How to Sharpen a Knife with a Stone: Grit, Maintenance & More

Posted by Tara Hohenberger on

No matter what knife you buy and how hard the steel is, at some point a dull knife needs to be sharpened. In this article we’ll discuss how to use waterstones to return a knife’s edge to its full potential. You’ll learn what a  sharpening stone is made of, what the different grit stones mean, and get to know how to confidently find the correct angle for a razor-sharp edge.

Multiple Ways to Sharpen a Knife

If you made it this far, we are assuming you are here to learn about sharpening a knife with a whetstone. There are other methods to sharpening knives but for this article we’re focusing on doing it yourself. If all else fails, find a reputable sharpening service but we recommend avoiding both manual and electric knife sharpeners

Professional Knife Sharpening Service

Calling a professional is a smart idea when a knife is damaged either from use or improper sharpening. In order to find a skilled sharpener, do research in your area or weigh the pros and cons of shipping your knife to be serviced. Ask for recommendations from people you trust. Be sure to find someone knowledgeable and experienced working with Japanese knives. They should  use a  whetstone and not just sharpening wheels.

Knife Sharpener

Some people are enthusiastic about automatic sharpeners, perhaps because  they feel a poorly sharpened knife is better than a dull knife or they don’t mind taking a risk with potentially ruining a cheap knife versus spending money to have the knife hand sharpened. Personally, we recommend avoiding automatic sharpeners entirely. Uneven sharpening, can ruin knives by taking away too much material from the knife blade and therefore shorten a knife’s lifespan. Plus, improper use can end up costing more, if you have to go out and buy new knives. 

Stone Sharpening

When you invest in good quality knives, the best thing you can do for the lifespan of the knife is learn some basic whetstone sharpening. Not only will whetstones restore a dull blade, but when you sharpen with a stone, you are in control of the result. By adjusting every step of the sharpening process, whether for the bevel, angle, pressure and grit of the final polish, you can customize the process to get the results you want for your knife.  

Choosing the Proper Whetstone

Choosing the right stone will make the job easier. Whetstones come in a variety of grits. The number indicates the roughness of the stone, with lower numbers being rougher (they remove more material faster).

  • 400 grit: Not necessary for everyday sharpening, but useful for small repairs and very dull knives.
  • 1000 grit: This is the standard medium grit best for regular sharpening. We recommend starting with 1000 grit for most sharpening situations.
  • 4000/6000 grit: A stone in this range is considered a polishing stone, and the higher the grit, the finer the polish on the knife’s edge. The grit you choose will be determined by how you use the knife. For example, if you use a slicing knife to cut raw proteins, you might want a slightly less polished finish for ‘grip’ when creating thin slices.
  • 8000 grit: An #8000 stone is a high grit polishing stone which is meant to complement a #4000 or #6000 stone. If you're looking for a very refined edge on your knife, this is the ideal stone to finish with.  Are higher grits available? Yes, some natural stones, ones that are mined from a mountain and will be higher grit (creating a smoother surface) than typical synthetic sharpening stones. High grit polishing stones create a mirror like finish on the edge of the blade. Is higher grit better? Not necessarily. 
  • Two sided stones: This is a type of sharpening stone where one side is one grit (such as medium) and the other is for polishing. They are a cost effective option (two for one) and great for chef’s on the go who want to have everything ready to sharpen knives quick at hand. Our best selling whetstone is the Chubo #1000 / #4000 Double Sided Sharpening Stone. Shop for Japanese sharpening stones on our website.
  • What about using a honing steel? A honing steel can be useful to realign a knife's edge. As the blade’s edge repeatedly comes in contact with a hard surface like a cutting board or countertop it can get bent of shape on a microscopic level and a honing steel helps to quickly clean up the edge. This is why you can sometimes see chefs honing their blades in the middle of service. One thing a honing steel can not do, sharpen the edge of a dull blade. In order to sharpen a knife, you must remove steel and the best way to do that is with a sharpening stone.

How to Sharpen Knife with a Stone (Whetstone)

The first time you try to sharpen a knife with a whetstone can feel a little overwhelming. It’s hard to know if you have the right blade angle. Follow this tutorial, go slow and avoid very low grit or diamond stones to minimize the risk of messing up your blade angle. In the following we’ll answer how to sharpen a knife with a stone for beginners.

Soak the Stone

Do you need to soak a sharpening stone? It depends on the composition of the stone but generally speaking, a water stone or whetstone needs water. Do not use mineral oil on whetstones. The water acts as a lubricant to slide the knife across the stone and the fine particles of steel that come off are mixed with the water to create a slurry. This abrasive substance further helps to sharpen the knife.

How long do you soak a sharpening stone? Some stones work fine with a ‘splash and go’ method, where you can dribble water on the surface and get to work, but most stones should be soaked until bubbles stop coming out. This usually takes 5-10 minutes.

Determine the Correct Sharpening Angle

What angle do you sharpen a knife on a stone? Most chef’s knives have a 15º or 20º angle. This is more or less the width of two pennies. Keep this in mind while you progress with sharpening.

Start Sharpening

Sharpening Steps

How long do you sharpen a knife on a stone? It depends on how dull the knife is to begin with, but usually start to finish the sharpening process takes about 15 minutes.

  • Step 1: Prepare the  stone and hold the knife with your thumb on the heel and your index finger on the spine.
  • Step 2: Maintain the proper angle. Most chef’s knives have a 15º or 20º angle. This is more or less the width of two pennies. Keep this in mind while you progress with sharpening.
  • Step 3: Apply moderate pressure to the first side of the knife and glide the blade across the stone until you feel a burr (accumulated material) build up on the opposite side. This usually takes 30 or more strokes.
  • Step 4: Repeat the same process on the opposite side.
  • Step 5: Switch to a finer grit stone and repeat the process on both sides
  • Step 6: Clean and dry your knife thoroughly.
  • Step 7: Rinse and air dry stone completely.

Maintain Your Stone

With proper maintenance a sharpening stone will last a very long time. Avoid soaking for longer than necessary. Once you remove the stone from water, allow it to dry fully before placing it in the box. Handle the stone carefully to prevent chips and cracks. Use a stone fixer to maintain a flat surface.

Maintaining Your Kitchen Knives

The most important actions you can take to care for your Japanese knives apart from regular sharpening is to use the right knife for the job. Keep in mind a knife’s size and blade width when cutting large hard ingredients. Use care around bones and avoid cutting frozen foods. Wash your blades carefully with soap and water. Rinse completely and dry before storing. Use knife oil as needed on carbon steel.


The more often you sharpen your knives (before they get very dull) the easier it will be to restore the blade’s edge to its optimal condition. The time you spend learning to sharpen with a whetstone will make your time in the kitchen easier and more enjoyable. For more information on sharpening check visit The Ultimate Guide to Sharpening Japanese Knives.

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