How sharp should a filleting knife be?

Question

I'm trying to learn to fillet and skin fish, and getting conflicting advice.

Most sources say that the boning/filleting knife should be quite sharp. But when an instructor showed me how to skin a trout fillet, the knife wasn't particularly sharp, and the technique seemed akin to scraping the flesh off the skin in one pass. I've even seen some information on-line by a surgeon who got good results with the "blunt dissection" approach, skinning a fillet with the handle of a table spoon. I haven't bought a boning/filleting knife yet, but in experiments my chef's knife (I know, too thick and stiff) tends to cut right through the skin.

I'm coming to the conclusion that a knife for this purpose should be only moderately sharp. (Part of the problem may be standards-- I hone my own knives, and I don't call a knife sharp unless I can shave the hairs off my wrist with it.) Am I on the right track?

Answer 1

It should be slightly duller than a fresh razor blade. Skill can make up for lack of sharpness, but if you don't have the skills you'll mash the fish more than slice. This is why instructors and surgeons can get away with dull knives; they've got years of experience cutting flesh.

Traditionally, fillet and boning knives are sharpened to a shallower angle than general-use chef knives, to allow a keener edge. The only knife in a cook's arsenal that should be sharper is the slicer, which sees rarer use, and needs to be super-sharp for thin slices.

Answer 2

I've even seen some information on-line by a surgeon who got good results with the "blunt dissection" approach, skinning a fillet with the handle of a table spoon.

The tissue that connects the fillets to the bones is usually pretty minimal and often doesn't require cutting so much as pulling. Sometimes it seems like you could do a decent job with just your fingers once you've reached the point of removing the fillets. The biggest reason you want a good sharp knife is to help you get to that point with minimal damage to the fillet. Fish skin can be tough, and the fins and tail are a lot tougher. A sharp knife will help you make clean cuts around the edges of the fillet.

Answer 3

As sharp as you can possibly make your knife.

Answer 4

I'm of the opinion that sharp knives are better than dull knives. You're less likely to try and brute force something when your knife is sharp, that when it is dull, and (accidental) cuts from sharp knives heal better and faster than cuts from dull knives. Whether or not you MUST have a certain sharpness to complete the task is a different question, but I'd argue the task will be easier and more neatly done with a sharp knife than a dull one.