Beans are an ideal staple: Not only are they easy to store, but once cooked they keep for days in the fridge or months in the freezer, which makes them a perfect make-ahead food.
Beans rarely go bad, but they do get old. In extreme cases they might taste musty, but more often age simply means they will require more water and time to soften up. Unfortunately, you have little way of knowing when beans were dried, though there are some visual cues; avoid packages with lots of broken beans, imperfect skins, and/or discoloration. Try to buy beans at a place where they’re frequently restocked. International groceries and natural food stores offer a great selection, and many specialty and regionally raised legumes are available online.
Store beans in a cool, dry place, not the fridge. Make sure they are tightly sealed, in either their original packaging or a plastic container or glass jar. Some people freeze their dried beans, but as this dehydrates them further, it’s not a great idea.
My recipes — and most others — instruct you to wash and pick over beans before cooking. This is because you will sometimes find discolored or bug-eaten beans, or pebbles, twigs, or small dirt clods. (This is especially true if the beans are not overly processed, not necessarily a bad thing.) Just take a minute to put the beans in a strainer or colander, run them under cold water, and swish them around with your hands while you give them a visual once-over.
Dried beans require a fair amount of water, heat, and time to become edible. How much water they absorb and how long it takes to cook them varies, depending largely on when the beans were harvested and dried. The time difference can be enormous — for example, chickpeas can cook in 45 minutes, or they might need 4 hours. (Soaking can save a little time; see “To Soak or Not to Soak,” page 428.)
The best way to cook legumes is at a gentle simmer in just enough water to cover them. Cooked this way, they will maintain their shape, even over long cooking. If you cook legumes at a rapid boil, the skins will tear, causing the beans to start to break down; if you’re looking for a creamy consistency, this is an advantage, but if you want intact beans, it’s not. The best way to test for doneness is by tasting them (eventually you’ll be able to tell at a glance when they’re nearly done); take the pot off the heat when they’re done the way you want them.