Shrimp are nutritious, delicious and quick to prepare. Having them in your freezer gives you a lot more dinner options. They can make scampi, paella, fried rice, and gumbo taste better. But if your frozen shrimp smells fishy or has freezer burn, it has spoiled and should be discarded.
Shrimp is one of the most popular seafood items around. The sweet, briny flavor of fresh shrimp is hard to beat. But like any perishable food shrimp doesn’t last forever. If not stored and handled properly shrimp can spoil and take on a foul, fishy odor. This distinct fishy smell is not normal and indicates the shrimp has gone bad.
So what causes frozen shrimp to smell fishy, and how can you avoid it? Here’s a detailed guide covering common reasons for fishy odors in frozen shrimp and tips to keep your shrimp fresh.
What Causes a Fishy Smell in Frozen Shrimp?
Shrimp naturally has a mild, ocean-like scent. Fresh, unspoiled shrimp should not have a strong fishy or ammonia-like odor. Here are a few of the most common causes of a stinky fishy smell:
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Bacterial growth – Shrimp is highly perishable and bacteria can rapidly multiply if the shrimp was mishandled during processing storage or transport. This will create a stronger unpleasant smell.
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Improper freezing – Freezing shrimp slowly or re-freezing thawed shrimp breeds bacteria and causes a fishy odor.
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Oxidation – Exposure to air causes oxidation in shrimp, creating a rancid smell. This happens more quickly at warmer temperatures.
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Contamination – Things like bilge water or diesel fuel can contaminate shrimp during fishing or processing leaving a chemical taint.
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Overcooking – Cooking shrimp for too long can make it rubbery and smelly. This intensifies any existing off-odors.
How to Tell if Frozen Shrimp Has Gone Bad
Aside from the smell test, here are some other signs that indicate frozen shrimp is spoiled and should be discarded:
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Unnatural coloration – Bad shrimp may appear yellowish or grey rather than translucent.
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Slimy texture – A sticky, slimy feel means bacteria has taken hold.
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Mold growth – Look for fuzzy mold on thawed shrimp. Discard any moldy pieces.
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Soft, mushy flesh – Frozen shrimp should still have some firmness when thawed.
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Ripped flesh – Damaged, ripped meat indicates poor handling.
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Discoloration – Darkening around veins may signal the start of decomposition.
Tips to Keep Frozen Shrimp Fresh
Follow these guidelines to help your frozen shrimp stay fresh and odor-free:
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Buy high-quality shrimp – Reputable sellers and recognizable brands are less likely to sell old, spoiled product.
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Check expiration dates – Don’t purchase frozen shrimp past its sell-by or use-by date.
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Inspect packaging – Avoid packages that are open, damaged or have signs of freezer burn.
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Keep frozen until ready to use – Thaw shrimp in the refrigerator not at room temperature.
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Use thawed shrimp promptly – Cook within 1-2 days; don’t refreeze thawed shrimp.
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Store at 0°F or below – Colder freezing minimizes chemical reactions that cause spoilage.
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Seal packages tightly – Prevent freezer burn by squeezing out excess air.
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Divide bulk packages – Smaller portions freeze faster with less oxidation.
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Clean freezer regularly – Eliminate any drips and spilled food that can cross-contaminate.
What to Do With Smelly Shrimp
If you thawed or cooked your frozen shrimp only to be met with a potent fishy odor, don’t panic. Here’s what to do:
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Discard the spoiled shrimp immediately so it doesn’t make other food smell.
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Clean out your refrigerator, containers, utensils and surfaces that came in contact with the shrimp.
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Contact the seller or store for a refund or replacement if the shrimp was spoiled upon purchase.
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Review how and where you stored the shrimp to prevent future spoilage.
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Wait 24-48 hours before placing new shrimp in the same freezer to allow odors to dissipate.
Frequently Asked Questions
Still have some lingering questions about foul frozen shrimp? Here are answers to some common FAQs:
Is it normal for thawed shrimp to smell a little fishy?
A very mild seafood smell is OK, but shrimp should never have a strong fishy or ammonia-like odor, even when thawed. Any noticeable stench means it’s gone bad.
Can you get rid of the fishy smell by cooking bad shrimp?
No. Cooking will not eliminate spoilage odors or make smelly shrimp safe to eat. Always discard shrimp with an unpleasant odor.
Is grayish shrimp ok or should it be translucent?
Good shrimp should look relatively translucent when thawed. Grayish, yellow or milky spotting likely means bacterial growth has occurred.
How long is frozen shrimp good for?
Properly frozen shrimp will last 9-12 months in the freezer before quality starts to decline. Discard any frozen shrimp over a year old.
Can refreezing thawed shrimp make it smelly?
Yes. Refreezing previously frozen shrimp can accelerate bacteria growth and spoilage. Only refreeze shrimp that was never thawed.
Does cooking shrimp in the shells help prevent a fishy smell?
Cooking in the shells can help minimize exposure to air and oxidation that worsens fishy odors. But it won’t prevent or eliminate smells from spoiled shrimp.
Will soaking shrimp in milk get rid of the fishy smell?
No. Milk does not have any properties that eliminate existing fishy odors. Discard smelly shrimp rather than trying home remedies.
The Takeaway on Frozen Shrimp Odors
Shrimp that smells overly fishy or ammonia-like has gone bad and reached an unsafe state.Make sure to source high-quality, fresh-frozen shrimp and store it properly to prevent spoilage and stinky odors. Discard any shrimp that has an off smell or visual signs of spoilage rather than trying to salvage it. Following these shrimp freshness tips will keep your frozen shrimp tasting delicious and odor-free.
Black Spots on Shrimp
If you find or are worried about black spots on shrimp, you have nothing to worry about if the spots are found on the shell. According to Louisiana Fisheries Forward, shrimp can occasionally have a discolored shell called black spot or melanosis.
This does not signify spoilage or the presence of bacteria. Instead, these black spots are caused by an enzymatic reaction between naturally occurring amino acids and sunlight. Shrimp with melanosis on the shell are still safe to eat. Some shrimp are processed with sulfites to prevent melanosis. If the shrimp you’re buying were treated with sulfites, it will say so in the list of ingredients. This is because sulfites are an allergen.
You can tell when shrimp are dead by the fact that their heads start to turn black if they are bought alive in their shells. The shrimp meat is still fresh and safe to eat if this starts to happen as long as only the head has turned dark.
Selecting and Storing Frozen Shrimp
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You can either buy shrimp frozen, raw or alive. According to the Food and Drug Administration (FDA), if you purchase shrimp raw — whether your intent is to cook or freeze them once you get home — make sure the shrimp is kept over ice at the store and has a pearl-like color with little or no odor. Purchasing live shrimp is rare. But if you decide to go this route, check for leg movement to ensure the shrimp are still alive and have not begun spoiling.
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According to the Auguste Escoffier School of Culinary Arts, frozen shrimp are actually fresher than “fresh” shrimp. This is because the frozen shrimp you see at the grocery store are usually thrown on ice immediately after they are caught or harvested and are kept frozen until they are sold. Shrimp that is sold raw on the other hand is most often frozen upon harvest, and then thawed before being sold. The raw shrimp have more time to spoil.
The FDA also says that frozen seafood can go bad, especially if it is left out in the warm for too long before being cooked. This can happen when shrimp thaws on the way from the fishing port to the store or from the store to your home.
For frozen shrimp that can be bent, freezer burn is a red flag. So are packages that are torn or open. Do not buy or use frozen shrimp if you notice any of these signs. Also, if you see that the “use by” date on the frozen shrimp package has passed, throw away the package and don’t eat the shrimp.
Once home, store frozen shrimp in moisture-free, tightly sealed plastic, foil or paper. When you’re ready to cook, put frozen shrimp in the fridge overnight to thaw slowly. If you need to cook it faster, put it in a plastic bag and put it in cold water. If you want to cook the shrimp right away, you can put it in the microwave and heat it on “defrost” until it’s still cold but not frozen.