9 Ways to Tell Your Fish is Fresh

Choosing fresh fish is a tough thing to do. While most of the fish in your local supermarket or fish store is going to look great sitting in a well-lit case, when you get it home it might not be what you expected. Understanding some factors which help identify fresh fish is a skill that may take years to master, but only a few minutes to learn. Here will we go over nine of my favorite ways to tell if a fish is fresh. I will break down this article into fresh fish and pre-cut fish, so you understand the differences.

Whole Fish

Checking the freshness of whole fish is something that confuses a lot of people. There is a lot of information out there to ensure you are making the right choice, but as with anything in the food world, there are some misconceptions. Lets take a look at some of these misconceptions, and learn a few more factors which will help you make the right choice in choosing the freshest fish available.

Here you can see the “glaze” of a fresh whole fish.

Eyes

Most people immediately look at the eyes of whole fish to determine the freshness. This is a good first check to make, but there are some issues with putting your whole decision on the look of the eyes. The eyes of fish, like humans, are a viscous organ containing a high water content. The eyes of the fish are the FIRST part of the fish to show signs of decay,so although the eyes may show signs of decomposition, your fish might be perfectly safe and delicious. Here are the real factors in the eyes which show freshness.
Cloudiness: Cloudiness in the eyes happens during normal decaying process, but can be sped up if a fish is laying in its foam cooler on its side so use discretion. While the fish is laying on its side, all of the bodily liquids settle to the bottom of whatever side it is laying on. This is why most of the whole fish you will see in a fish market display case will have one clear eye, and one eye that is cloudy, bloody, or discolored. Unless you actually consume the eyes of the fish, as some cultures do, you wouldn’t need to have completely clear eyes. Do not put your whole decision into the look of the eyes.
Bulge / Sunken Look: The more important aspect while looking at the eyes is the actual bulge of the eye in the fish. A very fresh fish will have eyes that are protruding very nicely. These eyes will also look like they have a nice glaze, or shine to them. When a fish has been sitting for more than 2 days, the eyes will start to sink into the head of the fish; not protruding out. Again, if a whole fish is sitting in an ice box, laying on its side, you may see one eye looking a little nicer than the other. Eyes of the fish are a very delicate organ, as are humans eyes, so in my opinion there are more trustworthy factors in determining freshness than the fish’s eyes.

This eye is very bright, clear, and no cloudiness. It looks to have a nice bulge to it.

Color of the Fish

When a fish is still alive, the coloration of the scales and skin is usually unbelievable. A rainbow of iridescent colors help the fish blend in with its natural habitat and help camouflage it against predators. When a fish is fresh, you will be able to see these radiant colors with no issue. Hues of blue, bronze, and silver will pop out to you. Some fish will have bright reds, greens, and aquamarine strewn across their fins and body. The underbelly of most fish is a white or cream color because when a fish is looked at from underneath by a predator, the white helps to blend them in with the bright white sunlight coming down from the top of the water.
To the consumer, you should be looking for fish with bright and radiant coloration to their skin and scales. The more dull and drab looking a fish is, the longer it has been sitting around. A fish with dull colors or a pale look probably indicates it was caught some time ago. Look for fish who shine brightly, and who look like they have a slimy, glazed look to them. These fish will be the freshest.

NOTE: If you go to a market who sells whole fish which have already had the scales removed, try to avoid them. Scales help to retain moisture, which aids in freshness, and after scales are removed, the breakdown process will speed up. Look for fish who still have the scales attached.

Mahi-Mahi is one of the most beautifully colored fish in our ocean when alive.
The instant a Mahi-Mahi is dead its colors start to drain out of it.

Softness of Belly

When a whole fish is caught and shipped to market, they still have all of their internal organs inside of them. This is obviously to keep the cost of the fish down. When a fish is sold in its whole form (head and tail still on) and has already been gutted, you can expect to pay a premium cost. You will see this commonly from Red Snapper which have become a staple at supermarkets and fish markets.
Because whole fish have their internal organs still inside of them, this changes the rate of decay. While a fish sits in a case, the stomach contents slowly breakdown the stomach lining and can affect the quality of the meat along the belly. With fish who eat a diet of oilier bait fish, or are bottom dwelling fish who consume clams, crabs, a sandworms, you will find a stomach filled with muck and mud, which can rapidly decompose the belly of the fish, increasing the risk of you getting a “bad” fish.

When I purchase whole fish who have not been gutted, I first check the consistency and feel of the stomach. A fish’s stomach which has started the decomposition process will be soft and squishy. These are fish you want to avoid; the potential risk of having the belly meat of the fish altered by decomposition is higher.
A fresh fish will have a stomach which is hard to the touch. The belly will be firm and will indicate that the breakdown process hasn’t started or it has not altered the meat of the fish to a point where the taste will be affected in a negative way.

Stiffness of the Fish / Rigor Mortis

Like the belly of the fish, the overall stiffness of the fish will tell you a lot about when the fish actually died. You can channel your inner forensic scientist when determining the time of death of a fish but here I will try to break it down simply.
Rigor Mortis is the process of the muscles of an organism stiffening after death. When a fish is killed, it will be soft and floppy ( this is called pre-rigor mortis). As a fish starts its natural decomposition, the muscles of the fish start to stiffen from the tail up towards the head of the fish. This is the fish entering into the rigor mortis stage. A fish can enter this stage an hour after being dead, and can stay in this stage up to 72 hours after death. This is the optimal time to purchase your fish.
Many factors can change the rate of this decomposition such as physical health of fish, the energy expended before that fish died, and the temperature at which that fish is kept after death.
After a fish has passed through the rigor mortis stage, it becomes floppy and pliable again. This can happen anywhere from six to 72 hours after the fish is dead.
NOTE: Smaller fish enter and pass through rigor mortis faster than larger fish. Fish who are handled improperly will pass through rigor mortis quicker than fish who are handled properly.

Gills

Gills are a very good indicator of how fresh a fish is. Gills are the fish’s lungs. In layman’s terms, water passes over a fish’s gills, and oxygen is absorbed by the fish.
Because of how vital this organ is to the fish’s health, checking the coloration and quality of them will give you good insight to the freshness of the whole fish you are looking to purchase.
Gills should be a nice red color, very bright and look almost bloody. Gills are made up of long thin fibers, and you will be able to identify individual tendrils in a fresh fish’s gills. When gills are old, they start to blend together and look more like a lump of slimy fibers. In addition, they will lose their bright coloration and become a dark red. In very old fish gills will appear brown.
NOTE: You should be looking for bright red colored gills which have not become matted together with other gill fibers.

A set of fresh gills will have a bright red hue to them, and you will be able to see the individual fibers.
Old gills will be brown in color, and they will start to slime over, causing the fibers to stick together into clumps.

Shine / Slime / Glaze

Overall, when choosing your next whole fish to grill, you should look for a fish which has a nice wet, slimy look to it. Fish have a natural slime to protect them from hazards in the water and predators. When the fish is out of the water it will still have the slime on it, but will lose the slime as it is handled, or sits in a display case. You are looking for a fish which looks like it is still wet. I like to use the term “glaze” because a fresh fish will look like it was glazed with an oil or epoxy.
NOTE: Refer to the first image to see the glaze on whole red snapper.

Smell

The last and most obvious factor in determining the freshness of a whole fish is the smell. The odor can go a long way towards identifying whether a fish is way past its prime or if it has just sat among other smelly fish. You can confidently ask to smell your fish before you purchase it, and any respectable fishmonger will oblige. The one confusing aspect to checking odor of a whole fish would be that whole fish have the head attached. The head of the fish is usually the most smelly location, so try to use your discretion while determining if the smell of the fish is just superficial or if it originates from the meat within the fish.
NOTE: Fish come from the ocean. The ocean doesn’t always have the most pleasant smell. Fresh fish from the ocean should smell like the ocean. It should not smell like rotting fish. If you can’t handle a bit of fishy smell, you should opt for pre-cut or fileted fish.

Filet / Pre-cut Fish

The next type of fish we will look at is pre-cut fish. This is usually pre-cut filets or fish steaks which lay in a display case for consumers to choose. It is usually harder to determine the freshness of prepared fish filets or steaks.

Smell

The smell of pre-cut filets is probably the best and most foremost factor in determining freshness. Fresh filets will have almost no odor. They will smell almost sweet to the nose. Again if you smell your filet and it has a tinge of ocean smell to it, do not be alarmed. If it smells like it has been sitting in the sun for hours, then you will be able to notice. The level of the smell of the fish should be correlated with some of these other factors we will look at with pre-cut fish to ensure you are getting the best and freshest piece of fish for you and your family.

The Look of the Meat

Fish have very low fat content. Even the fattier fish (tuna, salmon, swordfish, halibut, chilean sea bass) are extremely low in fat relative to their land based counterparts. Because of this, most white fish breaks down rather quickly without the benefit of fat to help preserve it. Because of this, white fish which is already fileted shows signs of breakdown differently than whole fish.

Color: The color of the meat will give the consumer a good look into whether the meat has been sitting around a case for a few hours, or a few days. White fish will have a pearl white to bright cream colored meat. The longer a fish sits, the darker the meat will look. A fresh piece of filet will have a nice shine and glazed look to it. It will look moist with a good water content. In addition to the freshness of the meat, you can see which fish have been bruised; this will be those red marks within a fish’s meat. Bruised meat has blood in it, and will probably taste a bit fishy compared to unbruised meat. Fish like salmon will lose color as it ages, so look for bright pieces of salmon and tuna. Avoid dull looking salmon.
NOTE: Tuna is a very different type of fish. Dark red meat on tuna is GOOD, brown meat is not. Look for deep red to bright red color on tuna.
Consistency: Because white fish have an even lower fat content than their oilier cousins, their muscle fibers are not as elastic. What this means for a consumer is if you notice a filet’s meat looks like it is breaking apart or splitting, this is an indication that is it getting on in age. The fibers of the meat will actually separate as the filet dries out and ages, and the color will also change with it. If you notice a filet of white fish like flounder has a darker creamy look to it, and the meat looks like its splitting and separating, you should think about a different piece.
NOTE: Purchasing fileted fish with the skin still attached will help with the preservation of moisture, and will help to keep the meat of the fish from separating.

You can see the color of this piece of cod is nice and white, but also hasn’t started the process of splitting or separating. This filet has the skin off so it will be harder to keep this filet fresh for long.

As with any food product, these are not laws. These are guidelines for making the best decision while purchasing fish. Some fish may look great in the store, they may not have any tell tale signs of being old but you may cook it and realize it wasn’t the freshest piece of fish. Use all of these factors in unison when determining which piece is best for you, but don’t let just one factor deter you from making the purchase. Like I said, it takes many years to hone your skills in choosing fresh fish so start practicing the next time you buy!

Enjoy.



Published by Filet To Table

Answering all of your most curious questions about seafood fare, and giving you a new confidence or curiosity about culinary flavors from our ocean.

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