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Knife Sharpening


Many sushi chefs sharpen their precious knives at the end of each work day. Edge life versus ease of sharpening - it is up to you to balance these considerations and choose an appropriate knife. However, you should choose a knife that matches your level of sharpening experience and meets your needs. If you are inexperienced with Japanese knives and water stones, try to choose a knife that is easier for you to sharpen.


Why so much Sharpening?


All knives must be continually worked against a water stone to be used at their fullest potential. As you familiarize yourself with the stone and knife, you may begin to change the bevel based on your needs.


When Should I Sharpen?


Ideally, you should sharpen the knife right out of the box. This will produce the strongest edge and is especially necessary for traditional Japanese knives. We recommend that customers sharpen their knives before they become too dull. Sharpening a very dull knife will require much more time. Stones can be fragile and should never be over-soaked. Over-soaking will decrease the stone’s quality and make sharpening more difficult. After sharpening, wipe clean and allow to air dry. It is preferable to store stones in a dry towel. Returning a wet stone to its cardboard box can lead to mold growth, which can weaken the stone resulting in cracking or separation.


Knife Sharpening


  1. Soak or splash with water.
  2. Put stone on wet cloth or base to stabilize while sharpening.
  3. Hold knife with your index finger resting on spine and thumb on flat of blade, and three remaining fingers grasp handle.
  4. Start with knife tip. Use two or three fingers of left hand to press edge of blade to stone.
  5. Keep a firm grip on the knife, with shoulders square to the stone and upper body relaxed. Press edge of blade to stone and push along stone, exerting pressure as you move forward and releasing pressure as you return blade to starting position.
  6. Repeat this procedure, pressing the edge closely to the stone and sharpening a bit of the edge at a time until you feel a slight, even burr along the entire edge.
  7. Once you have a burr, reverse the blade. Start with the tip. Exert more pressure on the downward stroke and remove burr, or establish a double-sided edge if desired.
  8. Japanese-Style Knives (Yanagi, Takobiki, Usuba, Kamagata Usuba, Deba Knives) Sharpen the entire cutting edge until there is a slight and even burr on the reverse side. 
  9. Place the blade perpendicular to and flat against the stone. Remove the burr with your middle and index finger gently pressing the edge to the stone and your thumb gently pressing the spine. Pressing both sides of the blade preserves the slightly concave shape of the reverse side of the blade and helps make future sharpening possible. Think of the motion as if you are "pushing" water off the stone. 
  10. Flip the blade over again and sharpen the shinogi line by moving your fingers away from the edge and pressing just below the middle of the blade. For optimum performance, it is very important to preserve the original shinogi line.
  11. Western-Style Knives Note the angle of knife to stone while sharpening. 
  12. Angle the knife to establish the cutting edge. A 10º-20º angle is suggested. A smaller angle will make a sharper, but weaker cutting edge. You can use two pennies to gauge an approximately 12º angle. Use this trick to help measure a consistent angle until you feel confident in sharpening.


Grits of Sharpening Stones

#220 Grit

Best used to reshape or repair chips. 

Caution: Be aware that the #220-300 grit stones are very abrasive, therefore it will shave off a lot of the material. We do not recommend beginner sharpeners to use these stones. #300 Grit

Best used to put on an edge quickly for very dull knives. 

Caution: Be aware that the #220-300 grit stones are very abrasive, therefore it will shave off a lot of the material. We do not recommend beginner sharpeners to use these stones. #1,000 Grit

The #1000 grit stone is the basic sharpening stone that we recommend customers use to sharpen knives. #1,200 Grit

The 1,200 grit stone is great for sharpening Traditional Japanese knives, because Traditional Japanese knives are more delicate than Western style knives. However, the #1,200 grit and #1,000 grit are interchangeable. For a more abrasive grit, we recommend using the nagura stone on your #1,200 grit stone, then using the mud produced to sharpen. #2,000 Grit

The 2,000 grit stone is still considered a medium stone. It is not as abrasive as the 1,000 or 1,200 grit stones, therefore it will take longer to sharpen. We recommend the #2,000 grit stones for those who prefer to sharpen knives very often (everyday or every other day), because it doesn’t work off as much material as the lower grit stones. #3,000 Grit

Uses: 

1. When sharpening knives, it is important to use medium stones and finishing stone. However, it is easier to use a #3,000 grit stone as a buffer in between, rather than jumping from a #1,000 grit stone to a #6,000 grit stone. 

2. Cutting oily ingredients leads to shorter edge retention. According to Mr. Sugai, one of the uses of the honing steels is to help take the oil off knives. If you are planning to cut meat such as chicken, it is best to stop at the #3,000 grit stone. Although, the #6,000 grit stone will give you a more refined edge, it will also be more prone to dulling faster. Using a rougher edge will maintain the blade for longer. 

3. Best finishing stones for boning knives. 

Caution: Please never soak fine stones unless otherwise instructed by the product. When preparing, simply wet the surface and it is ready for use. Failure to do so will result in the stone cracking or weakening.#5,000 Grit

Uses:

1. Great stone to use in between the sharpening process. Using a stone in between a medium stone and a high grit fine stone will make sharpening easier and faster. 

2. Recommended for Western made Western knives. (i.e. German knives) 

Caution: Please never soak fine stones unless otherwise instructed by the product. When preparing, simply wet the surface and it is ready for use. Failure to do so will result in the stone cracking or weakening. #6,000 Grit

The basic finishing stone. 

Caution: Please never soak fine stones unless otherwise instructed by the product. When preparing, simply wet the surface and it is ready for use. Failure to do so will result in the stone cracking or weakening. #8,000 Grit

The best finishing stone for the sharpest and most polished blade. We recommend this stone for those working with mostly produce and non-fatty ingredients. 

Caution: Please never soak fine stones unless otherwise instructed by the product. When preparing, simply wet the surface and it is ready for use. Failure to do so will result in the stone cracking or weakening. Nagura Stone

Uses: 

1. Dirt is trapped in medium and fine stones after being used. The trapped dirt makes the stone slippery and virtually useless to sharpen. The Nagura stone helps clean the stones by polishing away the dirt.

2. If you own a #1,200 grit stone but want a rougher stone for a specific knife, you can use the dirt/mud in the stone to sharpen your knives. By using dirt/mud the #1,200 grit stone becomes #1,000 grit or lower. Depending on how much mud is being used, sharpening knives will be easier and faster. (Please be aware that this change of grit only occurs while using the dirt. Once you wash the mud off, it will return back to normal.) Natural Stones

In Japan, there is a market for natural sharpening stones geared toward high level craftsmen and woodworkers. These stones must be carefully selected from the mountain, hand quarried, hand cut, and hand polished, which often makes them extremely expensive. Natural stones may have holes towards the middle and the grit may vary on different parts of the stone. Korin carries a variety of natural stones and can recommend a stone to match a particular knife. However, we do not recommend natural stones for inexperienced users. We ask customers to understand the risks involved in purchasing a natural stone, and that we cannot guarantee natural stones. 

Best alternative: The Mizuyama stones - These stones provide the best of both the natural stones and the manufactured stones. There are no risks of holes and there are natural stone powders inside to give customers a higher quality stone. 

Diamond Sharpening Stone

Diamond stones are becoming popular with professionals. They require less maintenance and should never be soaked. A light splashing of water is all that is required, making them convenient to use in a busy kitchen. Diamond stones allow for very quick sharpening but we do not recommend them for inexperienced users. They are abrasive and can remove a large amount of material from knives. We recommend applying very light pressure for the first 40 uses.