Safe Fish Storage and Preparation

—by Kate Wagner, HPC Member

The consumption of fish and seafood increases dramatically in February and March, as many Christians observe the season of Lent. This is a good time to educate ourselves about how to buy, store, prepare, and cook fish safely, as well as how much fish is safe to eat.

Buy the Best

Fish tastes “fishy” when it hasn’t been handled properly. To avoid “fishy” fish, use your senses when making your purchase. Fish should have a fresh and mild odor. It should be firm to the touch and “spring back” into place after you remove your finger. If you can see your finger print after you touch it, or if it has a strong odor, it's not fresh.

Don’t buy cooked seafood, such as shrimp, crab, or smoked fish, that is displayed in the same case as raw fish. Juices from the raw fish can transfer bacteria onto the cooked or ready-toeat fish. For frozen seafood, avoid frost or ice crystals. These are signs that the fish has been stored for a long time, or thawed and refrozen.


Because of its high protein content, fish spoils quickly. Spoilage begins as soon as the fish dies. Ice is the key to fresh-tasting fish. One pound of ice for each 2 pounds of fresh fish is a good rule of thumb.

Freeze fish at 0° F or lower. Fish stored at 15° F for as little as 2 weeks will show a significant loss of quality. Freeze for no more than 4-6 months. Never refreeze fish.

If refrigerating, store fish in the coldest part of the refrigerator. Allow air to circulate freely around the package. Store uncooked fish below ready-to-eat foods.

Guidelines for safe storage:

  • If seafood will be used within two days after purchase, store it in the refrigerator.
  • If seafood won’t be used within two days after purchase, wrap it tightly in moisture-proof freezer paper or heavy-duty foil or freezer bags to protect it from air leaks, and store it in the freezer.

Thaw It Safely

Fish cooks more evenly if thawed before cooking. For best quality, thaw overnight in the refrigerator. If you need to thaw fish quickly, place it in a sealable plastic bag and put it in cold water for about an hour. To thaw in a microwave,, use the “defrost” setting; remove the fish while it is still icy but pliable. Cook immediately.

Preparing and Cooking Fish

If you are baking or broiling fish, allow 10 minutes per inch of thickness. Flesh should be white and flaky (155° F on a food thermometer). Don’t overcook it. Cooking fish for too long or at too high a temperature will toughen it, dry it out, and destroy the flavor. If you don’t have a food thermometer, there are other ways to determine whether seafood is done.

  • Fish: Slip the point of a sharp knife into the flesh and pull it aside. The flesh should be opaque and separate easily. If you cooked the fish in the microwave, check it in more than one spot.
  • Shrimp and Lobster: The flesh becomes pearly-opaque.
  • Scallops: The flesh turns milky white or opaque and firm.
  • Clams, Mussels, and Oysters: When the shells open, they are done. Discard those that don’t open.

Cooking also destroys harmful bacteria and parasites. Outbreaks of the broad fish tapeworm infections have occurred in Minnesota due to the consumption of uncooked pickled pike. Don’t eat raw fish unless it has been frozen at 0° F for 48 hours to destroy parasites. After freezing, it is safe for pickling.

Prevent Cross-Contamination

When you’re preparing fresh or thawed seafood, it’s important to prevent bacteria from the raw seafood from spreading to ready-toeat food. Take these steps to avoid cross-contamination between raw and cooked foods:

  • Wash hands thoroughly with soap and warm water before and after handling any raw food.
  • Wash the cutting board with soap and hot water to remove food particles and juices after using it for raw foods such as seafood, and before using the board for cooked or ready-to-eat foods or preparing another food item.

As an added precaution, sanitize cutting boards by rinsing them in a solution made of one teaspoon of chlorine bleach in one quart of water. Plastic boards can go through the wash cycle in your dishwasher. Or, consider using one cutting board only for raw foods and another only for ready-to-eat foods such as bread, fresh vegetables, and cooked fish.

As a rule of thumb, avoid using cutting boards that are made of soft, porous materials. Instead, choose those made of hard maple or plastic, and make sure they are free of cracks and crevices. Smooth surfaces can be cleaned more easily and thoroughly.

Cross-contamination can happen once your seafood is cooked, too. Here are simple ways to keep your seafood safe when serving:

  • Place cooked seafood on a clean plate for serving. If cooked foods are placed on an unwashed plate that previously held raw seafood, bacteria from the raw food could contaminate the cooked seafood.
  • Use clean utensils to serve food, not those used to prepare raw food.




University of Minnesota Extension Service Department of Food Safety Education and Research and the US Food and Drug Administration Center for Food Safety and Applied Nutrition.

For information about safe amounts of fish to eat, see this article at the Minnesota Department of Health.