SANTA ROSA -- Wines made with environmentally sensitive methods in the vineyard or winery are increasing in number in the marketplace, but also increasing are consumer sensitivity to the price of such wines, confusion over their greenness and claims of sustainability, according to experts this morning at a large conference on green wine.

Consumer surveys in 2007 and this year show greater interest in wines made with green method, with significant influence in whether to purchase wines with "organic" and other key terms on the label coming from "movement environmentalism vs. personal health concerns," Christian Miller, president of Full Glass Research, told the audience of a couple of hundred industry professionals at the Green Wine Summit.

Yet, consumers surveyed aren't so clear on what those terms mean and are increasingly skeptical of pseudo-sustainability in marketing language.

"There's a lot of confusion out there and a real need to deal with it," Mr. Miller said.

Forty percent of respondents said they didn't know what "green," "natural," "organic" and "sustainable" meant on the label. An equal proportion said regulation and certification for such terms should be required.

"It shows they need help in deciding," Mr. Miller said.

There could be potential for a premium tier of environmentally produced wines.

"Mentally, they are accepting there is a premium to be had on these wines," Mr. Miller said.

However, one of the reasons noted in the survey for not buying wines labeled as "organic" was "don't care." That response jumped to 33 percent this year from 18 percent in 2007, suggesting that value may trump values at some price point, according to Mr. Miller.

"It indicates there is some economic pressure from the trading-down phenomenon," he said.

However, a major reason survey respondents said they did not purchase such wines was they didn't see them for sale. The reduction in that response to 41 percent from 49 percent in 2007 parallels a 12 percent year-over-year increase in wines with labels that mention environmental sensitivity.

A source of confusion about green wines comes a growing source of wine information for consumers, blogs other Internet-based forums run by what really amount to other consumers rather than trained or highly experienced tasters, according to speaker Peter Granoff, a partner in Ferry Plaza Markets in San Francisco and Napa.

"Many consumers are confused, and so are many of the experts they listen to," Mr. Granoff said. "If we do not get our heads around what green means, it will descend into hype."

He pointed to confusion over "organic farming" vs. "organic wine." Speaker and green wine icon Paul Dolan noted that the more than 50 wineries that note use of organic farming and the dozen-plus wineries that note they do not use sulfites need to hammer out this distinction. Currently, sulfur dioxide used in winemaking as a preservative is considered as a synthetic additive in considering organic wine certification, while sulfur used as an antifungal agent in vineyards is allowed for organic vineyard certification.

Conference speakers noted public concerns about health effects from sulfites and additives in general in consumables is a troubling aspect for the wine business. Mr. Granoff pointed to the "European travel problem," in which Americans taste European wines that don't list sulfites on the label and then see the same wine in the U.S. with sulfites listed.

"There are perceptions that sulfites are added for the American market," Mr. Granoff said, noting that the industry needs to acknowledge what he called "quality problems of wines without sulfites."

Mr. Miller said industry "on a high level" needs to change the way green wine is communicated, calling for consistent, credible standards for labeling and third-party endorsement and certification.

Mr. Granoff said.

Sixty-one percent of the respondents in Mr. Miller's 2009 survey were concerned about "greenwashing," a significant increase from 2007 sentiments.

"Greenwashing is a big and growing issue," he said.

Companies and organizations have faced increasing criticism for claims that a product or process has a lower environmental impact.

A number of existing and up-and-coming certification programs for industry facilities and practices were noted at the conference, including Fish Friendly Farming, known as Napa Green Certified Land in Napa County; Sustainability in Practice on the Central Coast; and Napa Green Winery.

The California Sustainable Winegrowing certification program, developed by the Wine Institute and the California Association of Winegrape Growers, is set to launch in January.

Ann Thrupp, manager for sustainability and organic development for Fetzer and Bonterra Vineyards in Mendocino County, said the wine industry must be cautious in the desire to display its efforts to consumers.

"There's a lot of competition on who can be more green," she said. "Hopefully, we can improve without being seen as greenwashing."