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What happens if you refreeze thawed fish?

Thawing and refreezing fish is generally not recommended from a food safety standpoint. However, if done properly, it may be possible to refreeze fish without too much quality loss. Here is an overview of what happens when you refreeze thawed fish and some best practices to follow.

Can You Refreeze Thawed Fish?

Yes, it is possible to safely refreeze thawed fish in most cases. However, there are some important caveats to keep in mind:

  • Quality will degrade – Refreezing will cause the texture to become mushier and drier.
  • Only refreeze once – Fish that has been thawed and refrozen should not be thawed again.
  • Use thawed fish within 1-2 days – For best quality, thawed fish should be eaten soon and not refrozen if possible.
  • Cook refrozen fish thoroughly – Refrozen fish should always be cooked thoroughly to destroy any bacteria.

As long as proper handling procedures are followed, refreezing thawed fish is generally safe from a food safety standpoint. However, it tends to have a noticeable impact on texture and quality.

Why Refreezing Degrades Quality

There are a few reasons why the texture and quality of fish degrades when thawed and refrozen:

  • Ice crystal damage – The ice crystals that form during refreezing cause damage to the cell structure of the flesh.
  • Protein denaturation – Thawing and refreezing denatures proteins in the fish, affecting moisture retention and structure.
  • Oxidation – Repeated thawing and refreezing increases oxidation, leading to rancidity and off-flavors.
  • Drip loss – Thawed fish tends to weep and lose moisture when refrozen, leading to dryness.

For these reasons, thawed fish tends to become mushy and dry with a mealy or spongy texture when refrozen. The flavor also deteriorates, with increased incidences of rancid and “fridge burn” off-notes.

Proper Handling for Refreezing Fish

If you need to refreeze thawed fish, follow these guidelines for best quality and safety:

  • Only refreeze fish that was properly thawed in the refrigerator, never at room temperature.
  • Make sure the fish was kept cold (40°F or below) during thawing.
  • Refreeze the fish immediately after thawing, within 1-2 days max.
  • Use airtight, moisture-proof packaging to prevent oxidation and freezer burn.
  • Portion the fish into smaller pieces or fillets before refreezing.
  • Freeze the fish as quickly as possible, at 0°F or colder.
  • Once refrozen, keep the fish frozen solid until ready to use.
  • When ready to use, thaw the fish slowly in the refrigerator again.
  • Cook refrozen fish thoroughly to an internal temperature of 145°F.

Following proper fish handling procedures from catch to plate is always advisable. However, if you do need to refreeze thawed fish, these tips will help retain maximum quality and safety.

How Long Can Refrozen Fish Last?

The shelf life of thawed and refrozen fish depends on a few factors:

  • Type of fish – Lean fish like cod keep longer than fattier fish like salmon.
  • Freezer temperature – Fish frozen at 0°F lasts longer than -10 to 15°F.
  • Freezer burn – Minimize exposure to air and moisture loss.
  • Number of thaws – Quality deteriorates more with each additional thaw.

Properly handled, refrozen fish will typically last:

  • Lean fish fillets: 4-6 months
  • Fatty fish fillets: 2-4 months
  • Whole fish: 6-8 months

Compare this to 9-12 months or longer for fresh fish continuously kept frozen. Eat refrozen fish within these time periods for best quality.

How to Tell if Refrozen Fish Has Spoiled

Signs that refrozen fish has spoiled and is unsafe to eat include:

  • Sliminess or very soft, mushy flesh
  • Gray, brown or yellow discoloration
  • Strong, fishy, ammonia or cucumber-like smell
  • Unnatural darkening/greening along bones or bloodline
  • Dry, spongy or gaping flesh
  • Unnatural stickiness or tackiness
  • Significant freezer burn or dehydration
  • Dull, faded appearance vs. glistening sheen

Always rely on your sense of sight, smell and touch to determine if thawed or refrozen fish has gone bad before consumption. When in doubt, throw it out.

Is it Safe to Eat Refrozen Fish?

Safety-wise, properly refrozen fish is generally safe to eat. However, special care should be taken when refreezing certain fish:

  • Raw fish – Only refreeze very fresh, sushi/sashimi grade raw fish once.
  • Smoked fish – Refreeze only if vacuum-packed; keep 3 weeks max.
  • Shellfish – Refreeze very fresh shrimp, scallops, etc. once.
  • Fatty fish – Higher risk; eat refrozen salmon, trout within 1 month.

Provided good handling procedures are followed, thoroughly cooked refrozen fish does not pose any greater food poisoning risk than fresh fish. However, people with compromised immune systems should avoid refrozen seafood whenever possible.

How to Use Refrozen Fish

Refrozen fish is best suited for dishes where texture and moisture are less important. Here are some good uses:

  • Chowders, stews, and soups
  • Casseroles and baked dishes
  • Fish cakes, croquettes, and fritters
  • Salads and sandwiches where fish is cut into smaller pieces
  • Sautéed or fried fish

Avoid using refrozen fish for sushi, ceviche, tartare, or where fish is served whole or in large fillets. The deterioration in texture and moisture will be more apparent.

Does Cooking Refrozen Fish Make it Safe?

Yes, thoroughly cooking refrozen fish to an internal temperature of 145°F will make it safe to eat from a food safety standpoint. The heat destroys any dangerous bacteria that could be present.

Bear in mind that cooking cannot reverse the quality changes from refreezing that affect texture and flavor. The fish will be safe to eat, but the eating quality may suffer.

Always cook refrozen fish dishes like casseroles, fish cakes, and chowders thoroughly until steaming hot throughout. Cook fish fillets and steaks to 145°F at the thickest part.

Partial Thawing Then Refreezing

It’s risky to refreeze fish that has only been partially thawed. The flesh on the outside edges may begin to spoil even while the inner portion remains frozen.

Only refreeze fish that has been completely thawed throughout. If caught in a partial thaw, it’s best to continue thawing the fish in the refrigerator until no ice crystals remain before cooking it.

Refreezing Thawed Frozen Fish

Commercially frozen fish from the store can be safely thawed and refrozen provided it was handled properly:

  • Thaw frozen fish sealed in packaging in the fridge, never at room temp.
  • Check that the fillets feel cold, firm and look fresh after thawing.
  • Rewrap and refreeze the thawed fish immediately if not using right away.

As long as the frozen fish was of good quality and thawed properly in the fridge, refreezing will not make it unsafe. However, the eating quality will decline.

Can You Refreeze Cooked Fish?

It is not recommended to refreeze previously cooked fish. The risks include:

  • Bacterial growth during initial cooling and thawing
  • Recontamination after cooking
  • Questionable quality due to leaching of moisture and proteins

Only freeze cooked fish if absolutely necessary, for use in recipes where it will be thoroughly reheated like casseroles. Otherwise, it is best to avoid refreezing previously cooked seafood if possible.

Storing Thawed Fish Safely

To safely store thawed fish that won’t be eaten right away:

  • Keep it in the fridge in an airtight container.
  • Use within 1-2 days at most for quality and safety.
  • Keep thawed fish as cold as possible, ideally below 40°F.
  • Place on a plate or bowl and cover to prevent contamination.

Avoid letting thawed fish linger for prolonged periods in the refrigerator. Try to freeze refreeze it within 1-2 days if it won’t be eaten soon.

Can Refrozen Fish Make You Sick?

Thawed, refrozen fish is unlikely to cause illness if handled properly. But there are some food safety risks to keep in mind:

  • Pathogenic bacteria like Listeria or Clostridium botulinum if severely mishandled.
  • Scombroid poisoning from time/temperature abuse of oily fish like tuna, mackerel.
  • Parasites like cod worm are a concern in undercooked refrozen fish.
  • Quality issues like rancidity and freezer burn provide favorable conditions for bacterial growth.

Properly refreezing fish and cooking it thoroughly mitigates most of these risks. But it’s especially important to handle at-risk individuals like pregnant women and children with caution.

Alternative Uses for Thawed Fish

Instead of refreezing, here are some other good uses for thawed fish:

  • Cook fresh and enjoy the optimal texture and flavor.
  • Make marinated or pickled fish dishes.
  • Use in raw applications like sushi, poke bowls, ceviche.
  • Prepare canned, smoked or cured fish like rillettes or brandade.
  • Cook and freeze breaded fish portions for later use.

Finding an alternative like cooking, curing, or marinating is preferable to refreezing thawed fish from a quality perspective. But refreezing thawed fish is generally safe when done properly.


While not ideal, refreezing thawed fish is an option if handled properly. Thaw frozen fish in the fridge, keep it chilled below 40°F, and refreeze it promptly after thawing for 1-2 days max. Refreeze fish only once, use appropriate packaging, and cook thoroughly when ready to consume. Implement strict sanitation to avoid bacteria. While safe, the texture and moisture will be compromised compared to fresh never-frozen fish.