Beans are also interesting as a social marker: Almost every culture has some sort of idea about what beans “mean.” In cultures where meat is an important part of the diet, beans are the first thing to go when fortunes improve, so beans become a marker of poverty there and low classes. It is like a unit of social analysis.

I couldn’t keep track of all the beans you wrote about, but it seems safe to say it’s in the three-figures range. How did you find them all?

Cookbooks don’t focus much on beans, so I mostly used agricultural reference works. In the 1970s, there were a lot of books published about introducing new bean species and agricultural techniques to developing nations.

What surprised me is that the beans we eat [in the U.S.] are almost all the exact same species. Black beans and kidney beans and pinto beans and Christmas beans — those are all the same species, and they’re just bred to be different colors and sizes. And, of course, the colors disappear when you cook them. People look at them in packages and think, “Oh, isn’t this beautiful,” but [the bean] turns brown when you cook it.

There are all sorts of beans that are really easy to grow and that are high in protein and low in fat that just have not been discovered. Some people are thinking about growing them, but Americans aren’t bean eaters, really. There are so many species that you don’t see in North America unless you look really, really hard.

Where did you get the recipes you include in the book?

The recipes are mostly all mine, but based on research. My favorite, I’d have to say, is the cassoulet — it’s the longest and most complicated, but if you have the right ingredients, it’s amazing. There’s confit duck legs and sausages, and [the dish] gets brown and crusty and beautiful. I never did get to Toulouse [France] for this book, but someday I will taste a real cassoulet.

In doing my research, I found it fascinating that in different cultures, beans are cooked in completely and utterly different ways. In the Philippines, they’re sweet and put on ice cream. And you find sweet bean paste in Japan, in cakes or frozen as bean pops — which are totally bizarre but great. In Africa, they’re ground up and fried into little cakes. In the U.S., we just think “Beans: You soak them and you cook them,” but they work with almost any flavor. You can pickle them, which makes them sour. You can salt them — like the salted black beans fried with soy or sweetened that you find in Chinese cuisine. Not many foods hold up to as many variations as that.

You include some strange recipes, too: Bean fudge from the Michigan Bean Council, and a bean fruitcake. Did you really try those?

I just put those in because they’re novel and a little gross, though I did make them. Of everything I tried, the thing I’d be least likely to eat again is natto [Japanese beans in a gelatinous mixture]. It was really, really bizarre — but I’ve been tempted to buy it again, just for the fear factor.

By the end of your year of beans, did you have favorites?

I really like tepary beans. They’re not easy to get, and they cost about $20 a pound, but for flavor and texture, they hold up well. They take several hours to cook, but it’s worth every second. But I think lupines are my favorite. Any good Italian grocery store will sell them; they’re called lupini. They’re more like olives — salty and a little sour and bitter — and you can cook them forever and they still remain crunchy. I have an addiction to them.

But one kind I still don’t care much for is lima beans. I didn’t include this in the book, but in cartoons there are a lot of things about beans, and in one cartoon I have, as a torture device, they feed people lima beans — like that’s the worst thing you could do to someone.

One thing that I was really surprised by were just how many different myths and rituals made use of beans; in particular, I was surprised to hear that in ancient Greece there was a concern that killing a bean plant meant killing a soul. Where did that come from?

It comes from Pythagoras; everyone in the ancient world comments on Pythagoras’ being vegetarian and not eating beans. Pythagoras not only wouldn’t eat them, but when [he and his followers] were being invaded, he wouldn’t cross through a bean field and was killed. The idea was that beans [contain] human souls in the process of transmigration. Souls go into the ground and are borne up through the hollow stems of the fava bean plants.

Where would you get that idea in the first place? Well, the rhizobium bacteria on the nodes of the plant’s roots draw nitrogen from the air, and add it back to the soil. But what I didn’t know is that the nodules also have something very much like human hemoglobin, except that it’s in the plant and binds with oxygen and makes it red like blood. So if you pull out a bean plant and break open the little nodes, there’s this “blood” inside. That might be why people thought beans were people being reincarnated.

Every time I cook with dried beans, they inevitably end up dry — and most of my friends report the same problem. What’s the secret to tender beans?

The problem is that the beans you find on the shelf in grocery stores often have been sitting there for a couple of years, and they get really, really tough and hard to cook — sometimes no amount of cooking will save them. Indian grocery stores are the best, not only for the variety but because [Indians] eat beans more often; the inventory moves there.

The universal rule is, if you can get them fresher, the better — dried but fresh. Soak them first overnight, and cook in absolutely plain, ordinary water. Not salt, not vinegar, not flavoring, not anything to start with. When they begin to get soft, then you can add the flavoring, and they’ll absorb it. Sometimes if you add salt, they never get soft. Or if you add some other flavoring, they harden. But I have to admit, I eat them out of a can more often — it’s just easier.

You write about how in Europe, there are bean classifications that denote heirloom varieties, and you even came across a gourmet food competition featuring heirloom bean varieties in San Francisco.

It’s sort of ironic: After so long of being looked down on culturally, beans have found a classy little niche. But it’s never just prepared ordinary pinto beans or navy beans; it’s usually some bizarre species. That’s the strange irony of the slow-food movement — it started as communist and now they’re selling these disappearing foods to gourmets. I don’t think it’s a bad thing because they’re promoting varieties that would otherwise disappear, but it’s kind of a reverse elitism. Traditionally, being elite has [meant] buying expensive stuff, like caviar and Champagne. This is turning all that on its head, saying we’re going to eat the lowest, most common of foods, and we’re assuming that only you can get it.

There are bean societies too, mostly in Europe. Some of them include growers and distributors, and they throw parties once a year and all get drunk and eat beans. Partly it’s financially motivated — I’ve met a few of them at fancy-food shows and things like that, and they all have agents there trying to sell these beans.

Americans aren’t really bean eaters, but beans do seem to show up in our comfort foods — like red beans and rice, and black-eyed peas — in ways that break along lines of race and class. What did you learn about that history?

Well, in some places, beans are stigmatized as immigrant foods. For instance, in Mexico there’s really no stigma about beans, but when Mexicans come to the United States they get called “beaners.” Then what you see is that later generations try to recover the recipes as markers of ethnic pride. To be genuinely African-American you cook black-eyed peas; to be Brazilian, you eat feijoada [a stew made of black beans, pork, onions and cassava]. Whatever it may be, there are things that are eaten traditionally that ethnic groups try to recover.

I think the best way to sell beans would be to use those recipes, the interesting ethnic ways beans are used. Goya has already started that; it began selling primarily to an ethnic market, but that trickled down to all sorts of consumers. Indian dals come in hundreds of forms and use all sorts of interesting beans with different textures and flavors, and those beans are the ones that are going to get people excited. Ethnic recipes and ethnic varieties are the future of beans.