Sure - but are we now just talking about wines that develop secondary characteristics in the time frame discussed OR are we talking about such wines that are bottled using synthetics?
As for the former, I would point to many pinots, including KB’s from 04, 05 and 06, Rivers Maries from 05, some 05/06 Carlisles, and definitely Fess Parker pinots from 05 and 06.
As for the latter, I don’t have as much of a track record other than the aforementioned Fess Parker SBC pinots and syrahs . . .
Hoping others will chime in here - or perhaps we can start another thread away from the Agglomerate subject.
I would suggest that all of you folks have had experience with aged bottles sealed with “Aglo” corks- if you have ever had a bottle of Champagne with a bit of bottle age on it. Every Champagne cork is made in the same manner (and has been for decades and decades)- small bits of cork glued together to make the necessary shape to stopper up the bottle of bubbly and put the cage over the top to keep it in place against the pressure. So the glue is nothing new, nor is the technique. Champagne stoppers are a combination of two fairly thin slices of natural cork (one of smaller diameter than the other) on the end closest to the wine, with these two glued together and then glued to the ground up cork bits that have been shaped in molds to attain the proper shape and glued together as well. Nothing new in the process of gluing the small bits of cork together.
What is new is that Amorim in the last several years (and probably some of the larger firms as well now) have mastered a cleaning process for the bits of cork that removes 100% of potential TCA prior to their being molded and glued together. That’s the good news. But as others observed, these corks do not perfome the same as “single punch” natural corks, which contain significant “veins” throughout their membranes that act as avenues for oxygen ingress in the very early stages post-bottling, before the corks reach 100% humidity, at which point the oxygen transfer rate through the corks falls off precipitiously. All research to date strongly suggests that this initial period of oxygen permeability is one of the chief methods in which wines avoid potential reduction issues in their early post-bottling period. “Aglo” or “Diam” corks do not share this same early period of oxygen permeability with single punch corks, so there is a possibility that reduction issues could plague wines sealed under these corks over long term storage- though again, the experience with Champagne anedoctally suggests that this may not be an issue with Aglos.
But in terms of keeping a wine safe and sound until secondary and tertiary aromas can evolve with extended bottle age, these closures should be just fine, as long as reduction does not become an issue. (There are probably long-term aging trials underway with these corks.) Certainly they have a long track record with Champagne of acting as a sound closure over the long haul in terms of preventing oxidation of the wines. And they have the added benefit of not requiring any different treatment of the wine pre-bottling, as wines to be sealed under “Aglos” are handled exactly the same as those to be sealed with single punch natural corks; screwcaps currently demand a wine to be prepared in a different manner to hold off the potential onset of reduction. Domaine William Fevre has gone to “aglo” corks for all of their village and premier crus since the 2007 vintage, as a potential means of warding off premature oxidation, and I am quite sanguine that these wines will age very gracefully.
The photo posted above is of the lowest grade “aglo” corks- not all of them are this short, and higher grades are produced with a thin slice of natural cork on each end (in Champagne method) and called “Twin Tops”, which have a more appealing aesthetic that is much more in line with single punch corks. In fact, I have seen some well designd print patterns on some of these “Twin Tops” that make them virtually impossible to distinguish from single punch corks without breaking the cork in half to see that the center section is indeed small bits of cork glued together.
Good convo here. I’m still suspicious that the Diam/aglomerated corks maybe are not identical mechanically to traditional corks. Same material, but without the veins that John G mentions. Could this make a difference in how they plug the neck of the bottle?
It usually seems that ‘natural’ corks expand much more than agglomerated ones when I pull them out. I suppose that indicates they have more air pockets. Will these agglomerated corks form as tight of a seal at the cork-glass interface? I know this is important since that’s how rubber corks murder otherwise good wines via oxidation. Maybe Diam has already worked this out, though.
We started using agglomerated corks (Amorim Twin Tops) in 01 and used them on all of our wines through 06. I have been very happy with how the early wines have developed in the bottle and have had a string of really nice 02’s and 03’s lately that are still vibrant and fresh. Our incidence of above sensory thresh hold cork taint has been remarkably low (less than .5%), and agglomerates are extremely consistent. I switched most of our wines to solid cork in 07 simply because of consumer perception. I’m still sold on agglomerates.
I’ve had several wines recently that have had agglomerated corks, but haven’t looked closely to see if I could tell which manufacturer they came from. I’ve had some bad experiences with rubber “corks” on wines just a few years old, but the agglo corks sound promising. Here are links to a couple of the manufacturer web sites with some interesting high level info:
To John Gilman
I hope you don’t mind me using your post to expand on points you have made since the closure debate, heavily polarised as it is, needs as much information as possible. I apologise for the extended length but hope the additional information is of interest.
There is also the Diamant Mytik [the sparkling equivalent of the still-wine DIAM cork] which quite a few of the top Champagne houses are now using in place of the longstanding agglomerate cork with the two discs [rondelles] of natural cork which provide the interface between the wine and the main agglomerate part of the cork.
Amorim certainly introduced the ROSA steam process for natural cork some years ago [recently improved still further] which in conjunction with radically improved harvesting and storage procedures and high tech testing facilities [Gas Chromatography-Mass Spectrometry] has succeeded in reducing Trichloroanisole [the chemical responsible for most of ‘cork taint’] by around 80% from 2001 to 2008. Scott Laboratories and IIRC ETS Labs are also involved do routine tests for the US Cork Quality Council [the members being the main cork producers] on the imported cork bales and the average TCA level has been reduced from 4 parts per trillion in 2001 to 0.8 ppt in 2008.
DIAM corks are produced by an ex-natural cork company [and now a significant competitor, like screwcaps, to the natural cork companies] using a different process utilising supercritical carbon dioxide to purify cork granules which are then blended with a neutral, FDA approved food grade binding agent and patented micro-spheres to control permeability and then moulded into corks and sanded to precise dimensions to form the stopper – with a guarantee concerning TCA. These are now produced with a choice of specified oxygen transmission rates and have started to be used even by top Burgundy producers, particularly in Chablis.
A few Burgundy producers like Laroche are also using screwcaps and the latest closure type to hit the news is a special plastic design [with MIT claimed as a design participant] by the Italian company Guala called the ArdeaSeal with Laurent Ponsot [no less] apparently deciding to put his wines under this new seal. Olivier Leflaive is also using the closure for some of his wines.
My understanding is that the oxygen involved in the best cork closures is from within the cork itself not through the cork and a bottle properly closed with a quality cork has been shown to be impermeable to external gases and TCA. AFAIK the only ingress in testing has been at the glass/cork interface in the neck where there has been an imperfect fit. I would be very interested in references to research/testing that have shown cork itself to be permeable to oxygen or any other substances.
It seems likely that no other closure performs like natural cork which could be characterised as both its [as yet still not precisely defined ] outstanding strength - and its occasional weakness in the sense that the best corks have certainly kept [the best] wines and allowed them to develop to wonderful states over many years while other lower quality corks have not provided such an optimal basis without even considering the potential for TCA - although the huge improvements made in recent years will have greatly diminished that latter problem.
The question of oxidation under cork versus reduction under screwcap does not appear to have been argued over in anything like the same way as TCA [against cork] and reduction [against screwcap] has been – with both camps providing an excessive polarisation of that debate. Of course that’s inevitable when one side claims the complete wine solution when the truth almost certainly [at least currently] is ‘horses for courses’. Reduction is not unique to the screwcap but it is certainly more prevalent [as the several chemical treatments like copperfining and bluefining testify] and oxidation is certainly more likely with cork than a screwcap. Winemaking is one of the keys to optimising closure choice and cork has allowed winemakers centuries to adjust to that unique closure.
As a complete aside I wonder if, just as reduction under screwcap with its no/minimal oxtrans [although engineered oxtrans is being worked on] may be primarily a function of winemaking so premature oxidation, as has been experienced with white burgundy, may be, at least partly, a function of winemaking changes in the mid 90s [SO2 usage, wine presses/pressing more lightly, batonnages, etc etc] geared to produce earlier, easier drinking, more ‘natural’/lower sulphur wines and thereby unbalancing the old, long established chemistry vis a vis the cork closure.
AFAIK Fevre are specifically using DIAM corks at least I have only seen DIAM corks on my lower level Fevres although I haven’t opened any 2007s yet.
You mentioned that you were curious about synthetic corks and their oxygen transfer rates. From the data I have seen, in clinical trials they tend to allow (by a pretty wide margin) the most oxygen ingress of any of the main closures. The oxygen ingress tends to be quite constant over the life of the wine, and the wine tends to have a fairly short shelf life as a result. My assumption is that the difficulty comes at the closure-neck interface and that the oxygen ingress occurs between the synthetic cork and the bottle neck. The best study I have seen to date was completed a few years ago at the University of Bordeaux by Dr. Paolo Lopes (who now works in the research department at Amorim).
Hi Nigel,
Very nice post and thank you for adding and amplifying on the discussion here. You touched on one point about oxygen transfer of natural corks, in the context of this paragraph:
“My understanding is that the oxygen involved in the best cork closures is from within the cork itself not through the cork and a bottle properly closed with a quality cork has been shown to be impermeable to external gases and TCA. AFAIK the only ingress in testing has been at the glass/cork interface in the neck where there has been an imperfect fit. I would be very interested in references to research/testing that have shown cork itself to be permeable to oxygen or any other substances.”
There is actually a research paper that will be published quite soon by Dr. Alan Limmer (PhD in Chemistry and New Zealand winemaker) that I believe will show that oxygen actually does travel through the pores of natural cork’s membrane during its first few months in bottle, and that this migrant oxygen is probably greater than the retained oxygen in the cork’s membrane that is introduced into the wine at the time of the cork’s compression and insertion into the neck of the bottle. Natural corks go into a bottle quite dry, but over a few months pick up water from the wine and soon reach 100% humidity, where they remain for the rest of their lives in the bottle, if stored properly. The oxygen permeability rate of the cork falls a thousand fold once it has reached 100% humidity (governed by a pair of basic chemistry laws), as the oxygen now has to pass through the cork membranes occupied by water.
It is this change (from “open” membrane avenues in dry corks for the oxygen to pass through, to “closed” membranes occupied by the H2O in the 100% humidity corks) that is probably the primary cause for the OTR performance numbers of natural corks in Dr. Lopes’ study- where the OTR falls off dramatically for natural corks between the sixth and twelfth months of the study, and then levels off at these significantly lower rates for the remainder of the study (and presumably for the life of the bottle of wine). If memory serves me correctly, Dr. Lopes’ study indicated that the interface of the neck of the bottle and the natural cork was not the point of oxygen ingress if the cork has been seated properly in the neck.
I liked your point also about adjusted winemaking practices perhaps being a contributory cause for the premature oxidation issues plaguing certain white wines since the vintages of the mid-1990s- due to upsetting the established chemistry balance that had grown out of generations of winemakers using natural corks for closures and having just evolved into finding an equilibrium that maximized aging capability. Certainly when it comes to white Burgundy, the 1996 vintage was clearly a year where many winemakers used less SO2 than would have been used a decade previously- as the style of the vintage (very clean must, no botrytis, high acidity) should have been a perfect year to use less SO2 at bottling and still have the wines age long and gracefully. But one has to remember that this was not done universally, and premox issues have appeared in this vintage from most domaines that I taste at regularly, despite dramatically different approaches to things such as SO2 regimen, battonage, type of press utilized and the pressure used at the pressing.
And we have to remember that premature oxidation is not a phenomenon particular to white Burgundy- it is endemic in other wines from the same period, such as white Bordeaux and Savennieres for instance. Certainly white Burgundy has been the poster child for premox, but, in percentage terms, I have had an even higher rate or premox casualties with white Bordeaux from the same era. One just hears about it less because the quantities involved with white Bordeaux that are cellared are significantly smaller than with white Burgundies. I am not sure, but I suspect that the causes you listed above as potential contributory factors to premox are rather Burgundian-centric and not shared by winemakers in Bordeaux or Savennieres over the same time period (but I may be wrong on this). It seems to me that if we look at universally shared variables across the wine regions that have premox issues we are more likely to eventually find the cause of the scourge.
In any event, thanks for posting here, as you have added a lot of useful information to the discussion.
2000 Rex Hill Vineyards Pinot Gris (USA, Oregon, Willamette Valley) 7/30/2010 Atwellian FLAW
Artificial stopper. Bottle was badly corked. In fact, it provided a perfect tutorial for my daughter on what “corked” means; color, nose, taste
John, many thanks for your additional comments and the above specifically. I will be very interested in Dr. Limmer’s paper referring to oxtrans through cork which AFAIK will be something of a first although perhaps the controversy that began with the alleged 1000+ variability of cork oxtrans due to MOCON testing on dry corks rather than the [naturally wet] situation in a normally stored wine bottle would perhaps be a logical parallel to the point you are making.
The1000+ variability claimed with dry corks, which was used as evidence of [even good]cork’s abiding unreliability [versus the screwcap in particular], was shown to be irrelevant since the wet cork tests [by ETS labs et al] showed that the variability [as distinct from the level itself] was not significantly different to other effective closures.
I have also read Dr. Lopes’s papers and his oxtrans measurement methodology including the use of impermeable varnishes to isolate the potential transfer routes at the glass/closure interface in the neck and [through the] closure alone. I had thought those had indicated that while certain synthetic closures certainly allowed continuous oxtrans, good corks, from immediately after bottling, did not although there was the possibility of [some] oxtrans at the glass/closure interface – plus of course the transfer from inside the cork itself due to compression.
I have also read Dr Limmer’s [and others] several papers on reduction and SLOs particularly as they relate to screwcaps versus cork as well as his major role in New Zealand winemaking - particularly the saving of the Syrah stocks as they were about to be destroyed and his resultant part in the burgeoning success of Syrah in NZ.
I will be particularly interested to see if Dr Limmer’s paper indicates how long it takes for corks [presumably a range] to become impermeable due to the change in water content. And how this, presumably short, period of oxygen/air permeability squares with other statements from closure tests which concluded that ‘orientation’ of the bottle had no effect on the development of the wine.
And, laterally, how the only test on external TCA permeability I know of [by the AWRI using radioactively tagged TCA applied to the top of a cork in a closed bottle] concluded that TCA from an external source, like a contaminated cellar or OWC or the cork of an adjacent bottle, did not penetrate through the cork to the wine. Perhaps in the latter case the corks had already reached the impermeable state prior to the application of the radioactive TCA. Nevertheless it will be most interesting to see Dr.Limmer’s paper and any peer reviews.
You are of course right that the potential ‘causes’ of premox I listed were “rather Burgundian-centric” but it would be difficult to imagine that the full range [my examples were deliberately limited since the full investigation spectrum is huge] under investigation in Burgundy - viticultural, winemaking and bottling including closures - wouldn’t cover the possibilities for wines from other regions although the timing of any relevant changed practices in those regions might have been different from those made in Burgundy.
“The cause of the scourge” as you put it may have a main vector but the evidence so far suggests that it ii multi-factorial which is why I have suggested there may be a parallel in the reduction issues that can occur with screwcaps i.e. not so much a problem with the closure alone [as in TCA] but with the way the wine is made and how that ‘works with’ the closure.
It may be possible that changes made to white burgundy [and more widely including Bordeaux and the Jura as you suggest] with the clear objective of making earlier developing, easier drinking, lower sulphur more ‘natural’ wines, altered the very old, tried and tested chemistry vis a vis cork as a closure thereby, among other things, advancing an oxidation event horizon which was always there – just previously many years later.
While a wider examination than just Burgundy might indeed yield useful information, the bigger missed opportunity IMO was to have failed to do an intensive piece of research with Burgundy producers into what changes they made [and did not make] in their viticulture, winemaking, bottling and closures in the mid 90s. I have suggested this in all the major premox threads on the major websites in the US and UK only to be told that the producers would not have agreed to participate even anonymously. That may well be true but AFAIK it was never attempted and a large sample which included the best and worst performers [measured by reported pox rates for their wines] would have enabled a differential analysis to be done which would surely have highlighted ‘hot spots’ and provided a clear focus for further research. While we may well have ended up with the usual suspects there would at least have been much less surmise and anecdotal evidence held up against very limited knowledge of what producers did and did not do - and how many of them were involved [or not] in such changes.