Sometimes when seafood has fermented or not been salted at all, in street food, it tastes sweet. It shouldn’t, because usually fermented fish tastes bitter, but after a while, it begins to taste sweet.
Why? What’s the chemical change that makes this happen?
Lots of very northern fermentation methods make it taste this way, but why?
It depends. The fishing industry and seafood isn’t exactly my are of expertise in this arena, but there’s a reason why fishing boats with freezers are more sought after than just “catch of the day” types. The latter has variances in time to market which may impact the freshnwss and taste, even if only by a difference of a day.
Seems lots of seafood just spoils really fast, which makes sense if you take into account the density of the meat. Things like Tuna or Salmon steaks are dense, and therefore would spoil slower than something like a whitefish or shrimp perhaps.