Figures from the San Francisco-based Wine Institute indicate California wineries shipped 428 million gallons to the domestic market last year, a three percent increase from 2003.

The retail value of the shipments is estimated at 15 billion dollars.

Analysts attribute the increase to a stronger economy and good reviews by critics.

Last year was a good year for reds. They edged out white wines by volume in supermarkets for the first time in at least two decades according to Institute Spokeswoman Gladys Horiuchi. 

"It could be consumers wanting to try the more classic wines and a lot of them happen to be red."

Although Americans still drink much less than residents of other wine-producing countries, consumption in the United States has grown over sixty percent since 1991.