WHILE TOP CHEFS INSIST ON USING FISH THE SAME DAY IT’S PURCHASED, that standard is sometimes unrealistic for mere mortals without a daily fishing boat service.

A good rule of thumb for the rest of us: Keep offerings from the ocean for no more than three days refrigerated.

They key to keeping seafood fresh is to buy it at the end of your shopping trip, so you can get it home quickly. Then put it in the coolest part of your fridge. If you’re really zealous, store it in a pan of crushed ice (put waxed paper between the fish and the ice). Some experts even advise giving the fish a rinse in salty water if you’ll be storing it for more than a day.

The more intact the fish, the fresher it will stay, so if you can find whole fish and are up for the deboning challenge, you’re better off buying that than precut. Larger fish, such as tuna and salmon, keep better than small fish, even if they are cut into steaks. Shrimp, scallops and crab deteriorate the fastest of all. The chefs are right on the money, don’t plan on keeping these for more than a day.