A new survey shows most US wine consumers don't know what the vintage date on a wine label means, and many believe that older is always better.

Commissioned by the California Association of Winegrape Growers, the poll showed only a third understand that a vintage date on a wine label refers to the year grapes were harvested, while 37% think it was the year the wine was bottled.

When asked to choose a moderately priced white wine that was one, three, or five years old, only 16% chose the most recent vintage while 44% chose the five-year-old wine.

The survey found that the misconceptions often lead to poor wine choices and disappointment with purchases.