About "Kurouchi"
Hello there! It’s Tomo.
Today, I’d like to talk about something called “Kurouchi”.
Today, I’d like to talk about something called “Kurouchi”.
Last time, I wrote about patina, and this time we’re diving into another feature often seen in Japanese knives.
Kurouchi refers to the black oxidised layer that forms on the surface of a blade during the forging and quenching process.
Usually, this layer is polished off to give the knife a clean, shiny finish.
However, when the black oxide is intentionally left on the blade, it becomes what we call a Kurouchi knife – also known as a black-forged knife.
However, when the black oxide is intentionally left on the blade, it becomes what we call a Kurouchi knife – also known as a black-forged knife.
In a way, it looks as if the blade is already rusted – but in fact, it’s just the natural oxide layer from forging.
Just to add to what I explained last time:
Kurouchi is a sign that the knife is made from high-carbon steel, and in traditional knives, even the cladding is carbon steel.
That said, these days we also have Kurouchi-style knives with stainless steel cladding.
This offers a balance between the rustic look and easier maintenance.
(Yes, it's possible – even if it sounds contradictory!)
This offers a balance between the rustic look and easier maintenance.
(Yes, it's possible – even if it sounds contradictory!)
Now, there’s also a technique called “kurozome” (black dyeing).
This is a special finishing process applied after the blade is completed, where the whole surface is darkened.
Thanks to this method, we can now create black-finished knives using various types of steel, allowing for more design-focused knife making.
This is a special finishing process applied after the blade is completed, where the whole surface is darkened.
Thanks to this method, we can now create black-finished knives using various types of steel, allowing for more design-focused knife making.
When we talk about traditional Kurouchi knives, we must mention Tosa Uchihamono from Kochi Prefecture.
Each blade is hand-forged by skilled craftsmen – rough and rugged, yet full of character and warmth.
They have an undeniable charm, with textures and finishes that are never exactly the same – truly one-of-a-kind.
They have an undeniable charm, with textures and finishes that are never exactly the same – truly one-of-a-kind.
Most of the traditional Kurouchi knives we stock are made from Aogami #2 (Blue Paper Steel #2).
This steel is renowned for its exceptional sharpness and long-lasting edge retention, far beyond that of standard stainless steel blades.
This steel is renowned for its exceptional sharpness and long-lasting edge retention, far beyond that of standard stainless steel blades.
That said, because these are full carbon steel knives, they do require proper care, or they will rust.
If you're the kind of person who enjoys maintaining your tools and watching them age beautifully, then a full carbon Kurouchi knife will be a perfect companion.
If you're the kind of person who enjoys maintaining your tools and watching them age beautifully, then a full carbon Kurouchi knife will be a perfect companion.
If you love the sharpness but aren’t too confident about the maintenance, a Kurouchi knife with stainless cladding is a great option too – especially with the newer black-dyed finishes!
And of course, if you simply love the look and style, that’s a perfectly fine reason to choose one as well!
By the way – speaking of Kochi and knives, I suddenly find myself craving Katsuo no Tataki!
That’s Kochi’s famous bonito sashimi, lightly seared and full of smoky flavour… I miss it so much!