Until a few years ago, Kenneth "Chip" Morris didn't know beans about beans. Now he's full of beans.

When the Clarksburg, Calif., farmer lost a major contract for tomatoes, he started looking around for a new crop to grow. He considered several before settling on beans.

Now Morris grows 90 varieties (classified as heirloom or organic) and sells them through select stores, at farmers' markets and online at www.beanbag.net.

Not just any beans, mind you. He grows -- and actively promotes -- heirloom beans, which he discovered at the Monterey Market in Berkeley. It was love at first bite.

"They're so beautiful, and they have a great history," he says.

Few people know they exist, so Morris and a handful of other heirloom bean growers around the country are working to change that.

"The more common beans, such as the pinto, the kind you find in every supermarket, are hybrids," he explains. "They've been bred to be stronger and to resist disease, which is fine, but they lost taste and tenderness in the process.

"Heirloom beans, on the other hand, have to be handled with great care, but their flavors are incredible," Morris says. "They're far more tender. More nutritious, too. They come in beautiful colors and vary quite a bit from one to another."

He describes a few: "The marrow bean is wonderfully smoky, like bacon. Christmas limas taste just like chestnuts. The eye-of-the-goat bean, a dream bean for vegetarians, seems to have all sorts of spices in it. You don't have to add any; it just naturally has their flavors."

Like heirloom varieties of other plants, heirloom beans hark back to the 19th century. They gradually surrendered shelf space to a handful of hybrids during the 20th century. The hybrids were developed for increased production and marketing durability, not for taste.

What makes a bean an heirloom? Mike Holleman, corporate chef for Indian Harvest Specialtifoods Inc., a major grower and distributor, defines them this way: "They must come from seeds passed down from generation to generation without any genetic modification."

Steve Sando, a Napa Valley farmer who does food commentaries for radio station KVON in Napa, says, "The trouble with the more common beans is that they're old, lack variety and taste ... while the taste of heirloom beans knocks your socks off."

Sando bows to no one in his appreciation of them. He eats some every day "and some days I'll eat them at every meal, even for breakfast -- I like them mashed on toast."

His favorite variety? "Whichever one I ate last," he says.

Among those he consumes most frequently are scarlet runners, which have a "beefy taste, especially if you mix them with mushrooms," yellow Indian woman ("marvelously creamy") and runner cannellini ("as light as the wings of a butterfly"). Runner cannellini, he notes, should not be confused with Eastern cannellini beans, one of the common supermarket beans, "which are not nearly as good."

Heirloom beans, even more than common supermarket beans, are also healthful. They're high in protein, fiber, vitamins and minerals and low in fat and cholesterol. "But to me that's just a fringe benefit," Sando says.

If you're feeling adventuresome, Morris, the Clarksburg bean farmer, suggests experimenting with different heirlooms to see which you prefer. "Then, the next time, buy more of the ones you like and try a few additional ones," he adds.

Where to get heirloom beans:

Many farmers' markets and some supermarkets carry heirloom beans. They're also available through the Internet or by mail order:

The Bean Bag, www.beanbag.net or (800) 845-2326 (website/phone currently not working)

Phipps Country Store & Farm, www.phippscountry.com or (650) 879-0787

Purely American, www.purelyamerican.com or (800) 359-7873

Purcell Mountain, Farms www.purcellmountainfarms.com or (866) 440-2326

Editor's note: For those who want to grow their own heirloom beans, seeds for several types are sold in the gift shop at Conner Prairie (a recreated 1840s village), north of Indianapolis, at Fishers, Ind. Learn about this wonderful living museum at www.connerprairie.com.