Couscous smells musty
A while ago, I found a great deal on a bag of couscous at my Middle Eastern grocery. It looked exactly like the stuff in the Near East box, so I've been preparing it the same way: boil water with a little olive oil and salt, add couscous, and let it absorb off the heat.
Recently, we've noticed that the finished product smells musty.
Does couscous go bad? I figured that since it's pasta, its shelf life ought to be essentially indefinite. I keep it in an air-tight glass container.
If the whole thing is old, I really don't mind tossing it all out, since it was only about $4 for 2 pounds. But I hate to go back to paying grocery store prices for those teeny boxes of name brand couscous.
Am I preparing it wrong? Is there something I could be doing (rinsing, etc), to take away the musty smell?