He said big costs and strange challenges could bubble up when winemakers overhauled bottling methods. "One of the issues we had with the PET when we first used it was trying to stand up the bottles on the bottling line, because they're a lot lighter."
Wentworth said winemakers would have to test how cardboard affected a wine's shelf-life. Too much oxygen entering a bottle ruined wine but Yealands' PET bottles had an "oxygen scrubber" to control incoming air.
Wentworth said only Kiwi and Aussie consumers seemed to link cardboard with cheap plonk. In Scandinavia, he said, nobody whined about casks, with premium French vintages there sold in cardboard containers.
The bottles did not impress wine writer and winemaker John Hawkesby. "I find it abhorrent, to be perfectly honest." Hawkesby said premium wine deserved a good glass bottle, and glass also conferred practical benefits. Seeing is believing - serious wine buyers sought clues about wine quality by looking through the glass. "If it's good wine, clarity of colour, especially with aged wine, is quite important."
Yet Hawkesby conceded consumer trends could prove him wrong. He said cardboard could appeal to picnickers, or even boaties, who wanted to keep weight down.
Graphic designer Kevin Shaw of London firm Stranger & Stranger is credited with the cardboard bottle idea.
In September, Quantum Pacific and cleaning products company Eco Planet started using similar bottles for a detergent.