How to buy fish at a fish market. First and foremost, get there early, preferably as soon as the local markets open. In most cases the fish is not refrigerated or on ice. The longer you leave it the more suspect your purchase becomes. The more organised local will at least keep sluicing salt water over the fish (but where is the water from you may ask?). Observe the following when purchasing fish. Whole fish is best as it lasts longer than fillets and also its easier to assess freshness and quality.
Check the Eyes
The eyes of the fish should be clear and shiny and have a puffy appearance. If a fish has cloudy and sunken eyes then don’t buy it. As old fish deteriorates and dehydrates the eyes are the first thing to go.
Check the Gills
The interior of the fish gills should be bright red, or pink and moist and uniform in color. When a fish starts to age the gills will become rather dull in appearance and take on a brown color. Fresh fish still has blood and so its gills are also bright red. If you are able to lift up the gill flap you will observe underneath spongy looking gills. If gills are slimy it’s a telltale sign that the fish is starting to go bad.
Check the Fins
Fish fins should present with clear definition and sharp, if they are tattered and broken then the fish might be old.
Check the skin
Check that the skin is bright, shiny, moist, taut and have a bright color and even slippery, and if fresh you can detect slime on the skin surface. This is a clear and protective coating that has that subtle sea aroma and if this moisture has a slimy and sticky consistency then it’s not fresh. If the fish lacks this it is because the fish has probably been washed in fresh water, which ultimately shortens shelf life and some of the flavor. If there are visible signs of discoloration or any fading on the skin surface then its starting to go off. Look at the scales, they should be shiny, consistent and no visible indents in the surface or bruising
Check the Smell
Fresh fish has a lovely “fresh” briny smell to it. There should not any overt fishy smell, or a sour pungent ammonia odour. The aroma of the fish should be clean and fresh and often has a soft and buttery note.
Check the Flesh
Check that the fish flesh is firm to the touch, and when pressed should be elastic and bounce back. If it leaves an indentation, feels rather soft and squishy and doesn’t bounce back its not fresh. If the flesh is slimy, or has a milky appearance and its developed a strong fishy odoor.
When looking at fish fillets they should no have any signs of discoloration, or darkening of the flesh, dark spots or signs of drying around the edges. Fish fillets should also be shiny and moist with a glistening appearance with bright and uniform color on its surface. Aging fillets have a dull appearance with visible gaps between the muscle layers and tend to curl at the edges. If possible get your fresh fillets cut fresh from a whole fish. If you are purchasing pre-cut fillets don’t buy fish that is on a tray wrapped in plastic as this can trap bacteria and hasten spoiling.
About Refrigerating Fish
Prior to putting your fish in the refrigerator, wash it properly in fresh cold water. Then dry it using a clean tea cloth or paper towel. Then wrap it in either plastic wrap or aluminum foil, I use sealable bags and express all the air out. If you have s vacuum sealing machine then it is a good way to prepare it. In general fish can be stored for up 2 days. This should be (40 °F/4.4 °C or less) prior to cooking or freezing. The longer fish is frozen the more flavor and texture will decline.
Handling Fresh Fish
If a fish has started to go off then no amount of refrigeration or cooking will eliminate Scombroid poisoning. After you catch your fish the optimum time to clean them is within 2 hours, and best eaten within 24 hours. How to keep them fresh, throw them in a bucket wit seawater or something similar? Maximum shelf life can be achieved when they are killed, have entrails and gills removed, also the head and the whole abdominal cavity empties and placed on ice. How to buy fish and How to Cook Seafood.