How do you make sure there are no parasites in salmon?

November 22, 2025 •

3 min read

Parasites in salmon can be a concern, but proper handling and preparation methods can eliminate risks. Ensure there are no parasites in salmon by cooking it to a safe internal temperature or freezing it according to established guidelines.

Quick Summary

Follow reliable freezing or cooking procedures to ensure salmon is parasite-free. Understand the difference between wild and farmed salmon risks. Safe preparation is crucial, especially when consuming salmon raw or lightly cooked.

Key Points

Cook Thoroughly: Heat salmon to a safe internal temperature of 145°F (63°C) to kill all parasites and bacteria.
Properly Freeze for Raw Use: For sushi or sashimi, freeze salmon at -4°F (-20°C) for at least 7 days, or follow FDA blast-freezing protocols.
Choose Farmed or Reliable Source for Raw Fish: Farmed salmon raised on formulated, parasite-free feed is lower risk. Ensure any raw-intended fish is from a reputable supplier who follows freezing guidelines.
Conduct Visual Inspection (Candling): Shine a bright light through a salmon fillet to check for the shadows of parasitic worms and remove them with tweezers if seen.
Practice Proper Handling: Keep salmon refrigerated or on ice, use separate cutting boards for raw fish, and avoid cross-contamination.
Avoid Lightly Cured Raw Fish: Be aware that curing processes alone, like salting or marinating, do not reliably kill all parasites in raw fish.

Essential steps to ensure parasite-free salmon

Parasites in fish, especially salmon, can worry consumers. However, simple techniques can ensure a safe meal. For any salmon not cooked to a high internal temperature, such as when preparing sushi, sashimi, or ceviche, proper freezing is crucial to kill potential parasitic worms like Anisakis.

The definitive guide to freezing salmon

The U.S. Food and Drug Administration (FDA) and other health authorities provide specific freezing time and temperature combinations to destroy parasites. These are designed for commercial operations but can be replicated at home.

Method 1: Standard Freezing: Keep salmon at -4°F (-20°C) or below for at least 7 days (168 hours).
Method 2: Flash Freezing: Freeze at -31°F (-35°C) or below until solid, and then hold at that temperature for at least 15 hours.
Method 3: Two-step Freezing: Freeze at -31°F (-35°C) or below until solid, and then hold at -4°F (-20°C) or below for at least 24 hours.

Most home freezers do not get cold enough for the flash-freezing methods, so the 7-day, -4°F approach is the most practical for home cooks. Always ensure the fish is completely frozen solid through to its thickest part.

Proper cooking to kill parasites

Cooking is the most reliable way to eliminate parasites in salmon, as heat will kill any parasites present. Use a food thermometer to ensure salmon reaches a safe temperature.

The FDA recommends cooking fish to an internal temperature of 145°F (63°C). Confirm this by inserting a meat thermometer into the thickest part of the fillet. At this temperature, the salmon's flesh will turn opaque and flake easily.

Visual inspection and sourcing

Visual inspection can provide extra reassurance, especially if buying fresh, wild-caught fish. The process is known as candling.

How to candle at home: Place the salmon fillet on a clear, clean surface and shine a bright light from underneath. This can help you spot the shadows of any tiny parasitic worms embedded in the flesh. If any are found, you can use tweezers to remove them or simply cut the affected part away. However, some worms can be embedded too deep to see.

Consider the source of the salmon. Farmed salmon is generally considered lower risk for parasites than wild salmon because its diet is controlled and free of live parasites. This is why many farms can sell their product to be eaten raw without prior freezing. Wild salmon, especially wild Pacific salmon, can have a higher natural prevalence of parasites like Anisakis.

Wild vs. Farmed Salmon: Risk Profile


Feature	Wild-Caught Salmon	Farmed Salmon (Aquacultured)
Parasite Exposure	Higher risk due to diverse natural diet and environment.	Lower risk due to controlled, pellet-based diet that lacks infective hosts.
Recommended Prep for Raw Use	Mandatory freezing according to FDA guidelines to kill parasites.	Can be eaten raw without freezing if supplier guarantees specific farming practices.
Common Parasites	Anisakis (roundworms), Diphyllobothrium (tapeworms).	Sea lice can be an issue in net pens, but are external. Risk of human-infective parasites is low if fed parasite-free feed.
Sourcing Info	Traceability is key; know your fisher and processing chain.	Requires documentation from supplier confirming feed and raising conditions.

Conclusion

Ensuring salmon is free of parasites is straightforward when following the correct procedures. Cook any salmon to a safe internal temperature of 145°F. For raw consumption, the salmon must be properly frozen beforehand or sourced from a reliable supplier who can guarantee parasite-free aquaculture methods. Visual inspection can be helpful, but is not a complete substitute for freezing or thorough cooking. By understanding the risks associated with different types of salmon and adhering to best practices, you can enjoy this nutritious seafood safely. For more information on fish preparation and safety, visit the FDA's official seafood guidance.

Proper salmon handling and storage

Proper handling is crucial to prevent bacterial contamination. Keep salmon chilled, preferably on ice, from the time of purchase until prepared. Use separate cutting boards and utensils for raw fish to prevent cross-contamination. For raw-intended fish, rapid chilling and controlled freezing processes are key to preserving quality and ensuring safety. When thawing frozen salmon, do so slowly in the refrigerator to maintain its best texture. Never thaw fish at room temperature. For cured salmon, like gravlax, commercial processors typically freeze the product to kill parasites before the curing process, as the salt curing alone is not enough.

Frequently Asked Questions

The term "sushi-grade" is not regulated by the FDA and is primarily a marketing term. Reliable retailers use this label to indicate the salmon has been handled and frozen according to specific standards to kill parasites. Buy from a reputable fishmonger and confirm their processing methods.

Not necessarily, if it comes from a trusted aquacultured source that uses a formulated, parasite-free feed. However, if the farm raises fish in net-pens in open waters, freezing is still required. Always ask your supplier for documentation of their practices.

Use a technique called candling by placing the fillet on a clear surface with a bright light underneath. This can reveal the shadows of parasitic worms, allowing you to remove them with tweezers. However, some worms may be too deep to see.

No, salt curing, marinating, or smoking without sufficient heat does not reliably kill all parasites. For gravlax or other cured raw preparations, the salmon should be frozen according to FDA guidelines first.

Standard home freezers generally do not reach the sub-zero temperatures required to reliably kill all parasites. The safest method for home freezing is holding the fish at -4°F (-20°C) or below for 7 days.

Wild salmon carries a higher risk of parasites because it consumes a more diverse natural diet that can include intermediate hosts. Farmed salmon, when fed a controlled, parasite-free diet, has a much lower risk.

For most fish, cooking to an internal temperature below 145°F increases the risk of foodborne illness. Some high-end fish can be served rare if they have been flash-frozen to kill parasites, but it is not recommended for home cooks without proper freezing verification.

Common parasites include roundworms (nematodes), like Anisakis, which are found in marine fish, and tapeworms (cestodes), which can be found in freshwater fish or anadromous species like salmon.