Live mussels can be poached similarly to any other seafood, as long as you’re careful not to overcook them (they cook rather quickly). 

Discard any that are closed & much heavier than the others (likely filled with mud), or do not close when their shells are pinched together or they are lightly rinsed with cold tap water.  If desired, first soak your mussels in flour water (see how to prep live mussels) for extra flavor and color and scrub the shells with water & a wire brush before cooking. 

Remove the mussels from the pot as they open so they don’t overcook.  If desired, after removing the finished mussels, you can then strain court bouillon, fish stock, or fumet and continue to cook it for use as a soup base or sauce. 

Discard any mussels that refuse to open. 

Once cooked, poached mussel meat can be used in soups & salads, breaded and fried, or added to a huge variety of other dishes.  If reheating them, make sure to do so only until just heated through.  They’ll toughen if overcooked. 

We do not generally recommend storing mussels in their shells after cooking.