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Koishi, Kurouchi, Kasumi, Nashiji, Warikomi

Fri Apr 19, 2013 8:52 pm

Koishi, Kurouchi, Kasumi, Nashiji, Warikomi, Hammered, etc.......

How much do these finishes add to knife prices and/or quality or ease of use. Been wanting to get the absolute best quality knife I can afford, and am wondering about how much the different finishes such as these (and Damascus patterns) add to the price. If anything.

In other words, say a $400 knife with a "finish" versus the same type of knife at $400 without it. Can a "better" knife be had for the same amount of money spent? Or are the finishes just part of the maker's process?

Re: Koishi, Kurouchi, Kasumi, Nashiji, Warikomi

Sat Apr 20, 2013 4:32 am

The terms listed describe not only the finish but also the cladding style, physical shape, and IIRC product lines. Many of the finish types are aesthetic and are a reflection of the polishing process. Kurouchi will usually be less expensive because less labor is comitted to polishing the sides of the blade. Knives with a mirror polish will definitely be more expensive. Cladding type and style can affect performance such as durability, rust, and in the case of damascus can be visually appealing too.

What attributes are you looking for in a knife?(It's kind of hard to define better) One that cuts well without food sticking to it? Or maybe something laser thin that falls through food? These two examples would be determined by the geometry of the knife. It all depends on the most important features you're looking for in a knife. I would say you can buy more knife for the money without an expensive finish. Value weighs heavily when I purchase knives.

The knifemakers could answer your questions better as I don't speak Japanese. Just a few words :)

Re: Koishi, Kurouchi, Kasumi, Nashiji, Warikomi

Sat Apr 20, 2013 9:44 am

Been a long night at work, but let me see if I can help you out a bit from what I remember:

Kurouchi is a "Blacksmith's finish" or something like that that darkens the outer layer of steel in a clad type knife. Some seem like a black oxide/bluing, others seem more like forge scale. There are many different ways/techniques to do this, some work better than others and last longer. Some are bluish, black or dark grey. Some are smooth and shiny, some are coarser and rougher. The finish is supposedly from the steel reacting to whatever is put on it, so the steel won't react as much to the food. I have found that some of the lower cost Kurouchi knives tend to have short height blade grinds and this can lead to wedging in the cut or more cutting friction where others cut beautifully.

The Kasumi (hazy?) finish is to show contrast between the soft steel and the hard core steel and again, there are many ways to do this. Stones give one look, but many companies choose to bead/sand/media blast the areas to show the difference between the 2 steels. Depending on how this is done, it can also add a lot of friction to the cut.

Nashiji is supposed to refer to the pear like skin texture. The surface has small dimples and stuff like that and is left in a rougher state. This helps break some surface friction on foods as there can be small air pockets and stuff. Nashiji blades are often smoother feeling than some KU blades, but not always. I usually see a Nashiji finish on stainless cladding, but not always.

Warikomi is when the softer cladding steel is wrapped around the hard steel on the spine, so the hard core steel doesn't show thru the softer steel at the spine. I think Murray Carter does a line like this, there was a great pic recently that showed this. Instead of a 3 piece sandwich of San Mai (soft steel, hard steel, soft steel) with the 3 layers showing at the spine, the Warikomi is more like a taco if the shell is the softer steel and the filling is the harder steel. These blades can be KU, polished, etc. It is the method of laminating the hard/soft steel together.

Hammered/Dimpled/Tsuchime/Koishi is the dimples/hammered marks on some blades. It is supposed to reduce friction in the cut (less material rubbing against the item being cut) and allow air between the blade and item being cut. Some are KU finished, others are more of a grey color. Some look like they are hand done, others look more machine/press done.

There are good and bad examples of each of these things. Just because a knife has a KU finish, doesn't mean that it will wedge or cut poorly or be overly thick. Just because the sides are fully polished doesn't mean that the knife will cut well. How the knife itself is ground will play a big part in how the knife performs. Most of the finishes do help reduce stiction to the blade compared to a polished blade side but not always, though, but other than that, they are somewhat cosmetic.

Re: Koishi, Kurouchi, Kasumi, Nashiji, Warikomi

Sat Apr 20, 2013 3:25 pm



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