Shrimp That Smells Like Ammonia [Raw, Frozen, & More]

Shrimp. A popular dish served in both restaurants and at home. Not to mention that it is commonly associated as one of the more expensive side or main dishes alongside steak.

Often served with rice or noodles, shrimp is delectable and coveted by people throughout the world.

But it can become quite concerning when you pop a piece of shrimp into your mouth, only to find that it tastes off.

Generally speaking, when shrimp tastes or smells off, like it was dipped in a batch of chemicals, toss it out immediately. When there is enough ammonia that it becomes difficult for sea animals to excrete the toxin, toxin build-up happens.

Leading to the animal becoming unpalatable because they have ingested too many toxins for the human body to consume without experiencing food poisoning or gastric distress.

Shrimp That Smells Like Ammonia

Shrimp that ends up smelling of Ammonia should be tossed out immediately, as ammonia indicates spoilage.

This is applied to raw shrimp, cooked shrimp, dried shrimp, and stock. Ammonia is the toxic build up of nitrogen in waste that can occur in pigs and cattle, as well as seafood such as shrimp and lobster.

 Foul Smell
Raw ShrimpFishy smell or rancid / ammonia (chemicals)
Frozen ShrimpWill not have much of a smell until cooked
Cooked ShrimpUnpleasant sour smell that smells obvious

The table, here, shows the differences in smell between raw, frozen, and cooked shrimp as a brief glimpse of what each will smell like.

As you can see, with both raw and cooked shrimp, you will notice that these are much easier to detect than when the shrimp is frozen.

Raw Shrimp Smells Like Ammonia

Raw shrimp that goes bad or starts smelling off will usually have a distinct scent like that of rotten eggs, rancid vinegar, or ammonia.

Ammonia occurs as a part of the cycle of decay, and is not to be confused with iodine, which we will discuss in a moment.

Something important to note is that when raw shrimp is frozen, for example, you will not be able to tell the difference through odor.

Rather, keep an eye on the expiration date before you start prepping the dish as this will be a clear indicator of whether it’s gone bad.

Otherwise, the only way you’ll be able to tell if shrimp has gone bad is when you cook it.

Cooked Shrimp Smells Off

Cooking shrimp will indicate whether it is fresh or not because, through the process of heating it up, the juices will spill out, and something will start smelling off.

Cooked Shrimp

This is why checking expirations dates are important, but also ensuring that only the highest quality of shrimp is chosen when shopping at your local grocery store.

As soon as something starts smelling off, toss it out, and don’t serve it as this will prevent you from having to go to the hospital.

Dried Shrimp Smells Like Ammonia

The same applies to dried shrimp – if it starts smelling off or smelling of ammonia, toss it out – as this means that it has too much toxic build up within the animal itself.

Although in terms of odor, this might be a little more difficult to check, as dried shrimp does not have the juices necessarily to tell whether it’s gone bad.

If you bite into it, and the taste is significantly off, throw it out.

What If Shrimp Stock Smells Like Ammonia?

Any shrimp that rests within shrimp stock or comes from the water that has too much ammonia or toxic waste, needs to be tossed and this applies even to shrimp stock.

Consuming this will likely result in food poisoning and gastric distress, as the toxic waste of ammonia is mixed within the stock itself and is not to be served to customers or those you’re cooking for.

Rather, ammonia occurs as an odor that results from the natural decomposition of waste inside the body of the animal.

So, for example, spoiled shrimp smells of ammonia because it is decaying and the bacteria is breaking down the animal, itself.

Shrimp can develop a distinctive iodine odor after feeding off certain animals because these animals.

What Happens When You Eat Rotten Shrimp?

Food poisoning always follows the consumption of spoiled goods, such as rotten shrimp.

Symptoms of food poisoning may include vomiting, stomach cramps, fever, and diarrhea.

In fact, over 90 percent of food poisoning cases as Salmonella, E. Coli, Vibrio, and Bacillus. You can find all of these in raw shrimp.

So, cooking spoiled shrimp, then eating it, can lead to serious health issues.

Food Poisoning

Food poisoning is just one of the two processes that happen after consuming rotten shrimp.

Symptoms of food poisoning to be on the lookout for, according to the CDC, include the following: nausea, vomiting, and diarrhea.

Thankfully, if only a small portion of the spoiled shrimp is consumed, it’s not the end of the world.

Especially because the body is capable of fending of nasty bouts of bacteria and viruses. However, when eaten in larger portions, the body can only fend off so much.

This is why proper food preparation and storage are so important to maintaining the integrity and freshness of the shrimp.

Gastric Distress

Gastric distress is like food poisoning in the sense that the symptoms linked with those of food poisoning.

However, it is more of an umbrella term that combines any symptoms that happen because of the distress of your gut health.

Some symptoms of gastric distress include but are not limited to the following:

  1. Constipation
  2. Nausea
  3. Bloating
  4. Reflux
  5. Diarrhea
  6. Abdominal pain
  7. Cramping

Experts at Med News claim that, when rotten shrimp is eaten, “the neurotoxins present in these parasites can poison the gastrointestinal tract causing either severe diarrhea or vomiting.”

How Can You Tell If Shrimp Is Bad?

There are specific key indicators that let you know when shrimp has spoiled such as the color, taste, and odor of the shrimp in question.

It is important to make sure that you are alert while prepping the food that you cook. So, through understanding these components you will be able to prevent a nasty case of food poisoning or gastric distress.


Any shrimp that has spoiled will have a look that is slimy, moldy, and faded in appearance.

To contrast, fresh, raw shrimp is a whitish-grey and is slightly translucent. When prepping, spoiled shrimp smells fleshy and sticks to your fingers, so be sure to toss it out


Shrimp that is rotten will have a rancid taste such as that of rotten eggs. When eaten, rotten shrimp will feel slimy.

Mold can often appear lumpy, depending on the product of food that has become expired. Any shrimp that has spoiled will always taste off.


The biggest key component in figuring out whether the shrimp has expired, apart from the expiration date, is that spoiled shrimp will smell very much like ammonia. Or rotten eggs.

A metallic smell and taste will always accompany ammonia.

So, keep this in mind when prepping and managing the shrimp to make sure that you prevent yourself from experiencing food poisoning or gastric distress.

How Long Does Shrimp Last?

Fresh, raw shrimp lasts 1-2 days in the fridge while frozen shrimp can last anywhere from 12 to 18 months, according to sources.

However, other experts claim that shrimp can only last up till about 6 months, such as the experts at Still Tasty.

Raw12-18 Months1-2 Days
Cooked10-12 Months3-4 Days
Dried Shrimp 1 Month

Raw Shrimp

Raw shrimp, as the table indicates, lasts about 1-2 days in the fridge while it can last anywhere from 12-18 months as claimed by sources.

Because of this confusion, it’s best to follow the expiration date, and use the guidelines necessary to check to see whether the shrimp has gone bad.

Cooked Shrimp

Cooked shrimp, according to experts, lasts 3-4 days in the fridge. Make sure to check the shrimp by taste, touch, and odor as the texture of spoiled, cooked shrimp is different than that of cooked shrimp that is fresh.

Dried Shrimp

Shrimp that is dried does not last forever and can expire within a month even after being stored in an airtight container in the freezer.

As always, be sure to follow proper procedure to prevent nasty bouts of food poisoning and gastric distress that can ultimately land you a trip to the hospital.

Tips On Storing Shrimp

Oftentimes, shrimp that is found in grocery stores are attractively packaged to avoid prolonged exposure to those annoying airborne particles.

There are steps when it comes to storing shrimp. And these steps include the following:

  1. Washing the shrimp so they are clean enough for storage, then consumption
  2. Cover shrimp with waxed paper
  3. Store shrimp in the coolest part of the refrigerator
  4. Shrimp can be frozen, but thawing them makes them lose their structure

Washing Shrimp

When handling and prepping shrimp, it’s always important to make sure to wash them before you start to saute them or cook them in the pan.

When washing shrimp, make sure to avoid using warm or hot water.

This helps to wash away any dirt or bacteria that might have been on the shrimp in the first place because, like chicken and pork, they easily absorb external factors. Such as bacteria and viruses.

Another good tip to keep them fresh is to store them over ice if they need to sit out while prepping for a party.

Covering Shrimp with Waxed Paper

Sealing them with waxed paper or wrapping them with airtight zip lock bags. This helps keep them from exposure to those annoying airborne particles.

These airborne particles are a concern in temperatures that are above 41 degrees and below 131 degrees.

The temperatures in between these two degrees are what the food industry calls “the danger zone” as this means that there is a higher chance of exposure to airborne bacteria.

Therefore, it’s vital to store foods, such as shrimp, in the freezer or refrigerator to maintain their freshness.  

Storing Shrimp in A Safe, Cool Place

After sealing up the shrimp in waxed paper or in airtight, zip-lock bags, it is important to store it in a safe, cool place.

Storing shrimp in a safe, cool space is the second step to ensuring that the shrimp is not in the danger zone – otherwise known as the zone where bacteria and viruses have the highest chance of growing.

Freeze Shrimp to Keep Freshness Longer

Freezing shrimp is a wonderful way to maintain the freshness of it longer but thawing it could cause it to lose its structure.

One of the best ways to maintain the freshness of shrimp, as shown in previous tables above, is to store it in the freezer in an airtight container.

Shrimp can last up till about 18 months although there are other claims that think that shrimp can only lasts up to 6 months.

Defrosting Frozen Shrimp

Because defrosting shrimp can cause it to lose it’s structure, placing it in the fridge for a couple of hours will allow it to thaw out more naturally.

Frozen shrimps

Sometimes, it’s easy to get impatient and use the microwaves defroster button. Using this, however, might cause the shrimp to not taste as fresh or be as flavorful as naturally thawing it out.

Why would this be the case? Sometimes, if you don’t pay attention closely enough, you might end up causing it to be “cooked” by selecting more weight than the shrimp actually is.

Meaning you go over the preferred amount of minutes it actually takes to defrost it.

What Bacteria Can Be Found in Rotten Shrimp?

Meat and seafood, when rotten, absorb some of the deadliest bacteria such as vibrio and e. coli.

Vibrio, in short, is a type of bacteria that can cause watery diarrhea, abdominal cramping, nausea, vomiting, fever, and chills.

It is oftentimes found in places such as salt water or brackish water, where shrimp live. If shrimp are exposed, they will absorb the bacteria and become too toxic for humans to consume.

E. Coli is often found in cattle such as cows and pigs. However, seafood is also capable of developing this type of bacteria.

When shrimp are exposed to these two variants, they are unable to excrete the toxic build-up and, as a result, develop the odor of ammonia and gas.

Final Considerations

To conclude, always double check expiration dates as well as the color, odor, and taste of food before serving it to ensure the health and well-being of those you serve.

Taking the time to effectively manage and store shrimp in airtight containers and in safe, cool places helps to maintain the freshness of shrimp longer and keeps you from having to throw it out the moment it goes bad.

Saving you time and money. Remember: when in doubt, toss it out! As always, stay safe and happy cooking.

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