Diam corks?

Closures (natural corks, screw caps, synthetic corks, etc.) are a controversial subject.

I had two experiences recently that made me wonder about what is best for fine wines.

First, a Burgundian producer told me that a fellow winemaker is unfailingly able to identify (blind tasting) wines from bottles with Diam corks. He says there is a characteristic reduction aroma (not that this is necessarily a bad thing).
I am not able to comment on this technical subject. What experience do others have?

Off on somewhat of a tangent, another winemaker referred to natural corks as “toxic”. He bottles virtually his entire (large) production with screw caps. He also said that experiments show that such wines age quite well, and retain more freshness than bottles with natural corks. He nevertheless pointed out that the degree of permeability is a major factor here, and that a hermetic seal is obviously not ideal for wines meant to last – and improve – for years.

Best regards,
Alex R.

Alex,

Interesting topic indeed - and one that I’m interested to be a part of for sure.

First off, the process in which DIAM’s are made - hitting tiny natural cork particles with super critical CO2 - has been shown to remove TCA but also to remove other ‘particles’ that provide ‘positive’ attributes to many of natural corks - a ‘woodiness’ perhaps, and some tannic compounds as well.

I have not heard of DIAM’s continuously leading to ‘reductive’ wines - that’s a new one and curious what others have found.

As far as natural corks being ‘toxic’ - well, that comment I just don’t get. Natural corks CAN be a great closure for wines to be consumed both in the near are far terms IF they are TCA free and if they are ‘consistent’ with their oxidative qualities.

Everyone on this board I believe knows that I am a proponent of screw caps, but not ‘blindly’. I will never say that they are the best or perfect closure because the variables involve with all closures makes it impossible to make that kind of statement IMHO. That said, as a producer of a consumer product, I feel ‘confident’ using screw caps both for near and far term aged wines and have used them for 13 years now - and I’m very happy with the results. I’ve been opening up some of the first wines I produced back in 2006 and 2007 and have been quite pleased with the aging trajectory I have seen. And for near term consumption, I can tell you that folks are oftentimes amazed that my 2011 or 2012 reds and my 2014 or 2015 whites are ‘that old’ and not 2016s or 2017s.

I think that DIAMs are potentially a fantastic closure - but I think it is still early in their lifespan and we just do not have enough datapoints to know what will happen with these wines over time.

Cheers.

Not sure what to do with unattributed, anecdotal comments…

Feels like [stirthepothal.gif]

Hey Alex,

I switched to Diam corks 5 years ago and I couldn’t be happier. I don’t have a strong bias toward any type of closure, although I do have a bit of a traditionalist bend, so sticking with a cork product was important to me. I just can’t go screw cap yet! Sorry Larry :slight_smile: I think possibly the best attribute of Diam’s is the consistency of the wines bottled with them. I have practically no bottle variation what so ever. At least that I have noticed.

I have never noticed a reductive note or any other aroma/flavor that was not in the wine to begin with.

As far as being able to unfailingly call out Diam blind… That’s an impressive trick.

Is he tasting only Burgundies? How many people there are using Diams? If the set of wines he tastes isn’t very broad, it’s possible the reduction is attributable to something other than the closures and he is just picking out the winemaking.

A lot has been published on this. I believe you can order your screwcaps with varying degrees of permeability.

I’ve never heard anyone argue that natural cork contributes a positive “woodiness” and/or tannins to a wine. Really? “Woodiness” sounds like an apt descriptor of TCA in some cases!

I love Diam; no TCA, and much better consistency than whole cork. We encourage our producers who haven’t switched to screw caps to use Diam. (I am only referring to actual Diam-branded corks, though, we have had the worst luck with other micro-agglomerates.)

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I think this idea that corks contribute some positive character to wine is one of the red herrings the cork industry is putting out, to distract from the essential problems with their product.

The so-called “corkions,” though there is debate about the name: cuarks and corkinos have also been proposed. Invisible, undetectable particles that are theorized to impart important flavor elements to wine. The wine industry has been quietly raising money and applying for federal grants to fund a major research project, which must be performed in ancient ice caves deep underground, to avoid the disturbance of magnetic brain waves emanating from zealous cork-believing winemakers at the surface.

I always enjoy the 100% guarantee. I would bet a zillion dollars he cannot do any better than statistically average in a blind tasting. That is utter and total horse-poop.

We have used Diam 10 and 30 for four vintages now. Still not much time in bottle obviously but the wines are fine and in the opening of 100s if not 1000s of bottles of wine we have encountered zero corked bottles. Maybe the corks won’t hold up as advertised over 30 yeas but regular corks don’t always hold up over that period either so I don’t know, other than some massive rate of failure in the next few years, that we would find them problematic at all.

Well, but that´s (imho) not the point to age bottles in the cellar for years - when they taste much younger after substantial time as they would under natural cork …

To DIAM: I´ve experience with 2 or 3 producers over some years now, and I haven´t experienced any negative effects so far (also no reduction taste) … the only thing I don´t know yet is: how long will they really keep tigh? 10-15 years is not long enough for me … (if I survive that long).

Nevertheless MUCH better than the “plastic stops” Ponsot uses … these show agressive acidity and almost no evolution after 8-9 years … I dislike them.

+1

(“I know a guy who knows a guy who says…”)

One does wonder, has anyone ever directly compared the diam corks to natural cork?

Have read a bit about differences in ageing and storing differences, but as far as I can see there are no long term direct comparative tests done.

I might be willing to “sacrifice” a couple of cases (red/white) that I have lying around that could be “retrofitted” with Diam corks and leave them for a decade or so. Perhaps we would have a conclusive “winner” then :wink:

Recorking would not be a true comparison.

I have wines finished with DIAM back to the 2008 vintage in my cellar. So far so good.

that’s encouraging. I’ve had only good experiences with diam but a friend did report to me that a producer he visited had been experimenting with them and claimed his wines developed an off odor after 5+ years under diam. I found this disturbing but cannot confirm from personal experience.

I know, more anecdotal whatever…

Depending on the producer, the cork type might not have been the problem. :wink:

I noticed with interest at the UGC that Domaine de Chevalier has gone entirely over to using DIAM with the 2016 vintage. I asked about it and they said in-house tests for ~5 years had convinced them it was the way to go.

My only extensive experience with DIAM is with Edmunds St John wines (who went over entirely to DIAM some time back) and I’ve never had any issues there at all — no off odors or tastes, no oxidized or prematurely aged bottles, and no TCA. The only question might be if the aging curve is changed, but too soon to tell.

And there’s a German retailer who claims that Diam taints wine and claims to have done blind tests where tasters could pick up the same thing in water exposed to Diam for a couple of hours. But, since no one else claims anything that extreme, it seems very dubious.

More of the story: Look for controlled tests.

But the fact that so many producers are happy with Diam after a decade is pretty compelling evidence in favor of the product.

I am always skeptical of anybody who claims to be “unfailingly” detect anything with wine tasting. I suspect in this case he’s telling a tall story.

Having said that, if Diam performs differently from traditional cork, it’s not unreasonable to suggest one might be able to discern a difference in the finished product. Logically, one would not expect two of the same wines under different closures to taste identical.

Exactly why I am skeptical of screwcaps. I love very old wine. I don’t want to open a wine I’ve aged for twenty years and find out it’s indistinguishable from one I bought last week.

“Perfect” corks allow essentially no oxygen penetration, according a cork industry study, so it’s not hard to imagine that the same wine under Diam and a natural cork could come out the same (unless you think the wine picks some good tastes/aromas from the cork).

It’s a persistent myth that corks allow in the perfect amount of oxygen. Many don’t allow any, and the variability is enormous.

(FYI, the study says that a small amount of oxygen contained between the cork cells enters the wine in the first six to nine months, but not after that.)



This ignores several things:

(a) You can buy screwcaps that allow differing amounts of oxygen penetration, so if the winemaker wants some oxygen ingress, he/she can have it.

(b) Oxygen exposure is only one of many processes involved in aging wines, and one of the riskiest. Lots of other changes occur that don’t involve oxygen, and thus may not be affected by the choice of closure.