The decision to change from traditional cork closure was a long and very thoughtfully researched process.

We love the natural feel and the sound of a cork as it comes out of a bottle but we do not like the flavour changes that can sometimes be given to our wine from it. In the time since we made the decision we have gained a lot of experience.

The key point to make is that we are very happy with the results and that Red wines do age under screw caps. Comparing our wines aged under screw caps with the same wine aged under corks there is a difference, but we are very happy to note that wine aged under screw caps is much more consistent.

One of the "THE BEST ARTICLES YET"
on screw caps is reproduced below:

Our efforts are greatly aided in this by a terrific booklet.

Screwed for Good?
The case for screw caps on red wines, recently published by Tyson Stelzer. Screwed is a 100 page magazine-format trawl through the minefield of issues in the cork-versus-screw cap debate. It’s a pretty good read and laced with forthright quotes from industry luminaries (Henschke, Grosset, Kerrigan, Mitchell) which comes out strongly in favour of screw cap closures for almost all wines, including serious red wines for cellaring.

The basic problems associated with cork fall into three categories: cork taint, random oxidation and bottle variation. Let's take them one at a time.

Cork Taint
Sometimes referred to as TCA (short for trichloranisole, the chemical name of the most common of the group of biological contaminants which can taint a cork). In the process between producing cork and actually closing a wine bottle under cork, at a number of points along the way it is possible (rather likely, in fact) for the cork to become contaminated with active bacteria. These bacteria are then reproduced in the wine as the cork and wine come into contact. The effect of this tainting is variable. At low incidences of bacterial growth, cork taint will rob the wine of some of its fruit character. At higher incidences, this "flatness" is overlaid with a highly unpleasant dank, musty character.

Estimates of the incidence of cork taint vary dramatically. Conservative industry figures have traditionally been in the two to three per cent range. Many in the industry now report figures around ten per cent on a regular basis. The variance factor also has a great deal to do with one's palate - firstly, we all have different sensitivity thresholds for all chemical compounds, whether it's sulphur, brettanomyaces, volatile acidity or cork taint. Education and consciousness are also factors - the more you are familiar with cork taint, the more you look for it, the more you dislike its effects, the more you are likely to detect it. Grape variety is a factor, too - highly perfumed wines, such as riesling and grenache, suffer most, as clean, clear fruit perfume is the first thing to suffer at minor levels of cork taint. If you're reasonably sensitised to cork taint, it's not out of the question to expect that about a bottle per box of wine you purchase will be cork tainted to some degree.

Random Oxidation
Failure of corks to seal properly, and not just in lower grade cork, introduces the possibility of the wine being oxidised, often to the point of undrinkability. While this problem can be caused by wine being bottled with excessive oxidant materials, most senior figures in the industry admit that it is often a cork-related phenomenon. Bottle leakage is an associated problem.

Bottle Variation
One of the cliches in the wine industry is the line that "there are no great old wines, only great old bottles". This twee axiom is merely a normalisation argument in cork's favour. What is being talked about is the situation whereby mature wine varies greatly from bottle to bottle: a first bottle of some cherished veteran, lovingly cellared, will taste/smell gorgeous, being the exact, heady reward of the cellarer's patience that had been promised long ago and anticipated for ages. The next bottle will be a faded, brittle memory, and a third will be vinegar. So, when you come to drink it, the fact that 1961 Bordeaux was a revered year, producing great wines in their youth, becomes irrelevant: all that matters is whether you have a good bottle or not. And what causes this variability? Unarguably the cork!

Putting together cork taint, oxidation, leakage and other problems (such as woody, dusty corkiness which is not actually taint), the failure rate of cork in the short term could be as much as ten to twenty per cent. Stelzer quotes Michael Kerrigan, winemaker at Howard Park: "I would expect to have negative feelings about fifteen to twenty per cent of the wine in some form or another due to the method of sealing the bottle." Stelzer rallies many other industry luminaries - Jeffrey Grosset, John Vickery, Keith Mugford, Brian Croser and so on, to the same point: cork is an unacceptably flawed technology. And this is taking only the short term into account. Introduce the problem of bottle variation, and the numbers get positively sickening. For those who cellar wine long term, add thirty-five per cent (a generously low figure, for argument's sake) failure of cork to engender the sought-after "good bottle" to the ten per cent or so we expect to be damaged by cork from the outset, and you'd almost wonder why we bother to cellar at all!

To be fair, synthetic corks have improved dramatically over the past decade, and they may well prove an acceptable solution at some time in the future. For now, however, the focus (in Australia and New Zealand particularly) is on screw cap closures.

Often referred to as "Stelvin" closures, we should refer to them generally as screw caps, Stelvin being but one of a number of proprietary brands of screw cap made and sold. These closures consist of a one-piece metal cap, which is snugly spun onto the neck of the bottle. Within the cap, however, is where the real work is done: the wine is properly sealed by both an inert polyvinyl seal in conjunction with a tin film air barrier, behind both of which is a polyethylene wadding to maintain pressure on the seal. The whole thing is a couple of millimetres thick. First developed in France in 1959, these caps been commercially available in Australia since 1970.

Until recently, nearly all of the focus on screw caps has been related to white wine, particularly riesling. As Stelzer is careful to point out in his book, a great deal of research and trialling, and even some commercial application, has gone into the question of their suitability to the sealing of red wine, both young and for serious cellaring. Screwed follows the story through whites to reds, and traces some basic winemaking technological concerns along the way.

But before we go on, a couple of observations about storing screw caps. Firstly, they handle temperature change, lack of humidity and so on, far better than cork. Temperature fluctuation is no good for wine - it particularly weakens cork, as the fluctuation of internal bottle pressure messes around with the seal, much more than it does with screw caps. And secondly, humidity seems to be of relatively little concern to screw caps as there's no cork to dry out (and they can even be stored upright). Nor do they allow tainting from environmental odour as corks do.

Screw Caps and White Wines
There is a strong association between riesling and the screw cap in this country. Most famously, Yalumba released their Pewsey Vale Riesling under screw cap between 1978 and 1983. It's a familiar tale by now that this was a disastrous move in marketing the brand, with sales suffering enormously. Despite Yalumba's ongoing affection for the technology, at present Pewsey Vale remains bottled under cork. Stelzer quotes Yalumba's gun white maker, Louisa Rose:

"The comparison is remarkable. With cork you will find increased bottle variation, possibly random oxidation or cork taint. With Stelvin [screw cap], it is apparent that the riesling has aged slowly, with variables eliminated."

The issue here is obviously marketing, to which I will return later.

Yalumba very generously gave me a couple of bottles from their museum of screw-capped Pewsey Vales - a 1973 and a 1978. As was initially the practice, the 73 was both corked and capped, containing a weeping, saturated little cork plug (which, fortunately, was not a bearer of taint) over which the screw cap was sealed. The 78 was closed pure-and-simple under screw cap. I'll not bore you with tasting notes, but both were remarkably fresh, delicious wines. They showed the benefits of age while suffering none of the possible detriments - oxidative tiredness, dried out glycerol, excess toastiness... thank you, Yalumba!

Pewsey Vale is not the only example, though. In Screwed, Jeffrey Grosset is quoted:

"I've tasted many bottles of the 1979 Heggies Riesling (bottled under screw cap) and they were all the same."

Nor were Yalumba the only people involved: somewhere along the line, most of our serious wine houses have experimented, researched and trialled, and not just with riesling. Bests, Krondorf, Penfolds and many others are cited by Stelzer, giving their experiences, proof-positives, occasional misgivings and so on.

Most readers will be familiar with at least some of this story and what has since transpired. Until 2000, screw caps were relegated to closing some very commercial Australian wines, despite many winemakers' frustrations with cork and optimism for screw caps. But twenty years down the track, many have acted with courage on their convictions, led by the Clare Valley Winemakers Association releasing, virtually en masse, their 2000 rieslings under screw cap. Most of them offered wine in either screw cap or cork, with some bottling entirely under screw cap. Most wholesalers reported selling out their screw capped allocations much faster than the corked alternatives, and retailers similarly attest to a surprisingly low level of consumer resistance. So, maybe, finally, screw caps are here to stay. And not just on riesling; we are seeing increasing amounts of Marlborough sauvignon blanc, WA semillon/sauvignon blends and roses with this seal.

There is a clear consensus that screw cap closure of wines such as riesling (provided the bottling is successful, which we'll come to later) gives a remarkable level of product reliability - each and every bottle in a case tastes and develops the same, there's no cork taint, and there's no random oxidation. And it's not as simple as just a glorious freedom from cork-related problems - screw caps may help our wine "taste" better, full stop! For example, Stelzer quotes Andrew Mitchell:

"Since we've been using Stelvins the differences between winemakers and sites within the Clare Valley just seem to be magnified. For instance, Polish Hill characters are even more distinct from those of Watervale than they have been in the past."

Many will accept that there are huge problems with corks and, questions of marketing/aesthetics aside, that screw caps are indeed desirable on young aromatic whites. The story doesn't stop there, however. If you take a good look around the shelves of your local quality wine purveyor, you'll see serious chardonnay, young fruity reds, and, yes, a rapidly increasing number of deadly serious red wines all bottled under screw cap - NZ stars such as Felton Road and Kumeu River, and Aussie topguns like Henschke, Grosset and many others have serious, cellaring red wines in the market under screw cap; and for every one line we can see on shelves right now there are many more in the pipeline.

Screw Caps and Red Wines
Stelzer quotes Keith Mugford of Mosswood:

"I am very confident that red wine will develop correctly under screw cap. We say that 'there are no great old wines, just great old bottles' and this is significant in considering the consistency of screw-capped wines. I'm pretty confident that red wines will age well."

So, what's at issue in the question of red wine ageing well under screw cap? Let's start (as Screwed does) with young reds. The issue of screw caps keeping the air out is a given (as it does with riesling, so with shiraz or any other variety) - the testimonies in Screwed are unambiguous about the qualities of screw cap compared with cork on the basics of air exclusion, avoidance of oxidation and bottle variation. And this from some of the most serious operators in the country, who have nothing to gain by jumping on a hair-brained technological or marketing bandwagon. Those arraigned by Stelzer in the case for screw caps argue persuasively about the freshness benefits that accrue: better fruit, better definition (including structural concerns). Retention of fragrance, focus, tannin definition - if you can't trust Stephen Henschke on such matters...?

The real question seems to be about what happens to wines as they develop - or more accurately, what is it exactly that causes wines to age and develop those ethereal secondary, perfumed, laid-out characters that those who cellar wine cherish so? For a long time, we've been told that corks allow a certain air interchange, some sort of mystical controlled oxidative influence. Read Screwed and have a think about it - oxygen flows logically suggest oxidation. The argument from proponents of screw caps is that "good" corks are almost certainly close-to-perfect seals, and that the conservative myth of regulated air interchange is bunkum. Air interchange through corks occurs in relatively poor examples and leads not to wonderful mature complex specimens but to flat, oxidised or flat-out dead wines. What causes the mysterious, lovely, complex character of well-aged wine is time. There remains a question about whether a wine needs to have a certain amount of "swallowed" oxygen at bottling (free oxygen digested into the wine which is then free to interact chemically through maturation), but this is equally available under cork and under screw cap.

There are no fixed answers, the "case" is not solved. Compare the following statements from two highly talented and respected winemakers. Trevor Mast: "The conditions are just too reductive (lacking in oxygen) for the wine to develop." Chris Ringland: "I have not seen any evidence that an oxidative (oxygen rich) maturation environment is beneficial for ageing."

Stelzer's job in canvassing the issue is all the more commendable for his constant preparedness to give voice to those who do not follow his preferences in thought and practice. And so it should be - we haven't seen enough ten-, twenty-, thirty-year-old premium wines under screw cap to argue with certainty that X is black and Y is white. The evidence in favour of the screw cap's basic superiority as a closure is, however, pretty secure.

And as for ageing? Probably the most damning criticism is that it may well retard development to a damnably slow rate! In time, your wine under screw cap will develop wonderfully - it may just take a hell of a lot more time than you're used to... but at all times, it'll still look fresh and vital. The question here is the notion of "Peter Pan" wines - forever young, at the expense of character development. On this, we simply cannot be sure. It may be, for example, that we are confused by old wine which still looks, smells and tastes "fresh", and mistake that for lack of maturity. Almost certainly, our wines will age much, much more slowly under screw cap. But the point that proponents of screw caps urge is that the wines will always be in good condition.

There is another concern, however: Penfold head winemaker Peter Gago is quizzed by Stelzer on whether Grange will ever appear under screw cap (Gago is generally sympathetic to screw caps, and Penfolds have trialled, and continue to trial, screw caps extensively). Gago's response is that for a wine aiming for serious longevity, the question of whether the primary materials in screw cap closure (the inert polymer seal and the pressure performance of the wadding) are able to last beyond twenty or thirty years is a "time bomb" question. Perhaps so, but don't all those expensive re-corking clinics indicate a similar fragility in the time performance of cork? And if we can have Grange re-corking clinics, then why not (if it turns out that screw caps aren't utterly perfect (and let's not set them up to be - they're just better!) re-cap our old reds if need be?

There seem to be no reasonable grounds for the preference of cork under any criteria, save for this one: screw caps have not yet been proved to perform adequately in the long-term ageing of wines - both for the security and desired character development of the wine. This is an utterly valid caution, and one that should be well-heeded. There is, however, a great deal of reason to believe that screw caps are our best current answer to the closure and maturation of wine (and that's not the same as saying we have good reason to believe that Saddam has weapons of mass destruction, or that DDT is safe!)

With screw caps, these difficulties are a form of technological magnifying glass. If "pristine" wine is the purported outcome of bottling under screw cap, so too can pristine retention of any unbalanced characters be seen as the corollary risk.

Excessive bottling levels of sulphur, retention of estery ferment characters, etc., etc. What goes into the bottle is very clearly seen down the track.

Generally, winemakers have to lower sulphur levels, be very, very careful that wines are clean and stable when they go into bottle, be aware of the changed head-space pressures, the amount of trapped oxygen and so on at bottling.

Stelzer quotes Adam Eggins of Taylors Wines in the Clare Valley, to the effect that screw caps "will preserve fruit flavour as long as the winemaker has done the ground work to get good clean fruit into a bottle in a balanced and stable manner."

This means carefully removing post-ferment sulphides and making sure the wine is squeaky clean when it goes into bottle. I'll not go on about it here - the questions get pretty technical and are canvassed at length in Screwed for those interested. There's also a great list of technical papers from the Australian Wine Research Institute and others that get right into the nitty-gritty of it all.

Anyway, it should be admitted that bottling under screw cap is a process that needs to be learnt, but also it seems pretty clear that this is occurring quickly. I've seen far less estery character, for example, in 2002 Clare rieslings than I did a mere two years ago. Nevertheless, we need to allow a learning phase. As quoted in Screwed, the admirably forthright Michael Kerrrigan explains:

"I allowed for higher dissolved oxygen in our screw-capped red wines to reduce reductive characters. I didn't 'sparge' them. The thing is that we don't know what the ideal amount of dissolved oxygen is. Perhaps 800 parts per million, perhaps 1200? It will take us eight to ten years to get it right. In the meantime we will probably have a few reduced wines out there, but I'd rather reduced wines than corked wines."

And this, I believe, is the way to view it. Sure, we'll see some wines that haven't slipped into screw cap as well as they could, but there are heaps of sub-standard wines out there under cork that are reduced, or oxidised, or whatever, even before the negative potential of cork is applied to the equation. And, way over on the plus side, in these hyper-allergenic days - we'll probably see a whole lot less sulphur dioxide bottled with screw-capped wines than has been the case with cork!

Overcoming the Kitsch of Cork
Stelzer quotes a major US buyer:

"I still believe the image the cork sends is one of upscale and a finer product."

It would be easy to observe that anyone who listens to such a butcher of language deserves all they get! But it's perhaps the most serious problem in the whole affair - selling the idea of wine closed in something other than under cork. And it's not just the buying public who have to be sold the idea. In reality, it's the modern-day marketeers who are at least as responsible.

On the plus side, we have real leaders in our industry - people like Jeffrey Grosset, Vanya Cullen, Stephen Henschke and many others, who are at once scientists, farmers and aesthetes, and who are prepared to put their case, their image and their product on the line. On the other hand, we have the ridiculous spectre of the (supposed) romance of the cork - which, once all the scientific, organoleptic and other arguments are said and done with, remains the acid test for many. "We all saw how Yalumba were hurt for being brave and true. Let's wait until someone else sticks their neck out and proves that the truth can prevail in the market" - has been the industry's overwhelming market response.

This supposed "reality" is perfectly lampooned by NZ wine critic Bob Campbell, as cited in Screwed:

"Just imagine the response, if the whole wine industry had been using screw-tops for generations and some bright spark popped up to tell us there was this great new thing called cork. Of course, it means that about ten per cent of wine will be tainted, there will be dulled fruit flavours, musty odour problems and variation in wines as they age. But hey, it makes a great sound when you pull it out of the bottle!"

This industry's greatest weak link is in education. For many years, nothing has been done (nothing overt, nothing concerted, nothing suggesting an industry speaking as one to its clients, speaking adult to adult) to educate "the consumer" about the problems with cork. It is merely feeble-minded, unconscionably conservative, to find cork "romantic". It's not romantic, it's just what we're bloody-well used to.

What's romantic about crumbled corks which leave you to hack and gouge in desperate inelegance? Or corks that don't adhere at all and simply spin around in a futile dance with that expensive, poncy tire bouchon you just bought? Let alone cork taint and all the rest. Apparently, they slew dragons once upon a time. Telling the truth to one's market, as an industry, seems rather a tame challenge, eh?

Read Screwed for Good? if you have any doubts; or ask your retailer for a mixed dozen of paired samples bottled under cork and screw caps (there's heaps of examples out there). And if you're a convert, attack that bloody myth of "the kitsch of the cork" everywhere you see it.

Screwed for Good?
The case for screw caps on red wines by Tyson Stelzer.
Available through Winepress: Phone (07) 3841 6997
or www.winepress.com.au - $11.95