by Brian Dodson

Created on: January 06, 2010

The first step in applying sharpening stones is to evaluate the condition of the knife to be sharpened.  If the knife is in horrible shape, chipped or so dull that it wouldn’t cut pork fat, you need a coarse sharpening stone to reestablish the basic shape and edge of the knife.  Coarse sharpening stones can be obtained in natural stones, artificial carborundum or alumina stones, and diamond steels.  The coarseness of these stones ranges from perhaps 325 grit to 1000 grit.  The coarser grit of a 325 stone is required to reshape a seriously damaged knife. 

If a knife is still relatively intact, but just dulled, needing reworking to establish a good foundation for a truly sharp edge, a medium grit stone is called for.  Medium grit will allow the reestablishment of a good edge without removing an enormous amount of steel from the knife.  Medium grit stones range from 1000 grit to about 5000 grit.  Note that bonded artificial abrasives cut metal faster than do natural stones with the same abrasive particle size.  A diamond steel is perhaps a better choice for medium grit work, because they remain flat regardless of how much use they see.  These stones will not produce the finest polished edge, but will give knife edges well suited for most kitchen work.

When the sharpest possible edges are required for precise kitchen knife work, fine polishing stones are called for.  These stones are in a class by themselves, both in terms of their fineness and the technique of application to a knife.  Diamond plates can be used as fine polishing stones, but tend to be a bit harsh to produce the best cutting edge.  More useful are Japanese  waterstones, which are composed of fine silica crystals embedded in a clay matrix.  These stones, which are used in a slurry made by rubbing a stone against a knife, range in grit size from about 5000 to about 30000.  These stones are softer than most sharpening stones, so that they do not become clogged with the material removed from the knife.  They form a slurry that polishes the blade, rather than coarsely grinding the edge. 

A progressive approach is necessary to establish a good edge on a neglected knife.  If the edge is just a bit dull, don’t attack it with a coarse sharpening stone.  Similarly, if the edge is in sad shape, don’t spend hours trying to sharpen it with a very fine sharpening stone.  However, when in doubt remove a bit more metal than seems absolutely necessary, and you will avoid a great deal of wasted effort. 

Sharpening kitchen knifes is perhaps the most important task to undertake in improving your cooking.  Learning the proper role of sharpening stones is a vital step in that quest.  The good news is that producing an exquisitely sharp edge on a knife is a rewarding process in itself.  There is no kitchen tool as valuable as a truly sharp knife.

Learn more about this author, Brian Dodson.
Click here to send this author comments or questions.