We recently discovered that my little boys love mussels. i've purchased them twice from Whole Foods (two different locations, Woburn and Medford) and once from Market Basket (Chelsea). I ended up tossing about half of the ones from both WF purchases, but only ~1/4 from the MB purchase, before cooking.
I'm pretty conservative about tossing them - I don't want to make my kids sick! - but is this typical? I sort through them and discard any that aren't tightly closed, then soak them in cold water for ~20 min and discard any that have opened and don't shut when I tap on them.
Is there a better place to buy mussels?