"You've heard of the French paradox?" said lead author Professor Magali Delmas of the University of California in Los Angeles.

"Well, this is the American version."

"You'd expect anything with an eco-label to command a higher price, but that's just not the case with California wine."

While the general public miss out on good quality wine, savvy oenophiles have an opportunity to save money.

"Wine made with organic grapes -- especially if it has an eco-label -- is a really good deal," said study co-author Laura E. Grant, a Ph.D. candidate in environmental science and management at the University of California in Santa Barbara.

"For the price of conventional wine, you get a significantly better quality wine."

"Wine made with organically grown grapes is higher quality," Professor Delmas added.

"Growers have to devote more time and attention and take better care of organically certified vines than conventional vines, and our results show that these efforts are apparent in the product."

The study found that the 'made from organically grown grapes' label not only negated the price premium for using certified grapes but actually drove prices 7 per cent below those for conventionally produced wines.

Only one-third of vintners using organically certified grapes actually advertised the fact on wine labels.

"Producers of two-thirds of these wines must suspect that consumers, for whatever reason, wouldn't appreciate the use of organically grown grapes," said Professor Delmas.

"Otherwise, why would they refrain from drawing attention to this benefit on their labels?"

One theory is that consumers believe that wines made with organic grapes lack preservatives -- a result of confusion with 'organic wines' that do not contain sulphites.

But certified wines made with organic grapes are allowed to use sulphites as a preservative.

"Organic wine earned its bad reputation in the '70s and '80s," Grant said.

"Considered 'hippie wine,' it tended to turn to vinegar more quickly than non-organic wine. This negative association still lingers."

Today's organic wines are still susceptible to taint as a result of the lack of added preservatives.

"Without added sulphites, the wine turns into vinegar after a while, and you're likely to lose out on the opportunity for your wine to mature into something considerably richer than when purchased, which is the promise of fine wine," Professor Delmas said.

"So while no-sulphites-added is fine for white wines such as Chardonnay that you usually drink 'young,' it is not good for a red wine like a Cabernet Sauvignon that you want to keep to drink in a year or two."

Surprisingly, green consumers are more likely to be motivated by personal benefit than a desire to protect the environment.

"Consumers buy organically grown food because they think it is going to improve their health," said Professor Delmas.

"That motivation doesn't go a long way with wine."

"If consumers want to drink something healthy, they'll reach for wheat grass, not an alcoholic beverage."

Professor Delmas hopes that consumers start to get the message that wine produced with organic grapes tastes better.

"Vintners and regulators really need to communicate better what wine with organically grown grapes means and the potential impact on quality," she said.

"I don't think they've done that, and I think it's too bad."

"It's a real missed opportunity."