There are a lot of things i hear on a daily basis from my customers or read online and every once in a while, i come across commonly misunderstood things or myths relating to japanese knives. I thought i'd start a thread where i can post things like that when i remember (or when someone asks me about them). If you have something to add, please feel free (just do a little fact checking first )...
so here we go...
Myth- Japanese single bevel knives have hollow ground edges because they are ground on big round wheels.
Truth- While the rough grinding is done on the large grinding wheels, much of the sharpening and finish sharpening is done on flat surfaces (like the waterwheel i have in my shop and also normal waterstones like you and i sharpen on). This doesnt mean that there cant be high and low spots. They can occur just the same (as they do on belt grinders with flat platens as well). No knives that i can think of off the top of my head are finished on the large wheels people always see in knife making videos. In fact, more often than not, knives are given convexed (or hamaguri) edges from the factory.
Myth- Japanese Single bevel knives need to have the bevels flattened and this is the way things are done in Japan.
Truth- ALL single bevel knives from japan (*that i know of or have seen),even cheap ones, have hamaguri edges. This doesnt mean that its always well done, and often times cheaper knives have poorly done ones. Even usuba and yanagiba. Its not just something done to strengthen an edge, but its also part of the way the knife interacts with food and food release. This is THE recommended way of sharpening single bevel knives by every japanese sharpening professional and/or knife maker that i have met. Flat ground bevels can sometimes be recommended to chefs to help keep things simple in their sharpening, but this is done with the understanding that they are sacrificing some of the performance aspects we look for from single bevel knives.
Myth (or misunderstanding or just cultural difference)- Microbevels are bad for your knife and an unnecessary sacrifice.
My opinion (cant really say truth on this one... its kind of subjective)- Americans (and many other western based cultures) tend to look for the maximum in things. Maximum sharpness, most acute angle a knife can hold, highest hrc, etc. However, you will see many chefs in Japan (the vast majority) use microbevels (koba) on their knives. They understand the small sacrifice in maximum potential sharpness is easily made up for by the increase in edge retention, increase in chip resistance, and ease in touching up the knife during a shift. This stands true for pretty much all single bevel knives i can think of- Usuba, Yanagiba, Deba, kiritsuke, etc. A lot of people seem to think this is just something for debas, but as it turns out its even more important on knives like usuba and yanagiba. Just remember, when you put on a microbevel, use light pressure and make sure to remove the burr.
What microbevels do is remove the very thin and brittle edge of the edge. This is one technique that can be used to get rid of wire edges.
Anyways, thats all for now. I'll probably add more later.
Thanks for posting this Jon, I for one am learning a lot from this, please keep it up!
Thank you for the myth buster post.
It would be helpful to have clarification of the purposes of traditional Japanese, especially the hybrid ones, such as a Mioroshi Deba, Kiritsuke. Also the Usuba is misunderstood.
How is the hollow ground side made?
Originally Posted by JBroida
the hollow ground side is cut in on that big wheel and cleaned up with a series of other wheels and buffers (and sometimes by hand as well). izuka-san also uses a sen to do the hollow ground side.
I guess i should have been more specific in referring to the front bevel versus the ura (back side)
Myth/Misunderstanding- The ever-fabled single bevel gyuto (with the exception of HHH's most recent one). People come to me all the time asking for a single bevel gyuto, sujihiki, etc. They think this will cut better, faster, easier, etc. than what they have.
Truth- People dont make these in Japan. They sometimes make extremely asymmetrical gyutos, sujis, etc., but not single bevel ones. They dont have hollow ground backs or other characteristics of true single bevel knives. Moreover, sharpening a gyuto as if it were a single bevel knife is rarely a good idea. I've been there and done that (as have many of us). The knives cut great, but they can steer horribly and the edges become fragile and brittle. Sticking to something a little less extreme in most cases will be much better (and in many cases is just flat out necessary).
Myth- Kiritsuke is the all-purpose knife of a Japanese kitchen
Truth- Kiritsuke is a hybrid blade... it is intended to combine the functionality of a yanagiba (for slicing) and an usuba (for veggies). It is not to be used as a deba (to fillet fish). Likewise, mioroshi is a combination of deba (for filleting fish) and yanagiba (for slicing). It is not to be used as a gyuto or usuba. People pick knives like these because they can carry/use one knife instead of two. However, they realize that while these knives can do both tasks, they wont be as good at either as the knife that should be doing the job (deba for filleting fish, yanagiba for slicing fish, etc.). Moreover, kiritsuke is NOT a gyuto (or a version of a single bevel gyuto). There are many kiritsuke-shaped gyutos out there now days, but dont confuse "kiritsuke-shaped" with kiritsuke.
Myth- Deba is great for breaking down chicken
Truth- Deba is not at all ideal for this, nor is this the intended purpose of deba. The japanese have knives for breaking down chicken- Honesuki and Garasuki. Deba is a fish filleting knife. That is what it is made to do and that is what it does best. Between all of the professional sharpeners on here, i'm sure there are more than a few stories of debas that needed fixing because someone decided it would be a good idea to split a chicken in 2 with one.
Great information, Jon. Thanks for these posts.
Senior Member/ Internet Hooligan
Jon - doesn't "kiritsuke" really just refer to the shape of the tip of the knife, like a "tanto" tipped knife (but angled back instead of forwards)? So anything (including a pocket knife) with that particular shape is a "kiritsuke?"
not when it comes to kitchen knives (though there may be some maker out there that uses it in a way different from what i am saying here... just havent met that person in japan yet). Based on the kanji 切付, one might guess that is refers to 切付ける as in a verb of cutting, but really it just refers to this specific knife. It has nothing to do with the tip shape. Thats why when people do something in that shape, they call it "kiritsuke-shaped" (or should call it such at least).
I'm guessing that this sometimes gets the same treatment as damascus in western knife maker's terminologies
Originally Posted by Vertigo