Introduction to sharpening Japanese Knives
A "Hocho" is an uncommonly sharp but also delicate tool. You should note the following if you are using one.
- The great hardness of the Hocho blade (approx. 59 - 61 HRC) means that it is not as springy as conventional European knives. This is because hardness always means brittleness. You do need to get the feel of these knives. Also, remember that the sharper a blade, the more delicate. So Hocho knives should not be put in the dishwasher. Pieces of cutlery are knocked together in the dishwashing process, and the blade may be damaged. For the same reason, do not keep the knife in the cutlery drawer with other objects but keep it separate, perhaps in a knife-block or wrapped in a teatowel.
- The shape and the properties of the "Hocho" are a response to the Japanese cook's wish to be able to cut the most delicate of foods with virtuosity. For this reason it must not be used to attempt to cut especially hard foods, such as bones or deep-frozen items.
- Traditional Japanese knives are not stainless. This is another reason not to take them near a dishwasher. The same thing is true today as in years gone by: the best knife blades are made of carbon steel, which simply is not stainless. However, it requires only a little care to keep them from getting rusty. Just dry them after use! Only before a long period of non-use does the blade need to receive a smear of oil The best protection is Camellia Oil.
- If the knife gets rusty all the same, it is not a disaster. The rust will disappear as soon as you sharpen it. Additionally you can use a rust eraser.
- Keep the knife regularly sharpened. The best way to sharpen a "Hocho" is on a Japanese waterstone. Dry running griding wheels are completely the wrong thing, and sharpening steels not a good idea. Domestic knife sharpeners should also be avoided. Any dry grinding wheel will cause the carpen carbon steel to soften, and if this happens the knife will no longer be much use. Steels and domestic knife sharpeners are too hard and coarse; they are quite likely to cause tiny individual cutting particles to break off. Japanese waterstones have just the right consistency for "Hocho", sharpening them efficiently without damage. They are soft and the bond between the grains is relatively loose.
- The choice of stone should be between grain size 800 and 1200, and it should be laid in water first for about 5 minutes. Position the stone so that it is unlikely to slip, and draw the blade over it at an angle of 10 - 15° with lengthways or circular movements under gentle pressure so that the whole length of the blade is treated. Do be careful to maintain the same angle throughout the process. The more acute the angle, the sharper will be the cutting edge - but, of course, also the more delicate!
- Knives made in three layers with the cutting edge sharpened from both sides have to receive the treatment on both sides. Those made in two layers and sharpened only from one side are only ground on the sloping edge. Be careful to hold the bevel against the stone over all its length.
- Honing is the removal of the fine burr that has arisen during sharpening, and the polishing of the blade. Here the choice of stone should be a hone of grain size 4000 to 6000 and you should give it the same preparation as the sharpening stone. The knife is moved over the stone in the same way as described above, but with a slightly more oblique angle (the knive is held a little more steeply). When honing, change sides often if the knife is made of three layers, but always maintain the selected angle if possible. For the knives made of two layers but sharpened on one side only, the treatment is basically the same but with one small difference, that the flat face is also taken over the stone, without lifting it at all.+ In this case, the stone must be absolutely flat.
- When you have sharpened and honed the knife, oil it.
There are some tips on getting a stone that has become concave flat again in the instructions accompanying the stone. A combination stone is usuallly adequate for sharpening if it has a 1000/6000 grain size. If you want to go deeper into the detail, there is a good selection in our sharpening stones section.