You Don't Know Beans...

In contrast, Sando knows that each heirloom bean variety has a distinct taste and texture. Rio Zape, purple-black-colored beans that first turned Sando on to bean cooking, have a chocolaty coffee flavor. Vallarta beans, Sando's first sale to the French Laundry, have a thick skin but are creamy and buttery inside. "Steve isn't selling 30 varieties for the sake of it. There are nuances to each one," says CityZen chef Eric Ziebold, who has Rancho Gordo's flageolets and pigeon peas on his menu.

In the past five years, Sando has collected seeds from Seed Savers Exchange, which preserves rare seeds, and traveled Mexico in search of new beans to bring to market. He finds many in Oaxaca, which is to food in Mexico what Bologna is in Italy, Sando says. He also has added hot sauces, dried corn, grains such as quinoa, and chili peppers to his line.

The business has developed something of a cult following. In 2007, Rancho Gordo had 150 acres under cultivation and sold 150,000 pounds of beans, up from 300 in 2001. This year, Sando predicts he'll sell 250,000 pounds.

If Sando has one message, it's that beans are versatile and easy to cook. Though he says he's "obsessed" with Mexican food (his collection of cookbooks includes dozens on Mexican cuisine), his new book also offers recipes inspired by India, Italy and Morocco. They all start with the same instructions: First, soak the beans in enough cold water to cover them by an inch. Sando soaks his for two to six hours, but with fresh, dried beans -- something that's not as oxymoronic as it sounds -- that's not always necessary. CityZen's Ziebold, for example, skips the soak and simply simmers them until they are tender.

Next, heat some oil or other fat and saute carrots, onions and celery, a classic mirepoix. Sando likes to uses one of the clay pots he has collected from Mexico, Colombia and Morocco (yet another obsession) because they heat evenly and add flavor. Then add the beans and water and bring to a boil, which helps break down the beans and makes them creamy. Turn down the heat and let the pot simmer until the beans are done. Sando's beans generally need to cook for one to two hours, far less time than older beans.

Despite Rancho Gordo's growth, Sando worries that there's a limit to how much the market for beans can expand. Although food mavens love the taste and diversity, some people will never be willing to spend several hours cooking.

And so, characteristically, Sando has a new plan: tortillas. Next spring, he plans to open a retail shop in Napa that sells homemade tortillas made with heirloom corn, such as Oaxaca's blue corn and Hidalgo's red. And if it's a success, he could start opening shops across the country.

"If I can get people excited about corn and tortillas in the same way we have about beans, we could begin rethinking what it means to eat like an American," he says.

Or, at the very least, give customers another good way to eat those beans.