AboutCarol Schlitt Expertise I can answer questions on home food safety, sanitation, home food preservation and commercial food safety (HACCP).
Experience I am an Extension educator, nutrition, wellness and food safety. I am a certified HACCP manager and a food safety instructor for the Illinois Department of Public Health.
Organizations International Association for Food Protection, American Association of Family and Consumer Sciences (Certified CFCS), National Extension Association of Family and Consumer Sciences, Society for Nutrition Education.
Education/Credentials BS - University of Illinois
MS - Southern Illinois University at Edwardsville
Question QUESTION: The other day we bought 4 pounds of mussels, and my wife and I disagreed about whether to discard the mussels that wouldn't close. I rinsed and tapped all of them. About half of them closed almost completely, meaning there was a tiny slit still open. The rest of them closed totally. I said we should discard those that didn't close completely before cooking because that means they are dead. She said cook them and just discard the ones that didn't open up after cooking them (7 minutes of simmering in white wine). In the end most of them opened widely. Who was correct?
ANSWER: Hi David,
The general rule of thumb is if you tap a mussel and it does not respond by closing, then you should discard it as it is dead.
You were right...you should have discarded those that did not close completely before cooking them.
Carol
---------- FOLLOW-UP ----------
QUESTION: About half of them did not close completely before cooking. The opening slit was about 1/16 inch or less. Does that mean they were dead, and if yes, how could they have opened after cooking? Most of them opened widely after cooking. Puzzled.
Answer Hi David,
Heat will cause mussels to open -- whether they were initially alive or dead. Those that did not close completely were probably still partially alive but just not healthy enough to completely close their shell.
For highest quality you want to consume those mussels that completely close when tapped.
