Last time I blogged about sushi, I mentioned some of the knives a sushi chef has to learn to use during their seven year apprenticeship. It seems like for every ingredient there is a different knife, it would take me seven years to just learn all the names let alone the different techniques each knife requires!

Since then I?ve managed a few more ?research? trips to my local kaiten sushi restaurant, and between mouthfuls I found out some interesting things about Japanese knives or ?hocho?.

The reason hocho are so strong, sharp and perfectly weighted is because they have a shared history with katana, the traditional Japanese swords of the Samuri. Sakai, near Osaka, was the capital of samurai sword manufacturing since the 14th century. In the 16th century tobacco was introduced to Japan, and Sakai diversified into producing extremely sharp knives to cut the tough tobacco leaves, which led in turn to producing knives for the kitchen. This is why, traditionally, a sushi knife would be made of an incredibly high-quality carbon steel, the same type used in the forging of katana - traditional Japanese swords. However today a sushi knife one would find in a modern kitchen does not use materials with such an intimidating history, instead they are mostly manufactured from top-end stainless steel alloys containing molybdenum for extra toughness.


The other large difference between a sushi knife and the average Western knife is the way in which it is sharpened. While nearly all Western knives are sharpened on both edges of the blade, a professional sushi knife is sharpened on only one edge, a style known as kataba. For right-handed knives, this is the right edge, and for the rarer knives made for left-handed cooks, the left edge is sharpened instead. Having only one edge of the knife sharpened allows for cleaner cuts and more precision, but learning to use only one edge is more difficult and takes many beginners some time to master.

Some blades have been further refined to include hollow recesses called grantons that create small air pockets between the blade and the slices. This reduces the surface area in contact with the food reducing resistance and also it keeps the food from sticking to the blade. Very handy when you are finely slicing tuna.

So there you have the curious historical link between the Samuri, smoking and sushi!