbage. That said, those in combination with an earthy wine can lead one to believe that they smell like something totally different.
Just another data point here.
Right. My concept of a mercaptan is a weird sweet garlicky cabbage type thing that just never goes away. I suspect the skunk here was a single bonded sulfide reduction related compound that would have improved with copper.
When people say barnyard they usually mean brettanomyces: horse/animal/game/manure smells (also bandaid, etc) = brett. Whether or not it blows off with air seems to be a matter of some debate, as is whether it is a flaw or a desirable quality.
Strong skunk smells are prominent in beer that has been bottled in green glass, but I’ve never encountered it in wine.
By any chance were you drinking this wine at a Phish* show? If the answer is yes there may be another culprit.
*Or really anywhere these days, but the point stands.
Some beers – particularly Belgians – are deliberately infected with brett.
Indeed, the smell of today’s pot is the closest thing I know of to the smell of a skunk.
Good discussion, and, as Larry says, a difficult one because it’s hard to know what people are describing when they label an aroma indistinctly. Like every aroma, you really have to connect it definitively to a chemical compound (or mix of compounds) through experience to be able to describe it properly. Once you smell a really bretty or corked wine, you know that aroma forever (caveat that there are a number of different compounds associated with brett).
I don’t think I’ve ever smelled skunk exactly in a wine, but I have described wines as “skunky” because of the closeness of aroma to that of skunk. But barnyard brett and skunk are quite different to my nose. A skunky aroma is almost certainly mercaptan (though there are skunk smells that come from other compounds, see this link https://users.humboldt.edu/wfwood/chemofskunkspray.html).
Back to the OP: it’s an interesting question. I don’t think I’ve experienced many (any?) wines where brett or skunky notes got worse with air, they are usually pretty obvious on opening. But it doesn’t sound impossible. I would say that those aromas are unlikely to “blow off” with exposure to air, as the compounds are pretty stable, and just simple exposure to oxygen isn’t going to change them. There are some simple sulfur compounds that will be oxidized by air, but not the more complex thiols and thioacetates that are responsible for skunky, rubber tire smells.
Yes, I really like many brett beers. 2nd Shift’s Katy is a local favorite that produces mild sourness and a tough of band-aid with hits funk rather than animal/barnyard scents. The skunk smell I’m talking about from beer isn’t something I’ve found in a brett-innoculated Belgian beer but rather your typical German and Dutch lager (okay, Belgian too) that isn’t intended to taste skunky but gets that way from light exposure through the green glass. Heineken, Grolsch, Pilsner Urquel, Stella Artois, etc. IIRC the interaction of light with certain hop components causes the skunk smell. Apparently green bottles block less of the offending spectrum than do brown bottles. I’m not sure why brewers persist with the green bottles regardless. This is reportedly caused by interaction with hops so presumably wouldn’t explain a perception of skunkiness in wine. I also seem to recall that hops and pot are distant related so many none of that is particularly surprising.
Actually that aroma is even more often found in Mexican beers like Sol or Corona, because they are bottled in completely clear bottles that offer no protection whatsoever from UV rays.
You can get that kind of skunk in wines, but the lightstruck aroma is a bit different in wines than in beers: the hops that get the UV treatment become pretty obviously skunky, whereas wines that get hit by UV rays usually become somewhat funky, lose their fruit characteristics and turn slightly papery or cardboardy in character.
I actually did a little experiment a short while ago on this. I got two identical bottles os rosé wines from a wine importer. I put the first bottle immediately in a fridge, whereas I kept the other one in room temperature, not protecting it from UV rays or anything. I served them after 6 months of this kind of treatment in a blind tasting. No-one suspected that they were two same wines, but many thought they were from the same region because of the same acidity, alcohol and apparent ripeness. Most people believed that the UV one was aged in old oak because of its rather diminished fruit flavors and its cardboardy quality that was somewhat reminiscent of old wood.
I checked with Oliver and he confirmed that dolcetto does tend toward reduction. So perhaps a New World producer who wasn’t as familiar with the grape didn’t control that as well as he/she might have.
Preemptive apology for the thread hijack but does anyone understand why certain grapes tend toward reduction? You read that a lot in reference to Northern Rhône Syrah, for example.
Obviously wine making style can tend toward more or less reduction but I have long wondered what phytochemistry differences account for it across grape varietals.
Don’t really know about the actual chemical processes behind it, but there is certainly a tendency for other grape varieties to oxidize very easily and some grape varieties to be susceptible to reduction. If you make a Grenache and Mourvèdre in identical fashion, your Grenache might be on its way to oxidation, whereas the Mourvèdre might be very reductive and skunky.
This is also a) the reason why Mourvèdre-driven bandols can be so bloody ageable; b) why the classic Rhône blend is usually 50% Grenache (more prone to oxidation), 30% Syrah (somewhat prone to reduction) and 20% Mourvèdre (more prone to reduction). If you want to make earlier-approachable style, increase the Grenache proportion or reduce the Syrah or Mourvèdre proportion. And for more cellarworthy style, vice versa.