Guide to using knife sharpening stones

Good quality kitchen knives can be pretty expensive – sometimes up to several thousand rupees for a knife made of high-quality steel.

Japanese knives are renowned for their extraordinary metallurgy that has been perfected over centuries, while German knives are also known for their good quality using modern technology. While such good quality knives will retain sharpness for a long time, they will eventually need to be sharpened.

Automatic sharpeners will do the job of getting the knife back to pristine cutting condition. However, a lot of professional chefs and cooking enthusiasts prefer sharpening knives with stones. This is an art that one learns over time.

There are various kinds of stones that can be used in the sharpening process, some of which are natural too. However, artificial stones are preferred because there is more consistency in the sharpening surface. Natural sharpening stones are found only in a few places in Japan, Belgium, England and the US. This makes people prefer artificial stones since they are available more easily. Also, sharpening knives with artificial stones is much faster than with natural ones.

The important thing to note is to check if lubrication with water or oil is required. Not taking care of this could damage the stone.

Whetstones or oilstones
These manmade stones have an abrasive material like silicon carbide or aluminium oxide. A silicon carbide stone can be bought for as less as Rs 200 at a hardware shop. This is a very basic stone that can be used to sharpen any tool like a chisel. These stones usually have a coarse surface and a fine one as well. The coarse one is used to do the sharpening by grinding into the metal. The fine side is used to give the knife edge a good finish.

However, there are better stones available that are specifically made for sharpening kitchen knives. These could cost about Rs 2,000 or even more. The finer surface they have is usually smoother than the ones on cheaper stones. Sharpening and finishing on smoother stones will give a sharper edge.

There are specific stones for sharpening knives with serrated edges. Using the right kind of stone is important since it will ensure that there is no damage to the expensive knife.

These stones generally have to be wet while sharpening. So, a few drops of water or oil have to be added as and when the surface becomes dry. Unless it is specifically mentioned that they can be used dry, lubricating them with water or oil is a must. Not doing so will result in the stone and knife getting damaged.

Japanese water stone
Apart from mastering metallurgy that produces excellent knives, the Japanese have also mastered the art of sharpening them with water stones.

Water stones are naturally occurring stones in the Kyoto region. These are sedimentary stones that contain silicate particles that are mixed with clay. These stones are found in different textures and the coarser ones can be used for sharpening and finer ones for finishing.

They have to be lubricated with water during the sharpening process. Good as they are, they might be difficult to source in countries like India.

Diamond sharpening stone
These are becoming increasingly popular due to the ease of use and quick sharpening that can be done.

They are made up of a small steel plate and have an industrial diamond surface on which the sharpening can be done. The fine diamond coating is usually in a pattern so that the fine metal removed from the knife can settle in the gaps. This enables the surface to be totally flat at all times.

Apart from sharpening stones, these stones can be used to repair the surface of damaged whetstones.