How to Open Mussels for Stuffed Mussels

Start by cleaning the mussels. Those with closed shells are alive. Tap a mussel that is open, or squeeze its two shells together with your fingers; if it closes within a few seconds, it is alive and can be used. Discard it if it does not close. Set aside any mussels with cracked or broken shells as well. Check them one at a time rather than inspecting an entire bucket at once. After cleaning, rinse the mussels several times in plenty of cold water, until no sand is visible at the bottom.

The hairy tuft protruding between the shells is the mussel’s beard, which helps it attach to rocks; remove it. Pull the beard firmly toward the wider end of the shell, not toward its pointed end; pulling in the opposite direction can damage the mussel meat. For stuffed mussels, it is easier to remove the beard before opening them. Because pulling the beard kills the mussel, do this close to cooking time, not hours ahead, and do not let the cleaned mussels sit out. Place the debearded mussels in a separate container, cover them with a damp cloth, and keep the container in the refrigerator.

To open a mussel, place it in your palm with its flat edge facing up. Insert a knife through that flat edge into the narrow gap where the shells meet, and move it away from the hinge, not toward it. Pry the two shells apart without breaking the hinge. Take care not to cut the meat inside; it should remain whole in the lower shell. If the shell is opened too far, the hinge will crack and the mussel can no longer be used for stuffing.

Inspect the opened mussel once more. If there is sand or sediment inside, clean it with your fingers and water. Remove any fragments left along the shell edges, since they can get between your teeth after cooking. Leave the meat in place, spoon the rice over it, and close the shell. Arrange the stuffed mussels tightly in the pot with their flat edges facing up; packing them closely helps keep the shells from opening and the filling from spilling out during cooking. Do not add the rice while it is hot: cooled filling puts less strain on the shell and will not burn your hand as you work.

Place a heavy plate on top of the arranged mussels and add a small amount of hot water; the water should not cover the mussels, only the bottom of the pot. Cover and cook over low heat. When cooking is finished, let the pot cool on its own and do not stir while it is hot. Serve stuffed mussels cold and keep them briefly in a covered container in the refrigerator; do not eat stuffed mussels left at room temperature for more than two hours. At serving time, the upper half of the shell is used like a spoon, so keeping the hinge intact is useful at the table too.