The overall impression
Shiny scales coated with a clear layer of mucus are a sure sign of freshness. Dry skin and a faded fish color are a sign of inadequate cooling. Any cut edges should look fresh and never be dried or brown.
The smell
It is best to check this on the gill cover or the abdominal cavity. Fresh fish smells neutral or a little bit like seawater and iodine, but it should never smell fishy or biting.
The eyes
These should be bulging, shiny and clear. Sunken eyes are a sign of storage issues.
The gills
When you open the gill cover, they should be bright red when the fish is fresh, and the individual gills should be clearly visible, not stuck together and not have excessive mucus. Grayish-white or yellowish-brown gills indicate loss of quality.
The consistency
If you press your finger firmly on the skin of the fish, it will remain firm with fresh fish and immediately return to its original shape. No impression should be left behind. Flatfish should also remain firm when lifting and not bend.
The abdominal cavity
It is also important to check the abdominal cavity! The blood remains on gutted fish should be clearly red in color. Brown-gray blood remains are an indicator of long-term storage.
Fins
They should never be stuck together or dry. Damaged fins suggest inappropriate catch or long transport routes. Make sure that they are well preserved and clean.
Fillets
They should shine, have a natural and clear color as well as a smooth cut surface. The fillet, like the rest of the fish, should not smell unpleasant. If the color appears dull and pale, the fillet is too old. Yellowish discoloration on the inside of the fillet also indicates quality loss.