STR said:
Fred, I asked the Japan Woodworker once a while back what was difference between the blue and the white and aside from the color and the carbon content they tell folks that the Blue steel is more brittle than the white. Thats what I was told anyway. I can't say one way or the other as both steels seem to me to be as good as any other steels I use. Just thought I'd pass that on. I've seen initial small chips on the edge if I don't first knock off the superficial weakened steel from the heat treating but once that is done they seem to me to be just fine. I have both and can't tell a difference in the way they work so to me its six of one half dozen of another in which one you get and use.
STR
Truthfully, I wouldn't pay too much attention to Japan Woodworker about cutlery. I buy from them wholesale and consider them to be poorly informed about knives. They are really woodworking tool people. Nothing personal. Nice folks and nice knives. There is no color difference, by the way, except in the paper wrapper in which they arrive from the mill.
White steel is the basic hard Japanese carbon steel. Blue has more alloying elements designed to make it slightly more ductile, more abrasion resistant and even more corrosion resistant (chromium.) This is what all the Japanese knife makers tell us. Blue is considered a premium over white steel by every one of them. The top of the line traditional japanese knives are always blue steel. The basic models are usually white steel forge welded to iron (kasumi.)
The differences are subtle and experienced mostly by sushi chefs who use them all day long and sharpen them every evening. A sushi chef will tell you that the blue blades are slightly better at retaining an edge and slightly harder to sharpen. They will tell you that the edges chip less frequently than with white steel blades. The hardness should be about the same (RC62-64) but the blue has slightly more abrasion resistance. A blue knife will last longer for them and is therefore worth the extra cost. Every sushi chef will tell you the same thing. That isn't a scientific analysis but it is consistent from user to user.
My own experiences with yanagis made of both materials is similar to yours. They are hard to tell apart. I have a white kasumi style and a blue honyaki style yanagi and both have full bevel edges (togidashi.) They cut exactly the same for me and sharpen the same for me. However, I sharpen them every few months, not every day. For me and probably for you, the kasumi white steel is more than adequate.
The one characteristic I do notice easily is the difference in corrosion resistance. A white blade will begin corroding the second it touches food while the blue blade will not. My blue knife still looks like bare steel. I wash them and dry them immediately after use. The kasumi knife (iron on the outside of the blade) has darkened normally, as one would expect.
