In the process of our Tohging (special knife sharpening by Tohg Sharpening), your knives went through geometrical optimization: the edge has been thinned with a clamshell profile, by hand with spirit, using seven whetstones in the traditional Japanese method. Because the blade is now thinner, it requires a bit more care to preserve this sharpness.
Below are tips to help you maintain the edge for as long as possible, and to restore sharpness yourself when needed, until your next tohging.
Every touch of the blade against the board dulls it slightly. The less contact, the longer the sharpness lasts.
Choose boards made from Japanese cypress, ginkgo, or high-quality rubber. The board is the hardest material your blade cuts, and using softer surfaces will greatly protect your edge.
Western and Japanese knives are based on different cutting philosophies. Western knives chop with weight and pressure, while Japanese knives slice through ingredients with sharpness. To use your Japanese knife correctly, slide it smoothly with minimal force.
Since tohging has thinned your blade, always sharpen at a small angle (closer to the whetstone). A larger angle will thicken the edge much faster. Simple sharpening tools can also be effective if used carefully.
The burr is the sign that sharpening is complete. Over-sharpening will unnecessarily thicken the edge.
High-quality knives can be made thinner and still retain sharpness longer. Even with tohging, lower-quality knives may lose their edge faster. If your knife does not hold sharpness as you expect, it may be time to upgrade.