Mussels are a protein-rich, savoury shellfish often used in Italian and Mediterranean dishes. Prepared correctly, mussels are an enjoyable, texturally satisfying component of many meals. However, when mussels still have sand in them at meal time, the gritty texture can ruin the meal for everyone. The act of removing the sand and dirt from mussels prior to cooking them is called purging. Though most commercially sold mussels are pre-purged, it doesn't hurt to go through the purging process again, just to make sure your meal will be a success.
Inspect the raw, live mussels to make sure the shells are not broken. Do not purchase mussels with broken shells; throw out any that you might have.
Smell the mussels to make sure they have a faint smell of the sea, not a strong fish smell. Discard or do not purchase mussels that smell strongly of fish.
Submerge your mussels in a large bowl of cold, fresh water. Being live, the mussels should close immediately. Discard any mussels that don't close.
Scrub the mussels to remove the barnacles and black fibres.
Dissolve 1/3 cup of sea salt per gallon of cold water in a bowl, and place your mussels in the solution.
Stir in 1/2 cup of cornmeal and leave the mussels in a cold place for an hour or two. The mussels will eat the cornmeal and expel sand and dirt from their systems.
Rinse the mussels to remove the cornmeal before cooking them.