Wine Trivia – Tech Controversies

Wine trivia, gifts, accessories, and technical aspects of wine production of interest to wine enthusiasts posted before this blog was born (November 2009) appear on this page, after links to more recent posts in this category:
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DIAM corks

14 September ’09

Wine closures have come in for a lot of scrutiny lately. Corks aren’t perfect, but is anything else better?

DIAM technical bottle closures are made in Spain from plastic micro-spheres combined with ground up natural cork. After being ground up, the natural cork component goes into a gigantic hopper (several stories tall). Carbon dioxide is injected at the bottom of the hopper in a very unusual condition: under more than 1,400 lbs-per-square-inch of pressure, and nearly 100 degrees Fahrenheit temperature. At that point carbon dioxide is in a ‘critical’ state between a liquid and a gas. The carbon dioxide rises to the top of the hopper as the pressure on it is gradually released. As the carbon dioxide passes through the cork it removes a number of compounds, most notably trichloroanisol, otherwise known as cork taint.

DIAM closures are then formed by heating the now clean natural cork particles with the micro-spheres and a little food-grade binder. The micro-spheres expand in the heat to fill the spaces between the granules of natural cork – think of a balloon being inflated in an irregular space. DIAM closures compress, and bounce back, like natural cork. But they cost about half of what wineries expect to pay for natural cork. And DIAM closures do not require a special bottling line, as a screwcap-type solution would.

Avoiding the risk of cork taint is only one closure consideration. Another important one is Oxygen Transfer Rate (OTR). Plastic corks have a fairly high OTR. They are best suited for wines which will be consumed within a year or two of release. Of course in the U.S. that covers the vast majority of bottles. Screwcaps come in two configurations: those with a plastic ring being held in place by the screwcap do have some OTR; while those with a saran/tin ring have no discernable OTR. The first type are most commonly found in Europe; the latter in Australia and New Zealand. Something between 85% and 90% of wines bottled in New Zealand now sport screwcap closures.

Natural cork falls somewhere between screwcaps and plastic in terms of OTR. So do DIAM closures. The difference is that DIAM claims to be much more consistent. DIAM comes in three forms based on degree of OTR. Natural cork is thought to be something more akin to rolling the dice on OTR. To pursue this line of inquiry, DIAM would like to fund some research at an independent lab comparing several bottles of the same wine (across a sample of some one hundred different wines). Analysis, both organoleptically by humans and mechanically by gas chromatograph machines, would document whether or not this claim for consistency is valid. That’s some research I’d like to see.

I’d also like to see research of that type done on bottles sourced in different cities. Of course it would be more of a commentary on distribution mechanics than on closures, but immensely entertaining nonetheless.

CA State Fair Wine Competition .2

22 June ’09

In 2008 a Two-Buck Chuck wine went Double Gold at CA State Fair. Does that mean judges there are bozos?
Turns out CA State Fair wine judges are more reliable than you might assume.

The CA State Fair hosts the oldest wine competition in North America. Obviously it is, in part, a promotional effort to boost an important segment of the state’s agricultural economy. Perhaps half the state’s wineries, around 700, participate most years. In fact over a million dollars (in aggregate) is spent on entry fees, not to mention the cost of the wines and shipping, at just four of the wine competitions held in the state each year. Unfortunately, it is an extremely rare occurrence for a single wine to win a Gold Medal in multiple competitions. Why would that be? Does the fault lie with the wines being entered, or with the quality of the judging pool? Five years ago the State Fair Wine Competition began secretly testing their judges for consistency in an attempt to shed light on these questions. The results are now being published in the Journal of Wine Economics.

The methodology was pretty straight forward. Judges were served triplicate samples of the same wine, poured from the same bottle, and served in the same flight of wines. Most of these flights contained around 30 wines overall. Some examples of extreme variation in medal awards were recorded, but these were not the norm. “Most judges were consistent in marking scores within a single medal range,” explain the author of the preliminary study, Dr. Robert Hodgson from Humboldt State University. “And panels were even more consistent than individual judges.” [cf: The Wisdom of Crowds by James Surowiecki, economics columnist at the New Yorker] Interestingly, individual judges were most consistent on what wines they did not like; less so when it came to wines they did like. Judges at the State Fair peg scores or awards to a scale with eight units of discrimination. For at least half of the test comparisons individual judges gave all the triplicate wines scores within two units of discrimination. That’s within the bounds of a single Medal category. That’s a pretty good outcome. Panels, however, gave scores to the triplicates within one unit of discrimination at least half the time. That’s a better outcome.

The bad news came the next year when advisors running the study were eager to see if the most consistent performers (dubbed “Super Judges”) would again out-perform the field. If so, improving the Competition would be a simple matter of gradually weeding out the weakest judges. Alas this desirable result was not to be. The statistical correlation between consistency of specific judges one year to the next was even slightly negative.

At the end of the day, “judges do not give medals; panels do.” Over 90% of the panels had a range on the triplicates that was well within the breadth of a single medal. Provocatively, however, the range of panel scores on most wine triplicates increased after panel discussion when pre- and post-discussion scores were compared.

1999 Behrens & Hitchcock (Kenefick Ranch) Cabernet Sauvignon

30 March ’09

Plastic corks are losers for aging more than a couple years. Even in expensive wines. Dark, big body, balance, gigantic black plum fruit, plus huge whack of VA.
From Napa foothills southeast of Calistoga. Tasted at dinner, from private collection. About $85 at 2004 auction.

This wine operation is highly regarded by the likes of Robt. Parker and James Laube, commentators who have never met a wine too ripe, alcoholic, or massively-structured for their taste. Hence this price must be considered something of a bargain. The vineyard, owned by a San Francisco neurosurgeon, is one of the most prestigious in the B&H collection. 1999 was an excellent vintage. And, if anything, drinking this wine at age ten should be considered a bit premature. How disappointing. I was more than a little surprised, upon removing the foil, to find it had a plastic cork. I’m no stickler for tradition, but I’ve never had much satisfaction from wines with plastic corks once they get to be five or six years old. The problem is that the cork is perfectly round, and tends to stay that way, while the neck of the bottle is never perfectly round.

Sure enough, the nose of the wine had that suspiciously obvious lift to the fruit component which is at once: impressive; and not quite right. It is oxidation, volatile acidity, too much acetic acid. In low-rent wines this phenomenon emphasizes a lot of unpleasant characteristics. In a high-rent wine, such as this one, volatile acidity carries the sensation of spicy blackberry jam further up one’s nose than it ought to go, and gives the smell an ether-like quality. The wine was nicely balanced for acid and tannin. It had lots of flavor density. In short, it was great wine ruined by too much access to oxygen while aging in the bottle.

Plastic corks are a technical device which attempts to avoid TCA, or randomly occurring taint from bark corks. In this instance it proved to be a terrible idea. A screw cap would have been preferable.

Riedel Crystal Stemware

9 March ’09

Georg Riedel is an elegant man and a compelling authority figure, like a stage hypnotist. Made some strong points, then wildly overstated his conclusions.

Many people I admire in the wine biz have completely bought Georg Reidel’s line about glass shape affecting the smell and taste of a wine. So I went to see what can only be described as one of their Stage Shows. No doubt about the fact Georg cuts an impressive figure. His shoes alone would have paid my mortgage for several months. And 120 people in the audience ate it up. Of course Georg did give each of them five fairly expensive glasses to take home.

Did any of his claims about the shape of the glasses hold water? Well, yes and no. It certainly is true that any wine tasted from a large wine glass will be more impressive than the same wine tasted from a slope-sided plastic cup. And I’m inclined to go along with his assertion that wide-aperture glasses emphasize fruity aromatics better than tall glasses with narrow mouths. But that is about as far as I can ride the bandwagon. I simply did not see the differences due to shape in the middle of the glass that he was exhorting the crowd to notice. Which is not to say that most of my neighbors in the audience stood unaffected. As a group they largely spent the hour whispering to each other about what a revelation these different glasses were, and how they couldn’t wait to buy fourteen different sets of glasses for use in their homes. I’m afraid I just could not overcome my sense of Mr. Riedel’s self-interest in the matter.