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How to Clean and Break Down a Whole Fish at Home

How to Clean and Break Down a Whole Fish at Home

You’ve probably seen it on TV. You’ve probably seen it at your local fishmonger too.

Heck, there’s even a whole Masterclass taught by none other than world-renowned chef Gordon Ramsey on how to do it.

Now, you’re probably thinking, “why should I learn how to clean and break down a fish?

I can just get my fishmonger to do it for me, or if I don’t have the time, I can buy the fillets, anyway!”

Let us give you five good reasons why you should learn how to break down your own fish at home.

1. You can GUARANTEE the freshness

The thing with buying frozen fish fillets is that you’re never really sure how fresh they are.

Sure, most of them will probably have a “best by” date slapped on them, but you’d be surprised just how many supermarkets have been caught tampering with these labels!

When you buy a whole fish, you can check the freshness of the fish before buying it.

Don’t worry, we’ll teach you how to choose fresh fish.

2. Buying a whole fish is cheaper

When you buy fish fillets, you’re not only paying for the fish itself, but you’re also paying for the cost of filleting the fish, as well as the costs of packaging, freezing, and transporting the fillets!

These extra steps add up the per unit costs of fillets, which is why, pound for pound, fillets are more expensive than the whole fish.

3. You can dictate the cuts you need

Different recipes call for different cuts. Do you need steaks for roasting?

Or maybe fillets for steaming?

Maybe your recipe calls for cutlets for pan-frying?

Buying a whole fish lets you be more versatile with the type of cuts you need.

4. You can use the “undesirables” for other recipes

After breaking down the fish, you’ll be left with all the scraps such as the head, tail, bones (if you fillet it), and the guts.

Don’t throw those away! If you’ve got a large fish such as tuna or salmon, the head and collar are the best cut for grilling.

Otherwise, you can use the head, tail, and bones for making a delicious fish stock for stews and soups!

What about the guts, you say?

Well, you can use those for garden fertilizer!

Fish guts are a great source of nitrogen and trace minerals for your plants.

5. It just feels so satisfying

Do you remember the first time you were able to cook rice perfectly?

What about the first time that you were able to make the perfect poached egg?

Didn’t you get that warm feeling of satisfaction and achievement?

Breaking down a fish is a great cooking skill to master, and one you’ll definitely feel proud of achieving once you do!

Types of Fish

When it comes to cooking fish, you can classify the fish according to either its shape or the fat content in the flesh.


When it comes to fish shape, this is useful in determining how a fish should be broken down and prepped for cooking.

Round fish

Round fish is the most common shape for fish, and it’s the shape that you generally think about when you imagine your typical fish.

Some great examples include trout, cod, and snapper.

They have a long, rounded body, and eyes on either side of their head.

Round fish can be filleted into two large fillets from either side of their body.

Their skin is edible, and it will be up to you whether to remove it prior to consumption.

Flat fish

Flat fish are less common, and tend to have their eyes on one side of their body.

They have leathery skin that needs to be removed before you eat them.

You can get four smaller fillets from flat fish: two from either side of the spine on top, and two on either side of the spin on the bottom.

Some examples of flat fish are sole and halibut.

NOTE: For this article, we will be talking about how to clean and break down round fish as these are easier for beginners.

Fat Content

The fat content in the flesh of the fish will determine how to best cook the flesh without it drying out.

Lean fish

Lean fish is usually white or pale in color, and can have as little as .5% fat.

The best cooking methods are either quick (frying or sautéing) or moist (poaching or steaming) because they can dry out quickly.

Some examples of lean fish are cod, sole, and snapper.

Fatty fish

Fatty fish are usually darker in color (reddish or pinkish), although there are some that are white, such as swordfish.

They are best cooked using “low and slow” methods of cooking such as roasting or baking to really allow the flavor of the fish develop.

Some examples of fatty fish are salmon, trout, swordfish, and Spanish mackerel.

Choosing a Fresh Fish

Whether you’re choosing fresh fish from your local supermarket or your fishmongers, here are five things that you need to look, smell, and feel for:

Bright and Shiny Scales

Freshly-caught fish should have bright, shiny, and tightly-knit scales.

If the scales look loose, dry, or soggy, it’s a clear indication that the fish is either old or was frozen and thawed.

Bright and Clear Eyes

The eyes should be clear, moist, and bulging.

If they look sunken and dull, move on!

Bright Red and Moist Gills

Open the sides of the head and inspect the gills closely.

They should be red or reddish-pink, and moist.

If they are sticky or pale, that’s a bad fish, my friend.

No Smell

Fishy smell? No way! A fresh fish should either smell pleasantly of the sea (if you’re looking at saltwater fish) or no smell at all (for freshwater fish).

Firm and Elastic Flesh

Poke your finger into the side of the fish. It should be moist, but elastic and springy!

If the fish feels dry, slimy, or your finger indent doesn’t spring back, it’s a bad sign of an old fish.

Scaling Your Fish

If your recipe calls for the scales to be removed, you can use the back of a knife or a fish scaler tool.

Actually, fish scalers are a good investment since many of them have a built-in compartment that can catch the scales as you remove them from the fish.

Here’s how to scale your fish:

  1. Rinse the fish under cold running water to loosen the scales.
  2. Grasp the fish firmly by the tail and scrape away at the scales using your scaling tool starting from the tail moving towards the head.
  3. Flip the fish and scale the other side in the same manner.
  4. Rinse the fish under running water again to remove all the scales left behind by the tool.
  5. Run your finger against the flesh to feel if there are any scales you may have missed. There will be a distinct difference between the texture of the scale and the flesh of the fish so you can easily feel if there are any scales left.

Gutting Your Fish

For round fish, the guts are found in the belly.

You must remove the guts completely before filleting the fish as any punctures to the guts can cause the bile to come out and cause a bitter, unappetizing flavor to your fish.

  1. Cut open your fish along the abdomen, starting from behind the gills to just above the tail. Make sure to use open the tip of your knife to avoid puncturing the guts.
  2. Scrape out the guts and set aside.
  3. Rub the inside of the fish cavity with rock salt to remove any oiliness and black skin left behind.
  4. Rinse thoroughly with cold running water to clean.

Filleting Your Fish

Finally, we’re here at the last step!

Filleting your fish!

Always make sure that you’re using the correct type of knife to fillet your fish.

Not only does it result in nice, perfect fillets, but it’s also a lot safer and easier for you.

The best knife is to use a filleting knife, but if you don’t have one at hand, you can also use a sharp chef’s knife.

  1. Make an incision near the head (under the pectoral fin) and another one near the tail. Do this on both sides.
  2. Beginning from the incision near the head, start cutting down the spine of the fish, using the bones as your guide. If you have a sharp knife, this should be very easy for you as the knife should just glide through the flesh of your fish. Make sure to slice as close to the bones as possible so that you waste as little flesh as possible.
  3. Cut through the body of the fish, keeping the knife as level and close to the bones as possible throughout the process. Check the fillet now and again (without moving the knife) to check if you’re still cutting it levelly.
  4. Once you’ve reached the bottom end of your fish (the second incision), your fillet should only be held together by the skin on the bottom area of the belly. Cut through the skin to remove the fillet.
  5. Flip the fish over and repeat the process on the other side.
  6. Once both fillets are removed, you can rinse them in cold water and pat them dry. Now you have two perfect fillets ready to cook!

🔪Here’s an easy video on how to fillet a fish

Final Tip:

Just like any other cooking skill, breaking down and filleting a fish takes time and practice so don’t get discouraged when your first few tries don’t come out perfectly!

You can practice with small, inexpensive fish such as tilapia or mackerel so that you can get the hang of filleting before moving on to more expensive fish such as salmon or tuna.

When you finally master this skill, you’re never going to buy frozen fillets again!