All of our Cockles have been purified before you receive them and are ready to cook.
If any of your Cockles are open prior to cooking, simply give them a little tap and they should close.
If they do not close after a tap of the shell then discard them as they have unfortunately died.
Cockles are most commonly steamed, or boiled for a few minutes until all of the shells open up.
If there are a couple that do not open after cooking, again discard of these.