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  • Jancis Robinson
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  • Jancis Robinson
9 Aug 2004

Jeffrey Grosset, world-famous producer of Clare Valley Riesling, has just announced a Aus$6,000 scholarship to fund research into the effects of oxygen on ageing  wine in bottle. As someone who pioneered the use of screwcaps both on his whites and then reds, he claims that information on ageing red wines in particular has so far been 'stifled'. So now he, the New South Wales Press Club and wine packagers Auscap and ACI are sponsoring this endeavour to facilitate research into "the role of oxygen in the aging of bottled wine. This will take the form of a study reviewing both scientific and non-scientific evidence and it is envisaged that results will include conclusions drawn to support the theory that either oxygen is essential or oxygen is not essential, and in what quantities, to benefit the aging of bottled wine."


More details from

Australian Closure Fund

P O Box 64


South Australia 5451


Enquiries to

Jeffrey Grosset, Grosset Wines, +61 8 8849 2175 or +61 417 808 776


The initiative was in part inspired by the following speech Grosset gave to the NSW Wine Press Club last November.


Australia's Quality Focus Gives Closure to Terroir


The purpose of this talk is to explain how and why Australia's quality focus has given closure to terroir.


To do this it will be necessary to present facts and theory which by necessity are a bit technical so I will introduce some fiction as occasional light relief and I will leave it to you to sort out which is which.


As someone who has, in the past, believed that marketing is sometimes little more than replacement of commonsense with concept, I will attempt to redeem myself today by using the very "now" marketing concept of brand as often as possible.  I will also touch on why, for the past three and a half years I have been determined to see more practical research and commercial development of inert wine closures of any kind, not just screwcaps, occur in Australia and why my efforts in this area have largely failed.


Some of this information has never been presented before yet there has been an awful lot written on the components of this title already, much of it ill informed and without scientific basis. 

I don't include Tyson Stelzer's first book on closures in this because I think he has captured the very mood of the day by documenting the wide variety of thought on screwcaps at this time.  The facts interspersed amongst wildly varying opinions, often lacking any sound basis, have prompted Harvey Steiman to comment in this month's Wine Spectator"If screwcaps win the day worldwide, Stelzer's book will have chronicled a turning point".


Terroir is not much better; a simple concept that has so many interpretations, some versions telling you more about the person giving it than they do about the word.  I'll give you some examples of what's been written as we go.


I'll also address how Australians are causing wine drinkers worldwide to re-think exactly why they drink and for some, to ask what is wine ageing all about, and for the rest of us, the sort that are here, to delve further into arguably the most intriguing of all wine attributes, the notion of terroir.


Closure types

The cork industry has changed remarkably little in the last hundred years.  In contrast, a number of closures which didn't exist previously have come into use.

It's interesting to note that Chateau Lafite used glass stoppers until the 18th Century.

How do we assess the appropriateness of each closure, and what is the relevance to expression of terroir?


A cork while being comparatively wonderful at preserving wine as it is so successful at sealing, and practical because unlike glass stoppers it can be removed relatively easily is, and has always been, flawed. There are two main reasons.
The first is TCA, that chemical taint that we are no doubt all aware of, and the second is the variable permeability causing some corks to allow oxidation of the wine. (Permeability here refers to the ability of oxygen to pass through the medium which in this case is cork.) A third flaw which can be significant but I will not discuss further is scalping, which is the ability of a medium to remove smells.

Cork taint is not a recent phenomenon. Problems of off flavours in wine due to cork were first noted in the 17th century.

The Australian Wine Research Institute has been keeping records of levels of TCA noted during their advanced wine assessment courses for more than 10 years.  Currently the average figure over the last three years is 6.5% TCA detected i.e. 6.5% of more than 3,000 wines presented have shown cork taint [strictly, TCA which could have come from a source other than cork? JR].  With the most recent three courses the figure is closer to 8%.

The International Wine Challenge run by Robert Joseph in London has averaged 4.6% and 4.9% over the past 2 years.  Other examples from around the world put the figure at 4.6% - 7.5% making an estimate of 6% overall a conservative figure.  This is excluding developed or oxidized wines, which are the result of porous rather than tainted corks.

Now in the face of such overwhelming evidence, and in fact, even if the problem were as low as 0.9% or 1% as many in the cork industry suggest, then surely to not just Australians with their strong quality focus, but to all wine producers, this would be unacceptable.  But I'm constantly overwhelmed by the creativity shown in building an argument to what appears a simple fact.

To help explain how I feel, I'll show you a quote that was in fact the inspiration for the title of this talk.

"New world reds are a different case to old world reds from classic wine regions with a track record of ageing over decades" 

This is a bit of a generalization, but I think it to serves the purpose of illustrating my point well.  For new world reds, it's all about the fruit quality.  But the primary appeal of aged old world reds comes from the non-fruit complexity.  Call it terroir, if you will.  Now if you are a custodian of this tradition, you would be very reckless to bottle your wines with a closure that is going to change their character."

Jamie Goode (UK) "Communication through the Circle of Wine Writers"

Jamie Goode is absolutely correct in this part of this statement; "you would be very reckless to bottle your wines with a closure that is going to change their character…" So I thought I'd illustrate this by taking the custodian of the maker of that wonderful wine known as Chateau Lafite who happens to be here and through this statement consider legally what he is jeopardizing.
   In fact, we could do a trial by Kangaroo Court.

So, as custodian of Chateau Lafite, by choosing to change from a seal that's known to be inert (a glass) to then use cork on your magnificent wines you are accused of recklessly endangering the reputation of the brand Chateau Lafite.

What do you have to say? 
(Answer) Well I'm French

Q. Why did you change from glass stoppers to cork?
A. I use very special high quality cork.

Q. Your special high quality cork will almost certainly result in 5% taint.  TCA is not something you can avoid by selection or paying more.
Are you not concerned because your wine is so expensive that more than 5% of your wine is tainted by the closure that you are using?

A. NO – Not at all!

This is actually correct because – Monsieur Lafite shouldn't be concerned because the wine is so expensive – we should all be concerned no matter whether the wine is expensive or cheap.  It's still the same problem – customers aren't getting what they thought they bought.

Q. Do you have a defence? (In the manner of a prosecuting lawyer)

A. The glass stoppers wouldn't always come out! …(Shrugs) What else could I do?

Now, 100 years ago or even 30 years ago, this response would have been correct, so M. Lafite is found innocent.  But let's have a look at the evidence available now.


Synthetic corks

These are made from a co-polymer material which just means more than one plastic from the polyethylene group.  This makes them relatively impermeable and they have similar elastic qualities to cork, but by being manufactured, should be more consistent than cork in terms of permeability.  Of course, the most important advantage is that there is no TCA.

The downside with synthetics is that so far the permeability has still been too high to be used on premium wines that may be aged, therefore their use has been restricted.  I see no reason however, why this technical problem shouldn't be resolved in the very near future.

Cork based products e.g. Sabate

In every case the problem with these is that, while they might address the permeability issue in part, the issue is TCA taint as it is with cork.

Crown seals

These are technologically similar to screwcaps but, of course, not resealable.  I'll cover these under screwcap.

Others such as Zork rely on the same technology as screwcap but in Zork's case face other technical problems at this early stage.  Which brings us to Screwcaps.

Screwcaps, ROPP, ROTE or ROTEL or Stelvin 

With the exception of the last which is a registered name but commonly used as a generic, these are all referring to the same thing.

The technical side of this is simple in principle but the details could be discussed for the rest of the day.  However, suffice to say there are two main areas where there have been improvements in Stelvin or screwcaps since the seventies.

1. The use of a sealer or wad that incorporates tin as the oxygen barrier such as is used on Stelvin 

2. The introduction of redraw and subsequent adoption of an international design standard.


The theory of closures

The theory of what is aimed for in a wine closure is best summarized by these quotes:

(Ageing) "It is the opposite of oxidation, a process of reduction or asphyxia, by which wine develops in the bottle" - Emile Peynaud; 'Knowing and Making Wine 1989'.

"Reactions that take place in bottled wine do not require oxygen" – Pascal Ribereau-Gayon in his 'Handbook of Enology, Vol. 2 2000'

Two of the most respected names in Bordeaux, Professors Ribereau-Gayon and Peynaud have researched this subject extensively over more than 40 years and their opinions are summarized here.

These opinions are shared by other prominent academics for example, Professor A Dinsmoor Webb.

"The exact identification of the compounds produced during bottle ageing and responsible for the complex bouquet of a mature wine is yet to be completely resolved… (but) it has been suggested that in the sealed container they are all substances that are chemically in a state of reduction.  The substances that are oxidized in a coupled reaction involved in reduction are almost certainly the phenolics which we know are oxidized during their polymerization.  Although scientists call these coupled reactions oxidation- reduction, or redox reactions, no oxygen from the air is involved.  Indeed, if oxygen somehow enters bottled wine through a poor cork, no ageing compounds will be formed.
A Dinsmoor Webb – Professor Emeritus (University of California at Davis) Retired.

Closures in practice

If we look at our experience with screwcaps versus cork our experience supports this theory. 

If we go back to the introduction of screwcaps in Australia in the mid to late seventies those closures have proved to be extremely reliable and utterly consistent.  The wines have with virtually no exception aged well.  They are fascinating wines.

The only problem with this significant base of commercial evidence in support of screwcap is that it is virtually exclusively on white wine.

I note as an aside that I've never seen off characters on any example of these old wines I've been privileged to taste.

The most definitive work on closures publicly available is of course the Australian Wine Research Institute's closure trial now in its fourth year.  Most of you would be aware that this trial comparing 14 different closures has shown screwcaps to be clearly the superior performer. However we cannot escape the fact that once again this is research done with white wine.

If we turn to more commercial experience. Famous UK wine writer Robert Joseph recently published the results of the first detailed comparative tasting which was held in the UK earlier this year where cork and screwcaps or crown seals of the same wine were tasted.  There were 49 wines from nine countries and 50 tasters.  The wines ranged from Sauvignon Blancs to Cabernet blends.  The clear preference was for screwcap and crown seals with the balance showing no preference except for one wine only where the tasters preferred the cork option.

This was not a scientific study but I think the results are nevertheless significant, and perhaps of most interest is the clear preference for screwcap on red wines.

Robert Joseph recently admitted that he used to believe that wine needs to breathe, until he began to think about all those bottles of port sealed with wax.  And, he said,  "What about wines occasionally rescued from the ocean floor?"

How does this relate to terroir?


Terroir is the French word for what some have known in Australia for thousands of years as "pangkarra".  Pangkarra is an aboriginal word used by the Kaurna (GARNER) people who used to live on the Adelaide Plains.  It is a word that represents a concept which has no English translation but encompasses the characteristics of a specific place that is, the climate, sunshine, rain, geology and the soil water relations.  About the closest we can get in English is to refer to the site but even that doesn't really cover the major components of terroir or pangkarra being the soil and the local topography.

The main difference between these two words is that terroir encompasses everything including the vine whereas the aborigines were not known for their viticulture and their term does not.

My feeling is that the vine doesn't change the site or at least not significantly and when applied to wine it's about the fact that the fruit reflects the site or place and a wine in turn will also reflect that.  So to get the concept of terroir it's important to think of all these attributes together rather than individually.

In essence, a wine has a certain taste not just because of the variety and vineyard management but because of its place.  To be more abstract, I would say that people who say, "this is my place, I belong here" rather than "this belongs to me" are more likely to grasp the concept.  That's certainly the way I understand it and I can tell you that there is more confusion about terroir than there is about Pangkarra.

I don't see winemaking as part of terroir but rather that poor winemaking can interfere with its expression and good winemaking can allow pure expression. That is of course, if the cork doesn't interfere with the taste.

Some would say that I'm not a believer in terroir - not in the sense that I'm a committed terroirist any more than I'm a committed Stelvinist (which I was called in the Sydney Morning Herald last week). However, just like I know that Stelvin works, I know that grapes grown at different sites such as with my Watervale and Polish Hill vineyards over a 23 year period, taste different and despite being vinified in the same manner and with viticulture and clonal differences being investigated there is no other explanation for the difference in the wines other than pangkarra, which is not a registered TM.

The introduction of screwcaps

Stelvin, the name given to the product Stelcap which was the screwcap used on spirits, was actually developed by Australians in the 1970s.  Now most of you would know the history of this.

The advantage of introducing screwcap on an aromatic white wine such as Riesling I think is obvious.  It's easy to pick taint on Riesling although taint occurs equally across all wine types.  In fact, most of the wines adopting Stelvin in the '70s were Riesling so because it had been done before, the re-introduction of screwcap in Australia was on Riesling also made perfect sense and this was a critical point.

Just to recap on the history of the reintroduction; in 2000 Clare Valley Winemakers worked with French glassmaker Saver to produce a premium Riesling bottle.  A critical point of this design was the ullage or fill height.  There were a lot of critics at the time of how high we set this, but that early decision was proved correct. Pechiney, who already worked with Saver were to supply the new ROTEL i.e. extra long stelcap as it was first called, with the liner being different to the spirits' caps in that it would include a layer of tin, known to be a very effective oxygen barrier, sandwiched between plastics.

In July 2001 the New Zealanders were nearly ready to change and I was invited to a meeting where they finalized their strategy.  ACI New Zealand had noted the details of our bottle and followed our lead pretty well.  The burgundy bottle they first made is pretty much unchanged today and I use this bottle on my Semillon Sauvignon Blanc, Piccadilly Chardonnay and Pinot Noir.

By this stage there were two main suppliers of screwcaps, Pechiney and the Australian producer Auscap.  I recommended that the New Zealand industry standardize on redraw from the start and was impressed that Auscap, whose caps couldn't be redrawn, gave a commitment next day to change their production post haste.  It's a reflection on the company but also perhaps on how persuasive the Kiwis can be.

In 2001 the first New Zealand wines hit the market. 

By 2002 the unexpected was happening. A few premium French producers started using screwcaps.  Michel Laroche who presented as I did at the Brisbane Hilton Masterclass in 2001 was bottling under screwcap.  So did Frederic Blanck from Paul Blanck in Alsace who came to dinner in 2001 and expressed his disbelief at what we were doing until he was served a seriously corked Paul Blanck wine that he had brought.

So its use is spreading but there is no question who has initiated this change. 

The question is – are there problems?  The answer is yes, but in the scheme of things they are minor.  I have stated for years now that the diligent commercial use of these screwcaps has proved to be technically flawless.  However, they must be high quality closures and they must be applied correctly.

How successful are screwcaps?

As an indication of the success of this re-introduction - in Australia in 2000 production of screwcaps was about 200,000 bottles – in 2004 that figure is expected to be 200,000,000. 

But while in the eyes of many consumers the introduction of screwcaps on whites, especially Riesling and Sauvignon Blanc, was not even questioned, the limited practical experience and even less commercial trials made for a far less compelling case for the introduction on red wine in the eyes of many wine producers and consumers alike.

Screwcaps on reds

In 2002 30 percent of my production of Grosset Gaia was offered under screwcap.  My approach was one of pragmatism.  I'll explain the logic that I followed.

The problem of cork taint is the same in red wine as it is in white but it can be less easy to detect.  With a lack of long-term trials on red this is how I saw the problem.

Stelvin uses what I'd call a super barrier which is PVDC, tin and Polyethylene.  This compares with a typical bag in box lining which is Polyester with atomized aluminum to produce what's known as metalised Polyester or METPET.  You will see (from this rough graph) that tin combined with inert plastics can provide an extraordinary barrier to oxygen. 

It's worth noting that Saran (PVDC-Nylon-PVDC) has been used without a metal lining in Europe for wines not intended for the cellar.

This is presented not only to show the effectiveness of the liner in Stelvin but to indicate that the developments in plastics offer us infinite possibilities, especially with the introduction of EVOH e.g. durashield. which is clear (ie no metal) and is used on banana puree, for example.

However, there are very few people in the world who understand the complete subject well enough to lead in product development.

This is new information that hasn't been presented before but this is what I had in mind graphically at the time of making the decision to bottle Gaia under Stelvin based on earlier unpublished work.

Pascal Ribereau-Gayon and others say that no oxygen is required for ageing premium red wines.

If you look at the performance of cork (taking note of the circumstantial evidence from the AWRI and other sources) that in comparative bottle tastings of the same aged wine, the less permeable corks tend to rate better.
you might then guess that the left side of this graph is the preferred area of permeability if one is to use cork.

So, if the theory says zero and practice says that cork is ok but not the more permeable,
- and there is some indication that less permeable is better,
- then with the information that we have now, the choice is straightforward:

A– cork,
corked wine plus a number of prematurely aged wines and a dramatic spread in the permeability resulting in every bottle being different and some inevitably ageing prematurely, or,

when I sell a case of wine, if the cellar temperature is similar then when the customer tastes a bottle after 10 years and finds it's drinking superbly chances are the other bottles will be equally superb.


The second challenge to screwcap introduction 

The introduction and rapid growth in use of screwcaps in Australia is an extraordinary achievement but the initiative has come from smaller producers.  Domination of supply chains has however, impeded the development of this initiative.

But, more important than that, there has tended to be a lack of dissemination of information which has resulted in a stifling of this Australian initiative.

The Melbourne family company Auscap is doing great things within their financial constraints.  They simply don't have the clout to invest in R&D and distribution.  Amcor and ACI are doing well now but concentrate on the needs of larger companies, as you would expect.

(Thank you:
Amcor, for the new permeability figures on saran, saran-tin and aluminium.
ACI for putting me in contact with Visy Closures for theories on cork behaviour
Saver Aus for permeability information
Scholle in SA for new info on plastics)


The future
The screwcap principle represents a critical change in the way we think and is likely to be with us for quite some time.  There will no doubt be variations on the theme such as Stelvin II and even other variations on the technology such as the Zork type principle as well as the inevitable improvement in synthetics.

Personally, it doesn't bother me which dominates as long as the consumer is getting the wine that was intended.

The improvements in plastics suggest that the availability of a plastic container with identical qualities to glass is not far away.

The possibility of using plastics to scavenge small amounts of oxygen opens debate even further. However in every case when I look at new ideas, I look at whether there's a need and whether they will endure – they're the one's that interest me.

The recent press release from Hardy's entitled "Vintage 2153 – It's all about the bottle" contrasts with what I see as important for the future.

Here are the four best designs from Vinexpo 2003 and I'll make just one comment on each:

"Does the world need another TV screen? Why have the REAL THING WHEN YOU CAN WATCH?"

Georg Riedel would never allow it!

What sort of water?  Does this mean Wine of Australia – Product of USA when consumed in LA? 

This can be done now - in fact I sit on a committee that debates the legalities of making wine without grapes [must enquire further into this, JR].  The brave new world is already here!

Who said wine doesn't travel well?

   Drinking less than one bottle should not be encouraged.
Or, if you buy a bottle to drink and only drink half it's not worth keeping.



For the first time in the world's history, the highest quality wines are now available in effective and completely inert containers AND closures.
This allows pure expression of grape variety and terroir, short or long term. No more use of the expression' no great old wine , just great old bottles'.
No more excuses!
But how do we find out if any oxygen at all is beneficial?
The answer is we need the knowledge, not a formula, if the aim is to make great wine. And I'm guessing if any oxygen is beneficial it will depend very much on the particular wine and the situation.
Australia is well positioned to lead in this.

The future for Lafite
We concluded that Darren from Chateau Lafite was innocent but if we continue with the hypothetical, in time Lafite will no doubt suffer loss of sales from changing consumer attitude, resulting in Lafite changing to screwcap, or more likely perhaps to an alternative like Stelvin II because it looks more sophisticated.

They will claim that the move is not following Australia at all but as the French manufacturing is already indicating they are instead following the initiative shown by the French glass and closure industry who have led the way in the supply of superior caps and bottles!  Lafite is merely part of the shift world-wide - and not just Australia! - to adopt this improvement.

M Lafite will not doubt remind us subtly of the fact that terroir is a French word and the importance of terroir remains.  We will all wonder why or how we ever associated consciously or not, cork and terroir. 
The loop is complete.  History will have been subtly re-written

George W Bush, in commenting on the way the French are the way they are is quoted as saying, "they don't have a word for entrepreneur!"

Australians by comparison, will no doubt be happy to continue to use the word terroir, despite the fact that the word pangkarra is a better fit for us without thinking for a moment of the marketing advantages of using the word that originated here, or that it almost certainly pre-dates its French equivalent.

Australians will then be free to apply ourselves to the next big benefit to consumers world-wide or the more cynical might say the benefit of industry elsewhere.  But perhaps we'll be smarter.

Australians are perfectly positioned to introduce technological advancements to the rest of the world and the introduction of screwcaps is a spectacularly successful example. 

But, the next time we go out to revolutionise quality as this has done or redefine a notion like terroir, I think we need to be a bit smarter. For the sake of our country and our children - not for them to have ownership, but for their sense of belonging - we could do well to become, to use an American term, just a little more "entrepreneurial".