They're actually two separate yet closely related varieties of beans - like Red Delicious vs. Golden Delicious apples. Dark ones have a firmer texture, fractionally more nutrition, and take a little longer to cook. They are, however, interchangeable.
Last edited by Wolf Goddess; 03-07-2009 at 06:04 PM.
I prefer the light (especially in cans) because the skins on the darker beans are usually a lot tougher. The difference doesn't seem quite as bad when I've cooked from dry, but in the cans it just seems rare to find a dark red kidney bean that has a tender skin. White kidney beans (cannelini beans) are great too.
I substitute one variety of bean for another in all sorts of recipes. There are a lot more varieties available in dry form (it seems). The nutritional comparison and calorie content is similar enough that most are exchangeable for each other in my exchange plan also, so I aim for variety. I love "pink bean," which look like perhaps a variety of large pinto, but they're a pretty rose color. I love the speckled beans too (but some lose their speckles once cooked).
My Etsy shop (currently closed for the summer)