A knife is a tool. A tool needs maintenance so that it can continue to work efficiently and pleasantly.
One of the main maintenances to be carried out on a knife is its sharpening. Indeed, through wear, the edge becomes dull and no longer cuts as it is capable of: the blade must be resharpened.
Here are two videos that I made where I show the sharpening of a knife with a symmetrical edge (which we mainly meet in our kitchens) and one of a knife with an asymmetrical edge (for traditional Japanese knives). I got more videos on my Instagram.
Here are the grit of stones recommended according to their use :
- grain 220/320: a stone to repair a very damaged blade, to redo a tip, it is also a good stone for grinding wide bevels and shape them efficiently
- grain 400/500: a stone for repair a damaged edge, redo a slightly broken point, resharpening the angle on a thick knife. It is used also for wide bevel works, it will grind less material than 200 grit stones, but will give more precision to finish shaping
- 1000/2000 grit: a standard sharpening stone for creating a clean bevel on a edge that needs resharpening, it will give a toothy edge that is good to go through hard skins veggies. On wide bevels it will erase the previous scratches, still grinding a good amount of material but not enough to shape or thin the blade.
- grain 3000/4000: a finishing stone to obtain a less aggressive edge, it will still have some teeth but it will also give a cleaner smoother cut, good for cutting vegetables and meat in general. For wide bevels, this is only polishing, erasing 1k scratches. It could be a good working finish for your knife.
- grain 5000/6000: a finishing stone to obtain a more polished edge and therefore a even smoother cut, for slicing meat, cutting vegetables in general if you want very clean cuts. On wide bevels, this grit will start to give a refine polish on hard steel, with reflection. On iron it will still live a fine scratch pattern and iron will appear dark.
- grain 8000/10000: a stone for polishing edge, mainly useful for cutting raw fish, such as for making sashimi or sushi. On wide bevels, hard steel will start to be mirror, iron will be very clean almost scratchless and bright color
Three accessories for sharpening:
A cork stopper can be helpful to grab the burr, especially when learning sharpening.
A leather placed/glued on a wooden board will finish polishing your edge and hone to obtain a very clean polished edge and a very nice cut.
A diamond stone (Atoma 140 type) or a flattening stone to resurface stones that tend to hollow out after several sharpenings. Sic powder (80 grit) on a piece of glass or granit is a little more messy but much cheaper and very effective.
About Belgium Coticule : It is a yellow stone that I love for sharpening. Mid hard, very abrasive. Great balance of fineness and teeth on the edges.
About natural Japanese stones:
These stones are rocks selected for their abrasive and polishing properties. Japanese stones are recognized worldwide for their quality. Natural stones do not have a "grit" as such but there are coarse, intermediate, fine, ultra fine stones; soft, semi-soft, hard, ultra-hard stones. I mostly use them for polishing but they sure can be used for sharpening too. Here are some examples :
- Natsuya (often a 1000/2000 grain equivalent): often large orange stones, very useful to start sharpening or give a working polish on wide bevels.
- Aizu or Mikawa Nagura (3k 4k grit equivalent): it gives a clean but sufficiently aggressive edge for cutting vegetables with soft skins such as tomatoes. On wide bevels it will give a frosty hard steel finish and dark color iron with nice details. You can also burnish with those stones and get a bright finish on iron.
- Ohira Uchigumori hato, Maruoyama shiro suita, soft and fine stones : equivalent to a 5000/6000 grit: clean sharpening for cutting meat and fish, but also vegetables. Very efficient stones on wide bevels to clean steel and iron. They will give a strong kasumi finish.
- Nakayama suita for exemple, or harder and finer stones : an ultra fine stone (equivalent to 8000 and more): mirror sharpening for cutting raw fish. Those stones will give give a refined kasumi finish for some of them or a polished bevel going more toward mirors and by burnishing showing every details in the iron.
There are many mines and many stones. Each stone is unique and has properties of abrasion, polishing, ease of use, etc.
Don't hesitate to ask me for advice on choosing a stone or if you need precision on sharpening.