Originally Posted by Tesseract
Dried beans don't really go bad that I know of.
In my experience, that's not true. When you buy dry beans, they should have an expiry date, and I suggest that you don't eat them if they are older. Let's just say eating beans that have gone bad is an experience not worth having.
One way I've learned for testing if beans are gone bad (but I don't know if it's a good test...) is just to notice if they float up to the surface when you put them in water for soaking. If they do, they've gone bad. However, this is not true for all types of beans. Black-eyed beans is an exception, as they float up regardless.