Prepare cockle clams for cooking by placing them in a bucket of salt water to remove dirt and debris. The clams should stay in the water from 30 minutes to 1 hour. Steaming is the preferred method for cooking cockle clams.
Cockle clams are safe to cook only if they are still alive. If the clam shell is open, tap the shell on a firm object to see if the shell closes. Cook the cockles with water and an acidic ingredient such as white wine or vinegar. Steam them until the shell begins to open. Once the shells open, remove the cockle clams from the acidic water mixture and serve.