How to Tell If Fish Has Gone Bad?

When fish spoils, a color visibly turning dull, a slimy and slippery surface, and a sharp smell close to sour or ammonia appear. The answer to how to tell fish has spoiled comes from knowing that fresh fish should have a mild, sea-like smell, and that a strong 'fishy smell' can actually be a sign of spoilage. Fresh fish generally has a mildly salty sea smell; a strong and unpleasant smell can be a sign that the fish hasn't been stored at the proper temperature for a while. The fish's eyes, gills, and flesh also give important clues about freshness independent of smell, and should be evaluated together. How Can You Tell Fish Has Spoiled?Several points should be checked together when checking a fish's freshness. The eyes becoming dull or sinking in; in fresh fish, the eyes are bright and plump.The flesh leaving an indentation when pressed with a finger and not returning to its original shape quickly.The gills turning pale pink or gray; in freshness, the gills are vivid red.A slippery, sticky layer forming on the surface.The flesh coming away from the bone easily; in fresh fish, the flesh clings tightly to the bones.What Mistakes Are Made When Storing Fish?Some mistakes that lead to fish spoiling early are common. Carrying the fish outside the cold chain for a long time after shopping.Storing the fish in the refrigerator on an open plate, uncovered.Leaving frozen fish to thaw on the counter at room temperature.Cooking fish whose smell has changed slightly by 'masking' it with plenty of spice or lemon isn't safe.Carrying the fish on the same tray as other foods without separate packaging can increase the risk of cross-contamination.Does Frozen Fish Show Signs of Spoilage After Thawing?Frozen fish can also show the same signs of spoilage after thawing — dull color, slippery surface, sharp smell — because freezing stops bacteria from multiplying but does not kill them, so spoilage quickly resumes from where it left off once the fish thaws. For this reason, it's recommended that thawed fish be cooked as soon as possible, without being left at room temperature for long. Fish thawed in the refrigerator can be refrozen without cooking, although its texture will suffer; do not refreeze fish that has been left at room temperature for more than 2 hours. Is Choosing Fresh Fish the Same as Checking for Spoilage?Choosing fish and checking for spoilage are closely related but cover different moments; the content on how to identify and choose fresh fish covers freshness criteria at the moment of purchase, while this content focuses on signs of spoilage after the fish has been brought home and stored for a while. In both stages, checking the eyes, gills, and smell are common reference points, and give the most reliable result when applied together. Knowing both of these stages makes it easier both to choose the right fish and to track its freshness after bringing it home. The answer to how to tell fish has spoiled is checking the eyes, gills, texture, and smell together. A mild sea smell is normal, while a sharp, unpleasant smell is a strong sign of spoilage. In doubtful situations, throwing away fish without cooking it is the safest choice against the risk of food poisoning. Keeping the fish continuously in the cold chain from purchase to the table is the most effective precaution to ensure these signs never appear.