Food & Drink, Libations

To screw or not to screw?

A friend of mine runs a large pension fund. He maintains that the real indicator of when to sell is when the investment is the story. He’s invested in gold at the moment, and told me when he sees the story on the six o’clock news that is when it’s time to sell. Lately I have come to the decision that this is likely a truth that can be extended to any number of areas.

For example, James Laube the venerated columnist of the Wine Spectator recently lashed out at vintners for continuing to use cork in the face of the much superior closure technology of the screwcap.

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Part of me is in complete agreement with Laube. A couple of weeks ago I had four – count ’em, four! – badly corked wines. One of them (Blackbird Vineyards Arise) cost over $50. Pissed off doesn’t begin to describe my state of mind.

The screwcap has been investigated – and used – by vintners going back to the 1980s. Penfold, the high church of Australian wine, abandoned their investigation due to consumer resistance. (You’d never know it, but wine is actually a consumer good, right up there with Cabbage Patch Dolls and Pokemon. Chateau Latour, the great French Bordeaux house is currently continuing a long term test with their wines using all modern closures. So far the only closure to comprehensively fail is the synthetic cork.

Aside from consumer romance over a centuries old technology is there anything to be said in defense of cork? Actually a great deal.

Currently cork sealed wines are “bad” or “corked” at a rate of around five per cent. This is the main rap against cork. Unfortunately it has come to the attention of the vintners that the cork is not always (not often?) The source of the failing. Barrels, racks, hoses, and even the filling machines have all been discovered to have infected wine with the dreaded TCA/TBA.

A small vintner in Washington confessed to me that he lost half a crop (i.e. that year’s profit margin and then some) due to an infected paper filter. They ran the bottling run in the morning, bottling half the crop. Then they cleaned the machine thoroughly, and changed the filter preparatory to bottling the last half that afternoon…

The ironic part of this story, is the vintner was swapping the filter to IMPROVE hygiene.

I have had a “corked” bottle of wine in the last year from a screwcap closure. I was so flabbergasted I had the provincial and regional wine reps over to taste the wine. They too agreed it was bad, that I wasn’t just suffering an acid flashback.

But it turns out that is not the only source of trouble. Testing by researchers have revealed that the gasket, the seal on the inside of the screwcap is subject to degeneration when the wine is stored for more than 18 months. Alcohol is after all a solvent. The synthetic seals leach various long chain molecules into the wine (PBA etc.).

But even when the bottle has a two part gasket with non-reactive stainless steel on the fluid side it turns there is a problem caused by that air tight seal much lauded by Laube. While the industry quietly ignores it, there is a growing body of evidence that wines bottled with screwcaps have a high, possibly hugely high on the order of 20 to 50 per cent rate of failure.

Virtually all wines have sulfur compounds in them. Some of them are residual from bottle disinfection but a fairly large portion come from the grapes and are by-products of yeast fermentation. Most of these compounds reacting out over time with oxygen. Cork allows for a very slow oxygenation of the wine, something that matters a great deal to wines that are intended for long term cellaring.

[We interrupt this column to inform you from here on in we are in serious cork dorkery, inorganic chemistry. People with weak minds or no interest should proceed slowly and cautiously.]

However some of these compounds, go through something called sulfide reduction. (There are also sulfites and sulfates and none of them are the same. Please follow the links if you slipped out of Grade 11 Chem during this class.)

Sulfides in wine produce the odour of cabbage, farts, or burnt rubber, the telltale smell of hydrosulfide. When exposed to a small amount of oxygen, they will react out into a sulfate. In a perfectly sealed anerobic environment like a screwcap they can interreact to produce those detestable smells and flavours and become stable ions. Research has shown this reaction to a permanent sulfide may be as high as 25 per cent.

To counter this winemakers are fining their wines with copper sulphate prior to bottle to remove as many sulfur compounds as possible. Unfortunately this reaction means stripping out many of the best features of wine (the complex sulfur molecules produce much of the bouquet of wine) and worse yet can contaminates the wine with copper.

While trace amounts of copper are necessary for nutrition, there is a fairly low allowable threshold for copper in food: It is after all a heavy metal. Recently a shipment of New Zealand wine was turned back at the German border because the copper present exceeded the EC maximum for safe human consumption.

The manufacturers of screwcaps have been promising an oxygen permeable seal for at least two decades. It is proving significantly harder to manufacture than they anticipated.

Understand I’m not going to reject screwcap wines from this point on. I will continue to buy and drink them, as surely as I will continue to buy and drink wines sealed with cork. However I donít think the argument is settled yet. And I certainly don’t think the answer is anywhere near as clear cut as James Laube does. In fact, my take is the issue is not the closure system chosen but the post-bottling quality control testing.

Columbia Crest is leading the way with their substantial, spectrometer testing of corks and wines to maintain quality control. I recommend all of their wines as an excellent deal, but here they have instituted a best practice that needs to be implemented industry wide.

If you want to try a wine that has all the sulfites and sulfides reacted out, I recommend Rozendal, an excellent organic red from South Africa. Your other alternative is wines that can cellar. Buy and store carefully and eventually you will find the wine improves, becoming finer and missing many of those noxious, over the top elements of young wine.

Rozendal, South Africa, 2000. $30.80 ***** (Available in Sask Government Liquor Stores)

James Romanow writes about Wine and all things Boozy for the Spectator Tribune. Follow him @drbooze.