I am able to taste a flavor in some fish (usually white fish) that most other people do not (I also can smell the asparagus pee smell, and am a strong taster ... but not supertaster?... of bitter flavors). What I would like is a way to predict whether a given piece of fish will have the flavor, so I can avoid it. I don't think that I can detect it as a smell. I find it unpleasant, but not intolerable. It doesn't seem to be a result of spoiling. At a guess, I'd say I encounter it in less than 20 percent of white fish. It occurs across species, so I might find it in cod, haddock, halibut, sole, etc. If I'm cooking up some fillets from the supermarket, that flavor might be in one piece, but not the next. My wife and I will often swap portions if I detect it in mine, and she notices no difference, where to me it's as obvious as if I'd popped a chunk of 80% dark chocolate in with a bite of fish. Not to imply that I dislike choco - I love it.

I don't ask everybody that I meet, so there might be others who detect this flavor, but I can't describe it, except... hmm... one-dimensional, the way a taste of metal would be one-dimensional... though it doesn't seem to be a metallic flavor either.

Anyway, would be obliged if somebody else knew what I meant, and especially if there's a way to tell if a piece of fish will be affected BEFORE I buy. Oh, and it's only in fish. No other food that I've encountered. Not affected by method of cooking. Not affected by seasoning. Anybody?

  • 1
    Do you ever detect it in just part of a fish? ie. when you refer to swapping portions with your wife, would both portions be from the same fish, or does that occur in a situation where the pieces might be from different fish (ie. in a restaurant or from 2 separate packages)?
    – Allison
    Mar 12, 2011 at 12:52
  • I get something similar from time to time with really fresh haddock (although in my case it's a horrible muddy taste when I exhale - I have no idea what it is). But the solution for me was to thoroughly rinse the fillets under a running tap, then leave to drip dry a bit. Not sure if it's the same thing but it might help :) Feb 11, 2017 at 23:17
  • Can you describe the taste in depth more so we can try to pinpoint it?
    – Jade So
    Aug 1, 2018 at 21:06

9 Answers 9


I have had this problem and thought it was the taste of tin-foil that I used to rolled up and put into the belly of the fish to stand it up in the oven. So, I was very interested to hear an interviewer on the radio 3RRR in melbourne, talking to a chef who mentioned fish, like Snapper, are susceptible to that metalic taste if they are caught and die too slowly. The slower they take to die, the more stress the fish goes through and the stress hormone accumulates in the flesh particularly around the belly. I think they said a pinker snapper is better than a pale one for taste.


I've noticed the same taste in cod that I buy at Kroger (surprising since Kroger is fairly high quality when it comes to most of their food). Perhaps mine is an age issue as I buy it when it's marked down for quicker sale. It doesn't seem to matter how I prepare/cook the fish.

  • 1
    My wife and I noticed the same thing in cod that we got from Kroger in Michigan. She says she's always noticed it regardless of cut or preparation or whether it's on sale or not. I agree that it tastes something like metallic, chemically, or industrial. Certainly not "fishy" from old or bad fish.
    – Brian D
    Sep 17, 2016 at 14:02

It is probably the process of cutting and cleaning the fish. It must be cut in such a way that the stomach part of the fish which needs to be cleaned must come out easily and completely without spilling over. I mean to say that the unwanted stuff inside the stomach must be cleaned without smashing it. Once it gets smashed the bitter tasting substance in the stomach spreads where ever it touches. And then it cannot be cleaned by any means. The same is reflected on to the flesh pieces after cooking the fish making it difficult to eat. My grandmother used to be always cautious about it when ever fish is cleaned and over the period I experienced that this is the cause of bitter taste in fish.


Phenylthiocarbamide would be my guess. Some people can taste it, and some people cannot, and that is genetical. It is extremely bitter if you can taste it. We used it in social conformity experiments in psychology: if you dont taste it, but everyone else, you conform or not etc...

Now, how that stuff gets into your fish... I remember something about it inhibiting pigmentation... so maybe it used to farm very white fish? test of this would be that you would never have this with wild fish or with coloured fish like salmon... assuming that colour comes from pigmentation, i am no biologist..

  • 1
    This seems to be the answer that understands the actual question being asked. One of my kids is a super taster and can't eat things that we take for granted as universally delicious.
    – Escoce
    Mar 26, 2016 at 15:39
  • This seems very unlikely to me. Sure, PTC is the well-known example of a compound that's awful-tasting for some, and unnoticeable for others. But it's by no means the only such compound, so it's a huge leap to suggest that specifically PTC is to blame here. It resembles bitter compounds in some plants, but I can't find any indication that it (or something resembling it) is ever present in fish. It can indeed be used to grow transparent fish, but that's a biology lab thing, not a fish farming thing.
    – Cascabel
    Jan 9, 2017 at 21:25

I had this problem about 25% of the time with Trader Joe's white fish. Also, certian beef at TJs. What I did was stop buying those particular pieces of meat from those vendors and try other stores. This method has reduced my finding bad tasting fish or meat to about 10% of the time. It also has led me to liking other meats and fishes.

I think you are looking for some technique that can be applied right then and there if you have the meat in hand. Unfortunately, this seems unlikely. Try other stores is my best answer...

  • Mixed batches, usually from supermarkets, or fish stores. Occasionally from restaurants. It's not a flavor I've ever noticed in meat or veg or fruit or grain. Just in fish. I don't think I've even met it in other seafood, which I also enjoy (crab, lobster, scallops, clams, squid, etc.). Just mostly in white ocean fish, rarely in pink-fleshed fish.
    – user5238
    Mar 20, 2011 at 21:17

My guess is this has something to do with the freshness of your fish. Read a little bit of McGee on the subject. I don't guess there is a way of predicting it.


Saltwater critters collect iodine in their flesh through the food they eat. Plankton and kelp contain iodine. So, anything that eats that or eats something that eats it can build up quite a taste in their flesh. Try soaking the filet in milk for about 30 minutes before you cook it. The fishy smell and iodine taste will be reduced quite a bit.

  • It seems very unlikely that iodine taste will happen in less than 20% of white fish. Your explanation suggests a more uniform phenomenon.
    – rumtscho
    Mar 16, 2018 at 7:16

I find that too i liken it to an a disinfectant taste. I saw a show one time that talked about how they use disinfectant to clean tanks at fish farms. To keep algae from growing Thats what the taste rends me of and i find it in cheaper priced fish. The more expensive priced does not have that taste. Makes me want to puke. I also get wild caught for sure.

  • It occurs across species, so I might find it in cod, haddock, halibut, sole, etc These do not come from fish farms
    – user34961
    Apr 26, 2018 at 7:35

My guess is the fish is contaminated. I just had cod that was bitter as hell and I cooked it plain. Its not supposed to taste this way. Maybe they are adding another preservative. Most of the people who think they are allergic to shrimp are not. They are allergic to sulfites which they put on the shrimp when they catch it to preserve it. A large percentage of the population is allergic to sulfites.

  • I doubt that it is contamination.
    – Brian D
    Sep 17, 2016 at 14:03