(NVR) - Karissa Kruse has a mission.

The charismatic president of the Sonoma County Winegrape Commission wants to raise the price wineries pay for Sonoma grapes, which now sell for much less than those in Napa County, and her approach is multifaceted.

Part of her strategy is to position Sonoma as a leader in sustainability. The commission’s board of grape growers has set a goal of having all of its members fully sustainable by 2020.

That’s an ambitious goal, but they’ve already made a lot of progress: half of the vineyard acreage already meets that goal and 64 percent are in the process of certification.

Is sustainability important to consumers?

In a 2015 poll, Nielsen found that 73 percent of millennials are willing to pay extra for sustainable offerings, up from 50 percent in 2014. Sixty-six percent of all consumers would pay more.

A study by Wine Opinions found that frequent wine drinkers would be more likely to buy Sonoma wines if they met the sustainable goals.

Kruse admits that the process is not easy. “Sustainability is confusing,” she said, and it has no legal definition. “How do you create messages that motivate to consumers?” And they in turn have to motivate wineries to pay more for the grapes.

Kruse, who is both a grower and vintner herself, has another challenge. She has to overcome Sonoma County’s notorious rivalry between its grape-growing regions, who only had to put “Sonoma” as well as their appellation on their labels starting in 2014.

Napa growers and wineries settled that issue long ago, and it’s one of the valley’s biggest strengths.

The wine and grape industry in Sonoma is different from that in Napa in other ways, too. Kruse heads a public commission funded by a mandatory assessment of 0.5 percent of the dollar value of the grapes on growers who sell more than 25 tons of wine grapes.

Wineries that grow their own grapes are exempt, but some pay voluntarily anyway for the benefits.

The growers have to approve of these assessments, and they must find it worthwhile. They recently voted to extend the commission for five years.