Shrimp is a delicate food that can go bad quickly if not stored properly. When frozen, shrimp can last up to 6 months in the freezer before quality starts to decline. However, there are some telltale signs that indicate your frozen shrimp has spoiled and is no longer safe to eat.
Appearance
One of the first signs that frozen shrimp has gone bad is its appearance. Good quality frozen shrimp will look firm and pale pink or light gray in color. As shrimp starts to spoil, it will develop a yellow or brown discoloration.
Frozen shrimp that has gone bad will also have a mushy or soft texture compared to healthy shrimp that is still firm when frozen. The flesh may appear mealy or gelatinous rather than firm. Severely spoiled shrimp may even have a slimy texture.
Examine the shrimp for any dark spots or pitting on the flesh as this indicates the growth of mold and bacteria.
Odor
Smell is one of the most immediate ways you can detect spoiled shrimp. Fresh frozen shrimp has little to no odor. As it starts to go bad, an ammonia or rotten smell will become noticeable.
The scent may be subtle at first but will get stronger the longer the shrimp has been sitting in the freezer past its prime. A very pungent “fishy” or rotten odor means the shrimp has likely gone completely bad and should be thrown away.
Expiration Date
The expiration date on the packaging is a good indicator if your frozen shrimp is still safe to eat. Commercially frozen shrimp typically lasts up to 6 months past its production date if stored consistently at 0°F. Once the expiration date has passed, the quality starts to go downhill.
For best quality, try to use frozen shrimp within a month or two of purchasing. But if the shrimp has been stored properly, even shrimp a few months past its date may be okay. Apply the sight and smell tests to make the final call.
Time in Storage
How long has the shrimp been sitting in your freezer? Frozen shrimp that has been stored for over 6 months should be tossed, regardless of what the expiration date says. The long storage time leads to declining texture and flavor.
Make sure to label any frozen shrimp with the date you put it in the freezer. First In, First Out (FIFO) inventory management also helps. Eat older frozen shrimp first before newer additions.
Temperature Fluctuations
Constant temperature fluctuations are one of the biggest enemies of frozen shrimp longevity. The shrimp must remain frozen solid at all times for best preservation. Any thawing and re-freezing will speed up degradation.
Check that your freezer is consistently maintaining a temperature of 0°F or below. Pay attention if you notice the shrimp has thawed and refrozen into a block of ice as this is a red flag that it may be spoiled.
Freezer Burn
While freezer burn does not make frozen shrimp unsafe, it definitely makes the shrimp dry and tough in texture. Freezer burn happens when the shrimp is exposed to air in the freezer which removes moisture. It appears as white/grayish spots on the surface of the shrimp.
Heavily freezer burned shrimp will still be edible if cooked properly but will have an unappealing chewy texture. Light freezer burn is not as detrimental to quality and can be minimized by vacuum sealing the shrimp.
Cooking Spoiled Shrimp
What happens if you cook expired frozen shrimp? Cooking can destroy some bacteria that has grown on spoiled shrimp but may not eliminate toxins the bacteria release as the shrimp goes bad. While cooked spoiled shrimp may not make you sick immediately, there are health risks involved.
The high temperatures during cooking can breakdown toxic compounds into non-toxic byproducts. However, it does not remove the off-flavors associated with spoiled shrimp. At best, cooking spoiled shrimp will result in poor texture and taste. At worst, toxins may still remain that can cause foodborne illness.
When in Doubt, Throw it Out
Shrimp that displays any signs of spoilage should be discarded even if you intend to cook it. The smell test in particular is one of the best ways to determine if your frozen shrimp has gone bad during storage. Trust your senses – if it smells funky or unpleasant, it’s not worth taking a chance by eating seafood that may have harmful bacteria present.
Proper Storage of Frozen Shrimp
To maximize frozen shrimp shelf life, ideal storage is important:
- Keep frozen shrimp at a steady temperature of 0°F or below.
- Minimize opening and closing the freezer door to prevent temperature fluctuations.
- Use airtight, moisture-proof packaging like freezer bags or vacuum sealed pouches.
- Place frozen shrimp on lower shelves of the freezer where temperature is coldest.
- Avoid overcrowding the freezer which reduces air circulation.
- Defrost frozen shrimp safely in the refrigerator, not at room temperature.
How to Spot Fresh Shrimp
When buying fresh rather than frozen shrimp, look for the following qualities:
- Firm, elastic flesh that springs back when pressed gently
- Bright color with translucent shells
- Sweet, mild saltwater scent
- Moist appearance without drying around edges
- Stores on ice or refrigerated below 41°F
Fresh raw shrimp has a more delicate texture and sweeter flavor than frozen. But fresh shrimp has a shorter shelf life of just 2-3 days in the refrigerator. Frozen shrimp provides more flexibility if you don’t plan to use it immediately.
How to Freeze Raw Shrimp at Home
To freeze raw shrimp at home:
- Buy fresh, high quality shrimp and use within 2 days for best flavor.
- Clean and dry shrimp thoroughly. Discard any spoiled pieces.
- Separate shrimp pieces so they freeze individually.
- Use an airtight freezer bag or vacuum sealed pouch.
- Squeeze out excess air and seal the container.
- Label bag with contents and freeze-by date.
- Freeze immediately at 0°F. Do not allow shrimp to sit at room temperature.
- Once frozen solid, shrimp keeps 6-12 months in the freezer.
With proper handling, raw shrimp can be successfully frozen at home for long-term storage. Follow the storage guidelines above to prevent freezer burn and quality loss during freezing.
Thawing Frozen Shrimp
Always thaw frozen shrimp slowly and safely in the refrigerator. Avoid thawing at room temperature as this allows bacterial growth in the outer layers while the inner areas remain frozen.
For quickest thawing, place vacuum sealed frozen shrimp in a bowl of cold water. Change the water every 30 minutes until thawed. Otherwise allow shrimp to thaw overnight in the refrigerator.
Microwave defrosting is not recommended as it cooks the shrimp unevenly. Only use the microwave if the shrimp will be cooked immediately afterwards.
Once thawed, use raw shrimp within 1-2 days for peak freshness. Do not refreeze thawed shrimp.
How to Tell if Cooked Shrimp Has Gone Bad
It is difficult to determine if cooked shrimp that was previously frozen has gone fully bad, as the signs of spoilage become less clear after cooking.
There are a few indicators that cooked shrimp should be discarded:
- Strong “off” odors, especially sour, sulfurous, or ammonia scents
- Unusual surface discoloration or mushy texture
- Sliminess
- Mold growth
Most leftover cooked shrimp lasts 3-4 days in the refrigerator if stored in an airtight container. Discard any cooked shrimp that is older than 4 days after cooking.
For optimal safety and quality, freeze cooked shrimp within 1-2 days. Portion into freezer-safe containers or bags and use within 2-3 months.
Can You Freeze Previously Frozen Shrimp?
Previously frozen raw shrimp can be safely refrozen if necessary, but the second freeze will further degrade texture and taste. Thaw the shrimp in the refrigerator before refreezing.
To refreeze cooked shrimp, allow it to fully cool first, then package in airtight containers or freezer bags. Avoid refreezing shrimp more than once as the quality diminishes quickly.
For best results, try to use thawed, previously frozen shrimp within 3-4 days in the refrigerator. Refreeze only if you cannot use up the shrimp in time. Store no more than 2 months before use.
Conclusion
Frozen shrimp can last up to 6 months in the freezer before going bad, as long as it is stored properly and consistently at 0°F. Look for changes in color, odor, appearance and texture to determine if your frozen shrimp has spoiled during storage. When in doubt if the shrimp has gone bad, it is best to discard it. Follow safe defrosting, cooking and refreezing guidelines to prevent foodborne illness from eating contaminated shrimp.