On Food and Cooking

begun to stiffen. Fortunately, fish in rigor
aren’t as tough as beef or pork would be.
It’s a mistake, however, to cut up a freshly
killed, pre-rigor fish into steaks or fillets,
and not either cook or freeze the pieces
immediately. If rigor develops in the
pieces, the severed muscle fibers are free
to contract, and they will shorten by as
much as half into a corrugated, rubbery
mass. If instead the pieces are quickly
frozen, and then allowed to thaw gradually
so that the muscle energy stores slowly run
down while the piece shapes are
maintained by some ice crystals, this
contraction can be mostly avoided.
In the case of a whole fish:
The skin should be glossy and taut. On
less fresh fish it will be dull and
wrinkled. Color is not a helpful guide
because many skin colors fade quickly
after the fish dies.
If present, the natural proteinaceous