I bought 1/2 pound of mussels and cooked them in a cast iron skillet with a little white wine and some shrimp stock on boiling heat.

Almost all of them opened after about 15 minutes, some did not. The ones that opened were done perfectly, and those were the ones I served.

Still, in the future - should I just throw away the rest, or would a few more minutes in the skillet be in order?

  • 1
    Man .. I shouldn't get on this site before lunch!
    – tomjedrz
    Jul 16, 2010 at 20:14
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    www.abc.net.au/science/articles/2008/10/29/2404364.htm Check out this site, it will debunk the myth about throwing away mussels that do not open. They are safe to eat.
    – John
    Jun 6, 2012 at 6:37
  • The primary source is the report Improving post harvest handling to add value to farmed mussels, by Nick Ruello, ISBN 0-9577695-12. It contains quite a bit of detail in the appendices, including specific advice to restaurateurs. Jun 6, 2012 at 12:42
  • 15 minutes? Sounds like about ten minutes too long to me. Is it because you are using a skillet (without lid?) and not a pot?
    – citizen
    Sep 11, 2012 at 20:29
  • @citizen Yes, the skillet (even though I pre-heated) is quite heavy and takes a bit more time to get up to temperature (I had recently purchased it prior to asking this question, and was still getting used to it). Once it's hot, 5 - 7 minutes is generally all it takes, even in a pan uncovered (closer to 7 uncovered).
    – user293
    May 6, 2014 at 14:45

5 Answers 5


You should throw them out. Mussels that don't open were quite possibly dead and decomposing for an unknown period of time prior to cooking. You don't want to take a chance here.

Just in case future readers don't know, mussels, clams, and other in-shell shellfish are still alive when you buy them, and they should be still alive when you cook them.

  • 1
    +1 - I concur. If the fraction of dead mussels was significant, I would go complain to the place they were purchased.
    – tomjedrz
    Jul 16, 2010 at 20:14
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    I agree tomjedrz. You should also be using them the same day of purchase, and keep them on ice in the refrigerator until they are ready.
    – hobodave
    Jul 16, 2010 at 20:16
  • Agreed. You really don't want to risk eating off mussels. Jul 16, 2010 at 20:42
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    You can keep the mussels in salt water in the fridge for some days, but not too long. Take out the dead ones immediately. The dead ones don't close when touched. Sep 13, 2011 at 21:43
  • Before you throw them out see abc.net.au/science/articles/2008/10/29/2404364.htm
    – TFD
    Jan 22, 2013 at 8:09

In the future, I would recommend the following: When washing the mussels before cooking, if any are slightly open try gently closing them. If they react by snapping closed themselves or they stay shut, it means the mussels are alive and well. If instead they react by immediately popping back open, throw them out (they are dead). I've found that the majority of the dead mussels are slightly open before cooking; they rarely are completely, tightly closed. Using this method, when you actually cook the mussels, you have a reasonably good idea that they are all alive and therefore safe to eat, regardless of whether or not they open all the way during cooking. After cooking there will likely be none that are closed, but if there are, there will likely be few and you can discard them if you like.


When mussels don't open when cooked, it means that they were dead before you cooked them. Don't eat them you risk becoming very very sick.


A friend of mine (professional cook) told met to steam mussels extra hot, lid closed. In about 5' they should be open and done. They are done when they open. Don't leave them cooking any longer than necessary as they'll toughen up.


As far as I know, if you spray fresh live mussels with cold water they will open slightly. If they don't open, throw them out.

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