Salmon is one of the most popular and nutritious types of fish. It is rich in omega-3 fatty acids, high quality protein, and various vitamins and minerals. Many people enjoy eating fresh salmon, but it can also be frozen for long-term storage. However, there is an important rule when it comes to freezing salmon: never refreeze salmon after it has been thawed.
What happens when you refreeze thawed salmon?
When you refreeze previously frozen and thawed salmon, the texture and quality of the fish deteriorates quite rapidly. The salmon flesh becomes mushy and watery in texture. The flavor is also negatively impacted, becoming more dull and muted. In addition, refreezing thawed salmon can allow for the growth of harmful bacteria. This makes the salmon unsafe to eat.
So why does refreezing thawed salmon have such detrimental effects on the quality and safety of the fish? There are a few reasons:
Ice crystal formation
When salmon is frozen, large ice crystals form throughout the flesh. These ice crystals physically damage the cell walls of the salmon. Then when the salmon thaws, these large ice crystals melt and the damage remains.
If you refreeze the thawed salmon, even more ice crystals form. The new crystals are even larger and cause even more damage to the delicate flesh. This leads to the mushy, watery texture.
Oxidation
Thawing also accelerates oxidation or exposure to air in the salmon flesh. This affects the fats in salmon in a negative way, breaking them down and causing rancidity. Refreezing thawed salmon further increases oxidation. This leads to major flavor and quality changes.
Bacteria growth
Finally, when salmon is thawed, any bacteria present has a chance to multiply. Usually salmon is frozen at extremely cold temperatures that prevent bacterial growth. However, thawing allows bacteria like Listeria or Salmonella to rapidly grow and multiply.
When the thawed salmon is refrozen, the bacteria are not killed off. They become inactive from the freezing, but revive once thawed again later. This makes refrozen salmon unsafe.
Proper thawing and refreezing of salmon
Now that you know why refreezing thawed salmon is undesirable, how should you properly thaw salmon if you want to refreeze any leftovers? Here are some guidelines:
- Thaw frozen salmon sealed in its package in the refrigerator over 24-36 hours. Do not thaw at room temperature.
- Cook the salmon immediately after thawing, until it reaches an internal temperature of 145°F.
- Promptly refrigerate any cooked leftovers in shallow airtight containers.
- Use leftovers within 3-4 days for maximum safety and quality.
- Cooked salmon leftovers can be safely refrozen for 2-3 months if properly stored in airtight packaging.
Following this thawing, cooking, cooling, and refreezing process will keep your leftover salmon safe while retaining optimal texture and flavor.
Alternatives to refreezing thawed salmon
If you find yourself with thawed salmon that you won’t be able to use up in time, there are some good ways to salvage it other than refreezing:
Cook and preserve
Cook the thawed salmon immediately and then preserve it by hot smoking, drying into jerky, or canning it. The cooking and preservation methods will prevent bacterial growth and spoilage.
Make salmon patties or salmon cakes
You can make fried salmon patties or cakes using thawed salmon, eggs, breadcrumbs or other binders. The cooking process will make the salmon safe to eat again.
Use in cooked dishes
Use the thawed salmon right away in salmon chowder, salmon salad, salmon pasta, or other cooked dishes. The thorough cooking will prevent problems with refreezing thawed salmon.
Pickle the salmon
Quick pickle the salmon in an acidic solution to preserve and extend its shelf life beyond the normal 3-4 days. Refrigerate pickled salmon for up to 2 weeks.
Safe thawing tips
To avoid having to refreeze thawed salmon, use safe methods to thaw it in the first place:
- Thaw in the refrigerator, never at room temperature or in hot water.
- Place frozen salmon in a bowl or leakproof bag before refrigerating.
- Allow 1 day to thaw 1 lb of frozen salmon.
- Cook salmon immediately after it is fully thawed.
Proper thawing means you can use up your fresh unfrozen salmon right away. You won’t have to worry about refreezing and its negative effects.
Storing fresh vs frozen salmon
Fresh and frozen salmon have quite different storage guidelines:
Fresh salmon storage
| Storage Method | Temperature | Maximum Storage Time |
|---|---|---|
| Refrigerator | 40°F or below | 2-3 days |
Frozen salmon storage
| Storage Method | Temperature | Maximum Storage Time |
|---|---|---|
| Freezer | 0°F or below | 2-3 months |
| Deep freezer | -4°F or below | 6-8 months |
As you can see, frozen salmon stays fresh and high quality for significantly longer than fresh never-frozen salmon.
Conclusion
In summary, it is not recommended to refreeze salmon after it has been thawed. Refreezing causes the salmon flesh to become mushy and watery in texture. Flavor is also negatively impacted. Most importantly, refreezing can allow bacteria to grow and pose a food safety risk.
Instead, thawed salmon should be cooked fully and consumed immediately. Any leftovers can be refrigerated for 3-4 days or refrozen only if they have been cooked. Follow safe thawing methods to begin with when thawing frozen salmon. Storing fresh salmon versus frozen salmon also requires different temperature and time guidelines.
By understanding why refreezing thawed salmon is problematic and learning how to properly handle frozen salmon, you can enjoy delicious, high quality salmon dishes safely.