1. Scrub all barnacles off of unclean mussels with a sponge, pot scourer or vegetable brush and some cold water.
2. The "beard" is the part of the mussel that allows it to attach itself to rocks. The fuzzy strand protrudes from the side of the shell.
3. Grab hold of the beard and pull firmly to remove it from the mussel.
4. The beard should separate cleanly from the shell (it may require a firm tug), and your clean, debearded mussel is ready to go!