Do you prefer Synthetic Corks or Screwcaps?

Robin,

Diam is a bark produkt, but the treated bark granulate has given up practically all its bark qualities, negative (taints and aromas of all sort) and positive (elasticity).

Two independent studies, one in the UK, one in AU (AWRI) have proven the total absence of TCA and bottle variation.

Here's about the AWRI 36 months Diam trial:

http://www.drinksmediawire.com/afficher_cdp.asp?id=217&lng=2

[Robin Garr]

Diam is a bark produkt, but the treated bark granulate has given up practically all its bark qualities, negative (taints and aromas of all sort) and positive (elasticity).

Two independent studies, one in the UK, one in AU (AWRI) have proven the total absence of TCA and bottle variation.

It's interesting, Michael ... It sounds quite a bit like Amorim's "technical corks," although I believe they use natural cork ends. Are you aware of specific differences between Diam's "Diamante" process and Amorim's "ROSA," for which Amorim makes similar claims about extraction of TCA below the perceptible (0.5ppb) level?

The fact of independent tests is interesting, and certainly reassuring (particularly in terms of predecessor Altec's poor history for both TCA and corporate misstatements about it).

It's interesting, Michael ... It sounds quite a bit like Amorim's "technical corks," although I believe they use natural cork ends. Are you aware of specific differences between Diam's "Diamante" process and Amorim's "ROSA," for which Amorim makes similar claims about extraction of TCA below the perceptible (0.5ppb) level?

Robin, from the moment you use natural cork ends, you can never guarantee the absence of taint, be it TCA or other.

As to Rosa and others, they use steam cleaning. That process can remove between 75% (says Oeneo) and 90% (says Amorim) of detectable TCA. I don't know about random oxidation which seems to be even a greater concern to Kiwi winemakers than TCA.

Diam is a completely different process. Cork granulate is treated by supercritical CO2 (at pressures somewhere between 70 and 100 bar). Supercritical CO2 has the qualities of both liquid and gas, and it's just about the most potent solving agent known. The technology derives from aroma extraction for the perfume and the food industry.

After this treatment the cork granulate *is* 100% free of anything that might even resemble to an aroma or unwished microbiological molecule.

The fact of independent tests is interesting, and certainly reassuring (particularly in terms of predecessor Altec's poor history for both TCA and corporate misstatements about it).

Robin, past history is "snow of yesterday", as they say over here. Austria has had the chance of being spared by the Altec catastrophy, so this says little to me.

I like the new approach, and hope that it could be a way to persuade French growers of better wines to make a change, e.g. Frederic Engerer of Château Latour who even sees a question about screwcaps as a deep personal insult, or Paul Pontallier of Margaux who almost started to yell at me when I dared to ask . . .

Robin, there is a long thread about Diam on this Australian forum, including very informative comments from Oeneo's Australasia rep:

http://www.winestar.com.au/forum/viewtopic.php?t=11997&sid=baac1dba586da06830c81d2079311e80

I also posted a link over there leading to the discussion over here.

Diam is a bark produkt, but the treated bark granulate has given up practically all its bark qualities, negative (taints and aromas of all sort) and positive (elasticity).
[/url]

I'm wondering what the point is of using cork element in the closure since it doesn't contribute anything. Why not use just the elastic polymer?

Cork affects the wine it seals and contributes to the complex flavours of an aged wine. Some cork enthusiasts have told me that is one reason for their dislike of alternative screwcaps for long term aging because the wine wouldn't taste the same as if it had been closed with cork.

Diam is a bark produkt, but the treated bark granulate has given up practically all its bark qualities, negative (taints and aromas of all sort) and positive (elasticity).

I'm wondering what the point is of using cork element in the closure since it doesn't contribute anything. Why not use just the elastic polymer?

Because pure synthetics have proven to have far too high ox-trans rates. In other words: There are no pure sythetic corks that don't let the wine age prematurely.

Cork affects the wine it seals and contributes to the complex flavours of an aged wine.

Sorry, but that's simply not true. Cork does contribute flavors — sometime good, sometimes bad —, but never in a even near uniform way.

Some cork enthusiasts have told me that is one reason for their dislike of alternative screwcaps for long term aging because the wine wouldn't taste the same as if it had been closed with cork.

OK, let the cork dorks have bottle variation, taint and randox.

I am with Peter Gago, Penfold's chief winemaker, who has top reds under screwcaps for 11 and 12 years now. He told me: "The wines do age slightly different, like the wines in cool cellar compared to a normal cellar."

Everybody seems to love large format bottles because the wine remains fresher and more youthful. I have absolutely no idea why this virtue suddenly should turn into the most vile vice when screwcaps behave exactly the same.

I am with Michael Laroche (Revue du Vin de France, March 2005): "Last year I uncorked 40 bottles of a Chablis Grand Cru: 3 exceptional, 25 acceptable, 9 slightly, 3 heavily corked." This and an exceptionally well-showing Mercurey 1966, an experimental bottling of Université de Dijon, convinced him to go screwcaps.

I am with Hannes Gebeshuber, producer in Gumpoldskirchen, Austria, whose figures run remarkably well along Michel Laroche's lines: "We do extensive cork tastings. Overall, 10% are neutral or almost neutral; 10% are definively tainted, but with 80% we get a remarkably wide array of flavours one wouldn't call taint. And now try to chose the cork flavor type to the wine type — impossible."

Because pure synthetics have proven to have far too high ox-trans rates. In other words: There are no pure sythetic corks that don't let the wine age prematurely.

I am still no wiser. Why use cork granules when they do not contribute anything?

Ox-trans is surely a result of poor elasticity. If the only elasticity comes from the polymer, why not use all polymer?

Cork affects the wine it seals and contributes to the complex flavours of an aged wine.

Sorry, but that's simply not true. Cork does contribute flavors — sometime good, sometimes bad —, but never in a even near uniform way.

Well, it simply is true that cork contributes flavour to wine. I am not talking off flavours of cork taint, just the flavour of cork. Whether or not it is uniform, I don't know. But then trans-ox with a cork is not uniform, hence bottle variation.

Some cork enthusiasts have told me that is one reason for their dislike of alternative screwcaps for long term aging because the wine wouldn't taste the same as if it had been closed with cork.

OK, let the cork dorks have bottle variation, taint and randox.

Again, I am not talking about cork taint, TCA or anything other than the taste of cork.

I really cannot see why DIAM includes cork granules, other than to attarct cork fans, since their treatment of it removes all of corks attributes.

Peter,

I am not a specialist in plastics. I have no idea why Diam works while pure synthetics don't. That's the way it is, I cannot explain it further, please respect that.

As to the contribution of taste by the cork, bottle variation is real, hence it is proven that inconsistent taste input is a fact. By snipping the message of two respected producers touting the same message and telling that you don't know whether taste input is uniform or not is putting your head into sand. Bottle variation is not only a result of ox-trans. Ox-trans variations result in younger or older tasting wines, not in different or muted flavours.