Oxygen membrane is a corker

A Melbourne company says its product avoids dreaded cork taint.

As New Zealand winegrowers increasingly use screwcaps to seal their award-winning vintages, two Australian companies are entering the market with technology that confuses even further the cork versus screwcap debate.

Up to 10 per cent of wines are estimated to be affected by the dreaded 2,4,6-Trichloroanisole or "cork taint".

Winemakers describe the taste as being like wet cardboard but the untrained palate may mistake it simply as dodgy wine.

Dozens of New Zealand wineries, including Villa Maria, Palliser Estate and Trinity Hill, now use screwcaps and restaurants favour the caps for quicker serving.

Over half of the country's still wines are expected to be bottled with screwcap "closures" this year.

But the war with cork is not yet won.

Enter ProCork, a Melbourne company that has designed a cork coated top and bottom with a membrane that is designed to stop oxygen getting through to the wine.

It says this preserves the wine better than cork or even screwcaps can. ProCork also retains the age-old use of corks, an important aesthetic consideration for many wine drinkers.

"The cork seal is five different layers which regulates the oxygen through the cork," said ProCork founder Dr Gregor Christie.

ProCork had just received the results of testing by the Australian Wine Research Institute, which showed wines bottled two years ago with ProCork corks let in less oxygen and maintained the character of the fruit better than regular cork and screwcap.

The Victorian winery Mount Avoca had led the way in use of ProCork, bottling 200,000 bottles with the corks.

Foster's company Vinpac has the exclusive rights to ProCork in Australia and New Zealand.

The New Zealand Wine Society's Cardmember Wines club was planning to use ProCork for some of the wines it offered to its members. General manager Mike DeGaris said the group would trial ProCork in January across its chardonnays and Hawkes Bay reds.

ProCork's affordability depended on what quantities the wine was made in. Screwcaps are considered one of the cheapest methods of sealing wine.

Adelaide company Zork has come up with yet another alternative - a "PopCap" made of plastic that snaps onto standard wine bottles using a metal foil seal to prevent oxygen leaking into the wine.

The Zork PopCap is a plastic closure that snaps onto a standard cork-mouth wine bottle and incorporates the metal foil technology of a screwcap to prevent oxygen from entering the bottle.

"We're getting very similar oxygen transmission rates to screwcap," said technical director John Brooks.

"It's all about getting to the wine inside ... the convenience of opening without a tool and resealing simply."

The Zork was more expensive than screwcap but similar to "cork in capsule" closures.

Although New Zealand winemakers are "fairly biased towards screwcap" they are taking notice, said Brooks.

Canterbury winemaker Bentwood was using the Zork to bottle pinot blanc, which is very sensitive to cork taint and oxidation.

But the main market for the Zork was the US, where wine drinkers associated screwcaps with soft-drinks and ketchup bottles but wanted something more convenient than cork.

Zork had sealed nearly 300,000 bottles in Australia, nearly all of which had gone to the US.

"The Americans aren't as precious about their wines as Australians. They're not as suspicious of plastic," said Brooks, who presented his closure technology with ProCork's Christie at the Sydney wine show at the weekend.