Fish is a delicious and healthy protein option to have on hand. But that frozen fillet or seafood needs thawing first before cooking up that amazing meal. Improper defrosting is a common food safety mistake made in home kitchens. As your Fish Safety Dad, let me walk you through the right ways to defrost fish and avoid potential bacteria issues or quality loss.

The U.S. Food and Drug Administration (FDA) estimates there are around 4 million cases of foodborne illness linked to contaminated fish and shellfish each year. Many risky pathogens can be destroyed by proper cooking temperatures. However, bacteria present in fish tissue or juices can spread in the kitchen and multiply rapidly during incorrect thawing.

But never fear. With some simple guidelines on hand, you can keep your family safe while enjoying the fantastic flavors of fresh fish and seafood after freezing. No matter if it’s flaky white fish, rich salmon, briny shellfish or another type, follow these best practices for defrosting.

Why Proper Defrosting Matters

Freezing fish to 0°F causes bacteria like Salmonella, Listeria or E. coli to enter a dormant phase. However, the microbes aren’t completely destroyed. As frozen fish begins to thaw and the temperature rises above 40°F, bacteria can revive rapidly if left in the “danger zone” between 40-140°F too long.

Juices from thawing fish can also spread pathogens around your kitchen. Contaminated surfaces and utensils then transfer bacteria to the defrosted fish or other foods. Thawing improperly leads to higher risk of foodborne illness – so let’s go over the safest techniques.

Thawing Times Vary by Fish Type

Defrost times depend on the size, thickness and variety of frozen fish. Follow these estimates:

• Fillets/Steaks: 1⁄4 to 1⁄2 inch thick – about 2 hours
• Whole fish: 1 to 2 pounds – 4 to 6 hours
• Lobster tails: 3 to 4 ounces each – 1 1⁄2 to 2 hours
• Crab legs: 7 to 8 ounces – 3 to 4 hours
• Shrimp: 1 pound bag – 1 1⁄2 to 2 hours

No matter the type of fish, allow ample time for full thawing in the refrigerator. Dense fillets, whole fish and shellfish require longer compared to thin fillets or shrimp. Monitor progress to determine total time needed.

3 Recommended Ways to Safely Defrost Fish

Now let’s review smart techniques for thawing frozen fish without damaging quality or risking foodborne illness.

1. Thaw in the Refrigerator

Refrigerator thawing is the foolproof method for any frozen fish variety.

• Place the frozen fish in a container or on a plate to catch drips. Thaw in the back of the 40°F or below refrigerator.
• Allow 6 to 8 hours per pound of fish. A 1 lb. bag of shrimp defrosts overnight.
• Cook fish within 1-2 days after refrigerator thawing. Do not refreeze.

The cold fridge temperature inhibits bacteria growth for safe, gradual thawing. While it takes more time upfront, refrigerator thawing gives you control to prevent pathogens from reviving in the danger zone.

2. Submerge in Cold Water

If you’re pressed for time, submerge wrapped fish in cold tap water.

• Place frozen fish sealed in a leak-proof bag. Change water every 30 minutes.
• Estimate about 30 minutes per pound to safety thaw fish.
• Cook fish immediately after thawing completes using this faster method.

Constant cold water accelerates defrosting. But you’ll need to monitor closely and keep that water very cold. Once thawed, cook fish promptly before bacteria can multiply.

3. Microwave Defrosting

A microwave can quickly thaw thin fish fillets in just minutes.

• Arrange fillets in a microwave-safe dish, covered with parchment to catch drips.
• Defrost at 30% power for 2 minutes, checking often. Rearrange and rotate to thaw evenly.
• Immediately cook the fish after microwaving to destroy bacteria. Do not refreeze.

Microwaves speed thawing by efficiently heating the outer layers first. But dense whole fish do not defrost as evenly. So the microwave works best for quick thawing of thinner cuts.

3 Thawing Methods to Avoid

Never use these risky fish defrosting methods:

• Room temperature – Leaving fish to slowly thaw for hours invites bacteria growth as interior temperatures enter the danger zone.
• Standing water – Submerging wrapped fish in warm water can also bring the internal temperature into the unsafe 40-140°F zone. Use only cold tap water.
• Outdoors/Garage – These unrefrigerated areas allow bacteria levels to rise as fish defrosts. Always thaw fish inside the refrigerator.

Thawing on the counter or in warm water allows fish to linger too long at temperatures where bacteria rapidly multiply to dangerous levels. Stick with the recommended safe thawing methods outlined above.

Handle Thawed Fish Carefully

Once fish is thawed, proper handling prevents contamination:

• Refrigerate immediately if thawed in cold water or microwave until ready to cook. Use within 1-2 days.
• Place thawed fish on a plate or bowl lined with paper towels in the coldest part of the refrigerator.
• Wash hands, utensils, sinks and surfaces that touched raw fish to avoid cross-contamination.
• Cook fish to an internal temperature of 145°F as measured by a food thermometer.

Follow these simple guidelines and you can safely enjoy delicious fish and seafood meals year-round, straight from the freezer. Let the Fish Safety Dad know if you have any other food handling questions!