Ever create a corked wine indicator?

I may be tasked with creating the smell of a corked wine in the not too distant future. Other than setting some newspapers out in the rain for a day or two then sealing them in a plastic bag for another day or two, anyone have any simple ideas how I could do this?

Well a cheat would be to use the fault kit of "le Nez du Vin" which has cork taint as one of it's scents.

regards

Ian

I was part of a tasting group that did this some time back. We bought a TCA analytical standard from Sigma Chemicals. I then diluted that down to a level that was convenient for spiking bottles of wine. We bought several bottles of the same wine and spiked it at levels from 5 to 100 parts per trillion. It made for a fun exercise.

Just be careful not to do this experiment in a winery, in a wine cellar or in a wine bar because once released, TCA taint can spread and multiply rapidly, this in turn impacting on many, many other bottles other than those under experiment.

Best
Rogov

Just be careful not to do this experiment in a winery, in a wine cellar or in a wine bar because once released, TCA taint can spread and multiply rapidly, this in turn impacting on many, many other bottles other than those under experiment.

Best
Rogov

Daniel, while your general advice seems eminently reasonable and airborne TCA can certainly infect wine that is open to the air I have seen no studies showing that TCA 'multiplies' - if by that you mean that it grows in concentration or becomes more plentiful when escaping from an open bottle of 'corked' wine .

In addition, airborne TCA has been shown [in tests by the AWRI using radioactively tagged material] not to penetrate the corks of closed bottles of wine. Of course I am assuming your 'many, many' comment implied these bottles were not open.

[Jenise]

I was part of a tasting group that did this some time back. We bought a TCA analytical standard from Sigma Chemicals. I then diluted that down to a level that was convenient for spiking bottles of wine. We bought several bottles of the same wine and spiked it at levels from 5 to 100 parts per trillion. It made for a fun exercise.

Was this so that each of you could test your own sensitivity? Any surprises in the group? (Would love to have put our dearly departed Richard Morgan to that test.)

That was it, Jenise. We gave everyone glasses with the different levels of TCA spiked into them. There were no real surprises - the folks who tended to pick up on TCA in regular wines were able to smell it in the spiked wines at low ppt levels. I was barely able to detect it in the highest level wines.

Lots of fun, though, and recommended for the more geek-oriented tasting groups.

That was it, Jenise. We gave everyone glasses with the different levels of TCA spiked into them. There were no real surprises - the folks who tended to pick up on TCA in regular wines were able to smell it in the spiked wines at low ppt levels. I was barely able to detect it in the highest level wines.

Lots of fun, though, and recommended for the more geek-oriented tasting groups.

Mike, did you mean "smell it in the spiked wines at low ppt levels" or was it that they were able to call TCA based on some other [than smell] characteristic like 'muted fruit'?

Can you also give us some extra data e.g. you say you were "barely able to detect it in the highest level wines" [not that unusual as you will know] but what was the 'highest level' you used. And the lowest level? And was there any sort of distribution around a mean and if so what was it?

How many non-spiked wines were the TCA samples placed among i.e. what percentage of the total tasting were the spiked samples?

A very interesting exercise and thanks for reporting on it. Final question: since you are referring to parts per trillion what equipment was used to spike the wine to specific levels and how accurate do you think it was? Many thanks.

[Jenise]

That was it, Jenise. We gave everyone glasses with the different levels of TCA spiked into them. There were no real surprises - the folks who tended to pick up on TCA in regular wines were able to smell it in the spiked wines at low ppt levels.

What might have been fun--or at least useful, anyway--would have been to prove to someone who would argue with you that a wine wasn't tainted while admitting that he'd never smelled cork taint (and that was our Richard). But aren't you the lucky wine to have the higher tolerance? You're almost never disappointed.

Nigel -

This was an informal evaluation that we did a few years back, so I'm a little hazy on the details. IIRC, we had six examples of spiked wine ranging from 0 to 100 ppt of TCA. Everyone got samples of all six and attempted to determine which contained TCA strictly by smell. I think there were only six or seven of us in the group, so there was no statistical evaluation done or anything like that. Some people were able to detect the TCA in all of the spiked samples. I was only able to get it in the highest level one. I made the dilutions using equipment in the lab where I work. This would include Hamilton microliter syringes, analytical balances, etc. I work in an analytical lab, so I'm pretty comfortable with that sort of thing.

Jenise - My results were consistent with a much more detailed look at TCA sensitivity that I participated in. Yeah, I can drink wines that no one else can stand to be in the same room with.

I may be tasked with creating the smell of a corked wine in the not too distant future. Other than setting some newspapers out in the rain for a day or two then sealing them in a plastic bag for another day or two, anyone have any simple ideas how I could do this?

Hi Jon - a couple of ideas

Go to your friendly retailer and asked if he/she has had any corked wine returned, then take a small sample to keep in a vial without too much airspace for oxidation.

Drop some swimming pool water into a glass of wine - the chlorine in the water can react with the wine to create TCA-like contamination.


Cheers,
Sue

FYI, if you go to the website for the Society of Wine Educators (http://www.societyofwineeducators.org) and contact them, they will sell you packets of most of the ingredients to produce the most common flaws to be found in wine. Including cork taint.

The kits come in tiny plastic vials, and you also get instructions to add certain amounts to create slightly over normal thresholds for each charactersitic, condition, or fault.

People going for their CSW or CWE can practice at home that way, so as to get better at identifying characteristics. (One portion of the CWE exam is identifying characteristics or faults/flaws. Usually there is a base neutral wine,then a series of 'doctored' wines, and you have to identify which is which.)

The kits are not expensive. And they are made to rigid standards in a lab, in order to be used for testing purposes.

And they can be fun with/for wine geeks.

They also sell sensory/aroma kits, created by a master perfumer in New York, consisting of essences of many of the most well known and often used descriptors. I have a popular seminar I developed with a previous company. It's called The College of Nasal Knowledge, and it's fun for participants, with anywhere from 8 to 16 'doctored' wines, both red and white. And it's amazing how poor most people are at identifying aromas---even very common ones.

Nigel -

This was an informal evaluation that we did a few years back, so I'm a little hazy on the details. IIRC, we had six examples of spiked wine ranging from 0 to 100 ppt of TCA. Everyone got samples of all six and attempted to determine which contained TCA strictly by smell. I think there were only six or seven of us in the group, so there was no statistical evaluation done or anything like that. Some people were able to detect the TCA in all of the spiked samples. I was only able to get it in the highest level one. I made the dilutions using equipment in the lab where I work. This would include Hamilton microliter syringes, analytical balances, etc. I work in an analytical lab, so I'm pretty comfortable with that sort of thing.

Jenise - My results were consistent with a much more detailed look at TCA sensitivity that I participated in. Yeah, I can drink wines that no one else can stand to be in the same room with.

Mike, thank you for this and please just ignore my further questions if you cannot recall the info particularly since it happened happened several years ago. However the 0 -100 ppt is already interesting since most of the detailed lab-backed studies I have read [and posted on here] have also shown enormous variation in individual TCA thresholds.

Could I ask again though please, was the detection, particularly at the lowest levels [can you recall what that was?] always by smell [as you first indicated] or were there some who sensed the contamination by detecting some other fault e.g. the wine tasted muted of stripped of fruit? You say that you could only [just] detect TCA at the highest level [even though you knew it was there in most of the samples] - but was your detection by smell alone or do you experience/sense some other negative feature before, or even when, you smell TCA itself?

Additionally, you have said that one/some? of 6 samples of wine given to each participant had 0 ppt [the rest up to 100 ppt] so can I assume that only 1/6th of all the wine sampled wasn't spiked? Do you think that might have affected those who sensed/smelled TCA at the lowest levels or were you the only person who knew that there was only one sample that wasn't spiked?

A more expensive way could be to buy a couple of Henri Bonneau bottles. You could enjoy the good ones - if any - and use the bad ones for your experiment. One may even suffice, if you are not unlucky that is.
Seriously, I have used the likes of the packets Hoke was talking about and with great effect.

Greetings from Sweden / Fredrik L

Nigel -

Everything we did in that exercise was by smell. Although the TCA levels were low and I don't think it's toxic, I preferred that everyone just smell the spiked wines rather than taste them. Therefore, scent was the only clue we had.

I can't recall for sure how blind the test was. IIRC, I didn't let anyone know the TCA levels prior to their evaluations but I don't remember whether they knew there was a negative control or not.

My thanks to all for your ideas, most of which I never would have thought of.

Nigel -

Everything we did in that exercise was by smell. Although the TCA levels were low and I don't think it's toxic, I preferred that everyone just smell the spiked wines rather than taste them. Therefore, scent was the only clue we had.

I can't recall for sure how blind the test was. IIRC, I didn't let anyone know the TCA levels prior to their evaluations but I don't remember whether they knew there was a negative control or not.

Mike , thank you again.

You're right, TCA isn't toxic - certainly at anything like the levels present in wine. My interest in the subject is presumably obvious but I am particularly interested in those who call TCA without ever smelling it i.e. based on taste alone without any corroboration from smell either at the time of the call or later in the test. Obviously that isn't relevant in your experiment.

However can you recall any anomalies e.g. a TCA call against a zero sample or a situation where someone could smell TCA at low levels but not at a high one?

Nigel -

I don't remember anything that seemed very anomalous. I'm pretty sure that no one thought the negative control contained TCA and that everyone other than myself picked up on it somewhere between 5 and 20 ppt. This was a group of very experienced tasters, though. And heck - you can't say much with n=7.

Nigel -

I don't remember anything that seemed very anomalous. I'm pretty sure that no one thought the negative control contained TCA and that everyone other than myself picked up on it somewhere between 5 and 20 ppt. This was a group of very experienced tasters, though. And heck - you can't say much with n=7.

Mike, I understand and thank you.

Nevertheless 5-20ppt covers most of the published sensitivity threshold results for individuals within expert panels although there were/are individuals to both sides of that range. And of course some who never really 'get' it.

There are similar situations with other wine aromas such as brettanomyces and sulphur like odours from reduction where the concentration of the chemicals varies the experience [sometimes from pleasant to unpleasant] even for experienced tasters - as well as the wide range of individual sensitivity thresholds all the way to anosmia.

I may be tasked with creating the smell of a corked wine in the not too distant future. Other than setting some newspapers out in the rain for a day or two then sealing them in a plastic bag for another day or two, anyone have any simple ideas how I could do this?

Jon, if only I had known this a couple days earlier. If I had, I could have sent you that bottle of Guy Brossard muscadet I poured down the drain.

I did the same as Filigenzi back in the early 90s. I still have some crystals of TCA. A small crystal goes a long way dissolved in water. It will thoroughly stink up wherever you store the canister if it is not hermitcally sealed.

My vial of TCA is inside of a sealed jar in the back of one of the fume hoods in the lab.

FYI, if you go to the website for the Society of Wine Educators (http://www.societyofwineeducators.org) and contact them, they will sell you packets of most of the ingredients to produce the most common flaws to be found in wine. Including cork taint.

The kits come in tiny plastic vials, and you also get instructions to add certain amounts to create slightly over normal thresholds for each charactersitic, condition, or fault.

People going for their CSW or CWE can practice at home that way, so as to get better at identifying characteristics. (One portion of the CWE exam is identifying characteristics or faults/flaws. Usually there is a base neutral wine,then a series of 'doctored' wines, and you have to identify which is which.)

The kits are not expensive. And they are made to rigid standards in a lab, in order to be used for testing purposes.

And they can be fun with/for wine geeks.

They also sell sensory/aroma kits, created by a master perfumer in New York, consisting of essences of many of the most well known and often used descriptors. I have a popular seminar I developed with a previous company. It's called The College of Nasal Knowledge, and it's fun for participants, with anywhere from 8 to 16 'doctored' wines, both red and white. And it's amazing how poor most people are at identifying aromas---even very common ones.

Hoke, I went to the web site and couldn't find a link. Now I see you probably meant I have to do the "contact" thing and then tell them what I want.

Yep. But you do get to talk to a live person that way, Bob.