Can this dual core Gyuto Deba be my new butcher knife?

[drrayeye (Ray Briggs)]

I originally purchased this knife as a dual core comparison to Dr. H’s Shun dual core santoku, but then discovered that debas were being used for far more than processing large fish in Japan. A slimmed down, modestly priced Kai Seki Magaroku Kinju is being used in Japan widely this way, and I’ve been able to repurpose one as a replacement for my old American Sir Lawrence.

This Xinzuo dual core gyuto deba is much closer to the original Japanese deba: 7 mm spine, high Rockwell hardness (60+), and cleaver level weight (382 gm)

I’ve now been using both the Kai Kinju, and the Xinzuo gyuto deba on meat, vegetables, and cheese, and both more than replace my American Sir Lawrence with two limitations: neither one works well with European style rock chopping nor cutting through bones.

The Xinzuo dual core, in particular, was great for slicing my tri tip–letting the knife do the work. For the finer trimming of my Choice New York strip, I preferred the Kai Xinzuo.

For activities where I want to chop, I’m still reaching for my cleaver, and I’m leaning to softer steels that are more likely to bend than chip for small bones–and my acorn squash.

[eugenep]

I thought it was specialized for fish butchery rather than red meat?

It looks too good looking and likely expensive for me to use on red meat with thicker and tougher bones.

Land animal bones might jack up that knife and it won’t be pretty anymore.

But I wouldn’t get a special knife for fish butchery - not just bc of the price -but because it’s like hell to have to sharpen all those knives periodically.

The Chinese has just one knife. But it’s a lot easier to sharpen since you’re sharpening just one knife.

[Chemicalkinetics (For the Horde!)]

Chinese have many knives, but they look alike so people say they have one knife.

fe. I would say that they have many knives, but they look alike.

[eugenep]

I always thought there was one main knife they use ? It would vary in length and thickness depending on choice of the cook.

But maybe you are on to something.

[Chemicalkinetics (For the Horde!)]

I think it depends. A lot of families do have one main knife, but that is true for Japanese too. Vast majority of Japanese either use a Santoku or Gyuto at home. Deba and yanagiba are not often seen at regular homes.
It also depends if the person plan to do some butchering at home or let the market/supermarkets do all the dirty work.

[drrayeye (Ray Briggs)]

Hi eugenenep,

It was–but that was then. Japan is already more diverse in sources of protein, and the deba is really the best butcher concept knife (single bevel) for them to repurpose. The Kai SM kinju is the type of affordable deba that works over there–and has found it’s way here.

There’s even an American version:

Hidden Gems - The 150mm Mercer Culinary Deba Knife

That single bevel design outperforms my American butcher knife at an affordable price with any protein–including beef.

As long as you don’t chop.

That still leaves room for my Wusthofs and Chinese cleaver: and I honestly love to chop.

Ray

[drrayeye (Ray Briggs)]

Here’s the Kai Seki Magoroku Kinju Deba side by side with the Kai Shun dual core santoku: both are 180 mm, almost the same handle, but the Kinju is intended for a Japanese single bevel repurpose, and the dual core is intended as a double beveled cultural fusion knife for Americans.

[drrayeye (Ray Briggs)]

What’s especially interesting in this comparison is that the knives, both manufactured by Kai in Japan, share almost the same handle and meticulous attention to detail in completely different price ranges-marketed to different buyers. The Shun dual core is marketed primarily in the United States–and currently sells for $329.00. The Kinju is marketed almost exclusively in Japan, but can be had on Amazon for $64.

Ray

[drrayeye (Ray Briggs)]

Can anyone explain what the difference is between the number of reported layers on damascus knives. My Xinzuo claims 110 layers and dual core–but I really don’t know the significance of the 110 layers.

Ray

[drrayeye (Ray Briggs)]

Dr. Hirokawa and I have completed our evaluation of the Xinzuo 18o mm gyuto/deba–still a mystery in terms of dual core construction. However, we tested it and the Kai Seki Magoroku Kinju 180 mm as repurposed butcher knives, and have noticed more and more that it works–and we’re not alone.

To celebrate, I prepped and prepared a beef stroganoff dinner for the two of us, and shared both the recipe and results on Hungry Onion. It was a great way to show how well the reepurposing works in a completely dkifferent world. I’ve decided to keep and regularly use both of them: the Kai SM Kinju as value, and the Xinzuo gyuto/deba as new technology.

For my birthday, in a month or so, I’m planning on buying a new kitchen knife to study–and I’ve got three interesting candidates: two dual core, and one very interesting Chef’s knife that represents Japanese-American fusion–if I can get an affordable one on EBAY: a Shun Fuji 81/2" Chef’s knife.

[drrayeye (Ray Briggs)]

Big challenge today for my gyuto deba. I bought a choice ribeye steak needing significant trimming. Also needed to cut up a kolbasa squash.

The heavy duty gyuto deba was nimble enough to do just the right amount of trimming, and strong enough to split the kolbasa squash into six parts. Three of them and a medium golden potato were to complement the steak.

The steak was seared in my Staub brazier–using the lid to simulate a hot oven of over 400 degrees (by my infrared gun).

Came out a delicious medium rare. Served with squash and baked potato.

Ray

[drrayeye (Ray Briggs)]

Grabbed my Kai Kinju deba to take apart a Fuji apple–like a gyoto. It’s weight forward, cleaver like, but has a completely different feel.

I can see why so many reviewers in Japan liked it so much.

Ray

[LastManStanding]

I think the number of layers contribute to how sharp a knife can be? And the core says how strong the cutting edge could be? Also it’s a main factor for getting a great design and to show off the workmanship for sure.
Anyway you have a good collection. I envy that.

[drrayeye (Ray Briggs)]

Hi, LasrManStanding,

There is no core on this knife–so each of two steels X55 are somehow “smushed” around. So, maybe the two steels complement each other–and that makes the knife sharper?

That’s the claim of the Shun dual core Japanese knife that my collaborator has–and it is both sharp and beautiful.

This one is still a mystery.

[Vecchiouomo]

To my mind the sharpness of a knife is a function of how well it was sharpened. The nature of the metal and the way it was forged, cast, stamped, or folded will determine not how sharp it is but how well it will hold that edge. If layering and folding makes a knife sharper, would it not be used as a technique for making scalpels and razor blades? If I am missing something I sincerely would appreciate an explanation.

[kaleokahu (Kaleo)]

Damascus steel layups can be effectively sharper by virtue of the edges of the billet at the cutting edge. For a number of reasons, the different alloys there have different toughness and abrasion resistance. When the blade is sharpened, there is not one smooth cutting angle, but tiny serrations along the primary bevels. And in most cases, by the time the billet is forged or ground to shape. the layup has a minute level of waviness–this means the very apex is also microserrated.

I think the so-called “dual core” is just a layup where some twist has been imparted in the forging. This is hardly new–smiths have been forging lenths of steel cable into damacus for decades. But the industrially made knives that Ray loves are laid up by machines and shape forged by robots.

The more interesting question for me is how to “decode” the number of layers claimed. For instance, how do you get to 110 layers? Well, if “dual core” is a pair of twisted billets, that’s likely 2 55s. But how do you get 55? Most people think of damascus as starting with two planar layers that are folded, which would be a factorial progression (2-4-8-16, etc.). But you can start with any number that can be successfully forge welded, and with a sufficiently powerful press, there needn’t be any folding at all.

As to why there aren’t damascus scalpels and razor blades, it wouldn’t be cost-effective to do for single use applications, and there may be no appreciable betterment. I believe these blades are electropolished to the spec’d sharpness with blinding speed, which would greatly complicate a uniform edge comprised of different alloys.

[Vecchiouomo]

The question about razors and scalpels was in jest. I understand how an edge with microserrations cuts more effectively, but if you define sharpness as the acuteness of the angle, does a damascus edge attain a finer angle? The beneficial effect of minor imperfections in an edge is well known to cooks. My lowly Sab always sliced tomatoes more easily than other straight edges knives like the gyuto or nakiri I used to have.

[LastManStanding]

I may not be using the proper blacksmithy words below, and definitely no science lab words. However, I think the answer is how condensed the particles of a metal is. I.e. if the metal is of “loose” particles then the edge will be blunt. It may look sharp but under a microscope it would be blunt. But a more condensed metal, under a microscope will still be much sharper. I think so, I’m not very sure. I’ll research it online when I’m on the computer. Phone research is a lame research. Lol.

[drrayeye (Ray Briggs)]

Hi Vecchiouomo,

The classical dual core theory is that two complementary metals can be processed to yield an edge sharper than either metal on it’s own. The recent practical realization of dual core has been through layering and folding of the two metals though there are composite alternatives.

The Shun dual core has folded the two metals into a geometric pattern in which the two metals alternate at the edge, creating potential micro serrations that presumably become more pronounced with use. My collaborator and I have seen no evidence for this whatsoever in his dual core santoku: the cut does not appear any toothier than my core cladded Shun Kaji–but it performs just as well as the harder sg2. The Shun dual core has been around for many years and widely used, but I’m not aware of any evidence from long term users of this micro serration effect.

The 110 layer Xinzuo Gyoto Deba does not have the same geometrical layering as the Shun dual core–nor do other 110 layer Xinzuo products–but the edge of this deba is extremely sharp, without any evidence of micro serrations.

Right now, based on the Shun dual core, it appears that a dual core with steel no higher than Rockwell 61 performs at the level of core cladded knives at least one Rockwell level higher.

I still have many unanswered questions.

[kaleokahu (Kaleo)]

@Vecchiouomo

if you define sharpness as the acuteness of the angle, does a damascus edge attain a finer angle?

I suppose it depends on what is meant by “the angle” and how that is conceptualized. “The angle” isn’t–ever–two planes meeting at an infinitessimally small point of a single atom. Ray could buy a 12k stone and there would still be a crude topography on a micro level. “The angle” is nothing more than the measure of the theoretical angle between the axis of the blade and the (theoretically) flat grinding surface.

The sustainable acuity of a blade’s angle is determined by the metallurgy and heat treatment, not whether it’s monolithic or laminated.