When will Australia’s most prestigious wine, Penfolds Grange, adopt the screw cap? It won’t, winemaker Peter Gago told me in Adelaide a few weeks ago. So are we doomed to throwing away the odd, corked $500 bottle forever? Not at all, says Peter.

But we’ll have to wait a little while for his solution. It’s radical and, arguably, made possible by screw cap’s commercial and technical success over the past decade.

The screw cap’s ready adoption broke the cork monopoly. In turn — albeit reluctantly and slowly — sections of the cork industry addressed the systemic, destructive problems of oxidation and cork-taint.

But the by the time Diam (a highly-effective, high-tech composite cork) arrived, masses of drinkers had abandoned the corkscrew forever and other innovative seals had arrived.

In Australia, for example, an Adelaide company developed and released the plastic, pull out Zork plug, while in Worms, Germany, Alcoa commenced manufacture of the elegant, glass Vino-Lok.

In developing the Vino-Lok, Alcoa surely looked to challenge rival aluminium giant, Alcan, owner, through its French subsidiary, Pechiney, of Stelvin, the original screw cap for wine.

And Stelvin is where the screw-cap revolution began. It fizzed for a while in the sixties and seventies, then faltered and faded in the eighties. But it simmered in winemakers’ minds before re-emerging in the late nineties.

The re-emergence in Australia rested on two forces – winemaker dissatisfaction with cork and the marvelous maturity, freshness and consistency of whites, mainly rieslings, that had survived from the short Stelvin boom of the sixties and seventies.

That white wine would not only keep but also mature well under screw cap for decades was proven. And winemakers both here and in New Zealand were aware of trials with reds in France a generation earlier.

Several Australian wineries – including Penfolds and Henschke — began testing the cellarability of reds under screw caps and other seals during the nineties.

Peter Gago says that Penfolds trials included Bin 389 Cabernet Shiraz 1996 and Bin 2 Mourvedre 1995. The results were – and continue to be — encouraging. What the trials show conclusively is that a top-notch red like Bin 389 matures exactly as you’d expect it to under a good cork – but without the loss caused by cork taint or oxidation.

It also shows that the seal survives intact for a decade.

A decade on from those trials, many of the top-end Penfolds reds have screw caps – including the recently released $150-a-bottle RWT Barossa Shiraz 2004. But as I’ve wondered before why, with the knowledge and confidence they had, did Penfolds not seize the leadership with screw caps? Instead they seemed to have opted for an equivocal, piecemeal rollout that hardly inspires confidence.

So, if screw cap is better for the other Penfolds reds, why not for Grange?

Well, says Peter Gago, ‘With Grange we’re talking about people cellaring it for thirty to fifty years. We’ve had trials for ten years, but we’ve got our fingers crossed that these wines will still be good in four or five decades. It’s the integrity of the seal, not ageing that’s of concern’.

He explains that while we know that screw cap seals keep white wines perfectly for thirty years, the chemistry of red wine is different and we simply don’t know for certain that the seal will last.

He recalls working with well-known sparkling-wine maker, Ed Carr, at the company’s Nuriootpa sparkling cellars. They observed that crown seals on sparkling red wines often deteriorated where those for sparkling whites didn’t.

Whether or not modern screw caps with their tin coated sealing wads will deteriorate in contact with red wine for fifty years is simply not known. We do know that some corks make the distance and some don’t.

We also know that top Bordeaux Chateau re-cork their museum stock every couple of decades. And Penfolds itself offers free re-corking clinics for customers with reds over fifteen years of age.

So, it might be argued that if screw cap is better than cork for the medium term, why not make the change and offer re-capping clinics? There’d probably be a lot less Grange lost than there is under cork.
But Gago believes the solution for Grange has to better than that, and that ‘it’s an engineering thing, and will be worth the wait’.

And we shouldn’t have to wait too many years for the Gago solution: glass-to-glass. He cites examples of industries containing gas with glass or ceramic valves.

Glass to glass, he says, is the ideal seal as there’s nothing to corrode – no perishable material like cork, the tin-coated wad in screw caps or the silicon ring of Vino-Lok.

He says the company engaged an engineer to develop the idea and already has a prototype – a glass disc held in place with a spring-loaded clamp. Once perfected, says Peter, it can be deployed rapidly.
As long as the mechanism creates the perfect seal – and that can be readily tested – wine maturation trials won’t be necessary. ‘We don’t need any air getting in. There’s enough in there’, says Peter, pointing to the neck of the 2002 Grange.

What’s in all this for the drinker? Well, better seals mean better wine. Winemakers and packaging engineers are at last closing what has been the weakest link in the quality control chain. Bring on the innovations, I say, and throw away the corkscrew.

Copyright © Chris Shanahan 2007