Look for fresh-smelling whole fish with shiny skin; reddish pink, moist
gills; and clear, bulging eyes. The flesh should spring back when you
press it lightly. Choose fish fillets that look moist and not dry. Get
tightly sealed, solidly frozen packages of frozen fish.
Avoid fresh whole fish whose eyes have
sunk into the head (a clear sign of aging); fillets that look dry; and
packages of frozen fish that are stained (whatever leaked on the package
may have seeped through onto the fish) or are coated with ice crystals
(the package may have defrosted and been refrozen).
Remove fish from plastic wrap as soon as you get it home. Plastic keeps
out air, encouraging the growth of bacteria that make the fish smell
bad. If the fish smells bad when you open the package, throw it out.
Refrigerate all fresh and smoked fish immediately. Fish spoils quickly
because it has a high proportion of polyunsaturated fatty acids (which
pick up oxygen much more easily than saturated or monounsaturated fatty
acids). Refrigeration also slows the action of microorganisms on the
surface of the fish that convert proteins and other substances to
mucopolysaccharides, leaving a slimy film on the fish. Keep fish frozen
until you are ready to use it. Store canned fish in a cool cabinet or in
a refrigerator (but not the freezer). The cooler the temperature, the
longer the shelf life.
Preparing and Cooking Fish
For fresh fish, rub the fish with lemon juice, then rinse it under cold
running water. The lemon juice (an acid) will convert the nitrogen
compounds that make fish smell "fishy" to compounds that break apart
easily and can be rinsed off the fish with cool running water. Rinsing
your hands in lemon juice and water will get rid of the fishy smell
after you have been preparing fresh fish.
As for frozen fish, defrost plain frozen fish in the refrigerator or
under cold running water. Prepared frozen fish dishes should not be
thawed before you cook them since defrosting will make the sauce or
Salted dried fish. Salted dried fish should be soaked to remove the
salt. How long you have to soak the fish depends on how much salt was
added in processing. A reasonable average for salt cod, mackerel,
haddock (finnan haddie), or herring is three to six hours, with two or
three changes of water.
When you are done, clean all utensils thoroughly with hot soap and hot
water. Wash your cutting board, wood or plastic, with hot water, soap,
and a bleach-and-water solution. For ultimate safety in preventing the
transfer of microorganisms from the raw fish to other foods, keep one
cutting board exclusively for raw fish, meats, and poultry, and a second
one for everything else. Finally, don't forget to wash your hands.