SAN FRANCISCO — When most people think about slow food, they probably imagine wealthy epicureans sipping organic wine and nibbling on farmstead cheeses. That the organization decided to have its first U.S. national conference here only furthered the stereotype: Slow food is for Prius-driving, Whole Foods-shopping, latte-loving liberals with plenty of time and cash on hand.

Slow Food Nation, as the conference was dubbed, aimed to create a very different impression. At formal lectures, impromptu outdoor speeches and even in the tasting pavilions, where those very wines and cheeses were being served, the talk was mainly about how to transform the food system — and slow food's reputation. Chefs, authors, activists and CEOs focused not on gastronomic indulgence but on new political relevance at a time when food is poised to take center stage.

"I don't care if the tomato was heirloom or organic if it was harvested by slave labor. A commitment to social justice needs to be at the core of this movement," Eric Schlosser, author of "Fast Food Nation," said at one panel.

"We need to get small farmers into the distribution system," Rick Schnieders, chief executive of food distributor Sysco, told an audience of activists at another.

"This is our time," Larry Yee, founder of the Association of Family Farms, announced at the unveiling of the group's food bill declaration, which aims to set the agenda for future farm legislation.

The four-day event, which ended on Labor Day, took place on a sparkling San Francisco weekend. The lectures, tastings, rock concert and film series attracted 50,000 people, organizers estimated. This despite the fact that slow food had to compete for attention with the two national political conventions — and, equally important here in California, the annual Burning Man festival.

Events were centered at City Hall Plaza, where, in front of the gold beaux-arts dome, slow food organizers had planted a victory garden of corn, squash, peas and herbs. Its goal: to show how food grows. The produce was harvested and donated to a food bank. Slow food hopes to plant a similar garden on the White House lawn, if whoever wins in November is amenable.

On one edge of the plaza were vendors charged with selling dishes made from fresh, sustainable foods at reasonable prices. Mexican huaraches, griddled corn tortillas with beans and salsa, cost $7; grass-fed beef hot dogs were $6; a scoop of ice cream was $3. Across the way was a farmers market, a mini version of the more famous one a mile away at San Francisco's Ferry Building.

On sale were local heirloom melons, tomatoes, peaches, raw milk, jams, cheeses and ice cream. Plenty of money changed hands; within a few hours of opening on Friday, California ice cream producer Bi-Rite Creamery had sold out of its strawberry, roasted peach and mint confetti flavors. But several vendors said their main goal wasn't to make money but to spread the word about good food.

"This is an unusual farmers market because we're not here to sell; we're here to educate," said Mark McAfee, the owner of Organic Pastures, a farm that produces raw milk in Fresno. "I'm here to be a broken record about the benefits of slow food."

Political messages were also being sent from the slow food soapbox, a small outdoor stage where, in front of an audience seated on hay bales, farmers, activists and performance artists made their pitch.

Among the presenters: a troupe of Hmong children who performed a traditional harvest dance; Anthony Khalil of the Bay Area's Literacy for Environmental Justice, who talked about strategies for providing poor communities access to fresh food; and David "Mas" Masumoto, a California peach farmer and writer with a cult following. Masumoto read several of his poems about the trials of working the land: "I remember the smell of my father's sweat," he read as a Japanese taiko drummer dressed in traditional costume provided a beat. "I remember $2-a-box peaches in 1961 and $2-a-box peaches in 2007."

The message appeared to be getting through. At a stand where volunteers were explaining how to compost at home, Lisa Martin, a 30-something Oakland resident, said she was looking to volunteer at a food justice organization or, at some point, make a career change. The conference, she said, "has brought together knowledgeable people on a wide range of issues that will get people to do something different in their lives."

Across the street, ticketed lectures and special sessions for food activists took even more serious tones. The panelists included representatives from the culinary, corporate and academic sets: chef and Slow Food Nation founder Alice Waters, essayist Wendell Berry, physicist and environmental activist Vandana Shiva and Bon Appetit Management chief executive Fedele Bauccio.

For two days, speakers debated such topics as how to address the world food crisis and how to bring fair wages to farm workers. Part of the answer, panelists agreed, was to clearly link food to the pressing issues already on the political agenda: rising oil prices, global warming and the skyrocketing cost of healthcare. The United Nations' Food and Agriculture Organization, for example, reports that livestock production generates nearly one-fifth of the world's greenhouse gases. And without cheap oil to produce fertilizers and transport food long distances, food prices will continue to rise.

"Politicians don't get it yet. But if they try to look at energy, health or security, they will stumble on food. It's all connected," Michael Pollan, author of "The Omnivore's Dilemma," told a packed house at the Herbst Theatre.