Double Bevel Knife Sharpening
Double bevel knives are incredibly versatile. They are one of the most commonly found knives in commercial kitchens and home kitchens alike. If you have ever been knife shopping at a homewares store, you have most likely only seen double bevel knives.
Simply put, they have an asymmetrical edge when looking down the knife, and knives are most often called “50/50” grinds, meaning the edge of the blade is shaped like the tip of a triangle. Double bevel knives can be very easy to sharpen with the correct technique and lots of practice, and if you follow these steps you’ll be push-cutting newspaper in no time.
1) The right whetstones.
Choosing the right whetstone for the job is critical in ensuring a satisfactory result. Usually for most knives, maintenance can be done with a 1000 Grit Whetstone. A whetstone with this grit will slowly remove microchips, and can be used for maintenance on a regular basis.
To polish the edge for increased sharpness, a higher grit stone can be used. The most common polishing grit for most knives is a 6000 Grit stone. The most popular grit in combination stones (a stone composed of 2 faces of separate grits) is the 1000/6000 Grit stone. However, most soft generic stainless steels will not perform well above 3000 grit. This is because the more you polish the steel, the less “toothy” the edge becomes, as you lose the micro serrations left by coarser stones.
For a knife that has larger chips, a lower grit (coarser) stone must be used first, in order to abrade the steel much quicker. We recommend a 280 or 500 grit to start, then progress to the 1000 Grit after this. Once you have the correct stone, let's make sure it’s in the right condition.
2) A flat stone is a happy stone.
As we are going to be pushing our knife up and down the length of the stone, the stone needs to be flat to achieve an even edge. Over time, a stone will wear out in particular areas (called “dishing”) and needs to be returned to a flat state to be effective. A flat blade on a dished stone simply won’t sharpen up as well as a flat stone.
This can be done cheaply with sandpaper and a flat surface, or much easier and quicker using the Atoma or similar style “Lapping Plate”.
For a worn out stone, draw horizontal and vertical gridlines about an inch apart. Place this side of the stone on a flat surface, onto the abrasive side of some sandpaper and abrade until the lines disappear. Alternatively, wet the stone after drawing the lines, place on a flat surface with gridlines facing up, and rub with the Atoma Plate until the lines disappear.
Some stones require soaking before use. Check the instructions with your stone or ask your retailer. Most stones benefit from 10 minutes of soaking in water. Do not permanently soak your stones.
Now that your stone is flat and prepared, we’re ready to sharpen.
3) The Correct Grip
For easy sharpening, we want to use what’s called a “pinch grip”, with your thumb on the side of the blade towards the heel, a finger down the spine, and locking your wrist and hand in place.
4) The Correct Angle
There are several different ways to ascertain the best sharpening angle, and this can be done using some angle guide clips or angle wedges. These are intended as guides, and should not be used beyond giving you an indication of the best angles to use. To begin, most Japanese knives are best sharpened at around 14-15 degrees.
5) Let’s begin!
Using your free hand, press with 2 fingers towards the tip of the blade. Place the knife on the wet surface of your stone closest to you. You want firm pressure, but not so much pressure that you can’t sustain an even angle when sharpening. Push in a long, even, steady stroke to the end of the stone. On the release of pressure at the top of your stroke, slide the knife back towards you in the same position. It is important to lock your arm, wrist, and hand to ensure your blade stays at the same angle the entire way through your sharpening strokes.
Repeat this motion while slowly walking your fingers down the blade unti you reach the heel after around 20 strokes per side.
6) The Burr
Perhaps the most important part of sharpening any knife is feeling for the burr. As you sharpen, you wear steel off the blade and fold this edge over to the other side, forming a small lip that you can actually feel. See if you can feel this burr forming on the opposite side of the blade. If you can’t, keep going with your sharpening until you can feel a pronounced, even burr the entire length of the blade.
7) Repeat for the back side
Follow the above steps for your opposite hand. If you’re now sharpening on your non-preferred side, don’t worry! You’ll soon become comfortable with practice, learn to lock your wrist, arm and hand and take it slow.
8) Progressing through the grits
Once you’ve achieved a strong burr on the opposite side, make one stroke on your initial sharpening side, this will centre the burr. You can now move up to your next grit.
9) Polishing & Burr Removal
Repeat this step on your higher grit stones, using slightly less pressure. Polishing does not require much force. To remove the remainder of the burr from the blade, you can run in softly through some cork, newspaper, or pass it over denim.
You should now be the owner of a very sharp knife!