Corks vs screwcaps - blind tasting @ Tablas Creek

WINE TALK
21

Tony,

I remember the whole Draper letter that was reprinted on the other board where he talked about their trials with all of the alternative closures . . . At the time, I think they were applying Vino-Seals by hand, leading to a lot of potential ‘oxidation problems’ that I do not believe he accounted for.

And with regards to screwcaps, there are obviously different liners that do allow varying amounts of oxygen in . . .

The mentioning of the AWRI Study by Henschke is interesting - the ‘take home message’ was that the best corks had the lowest levels of trans ox - very similar to the einws under screwcap with saratin liners . . . Not sure one should immediately ‘assume’ that if A = B and B= C then A = C here . . . but the logic is heading in that direction with regards to trans ox and its effects on wine development . . .

Cheers!

22

There’s quite a bit of Australian experience with parallel closure trials dating back decades now. The clear message for whites, especially riesling and semillon, is that the cork lottery is simply not worth it. Screwcapped whites, assuming no one stuffed up the sulfur regime, the bottling prep or the application (ie same things you can stuff up with cork), have been shown to age perfectly well, and more consistently than cork-sealed wines.

There are some people here of the opinion that they can accelerate the development (via oxygen ingress) of red wines through using a cork closure - presenting wines earlier that look better, as young wines, and favour cork for this reason. Personally, I would disagree, and think there is something a little strange about using a sub-standard closure to prematurely age wines so you can generate cash-flow.

If you use data sets like major wine shows here, the screwcap is clearly the preferred closure for the vast majority of Australian whites and reds, across all styles and pricepoints (sparklers a slightly different story - with takeup of crown seals and Diam corks).

A lot of winemakers here - people who really care about presenting their wines in the best possible way to drinkers, over the lifespan of the wines - will say that if it weren’t for some “backwards” markets overseas, they would do all their bottlings under screwcap, and give up on any use of cork at all.

23

In the August 20, 2007 APPELLATION AMERICA posting “To Screw Cap Wine Bottles or Not”, > Tablas Creek > Vineyard General Manager Jason Haas said, “Industry estimates range from three percent to as high as 10 percent of corks are tainted. Even at three percent, this is a very large number of bottles that are ruined each year. For a winery the size of Tablas Creek, this means that we could potentially release over 5,000 compromised bottles.”

To cork or not to cork? George Taber wrote the book on it. To cork or not - America" onclick="window.open(this.href);return false;

For lengthy “discussions” on TWBTSNBM, see also:
http://dat.erobertparker.com/bboard/showthread.php?p=2590647&highlight=paul+white#post2590647" onclick="window.open(this.href);return false;

http://dat.erobertparker.com/bboard/showthread.php?p=2506254&highlight=paul+white#post2506254" onclick="window.open(this.href);return false;

http://dat.erobertparker.com/bboard/showthread.php?p=2434449&highlight=paul+white#post2434449" onclick="window.open(this.href);return false;

24

This from Dr Ronald Jackson (Wine Report 2009, p. 390):

Oxygen and Cork

The relative merits of cork versus alternative closures will probably remain unsettled for decades. However, the debate has had a beneficial effect on research into bottle closures. The latest in a slew of recent studies has investigated how oxygen enters wine in stoppered bottles and the dynamics of the process. > Lopes and co-workers have discovered that most of the oxygen that enters wine closed with natural cork does so during the first month.

Subsequently, ingress falls sharply, becoming negligible after a year. > By comparison, technical cork (composed of cork particles) is far superior in limiting oxygen uptake, whereas synthetic cork is considerably worse.

Why does oxygen ingress vary so much over time with natural cork? Scientists cannot as yet give a definitive answer, but > a major factor probably involves the oxygen contained within the cellular structure of cork. > Cork consists of multiple layers of empty cells that act like miniature gas pockets. A cork of average length consists of a series of cells about 500 cells deep. When the stopper is compressed for insertion into the bottle, pressure on the air in each cell increases. This either diffuses outward into the surrounding air or is absorbed by the wine. Because air contains about 23 per cent oxygen, this can contribute several milliliters of oxygen to the wine. In contrast technical cork is made from cork particles and glue compressed together in a mould. That means that some of the oxygen in the cork cells is forced out during production. In addition, technical cork is less resilient than natural cork and is compressed less prior to insertion into the bottle. The greater oxygen permeability of artificial (synthetic) corks is undoubtedly explained by the slow but continual ingress of oxygen through the stopper.

Only with time, experience, and controlled study will the benefit/deficit consequences of limited oxygen ingress on wine development become clear. There is no perfect bottle closure, just options with different consequences – some good, some bad, some indifferent. > In the past, we experienced only the consequences associated with quality variations in natural cork. The wine world is much more complex today, with closure options now encompassing not only natural cork, but also hybrid cork, technical cork, a diversity of synthetic corks, glass stoppers, crown caps, and screwcaps. As the famous oenologist Vernon Singleton said years ago, “Wine is, and must remain, I feel, one of the few products with almost unlimited diversity…keeping the consumer forever intrigued, amused, pleased, and never bored.”

Instead of typing it out, I lifted it from the following blog:
Welcome at Flying Wine Writer | Jan Rook | Wijnplein" onclick="window.open(this.href);return false; [thumbs-up.gif]
Jamie Goode alluded to such research awhile back on TWBTSNBN [wink.gif] .

25

Nomacorc leads “major” [wink.gif] study into closures
January 7, 2009
by Richard Woodard

http://www.decanter.com/news/274824.html" onclick="window.open(this.href);return false;


According to John Casey:

Nomacorc’s belated foray into post-bottling chemistry seems more like a marketing ploy than an exploration of the boundaries of knowledge.
John Casey, North Ryde, Australia

Apropos nomacorc in a related thread this weekend
All Muscadet should be screwcapped! - WINE TALK - WineBerserkers" onclick="window.open(this.href);return false;

26

I’ve got about 8 bottles of 2003 Mitolo GAM bottled under screw cap left that were originally issued for the Australian market. Anyone in New York have a 2003 under cork that we can compare over dinner? I’ve got the 2004 under cork, but I do not think that is a good comparison for scientific purposes. The storage differences between the two 2003s will be more variability than I would like to have.