Do note that during the super-critical CO2 process, many compounds are ‘stripped’ out of DIAMs, including TCA. Could phenolic compounds be stripped at the same time, thus preventing them from contributing in the way that Dustin mentioned? Curious to hear what you find out.
And as far as screw caps go, we’ll need to go round and round about this again. There is a transfer of oxygen, even with saratin closures. The AWRI study showed this back in the day and I’ve seen nothing to ‘dispute’ this. Sulfur compounds? Still not seeing this on a regular basis . . .
I will post the data I have ASAP. Still waiting on my source, and pinged him again earlier today. From what I’ve seen, the evidence for retention of compounds associated with reduction is high under screwcap. Which is not what I would call “bad” but leads to unpredictability in the aging process in comparison to historical data on how specific wines age. Say a Bordeaux that can improve for 50+ years under a clean and intact cork seal. I have no basis to say that different evolution that is different is or would be “bad”—but I don’t think it’s controversial to say it is likely not the same. It’s a different science experiment.
If commercially, screwcap makes sense for your wines, I have no basis to claim you are wrong or the data for your case is not there for you. I can only say we don’t know how the same wine (each different wine) under screwcap and under a perfect cork seal will age 10, 20, 30, 40, 50 years out. And I am personally interested in the long game view based on what I like to drink and when I prefer to drink it.
Not going in circles whatsoever - and yep, there is no research that has gone out that long. The landmark AWRI study only went out about 10 year - and not sure that they’ve kept it going (anyone know?).
One of the ‘challenges’ of a study like this would be to find ‘perfect’ cork - again, studies have shown how variable they tend to be, and getting ‘reproducibility’ in natural corks is very very difficult.
I also believe that most people have already made the determination beforehand that wines cannot age and continue to develop ‘as they should’ under screw caps - and I think it will be difficult to change their minds, regardless of what ‘research’ may show . . .
Instead of using the word perfect, I should have said “clean and intact” as previously in my post. No one is denying that cork has a natural variability and I suspect that specs, tolerances, and quality controls in the cork industry have changed and improved over time as discussed in part above.
My note specifically stated “screwcap serantin”. I was not generalizing screwcap because there are different liners. The data consistently show OTR of microagglo to be very close to serantin and therefore are more prone to developing reductive characteristics (and Larry there are plenty of studies that show the evolution in serantin to be very little if any). I am not hating on micro agglo corks (I sell millions annually) I think they are a great product for faster rotation wines despite what claims some brands of them make.
There is a 70% difference in phenolic contribution between a natural cork and micro agglomerated cork.
I was party to an exchange with people who have tasted the same wines bottled with natural cork and Diam. They noticed the “phenolic contribution” and distinctly preferred the wines without it, i.e., under Diam.
I have many bottles standing up in my locker, and I have never detected anything different about them than those on their sides. And given how little the wine penetrates a really good cork, I’m skeptical that the cork itself is contributing much if anything to the aging process - unless it’s some kind of catalyst, which I’ve never heard claimed.
there is a significant amount of phenolic compounds inherent in cork tissue (tests show around 40 different). There is a reaction of cork phenolic fractions with wine compounds that we believe contribute positively to wine evolution. We have an ongoing study that will be published and when that happens i will share more.
We have customers in Champagne that have always preferred to do the tirage with a natural cork instead of a crown cap and this led us to want to understand more what could be the positive contributions of wine aging with cork.
The compounds are far less (around 70%) with micro agglomerated cork.
I’ll take a stab: ‘last-ditch attempt to distinguish cork from more modern closures by persuading people of the implausible idea that packaging can and should add flavor, not just protect the product.’
I don’t think it’s realistic to expect someone whose livelihood is tied to natural cork not to defend it as a closure. Frankly, I think the cork producer’s big mistake was not getting into the alternative closures business early on as a hedge. Because eventually, I think they will go the way the buggy whip manufacturers did in the early part of the last century. It may take many more years, but it will happen eventually.
I notice you’re avoiding my point, and I don’t blame you. Would you care to address it? How many wine producers think that cork should add flavor? A sort of added overlay of terroir from Portugal or Sardinia, perhaps, to go with the added flavors of TCA and oxidation that we know cork already contributes?
I did not say that cork should add flavor… I said -
“Another important component which we are studying and believe based upon the results we already have is that there is a significant positive phenolic contribution of whole piece natural cork that you get very little of with micro agglomerated corks and obviously zero of that with plastic or screwcap closures”.
someone asked about microagglomerated cork and i mention the above and you twist into me saying cork should add flavor??
i am not here to defend my product or get into a cork vs X debate. As said previously, i think microagglomerated corks (diam included) is a good product and i sell in millions of them and the statement i wrote above was me sharing differences between microagglo cork and whole piece natural.
The OP was about premox and questions were raised by the OP related to the production methods of natural corks and i agreed with him to answer. If you have questions related to that, i would be happy to continue the dialogue.
FYI, Michel Ampeau checks every bottle in front of a very strong white light before shipping orders. I’ve been there while he was doing it, and asked about it. He said it was to find his oxydised bottles so they wouldn’t get shipped. According to him, up to half the bottles are rejected, depending on the wine’s age.
“Though I continue to believe that the seal is the only sensible/logical explanation for the variability of bottles (which is the whole premox-plague: the variability of bottles that turn bad and others don’t).”
Though it would make sense that the only logical explanation for the variability of premox expression bottle to bottle is the cork (assuming that a case with several affected bottles are all from the same barrel, and thus barrel variability would not account for bottle variability), that does not mean that it necessarily accounts for the “whole premox plague”. You could theoretically have a factor or variety of factors that make the wine more vulnerable to premox, and the cork could account for the variability of expression or degree of,oxidation from bottle to bottle within a case.
This is exactly what I’ve always assumed to be the case: there are one or more issues, apart from the cork, that have changed and are responsible for the higher incidence of premox; and the cork, whose variability was not nearly as important in earlier times when those factors weren’t present, has now become the last line of defense - so it’s vulnerability has been exposed with a bright light. My own opinion is that blaming cork is the wrong answer, though it does illuminate the frailties of cork as a closure.
If he’s rejecting up to half the bottles, I’d submit that M. Ampeau is not the person we should look to (per Stuart’s suggestion) for the solution to the premox problem!