Last week I made paella using the recipe from America's Test Kitchen. It turned out beautifully, except that something was wrong with my mussels. They seemed fine when I scrubbed them... I threw out a few that were spoiled but the rest of them were tightly closed.
This recipe uses a dutch oven and finishes cooking in the oven (I guess this is blasphemy for paella hounds). Anyway, the recipe said to arrange the mussels in the rice hinge side down, cover the pot and put it back in the oven for 10-15 minutes. After following these instructions, most of the mussels had opened, but they did not look normal. Instead of the familiar plump oval shaped morsel, there was very little meat, and what was there was sort of mucus-y and stringy. Some of them looked a little more normal... most of us did not eat any mussels since they were questionable. However, my grandmother insisted that they were fine... she ate a lot and did not get sick. Any ideas?? Do you think that they were simply old? We bought them from a reputable seafood dealer but this was in Pittsburgh, PA...
Well if they were closed tightly before cooking and opened when cooked, I'm sure they were fine. Sometime you just get small mussels in larger shells. It can have something to do with being wild versus farm raised as well as the season. But, as a rule of thumb, better safe than sorry when it comes to shell fish/mollusks. I'd rather risk wasting $10-$20 worth of mussels than be in the bathroom all night.
I've recently been disappointed with tiny mussels in large shells too. Taste was fine but scarcely worth the trouble. Frozen New Zealand mussels are are useful alternative, if they're not too old (check the packing date on the box) but of course the fact of being on the half shell diminishes the amount of juice you get for your paella.
I've found most fresh mussels in my area (Boston) to be very small regardless of the size of the shells. I usually prefer to use the frozen mussels I buy from Asian grocery stores which are enormous. I think these are New Zealand mussels, or something similar. I would not put these into a hot oven for any length of time, they just need to be warmed briefly.
Is it possible that it was overcooked and the meat looked small because all the moisture was cooked out so it wasn't plump looking? Cooking in a dutch over may have been too much heat for the mussels.
The worst mussels I have had - and by that I don't mean toxic, just crummy - were small, shrivelled and skinny. I think this has to do with how long they've been from harvest and how they were kept before sale. I figure that they're living creatures, right? So they have to eat and be taken care of to stay healthy and plump. I suspect that some mussels suffer in transport, losing weight and getting badly jetlagged. I have, therefore, become quite picky about buying them. If the bag looks like it's been around a while, if many of the mussels look broken or unhappy and if too many of them turn out to be defunct when closely examined, I won't buy them. This is probably what happened with yours. Skinny, grumpy and hungry mussels. It happens.