Have the investment and new product development measures taken by cork manufacturers during the last decade to better control TCA (the chemical that causes musty, mouldy taint in wine had any real impact on our perceptions of cork as an effective stopper?  

Lab research

It was Dr Christian Butzke, president of the American Society of Enology and Viticulture, (ASEV), who wrote in 2009, that TCA was no longer a major problem for the USA wine industry. As chairman and chief judge of the Indy International Wine Competition, he reported that less than 1% of the wines entered were noticeably corked.

Going some way to achieve this redefining position for cork closures has been the California-based Cork Quality Council (CQC). Before CQC members (cork manufacturers and suppliers) accept any cork lot into stockholding, samples are sent to third-party ETS Laboratories for GC/MS analysis (gas chromatography / mass spectrometry) of TCA.  They have reported an 80% decrease in the incidence of TCA contamination since 2002.

Since 2007, technical corks are also systematically tested, and reveal remarkably similar results to single piece stoppers. Peter Weber, the director of the CQC estimated “that our group now supplies about 80% of USA corks.”

Weber explained the early quick win for the CQC “When we first started chemical testing for TCA we enjoyed very quick improvement. Most of which was because we could now see what sources were supplying “good” corks. It was easy to instruct the manufacturers to redirect their purchases away from [less good] suppliers.  We probably achieved a 50% improvement from this type of adjustment alone.”  As manufacturers increasingly used high-tech equipment, the pre-screening process showed continued improvement.  

On the other side of the pond data is rarer, and an almost visceral mistrust of the cork industry’s ability to put its house in order appears to have developed in the past decade.

Cork harvest from tree

The picture for cork closures is also now blurred because a lot of mainstream merchants and big retailers moved away from cork-based stoppers into either or both synthetic and screwcap. Bottle Green’s wine director Nick Butler said “we have reduced natural cork closures in the wines we sell to less than 20%.”  It’s a similar picture at Alliance Wines, where business development director Fergal Tynan MW said “we moved almost all of our own production wines to screwcap some time ago, This remains our preferred closure, far from perfect but offering the best overall solution at the moment.” 

Whether retailers initiated this trend is a mute point.  Sainsbury’s winemaker Clem Yates said “over the past five years most of Sainsbury’s own label wines were either under synthetic or screwcap with little natural cork used in the range.” Direct Wines’ product manager, Martin Campion echoed this approach, saying “we are buying more wines under screwcap than ever before.” But added “we will continue to take the more classic wines under natural corks,”

Despite this loss of market share by cork stoppers, within the cork share of market there appears anecdotally to have been modest improvement, though monitoring of customer complaints is unreliable, and many retailers don’t attribute credibility to these data. Thierry’s winemaker and quality manager, Jeneve Williams, urged caution regarding false positive reporting of customer complaints, saying “cork taint is still an issue … though products such as Diam have made a difference to the incidence rate along with the efforts of the cork industry to improve quality of production processes”.

Thierry’s Burgundy supplier Mommessin supported a slight improvement. Their quality manager, Paul Correia said “‘we still do in-house batch testing on the corks because the R&D programs implemented by cork suppliers started only 10 years ago. The rate of cork taint has decreased – I rejected 4 lots in 2009, 4 in 2008 but 14 in 2007, so the quality has improved but cork suppliers have more to do.”

This leaves anecdotal evidence largely coming from tastings and observed experience, and carefully monitored wine competitions provide some clues.  Thomas Costenoble, director of the Concours Mondial de Bruxelles, where taint issues have been analysed since the competition started in 1994, said cork “problems decreased significantly, however we cannot say that TCA disappeared. This year 120 samples came back to the preparation room (~1.7% of the total) [all faults: TCA, oxidation, reduction, re-fermentation etc]. No more than 66 samples were really suspected of cork problems (0.9%).”

The International Wine and Spirit Competition (IWSC) have only more recently been measuring faults.  Competition director Frances Horder, said “we have measured requests for a replacement bottle, by closure type, for the last 3 years, and added fault types last year. In 2007 and 2008, 8.3% of bottles with natural cork were replaced, falling to 7.2% in 2009.  Just under half of these were identified as due to TCA, so 3 to 4% of the total. … anecdotally this year also looks better.”  So significantly different figures, but a slight downward trend.

This is confirmed by the more traditional merchant sector of the UK market. Patrick Sandeman of Lea and Sandeman said “I would confidently say that we have had far less of a general problem with corked wines over the past decade because the cork producers have finally realised that they had a problem and it needed sorting.” Anecdotally, at a recent Lea and Sandeman tasting, Sandeman said “of the 130 or so wines which we opened, of which upwards of 80% were under cork, we only came across one bottle which was very definitely corked.”  Elsewhere, Joel Lauga sales director at Great Western Wine and Ewan Murray, the head of tastings, events and PR at the Wine Society have guestimated reductions in cork taint from 10 to 20%.

Some positive stories have emerged. Yates said “we have recently reviewed the Sainsbury’s closure policy and we feel that the risk of TCA has decreased, so we’re in the process of working with Amorim to use a more sustainable FSC (Forestry Stewardship Council) natural cork in a wider range of own label wines.”

One or two others have revised their views on cork. Sandeman said “a decade ago we were very much in favour of Stelvin, but our attitude has changed back in favour of cork for many reasons – aesthetic, environmental, and quality. Cork will always be the best closure so long as it works, and increasingly it does so.” Waitrose buyer Andrew Shaw’s views on cork closures have “gone full circle – it’s once again seen to be the best closure if managed correctly”, but 60% of Waitrose’s sales are of screwcapped wines, so “reduction [a different type of wine fault] is a potentially greater concern.”  

Despite the promising news, hesitancy and caution remained the watchwords of the trade, with Lauga saying “the rate of infection, although better, is still too high to regain wide confidence especially for new drinkers. We still rate cork closures high risk.” Yates was similarly strident, saying cork taint “seems to have reduced dramatically from recent years, but there are still very dangerous levels of TCA which just dumb the fruit and are not obvious even to the trade so therefore still have a large potential to negatively influence the consumer.”

Cork taint is unequivocally still an issue.  Butler said “why invest so much in the wine, packaging, marketing and then possibly risk it all with a risky closure. Certainly my perception is that the cork manufactures have improved their systems, supplying better cork, more consistently BUT the vulnerability to random TCA issues persists.”

The message is clear from the UK.  The cork industry still has plenty of work to do.

Equipment developed in the 1990s by NASA to keep fruit and vegetables growing and healthy on the space station has been found to remove airborne TCA – trichloroanisole, the chemical that causes mouldy, musty taint in wine.

Independent proof of concept trials by UK specialist drinks industry laboratory Corkwise found it removed 90 to 95% of airborne TCA within 24 hours.  The potential applications for the wine industry are manifold. Corkwise’s Geoff Taylor mentioned “anywhere that stores wine either in bulk or bottle. Particularly prone locations would be old cellars, warehouses where there is dampness, wood for example, old, expensive wine.” But, he added “even modern cellars can become readily contaminated with TCA.”

Alistair Thompson, general manager of Surrey Diagnostics, UK agents for the kit said: “Airocide works by photo-catalytic oxidation. Air is passed on bed of a titanium dioxide catalyst. This is irradiated by UV bulbs, and organic contaminants are oxidised.” Water vapour and carbon dioxide are the final oxidation products of organic compounds. A difference from filters is that filters trap things, whereas Airocide destroys them, leaving just CO2 and water.  

That Airocide doesn’t remove 100% of airborne TCA is explained by Taylor: “once a room or cellar or warehouse becomes contaminated, some TCA is readily absorbed into the walls, floors, ceiling and packaging materials. Wood and cardboard particularly act like sponges. As the aerial levels drop, trace levels of TCA are fed back into the atmosphere. The crucial point is the very significant reduction.”

Chateau Montelena in California has used Airocide in the fermentation cellar and wine library for more than three years.  Their winemaker, Cameron Parry said: “The cellar went from having a slightly musty smell, not surprising for a 127-year-old building that is half underground, to having virtually no aroma, and no musty tones at all.  Really the only thing you smell in the cellar now is the oak from the barrels and wine if racking is taking place. I am very confident in the Airocide units and do not have any fears about exposing the Montelena wines to the cellar air.”

A flurry of activity, mostly generated by customer demand for innovation, has seen several new closures on the market, both for premium and high volume wines.  TCA (2,4,6-trichloroanisole, the chemical that causes musty off flavour in wine) has given way to OTR (oxygen transmission rate); new stoppers have been brought out for sparkling wines, and marketeers are getting back on the act as closure choice becomes a way to differentiate brands.

Three new sparkling wine stoppers have appeared.

Three new sparkling wine stoppers have appeared. Alcan’s Maestro stopper has all the pizzazz Champagne could want, and it is built around the utilitarian crown cap, which frequently does the stopper-work in maturation cellars before disgorgement.  The functional cap is dressed to the nines with thick foil and the new one-arm bandit opening mechanism. 

The business bit of of the Maestro

Crown caps with synthetic liners have been used in Champagne for more than 10 years. Maestro uses a single piece liner of “unique shape that gives it a better sealing, with a thicker layer of polyethylene” said Mathias Mélan Moutet, president of cap-maker Solocap-Mab, which, he said, gives it a CO2 loss well within the lowest third of the CIVC’s ‘acceptable’ range.

Bruno de Saizieu, the commercial and marketing director of Maestro-maker Alcan Packaging Capsules cheekily smiled “the effort to open it is easy enough for a woman to do”. The opening is made simpler without the foil to unwrap and the wire to unwind. Restaurants should love it.

Australian company Zork has brought out a plastic stopper for sparkling wine, based on the technology for its still wine stopper. It comes at a cost they say is comparable to cork-plus-wire, but, said marketing manager Jo Baker “the big cost saving for producers is to opt for no [foil].”

Zork sparkling

Evans and Tate have used this on their new sparkler Zamphire.  Rosemary Scott, their general manager for global sales and marketing, said “the re-sealable closure appeals to consumers as it allows them to have a glass or two, reseal the bottle and save the rest for another day. Equally, almost 50% of Australian sparkling wine consumers who we surveyed said they found it difficult to open bottles. The new closure allows more control when opening while still providing the traditional ‘pop’ and ceremony.”

The semi-sparkling (frizzante) market is big in Italy, and Guala Closures has brought out the ‘Moss’ (Italian for slightly fizzy) screwcap for semi-sparklers. Marketing manager Anne Seznac said the screwcap “was used for small formats, but not for big formats until requests came from Italy, Argentina and Brazil” for something easy to open and close for younger consumers.” A polyethylene liner was developed, but the shell of the screwcap and the bottle are the same, so, she said, only an adjustment to the block pressure of the capping heads needs to be made.

With Prosecco resurgent, as well as semi-sparkling usually attracting a lower duty rate in the UK than sparkling, this could be an interesting development, although Neil Bruce, wine director at Waverley TBS said he would want to know “firstly, if we have a need for a semi-sparkling. Is there enough innovation in the wine?” With 85% of Waverley’s business being in the generally slow-to-innovate, fragmented on trade, he added innovation in the on trade “tends to be supplier led.”

'Moss' screwcap for semi-sparklers

For still wines, a number of premium products have been launched and brand differentiation is emerging as a consideration for choice. After nearly five years without reported quality issues, glass stopper Vinolok’s general manager Siegfried Landskrone said the stopper’s “attributes combine the oenological standpoint of a proven system, and it meets the aesthetic view of a new trend for customers – it’s easy to open, there’s no extra tool, it’s a more modern and fashionable way, and it meets the emotional requirements for how a closure should look.”  

Landskrone said: “Vinolok is moving from a purely technical solution, where the main contact was the winemaker.  In the last 18 months this has changed to the sales and marketing guys. Where people are producing wines for export, more wineries are looking for marketing strategies to makes attractive packages.”  He added in terms of cost Vinolok is comparable to high quality natural cork, so it’s not an option for many.

Peter Gago, chief winemaker for Penfolds agrees that “aesthetically and psychologically people have a lot of trust in glass.” Indeed Penfolds are at the very early stages of trialling two prototypes of true glass-on-glass stoppers, though phase one is not yet complete, Gago’s confidence notwithstanding: getting a glass disc appropriately fixed onto the levelled top of a bottle. If this development is successful, said Gago, “it will be for wines meant to age long term, the upper end of our portfolio,” adding “the proof is we have bottles [Grange] under this seal for over a year now. It’s working.”

Another product aspiring to the premium niche is Econatur from cork producer Juvenal. Cork is undeniably the most environmentally-friendly wine stopper, and Juvenal have amalgamated cork harvested from their 600 hectare organically-certified forest with cork from FSC-certified forests to produce a range of corks they market as ‘chemical-free’. 

Econatur one-piece cork

Rui Pereira, sales director of Juvenal said “the idea had been just to do single-piece cork, but there was pressure from customers to include technical corks”, which has already given Juvenal orders for 1m stoppers.  

At the high volume end of things, cork giant Amorim have re-launched a single-piece cork stopper, targeted at the fighting end of the market where clients want whole cork not technical (cork particles/discs of whole cork), but have not been able to afford it. It is cited as being able to undercut the alternatives by up to 50%. 

Communications director Carlos de Jesus said Aquamark is a single piece “lower quality natural cork stopper wrapped in new technology, which is sensorially neutral and has a visually-appealing result while keeping costs at a price point that brings natural [single piece] cork stoppers to price sections from which they were previously excluded.”

The price range was given between €35 and €110/1000, and de Jesus added: “Since we launched five months ago, 100 new clients have started using it, including some brand new customers.”

Acquamark stopper

The cost competitiveness of such a product may be the only thing that gets the UK trade interested. Matt Dickinson, director at Thierry’s said: “I look at [innovation] from two perspectives: what will the consumer think, and what will our customer think? And what about the cost? Can we benefit because of the cost, or for profile?”

He explained: “For cost and profile, commercially it depends on type of product. If mass market, finding as perfect a closure as possible for as little as you can pay is the route to go down. Any saving we can make on any aspect of packaging is a good thing, especially if it improves the overall quality of the liquid.” But, he warned. “the consumer is key to all this. If they don’t accept a particular type of closure, you need to find ways of bringing them on board.”

A different strategy has been adopted by Nomacorc who are working with scientific institutions to understand oxygen management throughout winemaking to arrive at “the sensory profile of the wine that the winemaker wants” said Malcolm Thompson, vice president of marketing and innovation, adding “OTR is one aspect. We have learned that oxygen management upstream is critically important. Ultimately we’ll look at pre-bottle ageing, micro-oxygenation and try to bring the whole process under control.” Adding “we’re aligning the research to our closures, and we can imagine a range of closures with different OTRs.” In the meantime their customers get valuable insight.

Such total control for reliability and consistency should elicit the interest of the big brand owners. Though, having adopted screwcaps 18 months ago, Greg Wilkins, director of Brand Phoenix, owners of First Cape, said: “for brand owners, consistency is the most crucial factor. We evaluate new closures periodically [but] we’re fairly conservative. Once we’ve found one that works, then the person who is the most important is the consumer.”

Pernod-Ricard’s wines development director, Adrian Atkinson was equally circumspect, saying: “Whist we do keep up to date on new closures, we have put a lot of time and research investing in screwcap closures – it is a commercially viable investment for Jacob’s Creek both now and for the foreseeable future.”

Ultimately, no matter the innovation, it has to stand firm with consumers. David Gill MW, director of Bottle Green said “It’s all very well if we or the retail buyer thinks it’s a good idea, but will the consumer buy it?”

Oxygen ingress has become the new black for the closures industries.  TCA (the  mouldy, musty taint in wine) is last season’s outfit, and environmental considerations remain an underground movement, threatening to move into mainstream fashion at any moment. 

In its efforts to forge an environmental path, cork closure champion Amorim held a seminar on the sustainable future of natural cork, presented by Dr Miguel Cabral, their research and development director. According to communications director Carlos de Jesus, the seminar covered “anything that people want to talk about – carbon footprints, the latest research and development, TCA, new products, new oxygen permeability research.”

But cool chic is all about oxygen management, and OTR (oxygen transmission rate – how much oxygen passes through/past the closure into the wine) is the new three-letter acronym of closure cool.  It’s during the last year or two that oxygen ingress through/past the closure has quietly become the accepted norm.  Screwcaps are no longer considered hermetic by the mainstream, though it is difficult to pinpoint the origin of this, as the Stelvin brand of screwcaps have been available with two differently permeable liners for more than 30 years, and, according to Bruno de Saizieu, sales and marketing director of Stelvin makers Alcan Packaging Capsules, have been marketed as such.  

Why is OTR so ‘of the moment’? Managing oxygen is related to the mechanical and physical properties of the closure in contact with the bottle bore or top of the neck. Closures need to be consistent, and, by and large, it is the industrially made closures, where each and every one is the same as the others in a batch, that are likely to perform most consistently. With such consistency of closure, and therefore, it is thought, of OTR, trials and observations can be made from which wine behaviour in bottle can be predicted with confidence.  Dean Banister, the sales director for Oeneo, who make Diam, said: “at Oeneo we’ve been talking about OTR for a few years now and for us it is the next big issue for closures. For me the subject is being led by Oeneo and Nomacorc because we can both actually control OTR with our closures whereas it is not possible with natural punched cork.”

Indeed, earlier this year, synthetic stopper supremo Nomacorc, with G3 Enterprises and Lallemand, founded O2inWines, a group bringing together industry technical leaders to expand science-based understanding of oxygen’s relationship with wine. Inter-Rhône has just become the fourth industrial member of this Association, alongside academic members such as AWRI, INRA, UC Davis and Geisenheim (institutions in Australia, France, USA and Germany respectively).

Nomacorc’s vice president, marketing and innovation Malcolm Thompson, said: “there’s quite a buzz associated with the whole oxygen management in winemaking. Some as a direct result of the conference, a lot of it as a result of work Nomacorc has done specifically”, which includes four initiatives with leading institutes across the world, researching the effect of oxygen on different grape varieties and bottling conditions.  He added “the research is step by step globalising, with four programmes at AWRI (the Australian Wine Research Institute), INRA (the Institut National de la Recherche Agronomique) the Geisenheim Research Centre and UC Davis. And we’re nearing a position to announce a fifth programme in south America.” 

PLASTICS

As well as OTR research initiatives, a new model of Nomacorc closure – Classic+ – has just been released, after a three year development programme. It has an OTR about 30% lower than their Classic model and Thompson said: “the Classic+ driver is from performance to preservation. We’re capitalising on breakthrough technology when we developed Premium.”  Classic+ adds another 12 to 18 months shelf life compared to Classic.

Nomacorc may have five different models on the market, but competitor Neocork  have adopted a different paradigm, with just a single product. Mark Coleman, their director of global business development, said with: “a decade of commercial performance in the marketplace, we’ve been reluctant to start compromising a proven formula because when you start changing materials or densities on such a technically engineered product, there will be compromises.” He emphasised their single product met the age-ability needs of 85% of the wine market, that is, drunk within a couple of years of bottling.

But trials are under way, he said “to address market demands of both a lower cost cork and one more suitable for wines intended to age five-plus years with products whose densities, mechanical and sensory attributes mirror the proven performance of our current product.”  Expect some news in late 2009/early 2010.

SCREWCAP

A similar time frame is forecast for news on new screwcap liners. At least two types of liner are undergoing trials, one with an OTR between the two existing liners on the still wine market, Saranex (higher OTR), and SaranTin (lower OTR), and one with a higher OTR than Saranex. 

At one of the leading screwcap manufacturers, Guala Closures Group, different types of testing has involved different materials. Their marketing manager Anne Seznec said: “we’re working on a liner with a 100% hermetic closure because we need to achieve an hermetic seal first, before we decide the rate of OTR that we want to put in the liner.”

Alcan Packaging Capsules vie for global top dog slot with Guala Closures in the long skirt screwcap market. De Saizieu said “we are making some trials with customers on finished products. We’re testing regularly those liners to be sure that what we expect is right with the wine. But this takes time because of the ageing.”

CORKS

While both synthetic and aluminium closures are industrially made and therefore batches are expected to be consistent, natural cork, being natural, is argued to have some variation.  Single piece natural cork is still the most widely used cork closure with Amorim alone making about 1 billion of them, but, being single piece natural corks, they’re naturally subject to individual variation, though the amount is widely, and often inaccurately, debated. A two to three-fold variation is oft-discussed among academics, and there is also an argument that the high level of cork compression inside the bottle neck bore eliminates much of any natural differences between individual corks.

It may be difficult to offer a precisely measured OTR parameter for natural whole-piece corks, but it should be possible on high quality technical corks, such as Oeneo’s Diam, even though we don’t yet understand what a specific OTR means in terms of wine development in bottle.  

Nonetheless, OTR becomes a relevant topic of conversation to further that understanding.  Since the launch of Diam in 2004, Banister has been doing his bit to move OTR up the agenda. In fact, he said “we have not produced natural punched cork for over two years and we ended supply of this product in most markets at the end of 2007.” He added, “We will be a single technology company in the next few years, focusing only on the Diam technology” which means their ‘Reference’ product will be gradually phased out.

PROCEED WITH CAUTION

With Diam, Oeneo offer four levels of OTR, which, Banister said “because of the low understanding of the effect of OTR on wine we offer them on the basis of wine ageing potential [shelf life].” There’s also a differential cost “because of the density of each closure and the size of the cork grains.”

Carlos de Jesus says Amorim’s technical granular cork Neutrocork is their fastest growing stopper, though it’s long way behind the volumes of twintop.  On the various merits of single piece versus technical cork, he said: “Cork offers different products for different price points for different wines. You wouldn’t cross a desert with a 2CV [car], you might want something better adapted. We’re creating different products for the market, which is becoming more segmented. No one else can cover so many price points, we can offer something for £1 bottle or £1,000 bottle. 

And he doesn’t think the single piece natural cork stopper will fall out of favour any time soon. Using Bordeaux growths as his example, he said “If natural cork stoppers did not give you predictability and consistency, natural cork would have gone long ago. There has to be some consistency, there is a common sensory thread running through [different bottles of the same] wine.” He has a point. High level blind tastings would be tricky without some consistency across the board.

Though our understanding of oxygen management is at a foetal stage, OTR  and the closure is only one aspect, albeit a crucial one, of many, involved in managing oxygen. Before bottling, management through the vinification process and at bottling are crucial.  And oxygen ingress rates are affected by environment throughout the supply chain, from point of bottling to the consumer shopping basket and beyond.   

The reality is that we don’t yet know which level of OTR is good for a particular country or grape variety, or vintage, or vinification method, or bottle age. As Banister said: “”Do we really understand OTR, in short no not yet. Much work is being done on this subject and we know it matters but as yet it has not been quantified, so many variables, wine styles, winemaking style, expected consumption date etc. And remember that oxidation to one person can be seen as nice development by another.”

2006 marked the ten-year anniversary of the Quercus Project. Its findings and report arguably marked a seismic shift in the sensibilities and responsibilities of the cork industry. The extent of reformation and revolution in the cork industry in those ten years was wide-reaching, and still continues. 

It feels as though we’ve known about TCA (2,4,6 trichloroanisole – the chemical compound that causes ‘corky’, or more accurately musty/mouldy taint) forever, but when Quercus was being put together in the early 1990s, it was not known if TCA was one of a range of agents responsible for off flavour, a minor player, or the main culprit. Quercus demonstrated how TCA could be formed, and that it was indeed the villain of the piece: 80% of musty/mouldy taints implicated TCA. The cork industry knew definitively where to focus attention and investment. Before this, it had been thought that taking chlorine out of cork manufacture would solve the TCA issue, until it was later realised than chlorine is ubiquitous.

But the cork industry was only just beginning to consolidate into a more vertically-integrated structure. Antonio Amorim, chairman of APCOR, (the Portuguese promotional body for cork) said: in the early ’80s, the cork business was configured so cork manufacturers were completely separated from the reality of the market. There was a clear separation between cork manufacturers and cork distributors, the latter being in touch with bottlers and having access to wine requirements. It was not clear that any technical issues raised at the time were in fact technical issues, but rather commercial, negotiation issues.” He added: “In the ’80s we were concerned with the physical and mechanical properties of cork stopper. It was only from early 90s that some larger manufacturing companies began taking control of importers/distributors in the consuming markets and by the mid 90s vertical integration was taking effect; we were dealing with winemakers regularly, getting feedback and access on a direct basis.”

So Quercus set out to identify the agent(s) responsible for off flavours; to identify what stages in manufacture these agent(s) were generated; to produce a strategy for cork stopper manufacture, and to produce a protocol and control measures for cork stopper manufacture. Essentially Quercus undertook a hazard analysis of cork manufacturing. Sofia Afonso, one of APCOR’S technical experts, said: “we can consider Quercus was the first step for developing control methods for TCA.  It was the first time people began to talk to each other in scientific way. It was one of the foundations to control methods and research for several studies that followed.” 

It’s most immediate success was the drawing up, through CELIEGE (the European Cork Federation), of the International Code of Cork Stopper Manufacturing Practices (ICCSMP). Though a voluntary code, it was the first attempt to lay down best practice in cork stopper manufacture, across different producing nations.  The ICCSMP code is now in its fifth edition (2006), with protocols updated to reflect new best practice, for example, cork stoppers not to be transported with materials likely to contaminate them.

This was followed, in 2000, by Systecode: a third party accreditation system that audits companies working according to the ICCSMP.   It’s estimated that more than 90% of cork stoppers are now made according to the code.

Sainsbury’s were one of the original partners of Quercus.  Howard Winn, their quality manager for beers, wines and spirits at the time, said “the cork industry realised it was watching its market disappearing. The Quercus Project was a good starting point. It catalysed a raft of things. Some of its recommendations were fundamental things which weren’t happening before.” 

By focusing on critical control points in the manufacture of cork, Quercus identified ways to eliminate and minimise risk, some of them very basic: not using the bits of cork bark nearest the ground as these to have the highest incidence of TCA; eliminating from stopper production cork planks contaminated with ‘yellow stain’ (which had a high concentration of TCA); keeping cork planks off the forest floor, and off bare ground; removing treated wood from the manufacturing process, for example, replacing wooden pallets with metal ones; and controlling the water used during the boiling phase.

Martin Hall director of food science at Campden and Chorleywood Food Research Association Group, and the original Quercus Project co-ordinator, said: “Quercus laid the foundations for technological development and innovation especially with boiling processes.  Innovations in boiling processes have largely removed the need for post-boiling stabilisation. Planks are now racked so there is less compression, significantly reducing the amount of water taken up into cork. This has reduced the amount of time for post-boiling stabilisation.  Also, water is re-circulated after each boil [to remove volatiles such as TCA extracted from planks,], etc. The process is now largely in the 21^st century.”  Passing the water through heat exchangers ensures the temperature is a constant 98-99°C throughout the hour-long boil, where previously it had been a static system – no circulation, dropping water temperature, no removal of volatiles from the water.

Over and above this have been proprietary innovations occurring later in the manufacturing process – DIAM and ROSA are the obvious examples. Brand-specific extra cleaning and processing technologies which remove even more volatiles compounds.

Hall believes the key things over the last decade have been “the acknowledgement and acceptance of the issue, and one that could be dealt with, and the foundation given by the Quercus Project with the boiling processes and the code of practice.”  He singled out Antonio Amorim as a prime activator of change saying change would not have happened without such visionaries.

In the immediate aftermath of Quercus, both the Altec (Sabate, now Oeneo) and Twintop (Amorim) brands or cork closure were launched. Even before Altec met its demise, Oeneo were working on supercritical carbon dioxide. Dean Banister, their commercial director, said: “investment with supercritical carbon dioxide started eight years ago. Capital investment was completed in 2000: research, the pilot plant and validation, and getting the technology right. It took two to three years to adapt supercritical technology to suit cork, getting the ratio of pressure and temperature correct for cork rather than coffee.”

The Natural Cork Users Group convened early in the new millennium – an ongoing technical dialogue targeted to drive down levels of mustiness in wine. The group addresses itself to international standards, quality improvements, and the exchange of expertise, and counts over 60 members of technical experts, trade representatives and research personnel. It was the first time that the supply chain – retailers, industry associations, technical institutions, and the cork industry – came together in a technical forum with the intent to work together.

The frontiers of technical research and innovation in cork continue to be pushed. Scientific research is ongoing in some two dozen or more institutions in a dozen or so countries, all of which developed work since Quercus reported. Barrier technologies such as Procork have been developed; management and control of closure permeability are high on the agenda of all closure manufacturers; new types of technical cork binding materials are being researched; the idea of cork as a positive flavour contributor, like oak, may not be so far away.  Banister said: “supercritical has identified another 180 compounds that it extracts such as vanilla, terpenes, benzenes. By adjusting pressure and temperature and time we can leave in x and y.  TCA comes out pretty fast, other compounds take longer to extract.”

Quercus found TCA was involved in 80% of musty/mouldy taints. That still leaves 20% coming from sources other than TCA. We now know some of these are TBA (2,4,6-tribromoanisole), and TeCA (2,3,4,6-tetracholoroanisole). We also know the omnipresence of chlorine has compromised entire wineries with TCA contamination, no connection with cork.  This is another of the frontiers to be approached.  

On the environmental front, one of Quercus’ objectives was ‘to ensure the viability of cork forestations in Europe’. Ten years on, the WWF (World Wide Fund for Nature) report has emerged to refocus attention on the environmental aspects of cork oak landscapes. And fortunately for the cork industry, WWF are addressing the wine industry, challenging it to use more natural cork stoppers for the sake of the environment.  A more relevant approach towards sustainable cork oak landscapes may be accreditation by the Forest Stewardship Council. Certification means cork growers can supply to manufacturers traceable cork planks from forests certified to adopt landscape-sustainable practices. Part of this sustainability includes forest regeneration to prevent the landscapes from eroding.

But big plantations to increase the potential for cork stopper production are well underway. APCOR’S chairman said: “in the last ten years Spain and Portugal have planted nearly 150,000 hectares of cork forest … [so] I’m predicting we will have 15-18% more cork in 10 to 12 years from now.”  These are big plans indeed for an industry that some would write off. It’s true that the cork industry has lost market share, but an estimated 95% share of, say, a 12-14 billion stopper market in the early 1980s, to an 80% share of, say, an 18 bn stopper market today, is still somewhere between 10% and 25% growth in absolute volume terms. With a 27-year lead time for any increase in cork raw material, suddenly these plantations seem like a good idea.

That Quercus brought together eight groups from six countries (France, Germany, Italy, Portugal, Spain, UK) in a multi-discipline team should not be underestimated. It apparently took many meetings even before a title could be decided upon for the project. But since Quercus and the ensuing code of practice, the cork industry has dramatically changed the way it does things.  As APCOR’s chairman, Antonio Amorim believes the seminal moments of the last decade to be: “the change in the cork industry’s attitude towards quality and quality-related investments; the verticalisation of  the cork sectors’ leading companies, and the industry-wide adoption of GC-SPME technology.” (gas chromatography – solid phase micro-extraction).

Despite what has been achieved so far, there is still plenty more to do. Amorim said “the cork industry must avoid complacency and look for a total eradication of TCA.” The expanding boundaries of science and technology may provide help. For the moment, Hall said: “What matters is: does the industry and the consumer acknowledge that there is an improvement?”