Put a cork in it!

G Magazine

Wine corks are rare these days, but greenies give it the seal of approval

cork is better for the environment

Cork creates a better environment for wildlife

Credit: Sky Rogers

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Opening wine used to involve such ceremony. A corkscrew would be produced, and with a flourish the foil cover would be removed. Then, with a creak and a pop of the cork, the party would begin.

But visit any bottle shop in Australia these days and you'll be dazzled by the shiny screw caps adorning most wine bottles - 70 per cent of all Australian wines, according to industry sources.

The romantics among us may miss the sound of celebration we associate with the popping of corks, but the pragmatists have happily turned to screw tops for their convenience and the purported improvement in wine quality.

Of course, the screw top versus cork debate goes beyond the emotional and practical to the technical and financial. In Australia, New Zealand, South Africa and the US, screw tops appear to be winning the argument on price and performance. But cork is now fighting back and claims to have Mother Nature on its side.

Sealing the debate

The problem with cork is its potential to let oxygen seep into a sealed bottle, tainting the wine in the process. Before the screw cap arrived on the scene, one to fifteen per cent of all wines (depending on which industry group, researcher, wine maker or wine taster you believe) were ruined because they were 'corked'.

First appearing on the scene in the 1970s, aluminium and plastics quickly convinced New World wine makers they were taint-free closures.

In a tit-for-tat, cork supporters claim the anaerobic environment in bottles sealed tightly with plastic or aluminium can cause a build-up of sulphides in wine and a distinctive smell of "cat pee".

What is clear is that cork has been losing out to the alternatives - between 2000 and 2005, worldwide cork stopper sales dropped by 20 per cent, according to a WWF report, Cork Screwed?

In the aptly named report presented to the London Wine Fair in 2006, WWF warned that if the trend continued or accelerated, 95 per cent of the world's wine market would be capped by screw tops or synthetics by 2015. Its main concern was the impact on the cork oak forests in the western Mediterranean.

"A healthy demand for wine stoppers means the forests can maintain their economic value and people will care for them. But if the demand for cork is not maintained there is a risk the cork oak landscapes will face increased poverty, more forest fires, loss of biodiversity and faster desertification," said Nora Berrahmouni, head of the WWF Cork Oak Landscapes Program in Rome.

Corking sustainability

Cork oaks (Quercus suber) can be grown in any dry climate; there's even one in the ACT, planted by Walter Burley Griffin.

But the trees thrive in their natural habitat - in the special mix of rainfall, wind, and soil conditions stretching in a 30,000-square-kilometre band across Portugal, Spain, southern France and Italy and along the North African seaboard in Morocco, Algeria and Tunisia.

Over the centuries, humans have lived in harmony with the cork oak trees, using their bark for fishing floats, insulation and, of course, wine; planting crops beneath their boughs; and feeding livestock on their fallen acorns. These 2.7 million hectares of cork landscapes are now listed in the top 25 biodiversity hotspots in the world, and support some 60,000 jobs.

In an age-old tradition, cork harvesters peel the spongy bark from the trees with hand axes. The trees can live for 300 years, and bark isn't harvested until a tree reaches maturity at 35 years, and then every 9 years thereafter.

Nowadays, the bark is converted into everything from wine corks, flooring, insulation, acoustics, and industrial products, to fishing rod handles, shoes and even clothing and handbags.

But it's the cork stoppers that generate the most return: they account for only 30 per cent of the volume harvested, but 70 per cent of the total cork market value. That's why WWF is urging wine makers and wine drinkers to choose cork and save the forests.

The world's largest cork producer, Portuguese company Amorim, has just released the industry's first sustainability report, which lists its myriad environmental benefits: harvesting does not harm trees, 85 per cent of the raw material is used and the remainder converted into energy for cork production, the product is 100 per cent recyclable, and cork forests act as giant carbon sinks and are managed in an environmentally sustainable manner.

According to a study by the School of Agronomy in Lisbon, the 736,000-hectare cork forests in Portugal alone removed 4.8 million tonnes of carbon dioxide (CO2) from the atmosphere in 2006, about five per cent of country's total annual CO2 emissions.

And each cork (weighing up to 4.8 g) fixes 8.8 g of CO2. "This means the total number of cork stoppers placed on the market by Amorim in 2006 fixed 25,000 tonnes of CO2," Amorim spokesperson, Carlos de Jesus proudly notes.

"There are a lot of arguments for and against cork - issues of consumer preference, technical performance, reduction, oxidation, cost," he adds. "But even if all these things were equal, there is one thing we can definitely say is not the same, and that's our ecological footprint."

Last year, French manufacturer Oeneo Bouchage, producer of screwtops, Diam (a composite cork stopper), and natural cork, released tests of its own carbon footprint, carried out by independent research agency Cairn Environment.

The results showed that screw top manufacture emitted more than four times the CO2 volume than that of natural cork, and manufacture of Diam emitted about double that of cork - even when factoring in the aluminium foil used to seal a corked bottle.

In Australia, cork has a supporter in recycling advocate Planet Ark. "Cork contains carbon in two ways: in the trees and in the product. And in recycling - as compost or as cork - the carbon within the cork remains there," says Planet Ark's Recycling Programs manager Brad Gray.

"By comparison, aluminium is a non-renewable resource and takes a lot of energy and greenhouse gases to produce. Even recycling aluminium takes a lot of energy, although a lot less than in its initial production. In that respect, cork is more sustainable than aluminium, particularly when recycled."

Turning the tide

Will these green credentials convince Australian wine makers to return to cork?
Alcan Packaging, manufacturer of aluminium screw caps is perhaps understandably unconvinced. Australian sales manager John Leake says, "Sustainability is a key topic for all of us.

But it seems the cork industry has failed to address a lot of issues in its report … for instance, how much energy is wasted [in production, transport and disposal] when people have to pour a bottle of wine affected by cork taint down the sink?"

Questions also remain as to whether shipping cork from the other side of the globe compares favourably with locally made aluminium.

The Winemakers' Federation of Australia (WFA), representing about 400 of Australia's 2,200 registered winemakers, including the top 20 major wine producers, has its own sustainability strategy. Called Sustaining Success, the scheme addresses issues of land stewardship, growing procedures, and winery management.

Under the strategy, the federation developed a Greenhouse Gas Accounting Protocol for international partners including New Zealand, South Africa and California. Amy Russell, WFA national resource management coordinator, says "We ... found a bit of the informtion supplied on sustainability is questionable and contains conflicting information on stopper usage and lifecycle assessment." So the WFA developed some methods for analysing the best kind of stopper to use.

"We have tried to get some consistency for the industry to assess its footprint using these formulae," she says. For now, though, it's over to the wine-makers to decide whether or not to use the WFA protocol.