I have been meaning to post this for a while now, but the issue is becoming more and more prominent that I need to say something now, before any more wines get hurt.
Some years ago I was fortunate to taste some trials which Michael Brajkovich MW (with some industry colleagues) had conducted comparing Diam corks with other closures. In that instance, me and a couple of my buddies were able to identify which sample had been closed by Diam, against screwcap and natural cork.
The problem with Diam then was flavour scalping. There was a definite loss of something – it was very difficult to say exactly what, but the Diam bottled wine seemed less bright and less aromatically interesting than the wine sealed with other closures.
I had completely forgotten about this until a couple of years ago when I purchased some white Burgundy from one of my favourite producers. I got the case home, whipped the top off and poured some wine to my dinner guests. Immediately I noted that something was wrong. This was a 2012 and obviously not nearly an alike vintage with the 2010 that I had been drinking up to that point, but it was vastly different from how I remember the wines from this producer.
Then I took a look at the cork that I had pulled out of that bottle. It was a Diam. This was the same cru, same wine, no change in production methods, just a different vintage, and a different means of sealing the bottle.
I had not thought that a closure would make such a big difference, but there it was. I was especially surprised that with a wine style like white Burgundy this would even be a critical factor, but thinking about it, one of the things I love about white Burgundy is the aromatic profile. Using Diam can be a massive compromise to that.
We are increasingly seeing Diam across a number of different regions and styles. J J Confuron is now using it for Premier Cru wines (I cannot afford the Grands Crus from this domaine so cannot tell you what kind of cork is there.) Diam may well be an ok alternative to lower value or entry level products, but for fine wine there has to be a big question over its long term viability. Michael Brajkovich MW tells me that there are higher grades of Diam now that may have better bonding agents and therefore less potential for scalping, but the highest grade that I have seen here so far is Diam 10. But I recently opened a case of a very flash Piedmontese wine from a famous producer and that had a Diam 6 in it. And the wine was not how I remembered it from last year’s vintage (which had a natural cork.)
My preference is either a screwcap or a good (i.e. uninfected) natural cork. From now on at this blog I will be noting whenever a wine is sealed under natural cork, Diam, or any other kind of cork. If I do not mention the closure then please assume that it is under screwcap.
And I would be interested to hear of anyone else’s experiences with Diam.