A top Portuguese wine maker has announced that he is switching from corks to aluminum bottle caps, causing alarm in the world's biggest cork-producing country.

Miguel Champalimaud, owner of the Quinta do Cotto vineyard, said that some critics had even accused him of lack of patriotism by moving to screw caps. "Today a cork is more expensive than a litre of wine. We have become cork salesmen instead of wine sellers," Champalimaud told the news agency Reuters. Quinta do Cotto, on the Douro River in northern Portugal , is among several premier Portuguese vineyards whose wines are gaining in popularity around the world.

Champalimaud said the change would save him about 25 US cents a bottle. Portuguese revenue from cork, which comes from the bark of the cork oak, is about $1.23 billion a year. The cork industry is hitting back with an advertising campaign featuring Jose Mourinho, the Portuguese manager of the top English soccer club Chelsea.