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Why does my fish smell like ammonia?

  • b

I made a skate wing this evening and one half of it (it was still on the "bone") smelled like ammonia after I cooked it. I vaguely recalled having a similar experience with cod at a restaurant years and years ago. Didn't make me sick--just very unpleasant when I ate it.

Now what makes fish do this?

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  1. I thought I read somewhere that in seafood buffet they add ammonia to mask fish smell of not so fresh fish. I'm not sure if they do it to raw fish at stores...

    1 Reply
    1. re: Wendy Lai

      The ammonia-like smell is because the fish is not fresh. It is a product of decomposition. Don't eat it if it smells like that. It might not make you sick, but then again it might. Why risk it or have an unpleasant experience? Fish should have only a briny aroma of the sea. If it has a fishy smell from being in plastic, briefly rinse in fresh water. If the fishy smell persists or is strong, take it back and demand a refund. For that reason, it's best to cook fish the same day you buy it.

    2. Why, oh why, would you eat something you found unpleasant tasting? That's the real question here.

      BTW, the others are correct, your fish was bad.

      1. Bella: Your Fish was most likely fresh.

        Skate is related to the Shark Family and often will have a Ammonia smell especially if it wasn't bled or dressed properly as is the case with all of the fish in this species.

        Most of the time the odor will dissipate during cooking, but sometimes it will persevere.

        I always request to smell any Skate or Shark before purchasing,[it's my dollar]or most of the time just request the fish cutter to take a whiff before wrapping. Most of the time he'll simply pick out another piece without the odor if it's even slightly off.

        Also remember that if you filet the Skate and Cook the Cartilege [no bones] separately they really taste good.


        2 Replies
        1. re: Irwin Koval

          Irwin, how do you cook your boned skate fillet so it doesn't curl up? (I've cut them into pieces and steamed them, they still curl but they cook evenly.) Tx.

          1. re: Aromatherapy

            Tx: Generally if the Skate your fileting is on the small side it's very difficult to avoid curling while cooking.

            If the Skate is larger sized then it's easier. You must be sure to remove all the white seams that are on the exterior sides with a sharp thin boning knife, then place the filet pieces between plastic and carefully pound out the meat to relax the tension but not hard enough to break the pieces apart. This is not always effective but it will prevent some of the curling during cooking as this seems to be the character of Skate. Remember there are no bones only Cartilege.


        2. I've had a terrible experience with ammonia-tasting skate a few years ago. I have eaten skate for practically all of my life with no problems whatsoever. One day, I noticed that the piece of skate had a very distinct ammonia taste. I stopped eating it after two bites. Three minutes later, I broke out into a horrible reaction. My face and body got swollen. The worst thing was that my throat also swelled up to the point I had a very difficult time breathing. I think that experience made me hypersensitive to skate. A year later, I had bi-bim-naeng myun (a Korean noodle dish)with some juice from a skate. My face got swollen within ten minutes.

          No longer can I enjoy the sweet stringly flesh of skate because of my experience with the ammonia skate. Please throw it out if your skate smells like ammonia. It took a trip to the ER and $1000 out of my pocket to learn that lesson.

          5 Replies
          1. re: Miss Needle

            Miss Needle:

            Please be very carefull when eating many Korean Dishes as Skate is often served even without many servers knowledge.

            At various Korean Grocers and Asian Markets in the Seattle-Tacoma area of Washington State it's not unusual to find for sale as many as 6 varieties of Fermented or Kim Chee Skate specialties that often are used as complimentry side dishes at Restaurants.


            1. re: Irwin Koval

              Irwin, thank you for your advice. Actually, I am Korean, and am careful to let the waiters in Korean restaurants know that I'm deathly allergic to skate (or called "hong-o" in Korean.) I've also noticed that skate has become very popular in restaurants lately. Too bad for me. :-(

              1. re: Miss Needle

                ohhhh I love skate when its prepared like this. I love that the koreans leave the bones in it too, so that it makes it extra extra crunchy.

                my mother makes a delicious dish of bi bim naeng myun with the skate added in. I think its called hwe naeng myun? or something along those lines

                1. re: bitsubeats

                  skate has no bones. it's cartilage, just like shark. they're cousins.

                  1. re: hotoynoodle

                    whoops! still, they are delicious and crunchy and add a great texture

          2. Sorry, folks, but the skate, being of the shark family, has a urinary tract that is unlike other fishes (or mammals), but empties through the skin. That is why the meat of large sharks, for instance, must be treated to get rid of the ammonia taste (we always used a sodium bicarbonate soak). The ammonia smell and taste is not noticeable in the smaller sharks (say, up to 3 feet) and I assume that the same holds true for the smaller skates. I don't know which variety of skate you purchased, but i know it holds true for the sting-ray.

            1. I heard that this occurs naturally in shark and they to treat it when its caught to neutrilize the taste

              1 Reply
              1. re: jackaranda

                it's not being neutralized, it's being purged.

              2. I've eaten many a shark over the last 30 years and Never had the ammonia smell, that smell is just a byproduct of decomposition and you shouln't eat it.

                1. Irwin Koval definitely knows what he's talking about. Fresh shark tastes like ammonia. I got a 360 pounder on board off of Malinde in the Indian Ocean. Although donated to local villagers, I tried some within hours of catch--ammonia taste and smell.

                  And thanks for the skate filleting tips, Irwin.

                  3 Replies
                  1. re: Sam Fujisaka

                    I beg to differ, I too have been in the Indian Ocean and many other places where I have had fresh shark, never - never had an ammonia smell or taste.

                    1. re: malibumike

                      I suspect both points of view are correct. The urea-like compund in shark blood would immediately start to break down into ammonia. People probably have very different sensitivity to the flavor. There are a few flavors for which individuals are genetically either "tasters" or "non-tasters".

                  2. I remember an Alton Brown "Good Eats" episode where he said ammonia smell in seafood = the beginning of decompostion.

                    1. I adore and often cook seafood
                      I am very sensitive to the amonia taste/smell in skate and have tried allsorts to clear it (with sucess!!) .. the solution ? simple..... soak the fish in a strong carbonate of soda solution (like 4 talespoons to the pint of COLD water) for at least half hour {More if it has a strong smell.}....we have even used "!liver salts" (eno's or andrews) I kid you not!!! when out of bicarb.......the treatment seems not to alter the dellcate(and wonderful ) taste at all .we have skate once a week and I promise the smell/taste IS NOT from the fish being bad ......thats just paranoia.! ! ! one suggestion (which I believe to be VERY cerdible is the ammonia smell is more promenent when a female skate/ray is in "season"..) so go for it enjoy skate anytime just soak it for a bit .................(try baking it in tin foil ..med oven with capers for 45 mins..........delicious................

                      1. smell of ammonia in fish is because it is old.

                        If you want the fishy smell gone though, use table spoon vinegar with a pint of water and soke the fish for a hour.

                        1. Any fish that has any smell other than the ocean is giving off a gas caused by a type of bacteria. That's the 'smell'. It's actually just on the surface of the fish (assuming the fish isn't really old) and can easily be removed by soaking the fish in fairly strong lemon water very briefly, like thirty seconds then rinsed off in cold water and patted dry. The acid in the lemon juice creates a chemical reaction with the enzyme in the bacteria which destroys the bacteria and with it the smell.
                          Skate is, as posted, a member of the shark family. All sharks basically urinate through their skins and so shark meat, even when fresh can smell of ammonia (pee). Personally I don't like to eat any species of shark for that reason. Soaking any fish too long in lemon juice simply begins a cooking process that dissolves muscle and you can end up with ceviche. LOL

                          1 Reply
                          1. re: Puffin3

                            You provided the best answer, and believe me skate wing does not make a best ceviche dish. You are funny.

                          2. is amonia good for you?? i just quacking cooked my fish smelled awfull , chef suppose to enjoy cooking but not when something smells odd!!!