TCA

originally posted by Oliver McCrum:
the curve of SO2 change under the Diam 5 is about the same as the average for bark corks.

That's not necessarily a particularly high bar to cross, just for the record.

Mark Lipton
 
Of course it isn't.

IMO pretty much everyone should switch to screwcap, which is far better in this regard and many others. I provide this information only because it bears on this discussion.

I should add that the reason I say 'he says x' is because I trust cork suppliers about as far as I can throw them. Before Diam was Altec, after all, which they represented as the last word but was in fact a disaster.

I want crown caps for sparkling wines, too, but I'm even less optimistic of that happening any time soon.
 
originally posted by Oliver McCrum:
Of course it isn't.

IMO pretty much everyone should switch to screwcap, which is far better in this regard and many others. I provide this information only because it bears on this discussion.

I should add that the reason I say 'he says x' is because I trust cork suppliers about as far as I can throw them. Before Altec was Diam, after all, which they represented as the last word but was in fact a disaster.

I want crown caps for sparkling wines, too, but I'm even less optimistic of that happening any time soon.

Is more about resistance from consumers or producers, or is it impossible to disentangle the two? I'd love to get more wines under screwcap and/or crown cap.

Mark Lipton
 
Many years ago I worked in a liquor store/wine shop in north Berkeley. One older subset of our regular customers bought the store brand of whiskey, gin and vodka, usually bottled in large bottles (1.75L). One day our supplier told us they'd switched to plastic bottles, because they were lighter (and no doubt cheaper). I was convinced that the regulars would rebel, but they were delighted; the bottles were more convenient.

Much of the trade (importation and distribution, I mean) is very conservative about screwcaps, but from what I hear the customers are for the most part ready to switch. I think we're the problem. In Italy there is the further complication of the DOC/G laws, which often stipulate bark cork. I have talked to my very good Prosecco di Valdiobbene DOCG producer about the possibility of completely downgrading the appellation they bottle under in order to use crown caps, we shall see.
 
originally posted by MLipton:
originally posted by Oliver McCrum:
the curve of SO2 change under the Diam 5 is about the same as the average for bark corks.

That's not necessarily a particularly high bar to cross, just for the record.

Mark Lipton
It isn't surprising either since AFAIK DIAM are not seeking a zero oxtrans but seeking to emulate the best of natural cork - just more consistently and with a guarantee of no detectable TCA.

I believe the top screwcap producers are seeking the same thing through liner developments in an effort to deal with the alleged reduction issues [and the considerable amount of chemical pre-bottling treatments practised by some producers] and the continued resistance in the market [presumably consumers and producers] to using screwcaps and DIAM for reds that are intended for long ageing.
 
originally posted by Oliver McCrum:
IMO pretty much everyone should switch to screwcap, which is far better in this regard and many others.

Interesting how this bored, in most respects the most piss & vinegar of 'em all, is relatively counter-revolutionary on the subject of corks, compared to, say, the more staid WLDG.
 
originally posted by .sasha:
Mark, I am going to start spamming this thread with EPL posts :-)

What, have I not lavished enough attention on the Jeebus bored of late? I'm somewhat surprised that you'd want to talk of the EPL given the early results...

Mark Lipton
 
originally posted by Oswaldo Costa:
originally posted by Oliver McCrum:
IMO pretty much everyone should switch to screwcap, which is far better in this regard and many others.

Interesting how this bored, in most respects the most piss & vinegar of 'em all, is relatively counter-revolutionary on the subject of corks, compared to, say, the more staid WLDG.
Some of us are exhausted on the question.
 
originally posted by MLipton:
originally posted by .sasha:
Mark, I am going to start spamming this thread with EPL posts :-)

What, have I not lavished enough attention on the Jeebus bored of late? I'm somewhat surprised that you'd want to talk of the EPL given the early results...

Mark Lipton

I could always blame it on closure in Wenger's water.
 
Two days ago I opened a bottle of the 93 Overnoy Poulsard, the selfsame that generated perhaps the most celebrated TN of all time. A shadow of lovely fruit lay under a thick haze of TCA. So I put a fraction into a decanter with strips of polyethylene and, after some twenty minutes, it was considerably less stiky (though still stinky). My question to the wise, or the savvy: if TCA is removed, is the wine left behind still compromised by years of coexistence between TCA and the aldehydes and esters and rebecas and whatnots? Or does TCA pretty much keep to its sulking self and, once it binds to the polyethylene, leaves behind a wine pretty much as it would have been without it? A secondary question would be whether any of the good stuff molecules might also bind to the polyethylene, throwing the ester baby out with the TCA bathwater?
 
originally posted by Oswaldo Costa:
Two days ago I opened a bottle of the 93 Overnoy Poulsard, the selfsame that generated perhaps the most celebrated TN of all time. A shadow of lovely fruit lay under a thick haze of TCA. So I put a fraction into a decanter with strips of polyethylene and, after some twenty minutes, it was considerably less stiky (though still stinky). My question to the wise, or the savvy: if TCA is removed, is the wine left behind still compromised by years of coexistence between TCA and the aldehydes and esters and rebecas and whatnots? Or does TCA pretty much keep to its sulking self and, once it binds to the polyethylene, leaves behind a wine pretty much as it would have been without it? A secondary question would be whether any of the good stuff molecules might also bind to the polyethylene, throwing the ester baby out with the TCA bathwater?

Seems like the time for an empirical experiment of your own, Oswaldo; what is there to lose?
 
I'm actually doing something of the kind, having poured the rest of the bottle into 187ml minis. I'll leave tonight's in the plastic for longer than 20 mins.
 
originally posted by Oswaldo Costa:
Two days ago I opened a bottle of the 93 Overnoy Poulsard, the selfsame that generated perhaps the most celebrated TN of all time. A shadow of lovely fruit lay under a thick haze of TCA. So I put a fraction into a decanter with strips of polyethylene and, after some twenty minutes, it was considerably less stiky (though still stinky). My question to the wise, or the savvy: if TCA is removed, is the wine left behind still compromised by years of coexistence between TCA and the aldehydes and esters and rebecas and whatnots? Or does TCA pretty much keep to its sulking self and, once it binds to the polyethylene, leaves behind a wine pretty much as it would have been without it? A secondary question would be whether any of the good stuff molecules might also bind to the polyethylene, throwing the ester baby out with the TCA bathwater?
Oswaldo, I have experimented in the past but no longer do so in any sustained way since I can never quite get over that smell and disappointment however much TCA the polythene [the secret is maximum surface area] manages to remove even after several applications. There is for me always something left [some TCA however diminished] and something missing [the intended TCA-free taste].

So, yes, I think, once sensed and confirmed as the odour becomes more obvious, the wine is inevitably compromised by the TCA that will not be completely removed however many polythene applications are attempted. So it is mainly the residual TCA not any chemical reaction between the TCA and the wine itself that will continue to affect the wine.

However I have known people with [relatively] high TCA thresholds claim that the polythene had removed all smell of the TCA for them - and that they were happy to drink the wine.

There may also be certain 'good' constituents of the wine [I don't know of any] that might also be adsorbed by the polythene but AFAIK not so that it would detract from the taste in anything like the way that TCA affects it. Put another way, I have placed polythene sheets into good wine and not noticed a significant difference between the same wine with or without the polythene treatment.
However it needs to be food grade polythene without its own scent of plastic otherwise that might provide an unwelcome addition. PVC which is widely used as clingfilm/wrap in the UK [although probably not in the USA] will remove TCA but the taste it imparts makes the operation IMO counterproductive.
.
 
Thanks, Nigel, that's helpful. Given that it's an Overnoy, I'm trying to reduce the TCA to a level where I can con myself into thinking that it doesn't prevent pleasure, an iffy quest at best.
 
originally posted by Oswaldo Costa:
Thanks, Nigel, that's helpful. Given that it's an Overnoy, I'm trying to reduce the TCA to a level where I can con myself into thinking that it doesn't prevent pleasure, an iffy quest at best.

So, what is the best approach? Use an impeccably clean glass roasting pan lined with the polyethylene to maximize the surface area? And original Saran is PVC, whereas Glad cling and new Saran Premium are LPDE (low density polyethylene; is one better for TCA removal than the other? (I am taking Nigel as saying PVC, at least the ones he's tried, impart flavor to the wine.)
 
I have variable results with original Saran Wrap (and much less effectiveness with other types). Sometimes after a couple of days, it does seem to remove TCA, although sometimes not. Even when it does, the wine seems slightly or more than slightly denatured, so to speak. I try this method fewer and fewer times now since I really don't get satisfactory results.
 
originally posted by Jonathan Loesberg:
Even when it does, the wine seems slightly or more than slightly denatured, so to speak.

That was my sensation last night, but it was hard to tell if it was a consequence of TCA removal or of the numerous other variables (extra day since opening, different foods, moods, and expectations, etc.), or even real.
 
originally posted by Oswaldo Costa:
originally posted by Jonathan Loesberg:
Even when it does, the wine seems slightly or more than slightly denatured, so to speak.

That was my sensation last night, but it was hard to tell if it was a consequence of TCA removal or of the numerous other variables (extra day since opening, different foods, moods, and expectations, etc.), or even real.

I am unable to say what is the direct cause. But since the process won't work without a couple of days of exposure to Saran Wrap, it doesn't much matter whether it is oxydation (not my impression), some other exposure effect or a side effect of the Saran Wrap. In Humean terms, the denaturing follows as an inevitable sequence and that's real enough for me.
 
Maximization of surface area occurs when you crumple up a big sheet of plastic wrap (I haven't done a study, but the original Jamie Goode post used LDPE, not PVC) and completely submerge it in the wine. If it's properly done, the removal of TCA should be complete within a minute or two, not days. The process can be sped up by stirring the wine within the container to move it over the plastic wrap. My own subjective analysis is that, though the TCA smell can be reduced or eliminated, the wine that's left is still damaged goods, less aromatic and fruity than an untainted sample.

Mark Lipton
 
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