Food safety — read this first
Stop and deal with this first
Throw away any clams, mussels or oysters whose shells do not open during cooking. Bivalves filter-feed and can carry viruses and bacteria that only thorough cooking destroys, and the Food Standards Agency advises that people who are older, pregnant, immunocompromised or very young avoid raw or lightly cooked shellfish altogether.
Some mussels or oysters did not open
A shell that stays shut after cooking is the one troubleshooting case in BBQHQ with a regulator's instruction attached, and the instruction is to throw it away. The Food Standards Agency names clams, mussels and oysters together, so the same advice applies to all of them and not to mussels alone.
Work out which one it is
Each cause below lists the signs that point at it rather than at the others. Start with the signs, not with the fix.
The shell did not open during cooking.
commonSigns it is this one
- The shell is intact and shut after the others have opened.
Why it happens: Opening is the doneness signal the Food Standards Agency names for clams, mussels and oysters, and it is mechanical rather than sensory. A shell that has not opened has not given that signal, and the guidance covers the failures as well as the successes.
What to do
- Throw away any that do not open. Do not prise them. — after cook, reliable
Next time
- Discard any that are already open and will not close before cooking, and cook the rest until the shells open.
What this covers
This is BBQHQ’s diagnosis for still raw in the middle, on the foods below.