Learn How to Fillet a Fish

Match Your Knife and Filleting Method for Improved Results
by Bill Rival

Filleting fish, like catching them, seems easy in ideal conditions, nearly impossible otherwise.

So start with a firm cutting board, a sharp knife with a comfortable grip and a blade of just the right length. Add a firm, fresh fish, wiped dry. Always cut against bone, or if you prefer skinless fillets, the skin, and two tidy fillets almost magically appear. Waste is minimal. Try to fillet fish with a dull heavy blade and your result may look more like lace curtains.

50,000 Fillets Later

Nobody fillets fish faster than commercial fishermen and the deck hands on head boats. The former fillet tons of fish in a season. The latter might fillet fifteen fish each for twenty to thirty anglers on the hour run back to the dock six days a week. "Quick and dirty" does the deed here. So most pros use whatever blade with decent steel is at hand. On big fish, commercial-grade butcher knives do the job; after a few years grinding, they refine to a shape much like butcher's boning or classic fillet knives.

Fish cleaning methods vary -- we'll discuss several later -- but one thing is certain, thick or thin, stiff or soft, pro's blades are razor sharp. In most cases, pros prepare several blades as it's easier to "switch than sharpen." I learned this on my uncle's boats when Frank and George would bombard me with fish parts if my sharpening failed to meet their standards.

Specialty BladesĀ 

Unless you overdose on yellow perch, or go totally mad and try to fillet tons of panfish, it's unlikely that any recreational fisherman will clean enough fish to become as quick as the slowest commercial fisherman. Even guides have trouble getting enough practice in these catch and release times. So you need to pay a bit more attention to your filleting "tackle" to overcome the lack of practice needed to perfect technique.

I just counted. My wife and I own nine fillet knives! These range from the smallest Normark blade up to a monster 14 inch long blade used for albacore and salmon. I've two favorites. One is the shorter of the two inexpensive wooden handled Finish knife models sold by Normark. The other is an eight inch long, heavier blade Buck folding fillet knife. Why these? Both have comfortable grips sized to suit the blade and task. The shorter Normark seems ideal for the smaller bass, crappie and trout I fillet and smoke. Its wood handle offers a secure fingertip grip for al fresco cleaning in frigid weather. There's a fancy black-handle model too. The larger Buck stashes nicely in my big fish tackle box and chugs through bigger fish ribs. So long as I don't use it in cold weather when my hands tend to freeze to the grip, it does a good job on fish from about five to fifty pounds. The larger handle suits the "whole hand" grip you need to slice bigger arcs and crunch through heavier ribs. So it suits steaking too. Bigger saltwater fish get the attentions of "Mac the Knife," a monster with an 11 inch blade solidly mounted on a large plastic handle. Backup knives get used too.

My wife's tastes vary. She uses a Shrade Steelhead knife with a Staglon(tm) handle for big fish fillets and a smaller model for trout. So it's important to realize that only "hands on" tries insure the most comfortable knife grip and convenient blade length for your needs.

When we have a batch of fish to fillet for freezing, I'll switch rather than fight dulled blades. All of our fillet knives hold a fine edge reasonably well and resharpen moderately quickly. Their blade shapes and hefts suit our filleting methods and hand size.

Blade Selection

Your selection should start with a blade length that suits the fish, for if you buy a fillet knife from a "name" manufacturer such as Buck, Normark or Schrade you know the steel selection suits. Oversized "Rambo" blades don't cut it with the size fish I catch; they might be handy in case of shark attack. Shorter blades suit, if they are at least the length of the top to bottom measurement of the fish plus an inch or two. For most freshwater fishermen, a 4 1/2 to 6 inch long blade is plenty.

Longer blades are both awkward and, like dull knives, may cause injury. (They get heavy when you have to fillet 100 yellow perch, too! ) The reason for this is balance. You need a much larger, or at least heavier, handle to balance the weight of macho blades. Such blades are difficult to manage for those with small hands.

Short knives merely take a bit longer. So I do keep a tiny Buck folder handy to trim out the most succulent morsels and lift out the delicious cheeks on medium to large-size fish. We steam these and serve them with cocktail sauce. Italian fishermen, and Chinese, think the cheeks the best part of the fish! We agree!

Your fillet "style" influences blade selection too. Filleting systems that crunch ribs off the backbone, and then slice ribs off the fillet, need a knife with more backbone -- this means stiffer too. As an alternative, you can slice through ribs with a heavy chef's knife or an electric fillet knife; then use a smaller, more flexible blade to lift ribs. I dislike the time lost switching blades.

Fillet blade shapes seem pretty uniform. A long thin, flexible blade suits just about everyone. Very thin bladed knives, like the Normarks, do break if you try to use them to open paint cans or where a Chinese cleaver better suits heavy rib crunching. Thick bladed knives good for chopping ribs off big fish simply won't slice efficiently over the flexible ribs on fish like trout. So thickness, like blade shape, remains a compromise.

Other design compromises abound. Knives that hold their edges a long time take a long time to sharpen. A knife that's only good for a few fish before it dulls, such as my favorite pocket knife, an old "Barlow" of my grandfather's like those mentioned in TOM SAWYER, regains its edge with five strokes and a quick strop on my belt. So it's ideal for stream days when a brace of dinner trout is all that's needed.

Its grip fits my fat fingers well. So do the wood handles on Normarks and the Staglon handles on my wife's knives. What's important is that you enjoy a secure grip on a comfortable material which wears well and is compulsively attached to your knife blade. As a rule fixed blade fillet knife grips are more comfortable and more durable than folders.

Steel Selection

Knife manufacturers, custom blade makers, and knife collectors get into all sorts of arguments about the relative advantages of different steels. Fortunately, knives in the same price range from well-known manufacturers perform equally well. Differences reflect varied filleting skills and, often, sharpening ability. So an old familiar knife made from traditional materials may work better than something "high tech."

Blade steels do vary with manufacturer. High carbons, the traditional 1095 steels with about one percent carbon which both sharpen fast and hold their edge reasonably well, suit those who don't mind a darkened or discolored blade that requires regular care and artful oiling. Stainless steels like the 440A run to 17 percent chromium. These seem a bit slower to sharpen and don't hold quite as nice an edge as high carbon steel for most tastes. However, they fillet nicely and rarely, but not never, stain or rust.

Shap SolutionsĀ 

Even the best knives fail if they aren't sharp. Years ago sharpening knives was an esoteric skill that required the ability to hold the blade at a very shallow angle to the stone. Today, Lasky Sharpeners, ceramic wands, diamond hones and a flotilla of other sharpening devices eliminate the need for major effort, or manual dexterity. Simply follow the directions and you can enjoy decent fillet results with most anything with an edge --- at least for a bit!

TIP: buy a small stone and glue it to the back of a knife sheath and it won't get lost. I also favor diamond hones attached with a string to my fishing vest -- It's tough to lose a fishing vest, especially when your wife threatens to replace the next loss with a bright orange model!

Then, so you don't nick your knife edge on a tile counter, or raise the wife's ire by slicing softer counter tops, get a cutting board. Add a clamp to hold the fish tail if you like. Purists tend to find these a bit clumsy except when cleaning catfish or bullheads which sometimes require three or four hands and, if you slip, hosing down the kitchen.

Since your knife choice depends so much on your method, it's important to see how each method works. It's rather interesting that the following methods are world-wide. It's vital that you realize that practice and, in particular, repetition, can make all these methods work!

Three Cuts/Three Parts Rib Chop

This most popular method starts with a diagonal cut along the line of the ribs from the top of the fish to the bottom. The blade is then turned toward the tail and the fillet sawed off while crunching through the ribs at the backbone. The entrails and belly are discarded and the belly meat trimmed off. Then the ribs are pared from the fillet and, if you like, the fillet knife run next to the skin to saw the skin off. It's easy, basic and both messy and wasteful if you don't use backbones and heads for soup and stock.

Rib Lift FilletsĀ 

This starts with the basic diagonal cut near the head, but then cuts back toward the tail by pressing the side of the knife against the backbone and dorsal fin as the knife tip bounces down the ribs without cutting them. This last depends more on feel than sight. You can get the feel by lightly running a knife point (not the sharp side!) over a closed zipper. A light knife with a more flexible blade does the job with the finesse needed.

At the aft end of the ribs, this rib lift method, and the following flip-flop method diverge. With the rib lift, reverse the blade to face the tail, stick the knife through the fish next to the backbone just aft of the vent , and, using the backbone as a blade rest, cut free the tail end of the fillet. Then free the head-end of the fillet by letting your knife run down over the ribs toward the belly to free the fillet. Flop the fish over so the second fillet is done in the same manner on the other side. A bit of trimming around fins and belly, and, if needed, stripping off the skin by running the knife under the skin with the fillet's skin side down does the job if you like skinless fillets or don't want to scale fish.

Innards stay put inside the rib cage for easy disposal along with the trimmed off skin. It's also a good approach for skin-on fillets. The method's disadvantage is the difficulty some have in holding fillets down while stripping off the skin.

Flip-Flop Filleting

Our favorite method diverges from the rib lift method when you finish running your knife point down the ribs. At the aft end of the ribs, the knife is allowed to punch down and through the skin so it comes out just aft of the vent. The knife is pressed against the backbone and the cut down to the ribs is swept to, but not through, the tail skin. Then the knife is removed and used to "peel" the flesh off the ribs. When the fillet is freed, except where attached at the tail, it's flipped over onto the board. The knife is reversed, and using the unfilleted fish as a handle, the fillet sawed off as the flexible blade puts lateral pressure on the skin. Tip: when trimming off skin move the fillet to the edge of the board so the knife stays nicely flat to minimize waste. The process is repeated on the other side of the fish. The result should be two skinless fillets and a body, innards intact, with the cut-off skin attached. Don't worry if you accidentally cut off a fillet, it's easy to simply cut the fillet off the skin, skin side down, as in the previous method.

Beware The Y-Bone

Fillets of fish with the infamous "Y" bone which lurks just above the ribs ready to choke the unwary in fish like carp or pike, take a couple of more cuts after the fillet is free on your cutting board. The first cut slices off the thin strip of meat above the Y bone, using the Y bone as a guide. The second cut slices off the larger lower section of meat from over the ribs. What's left is the triangular Y bone and a small amount of meat within the Y that's good for stock or grinding.

Cutting Up Catfish

"Look ugly, clean tough, eat good" describes these scaleless whiskerfish. The traditional catfish cleaning method involved messy skinning with pliers and various "cat contraptions" such as nails through heads, or tail clips. Given a very sharp knife, or my favorite single edge razor blade, to cut the skin through along both sides of dorsal fins, either the rib lift or flip-flop methods work with small catfish. The basic three-cut method works well with an electric fillet knife. Then it's easy to pare ribs off the fillet and, with the fillet skin-side down, saw off the meat without much waste. Big catfish should be steaked.

Lifting Lateral Lines

Lateral lines vary in width and thickness. I really like the strong, fishy tastes of fresh fish, but these dark bands collect any strong tastes and contaminants. Carp, if you handle the Y bones, seem quite edible from decently cool water, when poached after you remove the lateral line. The taste of most bass, pike and a number of marine species like tuna improve if the lateral line is carefully removed with an extremely sharp knife. Don't bother for salmon or trout.

Partial Filleting

It's tough to beat salmon steaks, so we steak our salmon and many other large fish. Then we fillet the tails with the flip-flop or rib lift methods. On very large fish it's sometimes necessary to cut fillets up into "half steaks" for even cooking. If fillets vary more than 50 percent in thickness, trim! If you don't, uneven cooking is assured.


Leftover heads and backbones sans innards boil up into a lovely fish stock -- see any decent cookbook -- that can be reduced, strained, frozen in ice cube trays and saved until used in sauces or soups. I grind fish bones and bury them deep under tomato plants too.

Final Cuts

"Catch it, cut it" remains the rule of our house. Any fisherman owes careful preparation to both his catch and his cook. Filleting skillfully, like the care paid to the catch, marks the skilled fisherman who respects both the catch and palate. To do less deprives both of due respect.

Freezing And Refrigerating

Fillet and ice down fish as soon as possible after they are caught. Smart fishermen do this on boat or bank between bites, seal fillets in plastic bags and dump them in a cooler filled with ice. Fresh fillets eat best. Fillets covered with water and quickly frozen keep best, but usually not more than a few months. They are edible longer, but they just don't taste as good.