Whetstones may be natural or artificial stones. Artificial stones usually come in the form of a bonded abrasive composed of a ceramic such as silicon carbide (carborundum) or of aluminium oxide (corundum). Bonded abrasives provide a faster cutting action than natural stones. They are commonly available as a double-sided block with a coarse grit on one side and a fine grit on the other enabling one stone to satisfy the basic requirements of sharpening. Some shapes are designed for specific purposes such as sharpening scythes, drills or serrations.
Grit choices should fall in line with the steel used to make the knives you plan to sharpen. If your knives are all European, relatively soft steel knives, then you could finish off your knives at the 1,000 – 2,000 grit level. There is a lengthy explanation regarding this topic but suffice it to say that at 2,000 grit, these knives can be made extremely sharp.
Sharp knives make the culinary world go round but finding the best knife sharpener isn’t as simple as walking into the store (do people still walk into stores?) and grabbing the first sharpener that presents itself. There are different types of electric sharpeners, some that are straightforward and some whose sharpening process involves as many as 3 or 4 stages. If you’re looking to keep things simple by using a sharpening stone well, there are 3 different types of them as well – oil, water and diamond – and they each have their pros and cons. So it can be confusing.
The goal in sharpening a serration is to maintain the ramp of the serration right to the edge. You do not want to create an edge bevel. Therefore we once again recommend the trusty felt pen trick. Paint the serration to be sharpened and follow your process. Evaluate if you are removing all the black. It should not take more than 5-8 strokes to resharpen if your angle was correct. Rotate or spin the sharpener as you go for the most even, consistent sharpening.
Now that you're holding the handle and the blade is in position, gently apply some pressure to the belly of the blade with your left hand fingers – "roughly the amount of pressure to semi depress a sponge," says Warner. Starting at the tip, glide the blade up and down the stone – around five strokes up and down is a good number. Then move to the middle – five more strokes. Finally five strokes up and down on the heel.
The composition of the stone affects the sharpness of the blade (a finer grain, usually, though not always, produces sharper blades), as does the composition of the blade (some metals take and keep an edge better than others). For example, Western kitchen knives are usually made of softer steel and take an edge angle of 20–22°, while East Asian kitchen knives are traditionally of harder steel and take an edge angle of 15–18°. The Western-style kitchen knives are generally in the range of 52–58 on the Rockwell scale, which denotes the relative hardness of a material.
In addition, the most prized of the natural Japanese Water Stones are quarried in the Narutaki District north of Kyoto, Japan and are commonly available as either bench stones or pocket stones in grits ranging from 120 to 12,000. On the other hand, synthetic water stones are made from Aluminum Oxide and commonly available as either bench stones or pocket stones as well in grits ranging from 220 to 8,000 and, although this is the same abrasive material used to make India Oil Stones, the difference between the two is that the binder that holds the abrasive together enables Water Stones to be much softer than India Oil Stones which, in turn, promotes faster cutting because the worn abrasive material breaks away more quickly and is replaced with fresh, sharp, abrasive material more quickly. In addition, because water stones do not become glazed or loaded with swarf like oil stones can, new abrasive particles are constantly exposed as the stone wears so it continues to cut consistently. Plus, they can be lubricated effectively with water (rather than oil which can ruin some water stones) which combines with the fine particles of abrasive from the surface of the stone to form a slurry which polishes the bevel as the stone cuts. However, it should also be noted that Water Stones do become uneven significantly faster than other types of whetstones although, their softness does make them easier to true again.