If your mussels are covered in mud or barnacles, rub handfuls of them together under running water before you start.
-Tap any mussels that are partly open and discard those that do not close tightly.
-Rinse or dip each mussel in cold water.
-Pull the straggly, hairy ‘beards’ from the mussels.
-(After cooking, discard any mussels that have not fully opened.)