How to Purge Molluscs

Wash the shellfish well, pressing each gently to ensure it is alive. It is not uncommon for a shell full of mud or sand to work it's way into the group. But, a good pinch will usually reveal these impostors.

Discard any shellfish which do not close relatively quickly when disturbed.

Immerse shellfish in 1/3 cup salt per gallon of cold water. Soak for several hours. This should encourage the little creatures to spit out any grit they've collected.

Drain and scrub once more.

Store on ice over a strainer, covered with a damp cloth. This keeps them cold and moist, but not immersed in fresh water (which will kill them and make them go bad).

Cook off a few and taste to check for grit. It's always better to find a problem before it's on a plate.