Fish and shellfish are highly perishable, so careful handling matters from the moment they are bought or received. Keeping them cold, clean, and properly stored helps preserve quality and lower the risk of foodborne illness.
This guide explains what to look for when buying seafood, how to store it, and the safest way to cook and handle it at home or in commercial cold storage.
How to Choose Fresh Fish
Whether you buy fish from a wet market, fish stall, supermarket, wholesaler, or seafood supplier, start by checking how it looks and smells. Whole fish should have clear, bright eyes and firm flesh. Fillets and steaks should look moist and fresh, without dry edges or obvious discoloration.
Fresh fish should have a mild smell. If it smells sour, rancid, or strongly of ammonia, it is better to avoid it. Color can give you some clues, but it should not be the only thing you rely on. Fish naturally vary in color depending on the species, and their appearance can also change with handling and storage.
Also check how the fish is being kept. Some sellers use refrigeration, while others use ice or another cooling method. The main thing is that the fish stays cold and has not been sitting in warm conditions for too long.
How to Choose Fresh Shellfish
When choosing shellfish, the signs of freshness depend on the type you are buying. For live oysters, clams, and mussels, look for shells that are whole and undamaged. Avoid any that are badly cracked or broken.
If a shell is slightly open, tap it gently. It should close on its own. If it stays open, it is better to leave it. Live crabs and lobsters should still show some movement. Shrimp and scallops should feel firm and have a mild smell. Avoid any with a strong or unpleasant odor.
If the shellfish comes with tags, labels, or source information, keep them with the product. They can help show where the shellfish came from and make it easier to trace if needed.
What to Check When Buying Frozen Seafood?
Frozen seafood should be fully frozen when you buy or receive it. Avoid products that feel soft or show signs of partial thawing. Check the package for tears, open seals, or other damage. Damaged packaging can expose the seafood to air and moisture and may affect its quality during storage.
Heavy frost or large ice crystals inside the package can be a sign that the product has been stored for a long time or has gone through temperature changes. Some frozen seafood is covered with a thin protective layer of ice called glazing. This is normal and helps reduce moisture loss during frozen storage.
Freezer burn is different. It usually appears as dry, pale, or discolored patches and can affect the texture and flavor of the seafood. When choosing frozen seafood, the main things to look for are a fully frozen product, intact packaging, and no clear signs of thawing or freezer damage.
What is the Best Temperature for Storing Seafood
Refrigerated seafood should be kept at 4°C (40°F) or below. For fresh fish, temperatures closer to 0°C (32°F) can help maintain quality for longer when the fish is stored properly. Frozen seafood should be kept at -18°C (0°F) or below.
The key is to keep the temperature as steady as possible. Frequent warming can shorten the storage life of fresh seafood and affect the texture and quality of frozen products.
How Long Can Fish and Shellfish Stay Refrigerated?
Storage time varies depending on the type of seafood.
| Seafood | Storage at 4°C (40°F) or below |
| Fresh fish | 1–3 days |
| Fresh crab meat | 2–4 days |
| Fresh lobster | 2–4 days |
| Live crab or lobster | 1 day |
| Shrimp and crayfish | 3–5 days |
| Live clams, mussels, oysters, and scallops | 5–10 days |
| Shucked shellfish | 3–10 days |
| Squid | 1–3 days |
These are general storage guidelines. The actual shelf life also depends on how fresh the seafood was when you bought or received it. If you will not use fresh fish within a few days, freezing it is usually a better choice.
How to Store Fresh Fish
Put fresh fish into the refrigerator or chilled storage as soon as possible. Whole fish can be kept on ice in a suitable container. Fillets and steaks can be placed in a covered container and kept well chilled. If you use ice, let the melted water drain away rather than letting the fish sit in it.
When bringing seafood home from a wet market, fish market, or seafood shop, avoid leaving it in warm conditions for long periods. For a longer trip, a cooler with ice or frozen gel packs can help.
As a general rule, seafood should not be left unrefrigerated for more than two hours, or more than one hour when the temperature is above 32°C (90°F). Commercial deliveries should also be checked and moved into the correct storage area soon after arrival.
How to Store Live Shellfish
Live oysters, clams, and mussels should be kept in the refrigerator at 4°C (40°F) or below until you are ready to use them. Place them in a clean, shallow container with a damp cloth or paper towel. This helps keep them from drying out. Do not seal them in an airtight container or soak them in freshwater.
If water collects in the container, drain it so the shellfish are not left sitting in it. Use live shellfish while they are still alive and in good condition. Refrigeration slows spoilage, but it does not stop it completely.
How to Thaw Frozen Seafood Safely?
The safest way to thaw frozen seafood is in the refrigerator. Place it in a clean container and leave it there until it is fully thawed. This keeps the seafood at a safe temperature throughout the process.
If you need to thaw it more quickly, place the seafood in a sealed bag and submerge it in cold water. Change the water from time to time so it does not become too warm.
You can also use a microwave if you plan to cook the seafood immediately after thawing.
Avoid thawing seafood on the kitchen counter. The outer part can become warm long before the center is fully thawed, which gives bacteria more time to grow.
How to Prevent Cross-Contamination
Raw seafood can spread bacteria to hands, utensils, work surfaces, and other foods. Keep raw fish and shellfish separate from cooked food and anything that will be eaten without further cooking.
After handling raw seafood:
- Wash you hand thoroughly with soap
- Wash knives, cutting boards, plates, and work surfaces before using them again.
- Keep raw seafood juices from dripping onto other food.
In the refrigerator or cold room, keep raw seafood in clean, leak-proof containers. Store it where any accidental drips cannot reach other products. Good separation and regular cleaning help reduce the risk of spreading harmful bacteria during storage and preparation.
What Temperature Should Seafood Be Cooked To?
Finfish should be cooked to an internal temperature of 63°C (145°F). Check the thickest part with a food thermometer, especially when cooking thick fillets or steaks. If you do not have a thermometer, cooked fish should lose its translucent appearance and separate easily with a fork.
Shrimp, lobster, and crab are ready when the flesh becomes firm and develops a pearly appearance. Scallops should also feel firm and no longer look translucent in the center.
For clams, mussels, and oysters cooked in their shells, the shells should open during cooking. Discard any that remain closed. Shucked oysters and clams should be cooked until the flesh becomes firm and fully cooked through.
Because different types of seafood show different signs when cooked, use the appropriate temperature or doneness check for the product you are preparing.
Seafood Cold Storage
A cold room is useful when seafood is stored in larger quantities or needs to remain chilled or frozen for longer periods.
It is commonly used by wholesalers, processors, restaurants, supermarkets, distributors, and seafood suppliers that handle more product than a standard refrigerator or freezer can hold comfortably.
For seafood, the main purpose of a cold room is to provide enough space while keeping the storage temperature stable. It also makes it easier to separate chilled and frozen products, organize stock, and manage regular receiving and dispatch.
A cold room is usually worth considering when storage volume increases, seafood is handled every day, or temperature needs to be controlled more consistently across a larger space.
Wrapping Up
Safe seafood handling depends on keeping fish and shellfish cold, clean, and properly stored from the time they are purchased or received until they are prepared or sold. Paying attention to storage temperature, handling, thawing, and cooking helps maintain quality and reduce food safety risks.
When seafood is handled in large volumes, a cold room provides the space and temperature control needed for regular commercial storage. Sunnyda Cold Room can support businesses that need reliable chilled and frozen storage for seafood.
Frequently Asked Questions
1. How can you tell if fresh fish is good?
Fresh fish should have a mild smell, firm flesh, and a fresh appearance. Avoid fish with a sour, spoiled, or ammonia-like odor.
2. How long can fresh fish stay in the refrigerator?
Fresh fish is usually best used within a few days. If you will not use it soon, freezing is a better option.
3. Can frozen seafood be thawed at room temperature?
No. Thaw it in the refrigerator, in cold water inside a sealed bag, or in the microwave if it will be cooked immediately.
4. Can you refreeze seafood after thawing?
Seafood thawed in the refrigerator can generally be refrozen, although its texture and quality may decline. Seafood thawed by other methods should be cooked before refreezing.
5. Why does seafood need to stay cold?
Seafood is highly perishable. Keeping it cold slows bacterial growth and helps maintain its freshness and quality during storage.
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About The Author
Evan Wang
I am Evan Wang, the General Manager, Marketing Director, and SEO Expert at Sunnyda Cold Room. I have over 20 years of experience in the refrigeration industry, and my expertise is in commercial refrigeration solutions.
I’d be delighted to share practical ideas about refrigeration products, project selection, export trade, SEO, and marketing.
Let’s connect!
