By Michelle Locke
The Associated Press

MANTECA, Calif. - Wine traditionalists beware: A new crop of vintners is joining the cubist movement, selling their wine in a box.<>`Boxed wines have been popular for decades and account for between 15 percent and 20 percent of wine sales by volume.

What's different this time is that wines that have won good ratings and competition medals are being released in boxes. They've also given the boxed wine genre a name upgrade, to "cask wines."

Wine in a box is most often wine in a bag in a box. The wine is sealed inside a plastic bladder with an attached tap that lets the wine out but doesn't let air - wine's nemesis - inside.

"Once people taste wine out of a bag that's high quality, they're hooked. They love it," said Chris Indelicato, CEO of Manteca-based Delicato Family Vineyards.

Delicato is putting award-winning wines in boxes, including its shiraz, which was rated a very high 90 points by Wine Enthusiast.

The trend comes at a time when wine industry officials have been looking for ways to make wine more accessible and convenient for consumers, turning to screw caps, smaller bottles and even aluminum cans, said John Gillespie of the Wine Market Council in St. Helena.

The bag used in U.S. boxed wines, including Delicato, was invented as a package for battery acid in the 1950s - but caught on in Australia as a way to sell wine.

Boxes stack up well to bottles since they're easier to carry, cheaper to produce, recyclable and more compact. Wine in a box will last more than a month after opening, compared with mere days for a bottle - which is a plus for people who like to drink just the occasional glass.

The new boxed wines are being sold in smaller packages (3 liters) than traditional boxed wines (5 liters). But they are more expensive, generally selling for $15 to $24 as opposed to $10 and under. Even at the high end, boxed wines aren't too pricey, since 3 liters is the equivalent of four regular bottles.

According to ACNielsen supermarket scanning data, retail sales of boxed wine were up 5.5 percent, to $204 million, for the 52 weeks ending May 8. Sales of 3-liter boxes had the biggest percentage jump, about 31 percent - although the standby 5-liter size dominated the category.