A bone between your teeth. It can spoil the tastiest fish dish. Filleting is the technique that puts an end to that. And with meat too it gives a cleaner, more tender bite.

Filleting is separating the flesh from the bones and removing skin, fat and silverskin. You use a flexible, sharp filleting knife and follow the bone with long, calm strokes.

What is filleting?

A fillet is a piece of meat or fish without bones. With fish that can be two fillets from one fish, with meat for example a chicken fillet from the carcass or a tenderloin that you trim.

You need:

a flexible, sharp filleting knife;
a steady board with a non-slip cloth underneath;
tweezers for the small bones;
a bowl for the trimmings.

Why do you fillet?

A clean fillet cooks more evenly, is nicer to eat and can be served quickly. Especially for children it makes a huge difference that there are no bones left.

A sharp knife and a cold fish: that is half of the work.

How to fillet a round fish

Think of salmon, trout, mackerel or sea bass. These fish have a bone structure of backbone and ribs.

Step 1 – Work with a cold, clean fish

Cold fish is firmer and slips less. Rinse it, pat it dry and remove the scales with the back of the knife.

Step 2 – Cut behind the head

Cut diagonally behind the gills until you feel the backbone.

Step 3 – Follow the backbone

Turn the knife and cut with long, even strokes from head to tail, with the tip as close to the bone as possible.

Step 4 – Lift off the fillet

Lift the fillet and cut it free underneath the ribs. Turn the fish over and repeat.

Step 5 – Pull the pin bones

Run your finger over the middle of the fillet. If you feel small bones, pull them with tweezers in the direction they lie.

Step 6 – Remove the skin

Lay the fillet skin side down, cut a little loose at the tail end and pull the skin away with small sawing movements against the board. If you want crispy skin, leave it on.

Flatfish and meat

Flatfish

You fillet sole, plaice or turbot differently: you cut along the centre line and work the fillets loose outward. On a whole fish that gives four fillets. Feel free to ask your fishmonger for a demonstration: it is a technique you see faster than you read.

Chicken

With a chicken you cut the breast fillet along the breastbone and work it loose in one piece. Chicken thighs can be boned by cutting lengthwise along the bone and freeing the meat around it.

Beef and pork

With meat you mainly trim: fat and silverskin off. Insert the tip of the knife under the membrane, angle it slightly upward and cut along the membrane with a sawing movement. That prevents the meat from contracting and turning tough.

Fish, meat and technique

Product	Knife	Watch out
Round fish (salmon, trout)	flexible filleting knife	feel over the fillet for bones
Flatfish (sole, plaice)	short, flexible knife	follow the centre line
Chicken breast	smaller, sharp knife	follow the breastbone
Tenderloin or steak	sharp knife	remove all silverskin

Recognising fresh fish

Filleting starts with good fish. Look for these signs:

clear, bulging eyes;
red to pink gills;
firm, springy flesh that springs back when you press it;
a fresh smell, of the sea and not of ammonia;
shiny scales that are firmly attached.

Keep fish cool, preferably on ice in the fridge, and use it within a day.

Cleaning first

With a whole fish you clean it before you start filleting:

Remove the scales by scraping from tail to head with the back of a knife.
Cut the belly open and take out the innards.
Rinse the inside of the fish clean, including the dark blood along the backbone.
Pat it thoroughly dry.

Checking ready-made fillets

Even a bought fillet can still contain bones, especially a salmon or cod fillet. Run your finger from tail to head over the middle. If you feel small bones, pull them out with tweezers in the direction of the bone.

Boning chicken

Lay the chicken back side up and cut along the backbone.
Work the meat loose from the carcass with short strokes, without damaging the skin.
Break the hip joints loose and cut the bone free at the leg.
Take out the bone and pull out the tendons.

A boned chicken can be stuffed, rolled or roasted in the oven.

The most common mistakes

Your knife is blunt

It tears the flesh and leaves ragged edges.

Solution: sharpen the knife beforehand.

You use a stiff knife

A knife that is too stiff doesn’t follow the bone.

Solution: use a flexible filleting knife.

The fish is not cold

Warm fish is soft and slippery.

Solution: keep fish cool until just before filleting.

You cut too deep into the fillet

A lot of flesh stays on the bone.

Solution: keep the tip flat along the bone.

You don’t check for bones

A single bone remains.

Solution: run your finger over the fillet and pull bones with tweezers.

What do you do with bones?

The bones and head of a fish and the carcass of a chicken are not waste. Simmer them gently into a fish or chicken stock, without letting them boil. That is the base for a sauce or soup.

That teaches you two things at once: cutting cleanly and being mindful of your ingredients.

Working safely

You fillet with a sharp knife on a smooth, wet surface. So work calmly:

put a damp cloth under the board;
always cut away from yourself;
keep your free hand behind the knife;
put the knife down when you do something else.

Practise with a whole trout

Do you want to learn filleting? Take a fresh trout; it is small, inexpensive and easy to handle.

Rinse the fish and pat it dry.
Cut behind the gills.
Follow the backbone to the tail.
Lift off the fillet and repeat on the other side.
Feel for bones and pull them out.

The first result is rarely pretty. It doesn’t need to be: the aim is to learn to feel where the knife runs along the bone.

Filleting flatfish: sole, plaice and turbot

Flatfish have four fillets, two on each side. The technique differs from round fish.

Lay the fish dark side up on the board. With the point of the knife cut a line along the backbone in the middle of the fish, from head to tail.
Insert the knife just above the bone and work the fillet loose outward with short, long strokes.
Do the same on the other side of the centre line.
Turn the fish over and repeat for the two fillets on the underside.
With a sole remove the skin before filleting: make a small incision at the tail, grasp the skin firmly and pull it in one movement towards the head.

Sole is a delicate fish that needs little handling. Let the fillets fry briefly in the pan with a little butter.

Trimming a pork tenderloin

Lay the tenderloin on the board and find the silverskin: the glossy, white membrane along the outside.
Insert the tip of a thin knife under the membrane, at the end.
Hold the knife slightly upward and cut along the membrane with a sawing movement while pulling the membrane taut with your other hand.
Cut away the excess fat.
Cut off the thin tip and fold it back or keep it aside.

This prevents the meat from contracting during frying and curling up.

Storing and freezing fish

Filleted fish is fragile. Keep it covered in the coldest spot of the fridge, preferably on a bed of ice, and eat it within a day. If you want to freeze fish, do it as quickly as possible and well packed: in portions, in a sealed bag or container, without air. In the freezer fish keeps, depending on the species, for several months. Thaw it slowly in the fridge, and never in warm water. If you eat fish raw or barely heated, such as in sushi, carpaccio or marinated fish, it must first have been kept for at least 24 hours at -20 °C or colder, to kill parasites such as herring worm (Anisakis). Buy fish suitable for that and ask your fishmonger.

Looking after a filleting knife

A filleting knife is thin and flexible and has a sharp blade. Rinse it straight after use with warm water, dry it and store it safely. Hone it regularly with a honing steel and have it sharpened by the butcher or knife sharpener when it gets blunt. A well-maintained knife cuts more easily and more safely.

Frequently asked questions about filleting

Do I always have to fillet?

No. A whole fish from the oven or grill often has more flavour, because the bone protects the flesh.

Why do bones remain?

Mainly the small bones in the middle of the fillet often remain. Feel them with your finger and pull them out with tweezers.

Which knife do I need?

A flexible filleting knife with a blade of 15 to 20 cm. For flatfish it can be shorter.

Can I ask the fishmonger to fillet?

Yes, that is common. Also ask for the bones and head for stock.

Do I leave the skin on?

That depends on the preparation. For pan-frying or grilling crispy skin is delicious. For poaching you often remove it.

Filleting at a glance

Use a flexible, sharp knife.
Work with cold fish and a steady board.
Follow the bone with long, calm strokes.
Check with your finger for bones and pull them with tweezers.
Remove the silverskin from meat.
Keep bones and carcass for stock.
Always cut away from yourself.

Remember this

Filleting isn’t about speed. It is about feel and control: a sharp knife, a cold fish and a knife tip that follows the bone. With practice it becomes faster by itself.