Thawing and refreezing fish is not recommended from a food safety perspective. However, if fish has been properly thawed under refrigeration and kept at a cold temperature, it may last for several days before going bad.
How should you thaw fish?
The best way to thaw fish is in the refrigerator. Place the frozen fish in a container to catch any liquid that seeps out as it thaws. Allow approximately 24 hours for every 1 pound of fish to thaw in the fridge. For example, a 2 pound fillet of salmon would take about 48 hours to thaw.
You can also submerge the fish in cold water, changing the water every 30 minutes until thawed. This method allows the fish to thaw more quickly, usually within a few hours depending on the size.
Microwaving is not recommended for thawing fish because it may start to cook the exterior before the inside has fully thawed. This leads to uneven cooking later on.
How long does thawed fish last in the fridge?
Thawed fish that has been kept chilled at 40°F or below will generally last for 3 to 4 days in the refrigerator before deteriorating. The timeframe depends on a few factors:
- Type of fish – Lean fish like cod and tilapia tend to last a day or two longer than fattier fish like salmon and tuna.
- Freshness – Fresher fish that was frozen quickly at peak freshness will last longer.
- Surface area – Fillets and steaks will last longer than small pieces or ground fish which expose more surface area.
For best quality, it’s recommended to cook thawed fish within 1 to 2 days. The taste and texture start to diminish after that time in the fridge.
Does cooking thawed fish restore freshness?
Cooking thawed fish that is nearing the end of its refrigerated shelf life can extend the time it may be safely eaten but it does not restore optimal quality. The texture and flavor of the fish will continue to degrade.
Any odors and slime formation indicate the fish has spoiled and it should be discarded rather than cooked and consumed.
Can you refreeze thawed fish?
It is not recommended to refreeze fish after it has been thawed. The moisture lost during the thawing process encourages bacterial growth. Refreezing may allow those bacteria more time to multiply to unsafe levels.
However, if thawed fish has been kept refrigerated at 40°F or below then it may be refrozen within a limited window:
- Lean fish like cod – 1 to 2 days after thawing
- Fatty fish like salmon – 1 day only after thawing
The quality of the fish will decline after refreezing. It’s best to cook fish within the recommended refrigeration times after thawing.
How can you tell if thawed fish has gone bad?
Rely on your senses to determine if previously frozen and thawed fish has spoiled:
- Sight – The flesh is discolored or has dark spots. There’s thick slime on the surface.
- Smell – An unpleasant “off” or ammonia-like odor is noticeable.
- Texture – The flesh is very mushy when pressed with a finger.
When in doubt, remember the old adage: “If it smells bad, it is bad.” Don’t taste fish that smells rotten or appears slimy.
Storing thawed fish to maximize freshness
To get the most out of thawed fish, store it properly to maintain quality and prevent waste:
- Keep thawed fish chilled at 40°F or less until ready to cook.
- Place thawed fish on a plate lined with paper towels to absorb excess moisture.
- Cover the fish tightly with plastic wrap to prevent drying out.
- Use thawed fish within 1 to 2 days for best flavor, texture, and freshness.
Quick tips for thawed fish
Follow these simple guidelines when handling thawed frozen fish:
- Thaw in the refrigerator, not at room temperature.
- Cook within 1 to 2 days after thawing.
- Discard if fish has an unpleasant odor or appearance.
- Don’t refreeze thawed fish more than 1 day after thawing.
- Store thawed fish tightly covered on a plate lined with paper towels.
How to tell if thawed fish is still good?
Here are some signs that thawed fish is still fresh and good to eat:
- Firm, shiny flesh
- Bright, clear eyes
- Bright red gills
- No discoloration or dark spots on flesh
- Mild, briny sea smell – not fishy or ammonia-like
- Flesh springs back when pressed gently
If your thawed fish has those characteristics, it should be fine to cook and eat within the recommended 1 to 2 day refrigerated shelf life after thawing.
What happens if you eat bad fish?
Eating spoiled fish can cause foodborne illness, with symptoms like:
- Nausea
- Vomiting
- Abdominal cramps
- Diarrhea
- Headache
- Fever
- Chills
The severity of symptoms and length of illness depends on the type of bacteria, amount consumed, and health status of the individual. People with weakened immune systems are more susceptible to severe illness from spoiled fish.
How to store fresh fish to prevent spoilage
Here are some tips for storing fresh fish to prevent spoilage and maximize shelf life:
- Keep fish very cold at 32-40°F immediately after purchasing.
- Place fresh fish on ice or in the coldest part of the refrigerator.
- If freezing, wrap fish tightly in plastic and freeze as quickly as possible.
- Cook or freeze fresh fish within 1-2 days of purchase for best quality.
- Don’t cross-contaminate by letting raw fish drip on other foods.
- Store cooked fish tightly covered for 3-4 days in the refrigerator.
Proper storage helps retain moisture, texture, and flavor while inhibiting bacterial growth that causes fish to spoil quickly at warmer temperatures. Handle fresh and thawed fish carefully to avoid foodborne illness.
Shelf life of common types of fish
The refrigerator shelf life of fish depends on the species. Here is a table summarizing how long different types of fresh fish will last stored at 40°F:
| Type of Fish | Refrigerator Shelf Life |
|---|---|
| Lean fish like cod, tilapia, flounder | 3-4 days |
| Fatty fish like salmon, tuna, mackerel | 2-3 days |
| Whole fish and fillets | 1-2 days |
| Shrimp, scallops, squid | 1-2 days |
| Smoked fish | 14 days |
The sooner fish is cooked or frozen after catching or purchasing, the better its eating quality will be. Follow basic food safety guidelines for storing, thawing, and handling fish to reduce foodborne illness risks.
Conclusion
For highest quality, it’s best to cook fish within 1-2 days after thawing in the refrigerator. Properly thawed fish can last up to 3-4 days if kept chilled at 40°F or less. Do not refreeze thawed fish more than 1-2 days after thawing. Discard fish with an unpleasant odor or appearance. Follow proper storage methods and rely on your senses when determining if previously frozen fish is still fresh and safe to eat after thawing.