WTN: Is it noble mustiness or TCA on this white port?

Andresen’s "10" Ten Year Old White Porto – Alc. 20%.

The nose of this white port was impregnated with a quite pleasantly musty and fungal aroma, which reminded me of fresh walnuts but also of some manifestations of TCA. This aroma was only dimly perceptible on the palate’s after-taste in the form of nuttiness but it was my first knee-jerk reaction to reject this bottle. Then I read the tasting note on the bottle’s front label, as follows –

“Very attractive golden yellow colour with pleasant aromas of dried fruit and raisins, ripe quince and a hint of honey and wild flowers. This old White Porto shows the typical mustiness of the typical 10 year old Tawny Porto, well matured, but more delicate and only slightly less complex. An exquisite Porto.”

This is a very accurate note and, once I set aside my prejudice about the musty nose, I greatly enjoyed the port. Indeed the bottle (50cl) still contains enough for two small glasses, which could turn out to be even better than on the first and second evenings.

Still, I find this difficult to rate. Let me say 15.5/20, being a compromise between 14/20 for the nose and 16.5/20 for the palate.

I can't answer not having smelled the wine, but the following info has been useful in resolving such mustiness/TCA questions, arising in the regular ongoing blind tastings I attend with very experienced people.

A TCA metaphor I use that others have found apt is cardboard mildewed after being wet with chlorinated swimming-pool water. Some people may like that language because it's vivid, but its point is to include elements some descriptions omit, and here we get to the point useful in discerning TCA cork-taint smell from simple mustiness or mildew (which surface as faults too, in some wines).

For TCA to form by the usual route in corks requires both the organism that generates it and available chlorine (typically from a cleaning agent in cork production, I understand). TCA smell has a chloriniferous edge, like chloroform and other simple chlorinated hydrocarbons. Everyone has smelled this edge who's been in a bathroom cleaned with chlorine bleach, or near a chlorinated pool. In those situations you may also smell free chlorine gas, but light organic molecules that become chlorinated have a distinct smell feature you can come to know if you encounter them. Some of those molecules are used in pure form as common organic solvents, and while those tend to be toxic, not something you want to smell much of, I find an olfactory feature common to all of them that I call a chlorine-bearing edge. It usually distinguishes TCA from other smells that otherwise overlap it. (In the table wines I know, TCA fault has other typical symptoms too -- it develops in the aroma on standing in the glass, and unless very faint it perceptibly suppresses fruit in the flavor.)

Anecdote: A capable US winemaker I sometimes taste with makes long-aging wines and is determined to avoid TCA. As part of quality control, his staff takes sample lots from each new batch of corks and immerses them for a period in clean Chardonnay wine. If any TCA is present, they can detect it this way. But the side story is that the resulting Chardonnay is the oakyest anyone has ever seen (because, he reminds us, the corks are made from oak trees).

Now I have a question for anyone who knows: Is TCA is as frequent in fortified wines as in regular table wines?

Thanks for that, Max. I do not think that the aromas in this port had a chlorinated edge but then I don't particularly associate that with the hundreds of mildly corked table wines which have come my way. A sometimes elusive whiff of dry cardboard is my commonest experience. The best test is to compare two bottles of the same side and that does not eliminate the possibility of contamination in the producer's cellar or a batch of defective corks. When I once complained about fungal flavours in a wine, someone on another board suggested the presence of "butandiole" rather than TCA; do you know what this is?

The offending aroma may well be a cellar or barrel generated flaw of which the producer is aware and which he is trying to pass of as "typical of 10 year old tawny port". BTW, I have drunk quite a lot of tawny and have never encountered more than mild nuttiness before.

Tim - I too found the comment about the typical mustiness of 10yo tawny port a bit strange. It is not a tawny port descriptor that springs to mind! I haven't heard of butandiole before, but there are certainly a number of different musty chemicals in addition to TCA - and I believe a number of them can get into wine from the cork.

Max - I think in the past the chlorine in TCA may have originated from the solution used to strerilise the cork, but as far as I know this is no longer practised. But there are other sources - environmental and as the result fungal infection according to Jamie Goode. Pesticides used on the tree too, I think I read somewhere - I wonder if that is what Jamie means by "environmental".

From what I've read on the subject, the use of chlorine-containing pesticides in cork forests was thought to be a contributory factor, but the truth is that there's plenty enough chlorine present environmentally for fungi to use to create TCA and related haloanisoles without chlorine-containing chemicals in the forests or cork factory.

In total, more than 2,000 naturally occurring chlorine compounds have already been identified.

Salute

Tim,

I've never heard 'mustiness' used as positive, and I wonder if you're right, that they're passing off a mild defect as a benefit. I've had wines matured in old large barrels that had a faint shadow of mustiness over them that resembled faint cork-taint (and the winery had replaced the large barrels recently, so more recent vintages lacked this shadow).

A “mustiness” aroma (whether it’s somewhat pleasant, negative, or “shadowing”) could also result from the wine “sitting” on its lees or sediment for a “long” time.

Salute

Returning to this discussion of smells, after an absence:

... I don't particularly associate [a chlorinated edge] with the hundreds of mildly corked table wines which have come my way. A sometimes elusive whiff of dry cardboard is my commonest experience.

I'm interested in this, because I often hear people describe (what we usually call) TCA fault as smelling to them like cardboard, sometimes wet cardboard. To my nose, cardboard is an incomplete smell model because a clear TCA fault also reminds me of mildew or mold, with a subtle aspect that for lack of better language I called chloriniferous edge. Not a gross halogen smell like Chlorine or Iodine, but a smell cue that I find in harsh form in halogenated solvents, in subtler form elsewhere. Maybe it's an individual idiosyncrasy. In the same way, oysters, crab meat, and fish eggs certainly taste different to me (and have different textures of course), but to different degrees, all share some breath of the sea. That's the sort of commonality I'm trying to evoke with "chloriniferous edge."