How to sharpen a Chef's Knife - Fred Whitlock

The chef's knife is the most important single tool in any kitchen, commercial or amateur; but it requires maintenance to perform properly. There are a countless number of tools and machines on the market to help the cook keep his or her knives sharp. Some of these are excellent products that can really help a beginner at sharpening get the job done. Others will do more harm to the knife blade than good. In this article we will talk about sharpening the chef's knife manually with a stone or set of stones. The images show me working with a Japanese water stone. However, the same procedures are appropriate for an oil stone or diamond stone or whatever stone you have. My intent is not to tell you that my method is the right method. I've seen cooks get great results with methods that look nothing like mine. I'm just trying to show you what I do and what works well for me.

The Burr

Before we start sharpening, let's look at the blade's best way to communicate with us. That is the burr. It is not critical to the edge. It is critical to judging how we are doing during the sharpening process. As you grind the blade against the stone, a small amount of steel will turn over to the side of the blade opposite the stone. It may not in the beginning, but it will after you have ground enough. This little bit of steel is the burr. When we turn the blade to the opposite side and grind it, the burr will disappear or turn over again to the side away from the stone.

You must learn to feel the burr as it is critical to the process. This image shows me resting the blade at an angle against my thumbnail. If I press the blade ever so lightly against the nail, I can feel the burr if the burr is on that side of the knife. If not I simply tilt the knife so that the opposite side of the edge contacts the nail and I will then feel the burr. This process involves cutting nothing. Don't stroke the edge against your nail. Just lay it there. The burr will become obvious with a little practice. You can feel different areas of the edge by simply moving the knife and laying a new part of the blade against the nail. Try it. You will see what I mean. If you have some other way of feeling the burr, then use it. This method has worked for me for many years.

We will talk about the burr during this article. You need to be able to feel it.

Bevel Angle

The chef's knife has a blade that tapers from the spine to the edge. The sharpening process will cut or restore the small bevels that for the edge. This bevel should be applied to the knife depending on the hardness of the steel. In general, European or American made kitchen knives should be cut at an angle of about 20 degrees between the centerline of the edge and the bevel. That would mean that the edge itself would represent a 40 degree angle. If the knife uses harder steel, such as the Japanese knives, you can reduce the bevel angle to get a sharper edge. I normally apply bevels of 12 to 15 degrees to my Japanese gyutos.

If the bevel angle is too acute for the hardness of the steel, the edge will deform quickly and the edge will be dull. If it is too obtuse, the cook is wasting some of the potential sharpness that the knife is capable of maintaining.

You can experiment with the angle. If the edge deforms, just reform the bevels to a more obtuse angle. No harm done.

Lubricating the stone

Some people will tell you it is not necessary to lubricate a sharpening stone. If the stone is diamond or ceramic then I agree. If it is an oil or water stone then I disagree. Oil stones work best when lubricated with oil and water stones work best when lubricated with water. The reason is that each has a matrix that holds the abrasive particles and that matrix is soluble to one degree or another in its respective lubricant.

The purpose of the lubrication is to suspend the particles of steel and abrasives that result from the grinding process. That way they can be "washed" or wiped away from the stone. Without lubrication, these particles will "load up" the stone and decrease its performance. Also, this slurry on the surface of the stone helps the stone cut faster during use.

So lubricate your medium stone and let's start grinding.

Grinding

The image shows me holding the knife blade against the stone. The angle between the blade and the stone is the bevel angle I have chosen. I then use a circular motion to grind the bevels. As I move the blade in a circular motion against the stone, I move it left and right continuously to be sure that I grind all portions of the length of the edge fairly equally. I continue doing this until I have raised a burr on the side opposite the stone. As soon as the entire length of the blade has a burr I turn the blade and begin grinding the side that has the burr. I do this until the burr has turned completely to the other side.

At this point the burr should turn very easily. One quick swipe of the blade against the stone on each side of the edge should turn the burr to the opposite side. If that is the case it is time to lubricate the fine stone and repeat the process. When the fine stone turns a burr easily along the entire length of the edge, the knife is sharp and ready to go do work.

You will notice that the burr is significantly smaller after being worked with the fine stone.

The important thing during all of this is that I maintain a constant bevel angle. We aren't looking for mechanical perfection but we do want the angle to stay the same throughout the process on both sides of the blade. I monitor my progress regularly by using the thumbnail test for the burr. Without knowing how to feel for the burr and monitoring your work, there is no way to sharpen knives effectively.

That is the grinding process. It is simple. It requires some practice and some patience but anybody can do it.

Steeling

You've probably watched TV chefs swiping their blades against a steel in a rapid and orchestrated set of movements. Try to ignore what you have seen. Let's take a look at steeling.

The purpose of steeling the edge is to keep it straight. As we use the chef's knife the edge will deform to some degree against the cutting board. The steeling process straightens out these deformations and the result is a knife that, while not any sharper, certainly cuts better. I recommend frequent use of the steel. Professional chefs and cooks steel their knives several times per day. A home cook should steel them with each use.

I recommend standing the steel with the tip on the cutting board and the handle in your hand. The image shows the position. Then choose an angle which is roughly equal to the bevel angle and place the heel of the blade near the top of the steel at that angle. Swipe downward and toward you in a single motion. Do this on both sides of the blade. You should be able to turn the burr each time you swipe the steel without applying any pressure against the steel. If that is the case, your knife is ready for use. If it is not possible to turn a burr easily with the steel then the knife is dull and needs to be sharpened. If you steel regularly, your knives will perform better and longer in between sharpenings. That's all there is to steeling.

Now that wasn't hard was it? Obviously, there is a lot more to sharpening and knife maintenance than we have covered here. There are many books on the subject. But this is a start. It should get you on your way toward better performing kitchen cutlery. And, if you have questions, drop in on the forums and ask them. Good cooking.

Fred Whitlock has been a professional cutler and knife dealer for years. He is a veteran of many cooking classes as well as regular lectures and demonstrations on the subject of kitchen cutlery and kitchen knife skills.