Any mussel experts out there?

For tonight's supper, I made a curried mussel dish from a recipe in the San Francisco Chronicle. I bought the mussels at a new place called "Fins" that just opened near here. They combine a restaurant and fish market, although I'd have to say the emphais is on the restaurant end. I bought two pounds of farmed mussels that came in a net bag. They looked just like the mussels I've bought at a high end grocery store here.

When I went to start scrubbing the little guys, I first noticed that we had more duds than usual. I tossed at least a dozen for being open and non-responsive to stimuli. That was a bit annoying, but the weird part came when we went to eat the ones that were left (and hopefully I can explain this in a manner that makes sense). They all opened to some extent, but instead of there being a discrete lump of mussel sitting there to be detached from its foot, there tended to be a rather thin "mussel membrane" that stretched the length and breadth of the shell. It was attached at numerous points with thin filaments and was nearly impossible to get out of the shell in one piece. These filaments also connected both halves of the shell and made it very difficult to open shells all the way. It made for a disappointing meal as you had to work a lot to get very little from each one.

So I'm wondering what happened here? I don't think it was the cooking technique as they were tasty and seemed cooked through. I'm wondering if this had to do with the time of year or the source of the mussels or something like that. We like mussels a lot here, so if there's something I can do to get better ones next time, I'd be grateful to know what it is.

Mike

Mike, I'm not sure what causes this problem in mussels but it may have to do with shipping/storage issues. I have seen this numerous times over my last year as a fishmonger. As for the dead mussels that were open, if you threw away about a dozen then that is about what I would expect to toss out of two pounds pre-pack.

Here is my suggestion: Never buy shellfish of any kind pre packaged. Ask your fishmonger to go through the shellfish right before your eyes and toss any that are open. If you are buying in the range of 7-10 pounds then you can buy the whole bag but they should cut you a deal to account for your loss. Also, your shellfish should be kept on ice; you need to be able to see this in the display.

If your fishmonger refuses to do this then you need to find another source. It usually indicates that they buy from unreliable sources and/or have poor storage capability. Try and find a place that focuses solely (no pun intended) fish retail.

One other thing: the best times to buy shellfish are during the months that are not spelled with the letter Y. These are the summer months and shellfish are usually considered out of season. That doesn't mean that you can't get good ones but is just a rule of thumb.

Hope that helps.

rwj

Thanks much, Robert! The ones we bought were on ice, but I think the idea of having the bag opened and the mussels sorted before I paid for them is a great one. Not something I'd have thought of but it makes obvious sense.

Mike

[Jenise]

Strange--it sounds like they just weren't developed, doesn't it? Like you got them in the placenta stage of life or something.

Strange--it sounds like they just weren't developed, doesn't it? Like you got them in the placenta stage of life or something.

Yep. Odd little things, and very disappointing to Miss Isabella. The curry was good, though.


Mike

Strange--it sounds like they just weren't developed, doesn't it? Like you got them in the placenta stage of life or something.

Jenise, I don't think that was the problem. If the mussels were the standard size (shell being about 2" long) then the meat inside should have been mature.

I think that this is a shipping/storage issue. When we cooked some mussels the other night (and anytime I cook them) there are always some that don't open fully or are just empty. I think that durning shipping you lose some and the same with storage.

This is just an educated guess, though. I can't say that I know for sure. What I can say is that it is strange that almost all of the mussels came out that way.

rwj

I've noticed this, too. I've been cooking mussels for about 35 years and they seem to get more anemic all the time.

I don't know the cause for sure, but I have a suspicion. There are varmints called "tunicates" that hang out on mussels and steal their food. This means the mussels take months longer to mature. They don't harm the mussels, but they do pilfer their nutrition. I suspect some musselmen are harvesting early.

I've noticed this, too. I've been cooking mussels for about 35 years and they seem to get more anemic all the time.

I don't know the cause for sure, but I have a suspicion. There are varmints called "tunicates" that hang out on mussels and steal their food. This means the mussels take months longer to mature. They don't harm the mussels, but they do pilfer their nutrition. I suspect some musselmen are harvesting early.

I think you've hit on it, Chef. From what I remember of mollusk life history from my days as a Biologist (before I repented and entered Computer Engineering), mussels of harvestable size are mature adults organisms. But not necessarily grown to full size.

Ah, tunicates! Although you'd never know it to look at them, they are actually distant cousins of ours--fellow members of the phylum Chordata, which includes mammals, reptiles, amphibians, fish, amphioxus--and tunicates. The larval tunicate resembles other chordates. It is a free-swimming organism with a notochord (cartiliginous rod--we have one in our backbones), and a fairly well-developed nerve ganglion cluster in the head (primitive brain). It swims hither and yon, seeking just the right rock (or mussel). When it finds what it thinks is just the right environment, it settles down and attaches itself to the rock (or mussel). It then absorbs its primitive brain and backbone, becoming as an adult essentially just a pair of filter-feeding siphons, a stomach, and genitalia.

The only other place this phenomenon occurs among the chordates is in university professors, who flit from place to place seeking the correct environment, then similarly metamorphose once granted tenure.

-Paul W.

Interesting! I could see this as being the problem, although the mussel farm these came from must have a hell of a tunicate problem. Still, they did seem to be at some different stage of life from a mature mussel, even though their shells were in the 2-3" range.


Mike

More info on tunicates and mussels in this story

So my next question: will the mussel shells develop to the proper size after a tunicate infestation?

Mike

Again, all I have is a suspicion. If mussels are like oysters, shell growth is dependent largely on water temperature and is not a true indicator of the meat size. Hmmm,that sounds vaguely obscene...reminds me of a Seinfeld episode...