Fish, whether from fresh or salt water, is a healthful addition to your diet, providing both protein and important nutrients. Fish, however, spoils quickly when it is improperly stored — thawed fish doesn't have a long shelf life.
Refrigeration is essential to keeping fish fresh and knowing how long fish can remain in a refrigerator until it must be used can help prevent potential illness.
Eat refrigerated fish within two days of purchase or wrap it properly and place it in the freezer.
Refrigeration at Home
The U.S. Food and Drug Administration guidelines for storing seafood recommend that all seafood, including fish, be used within two days of purchase. It can be stored in a refrigerator, but if you will not use the fish within that time frame, wrap it tightly in freezer paper, foil or plastic wrap and store it in the freezer.
The American Heart Association recommends setting the refrigerator temperature to 40 degrees Fahrenheit or lower to keep fish fresh. Food items, especially seafood, held at temperatures above 40 degrees Fahrenheit for more than two hours should not be consumed due to risk of bacteria that can lead to food poisoning.
Field and Market Storage
If you are an angler and plan to eat what you catch, place your fish in a plastic cooler in plenty of ice. Leave the drain hole of the cooler open to allow water to escape from the cooler as the ice melts. Close the drain hole only when transporting your catch.
With enough ice, properly chilled fish will keep in your cooler until you reach home. Place just enough water and ice in your cooler to allow your fish to sink down into it with a gentle push, as recommended by the Alaska Department of Fish and Game.
When buying seafood, look for fish that is properly refrigerated at the fish market or grocery store. Typically, this means the market stores the fish either directly in a refrigeration unit or on ice within a display case. Also, ask yourself if the establishment is practicing safe food handling methods and if it looks and smells clean.
Read more: How Do I Know When Salmon Has Gone Bad?
Good and Bad Fish
Fish should have a mild and fresh smell. The eyes of fresh fish should look clear and should bulge just a little. Look for firm and glistening flesh that springs back when pressed. Whole fish should be free of body slime and have gills that are bright red in color.
If your fish smells sour, fishy or has an ammonia-like odor, or if the flesh color is dull, the fish may be old and should be discarded.
Frozen Fish, Thawed in Refrigerator
Avoid thawing fish at room temperature. This can lead to food poisoning. To thaw frozen fish properly, place it in the refrigerator overnight. This will allow the fish to thaw gradually and prevent it from spoiling. As an alternative method for thawing fish, place it in a sealable plastic bag and immerse it in cold water until thawed.
Thawing fish in hot water is not recommended — this can cause the superficial meat to begin to cook while the inside is still frozen. When it is completely thawed, keep the fish in a refrigerator for no more than two days before eating it.