Specifically, mine. Last weekend I was invited to a birthday function on a yakatabune and had some other matters to attend to, so I didn’t go fishing (apart from sneakily dropping a baited line from the aft of the ship during the party). Since I haven’t posted recently I thought I might put this online, as many visitors at various stages have asked about the knives I use for my cooking. Also, I don’t think there is a resource online that describes the process of looking after traditional Japanese cooks knives in English; the process isn’t half as mystical as one might imagine and is fairly straightforward.
Basically I have three stalwarts that do almost all the main work in the kitchen:
From top, aji-saki (‘aji-slicer’), large deba (lit. ‘protruding blade’) and nakkiri (lit. ‘vegetable cutter’). The aji-saki, sometimes referred to as kodeba (‘little’ deba), is used for scaling, gutting and filleting small fish; I had a friend make a small leather scabbard for it and take it with me when I go fishing, in case I want to make sashimi on board or sun-dry some of the catch. It is not expensive (I think I paid about 3000 yen for it) and quite hardy. I bought it from the well-known cutlers in my old neighbourhood Asakusa, called Kikusue.
The deba is designed to cut meat and fish. Its blade is very thick and it is ideal for preparing large fish, as well as any type of meat, with or without bone. It can slice a spare rib just as easily as splitting the head of a tai snapper in half. Often I cut straight through the meat or fish and the blade gets embedded in my chopping board. This blade seems to keep its edge much longer than the others. The handle is made from hinoki Japanese cypress – a wood which, so they say, will last a thousand years before it rots – and held in place by deer antler. This is the most expensive of my knives, and I bought this one from the Kyoto knifemakers Aritsugu, a family-run business that has been in business for more than four centuries. For no extra charge they engraved my name on the blade.
The nakkiri is a knife from Kyoto and is used exclusively for vegetables and fruit. It rusts very easily but is excellent to use. When sharp, it literally glides through vegetables; you will never cry when chopping onions with this knife. I could never face using a standard Western cooks knife after using this for so long. This too I bought from Kyoto Aritsugu. Generally cooks here in Tokyo will more often use a knife called usuba for vegetable work.
I also have a specialist knife, a yanagiba (‘willow blade’) specifically used for slicing sashimi. Its blade is long and thin, perfectly designed for slicing fillets into thin pieces of sashimi, in a single stroke. The handle is made from hinoki and water buffalo horn. I bought last year at Tsukiji Aritsugu, and is too engraved with my name.
Traditional Japanese knives contain a lot of iron and will rust very quickly. However, the softness of the metal does mean that they sharpen very easily; in a few minutes I can get my knives sharp enough to shave with. Firstly you need four specialist items, from right: nakatogi whetstone, shiage whetstone, toishinaoshi grinder, and brush made from nylon rope. The first three can be bought at any cutlers here in Japan; I purchased mine from the retail store of Tsukiji Masamoto at Tsujiki central market simply because they were the cheapest I could find, for exactly the same product. The brush is not essential and can be substituted with any sponge or thick towel, although I was given the nylon one by a friend of mine who is a tuna dealer at Tsukiji and makes them himself (its use will become clear later). The whetstones are man-made (gousei) which are a third of the price of natural stones, and although they do not last as long, are perfectly fine for an amateur such as myself.
The whetstones should be soaked in water until saturated. The surface of the whetstone is then ground flat using the toishinaoshi. This is done for two reasons: firstly, if this is not performed each time, only the middle of the stone is worn away and the knife is sharpened in an uneven manner. Second, by definition sharpening a knife on the stone will leave particles of metal from the blade’s edge embedded in top layer of the stone, so this needs to be removed.
The cutting edge of most Japanese blades is ‘one-sided’ and the knife is made so that it can be ground at the correct angle just by holding it against the stone. The blade is drawn in a circular motion towards ones body. This is repeated until the blade is sharp.
The next step is to turn the knife over and ‘straighten’ the sharpened edge using the shiage stone, which has a much finer texture.
The last stage is to ‘polish’ the blade using the nylon scrub. This removes the metal dust of the knife created during sharpening. If you don’t do this, you will get iron dust in the foods you cut with the knife; you can actually taste this when eating sashimi (yuk).
Different chefs have different methods of testing their blades. The easiest way is to touch the blade with one’s thumb or fingers and feel the edge. If it is not sharp enough I start out over again.
This blade will take the fine hair off my finger, so it is done!
After sharpening the blades are wrapped in waxed paper and stowed away in their correct boxes. Old newspaper works just as well and even the posh sushi restaurants in Ginza use it (although I doubt they would let their customers see it)! If the knife is not going to be used for some time, some professionals protect the blade with shark liver oil.
Well I think that is enough trade secrets revealed for the time being…most cutlers here in Japan offer a professional sharpening service that is very cheap (usually 500 yen a go) and the old hands have a variety of tricks and methods to get your blade into top form. However, as one friend of mine said, you are not a real ryouri-nin (chef) until you sharpen your own knives! I started doing it for the more practical reason that a professional sharpening job takes two or three days, and my kitchen can’t do without its knives for such a period of time. Lastly, I must acknowledge all the patient help and advice (and shopping trips to Tsukiji market) of the owner of Tsukasa Restaurant, Botancho, Koto-ku Tokyo, who kindly taught me everything I know about Japanese cooking knives.