View Full Version : Lookin for new Japanese fillet knife

07-12-2013, 04:35 PM
Not sure if this is the right room for this. I'm looking into a nice fillet knife. I was looking at the Japanese deba. I have a hard time with feeling the back bone of bigger fish and would like to cut right through the rib cage and then remove. I'm also a lefty and have seen a lefty edge only. I have no clue what the benefit to this is. Looking for advice.

07-13-2013, 03:44 AM
I'll try my hand at this with what I learned from the forums when I was interested in Japanese single bevel knives. Someone please jump in and correct me if I'm wrong.

Are you a home cook or do you work in a pro kitchen? What type of fish do you fillet? What kind of knives do you currently have? And do you have a good sharpening set-up?

I don't think the Japanese style of technique cuts through the bones of the fish besides the head, possibly the tail and the fins. You may want a chinese or western cleaver for other bone cutting tasks.

Japanese single bevel knives (JSBK from now on)are sharpened on one side. For a Left-handed knife, is sharpened on the left hand side of the knife (with you holding the knife, edge downward, and pointing away from you). Left side is somewhat convexed to prevent food sticking to the blade face. The right side/back side of a Left-handed knife is slightly concaved or has a hollow grind to reduce pressure and drag on the food and to also reduce sticking to have a clean cut on the food. JSBK are generally cut in a certain way to utilize these features.

One thing about JSBK is that the handed knives tend to steer in the direction that it is handed in because of the concavity and convexity, ie right-handed to the right or left-handed to the left. Some people can compensate for it, so unless you have the experience or skills, it's probably best to stick with a left-handed knife.

Here's some good resource from one of our own Jon Broida on the knife geometry, images, and a few videos for you to understand better:
Itasan a Japanese chef with tons of invaluable videos on fish filleting, Japanese cutting and cooking
I would also look up other salmon, tuna, and fish filleting videos.

Here's my personal recommendations for you, learn from the videos and fillet your fish with a sharp gyuto/chefs knife or petty/utility knife (~6 inches) first, or a western filleting knife. Do your research before you spend money on a deba and having to deal with certain cutting styles and knife steering. If not used properly, the knife may not cut well, and you would not be happy with the knife.

07-13-2013, 05:08 AM
Correction! I realized I had the steering flipped around after thinking about it.
EDIT: One thing about JSBK is that the handed knives tend to steer in the direction that it is handed in because of the concavity and convexity, ie right-handed to the [left] or left-handed to the [right].

Also because of the high asymmetrical bevel angle

07-13-2013, 07:08 AM
This is all based on my experience as a sushi chef, this is by no means definitive and please correct me if I'm wrong (all you pros out there) ;)

The ability of a deba in breaking down fish, both round and flat, is more dependent on the cook's skill than the knife itself. In the right hands a deba can do amazing things. I find it is more versatile and easier to control than a western fillet knife. However, both types can get super clean fillets. The deba has quite a learning curve, like all JSBK, to become proficient. That is the part that really matters.

My suggestion is to watch (and study!) those videos gconcept999 posted and the videos from Japanese knife society, get a lower-end or used deba, a few different fish, and have a go. The ones we usually train new guys on are mackerel and striped bass, as they are a good size, economical and easier (IMO) to work with. See what it feels like, how it works for you and practice practice practice. BTW, in my experience San-mai oroshi is simple compared to Go-mai oroshi. Try flat fish later on when more proficient.

Steering shouldn't be an issue with a deba used only for breaking down fish, as the very shape and design of the knife are meant to facilitate the techniques it requires. The types of cuts executed on fish are generally to either separate the various parts (i.e. head and guts from the body), to remove the fillets from skeleton, remove bones from fillets (like the rib bones) or to break down hard bits like the skeleton/head into useful sizes. Generally, the knife "runs along" some line or surface, with one side staying put while the other is separated and/or removed. There are nuances in how to cut through bone, like what part of the edge one uses and what points in the skeleton one targets. Also, one's wrist needs to develop strength and stamina for a heavy knife. Deba are used at various angles and directions as a butchery tool, thus demanding flexible wrists, elbows, and shoulders.

I have only had to overcome steering issues when using single bevel or asymmetrically ground knives in general food prep (chopping, slicing, mincing, etc.) such as that of usuba or gyuto. It was usually when a single bevel or highly asymmetrical knife travels through a big stack of product on a board. To learn to deal with this, for a while I used a Shun 210 yanagi as a line knife for everything, veg meat seafood etc etc, and this forced me to learn to correct for the steer. Instead of looking at the bevel side of a JSBK, look at the hollow ground back side as the line guide for a cut's plane. (if that makes any sense).

As a lefty, using a mirror image of the righty process/technique should work. And there is a lefty yoshikane on JNS, that at 185mm and less than $200 bucks shipped, might be a good place to start. Best wishes and good luck!

07-13-2013, 08:34 AM
i agree with this very much from the how to use point of view