I’ve been really holding back on putting together this post. Not because I don’t think it’s important as a technique or worth the effort, but because I just wanted to get it right. Like making your own pasta, filleting fish is not hard but it’s not easy either. It’s a skill that you have to build over time and with practice. Every different type of fish is a little different, sizes constantly vary and every time I think I have a solid handle on the skill, I still manage to butcher at least one size of a perfectly good fish. So I’m no pro yet, but I’ve done this enough to put together a decent (and somewhat lengthy) beginners post.
I would advise not to try learning this skill an hour before a big date or when expecting a lot of company. An important evening is usually better just buying the fillets or having your fish monger do the dirty work until you’re comfortable with the process.
One of the main distinctions you can make when breaking down fish anatomy is which type of fish is it. Most fish fall in to one of two categories:
Round fish - bass, trout, cod, salmon, snapper
Flat fish- flounder, sole, fluke, halibut, branzini
For this post we’ll focus on round fish (specifically with a red snapper – yes yes, they’re endangered/delicious/whatever) since that’s the type you’re more likely to come across on a fishing trip or buying whole in a market.
Most fish mongers will have the fish gutted for you when you buy it, but if not, you actually don’t need to worry about removing the intestinal track/gills/etc if you’re only trying to cut your own fillets. Gutting a fish is for another post/when I finally find someone to take pictures of me going through the somewhat messy process.
The first step in the process is to remove the fins and flippers from your fish. The reason is so you don’t fuck your hand up in the next step. The ends of the top fins especially can really inflict some pain if your hand grazes them at the wrong angle so it’s best to remove these first with sharp scissors/shears.
Now it’s time to descale your fish. You can usually get your monger to take care of this for you, but if you prefer to try it yourself the first thing you’ll realize is that 1) you have no idea where to start 2) once you figure it out, you’ve got scales flying everywhere.
The best cheat I’ve found is to fill your sink or a bowl with cold water and descaling under the water so that the scales aren’t flying everywhere.
Starting at the tail-end, work your spoon against the grain of the scales firmly. You don’t want to be tearing the fish apart to do this, but don’t worry too much about damaging the skin underneath the skin either. Once you get it going it becomes easier. You’ll know you’re done when both sides are smooth.
Scales sink to the bottom of the bowl and don’t cover your kitchen. Rad.
Now the trickiest part. For round fish, you want to start at the head, cutting right behind the gills to maximize the amount of meat in your fillet. Cut to the spine.
Make an incision about 1/2 inch deep at the top of the fish, slowly working your way across the spine. Try to avoid cutting over into the other side of the fish.
Now the hardest part: gently ease the fillet back, sliding the knife along the spine about an inch at a time slicing the fillet away from the body. This takes a little practice, and more often than not, I find I do the right side of the fish better than the left.
Peel back slowly and separate from whole fish using your knife to make long, shallow cuts along the spine. Make final cuts to separate fillet from body.
And vuala! Run your hand along fillet to feel for any bones, removing them with tweezers.
NOTE: If you put the fillet skin side down on a bowl it makes it a little easier to get at the bones.
Remaining tail and spinal cavity can be used for stock. Discard the head and guts.