This is a follow-up post to my first Essential Skills post, “How to Buy a Knife“. Now that you know what to look for in a high-quality knife you need to know how to keep that knife sharp. While there are many different methods and products for maintaining and sharpening your knife’s edge on the market, I’m going to cover 3 basic tools: honing rods, manual sharpeners, and electric sharpeners. Before I get into explaining those tools to you, lets first cover exactly what makes a knife sharp (or dull!).
What makes a knife’s edge sharp?
The next few lines may sound overly complicated or scientific but bear with me… knowing this information will help you to understand how, when, and how often to sharpen your knives for the best results. And believe me, if I can figure this stuff out, you definitely can!
The cutting edge of a kitchen knife is thin and V-shaped. Exactly how thin the edge is will be defined by the blade’s angle. The more narrow the angle of this V-shaped edge, the sharper (but also weaker) the knife will be. For example, most European-style cooking knifes have an angle between 20-22 degrees (measured from the vertical) whereas Japanese-style knives often have smaller angles, 10-16 degrees. Why is this important to know? Because every method of maintaining or sharpening will not be successful unless you utilize the angle of your knife in the process.
- For example, if you have a European knife with a 20 degree angle, you must hold your knife at a 20 degree angle when honing (see below for more info). Maintaining a correct and consistent angle during honing and sharpening ensures the sharpest possible edge.
Another technical term I think is important to know is microserrations, or teeth. These are serrations so teeny tiny at the cutting edge of the blade that our eyes cannot detect them. As the microserrations degrade with time they need to be corrected (or realigned) to maintain the sharpness of the edge. This is done with a honing steel. After a longer period of time the serrations may degrade beyond maintenance and must be repaired with a knife sharpener, which actually grinds metal away to restore the perfect V shape and angle.
How to evaluate a knife’s sharpness: use these tricks to see if your knife needs to be sharpened or to test how efficient your honing steel or sharpener is.
- Slice a tomato or lemon – the knife should glide through with ease and a clean cut
- Cut a sheet of paper – this is my favorite way (its the most fun!). Hold a sheet of paper in the air and carefully pull your knife blade down through the paper from the top. It should cut easily and evenly into the paper and create a slight curve.
What makes a knife’s edge dull?
By now you may be wondering how exactly those microserrations degrade over time or how that expensive knife you bought that was once perfectly sharp is now painfully dull. Your cutting board dulls your knife, not cutting through food. The more forcefully the blade hits the cutting board after each down-stroke, the faster your knife will dull. If you feel your blade is dulling too fast, pay attention to your chopping. Are you taking out your daily frustrations by hacking up a poor onion? See if you can ease up your chopping style to keep your knife sharp.
How to maintain a sharp edge:
While not mangling your vegetables like a mad-man may help to prevent your blade from dulling, the best way to keep your knife sharp is through proper maintenance. In my last post I compared shopping for a knife to shopping for a car in that you need to test drive it to see if it suits you. Similarly, your knife require routine honing like your car requires routine oil changes. Before I began working at Sur la Table I had no clue how to properly maintain my knives. When I eventually learned that you are supposed to hone your knives weekly, if not after every use, I was shocked. That seemed excessive (and inconvenient). Then I learned about angles and microserrations and it all started to make sense. If you want your knives to be high-quality, they will require high-quality care. Getting into the habit of honing your knives regularly is like getting into the habit of flossing your teeth daily: you’ll no doubt forget or forgo sometimes which won’t ruin your teeth instantly, but consistent abuse will definitely take its toll and you might need to visit a dentist (or in this case, a professional knife sharpener).
What is a honing steel?
A honing steel (or sharpening rod) is a long, circular or oval shaped piece of hard material (such as tungsten, diamond or ceramic) that maintains a knife’s edge when properly used. Lately more companies have been referring to honing steels as “sharpening steels” which can be misleading in some cases. Steels repair those microserrations after your knife has been used but will not remove metal from the blade. Honing steels will maintain your knife’s edge but don’t sharpen it. Knife sharpeners will re-create the microserrations and remove metal off the edge of your blade (which I’ll cover in detail below).
- Advantages: quick, inexpensive, makes necessary repairs to microserrations
- Disadvantages: will not make a dull knife sharp, requires frequent use (depending on the type of steel)
Types of honing steels:
- round vs. oval: while these two styles are fairly comparable, I find that oval steels are easier to use and more efficient. The best way to see what style you prefer is to try each out.
- steel vs. diamond & ceramic: the material of the honing rod provides different advantages and disadvantages. Diamond and ceramic, which have become more popular and widely available, are much harder than steel and actually have the ability to abrade metal from the edge. Because of this ability, diamond and ceramic honing rods require less frequent honing (monthly instead of daily or weekly) which makes them preferable (to me at least).
How to use a honing steel:
A knife should be honed ideally after each use (depending on the type of steel you have, see above) or at least weekly. If you’ve never used a honing steel before remember to focus on your angle, not speed and keep your wrist straight.
- Grasp the honing steel by its grip and set it vertically upright so the tip, or anchor, is resting on a non-skid surface.
- Take your knife and hold it at a 20 degree angle (or whatever the angle of your knife is) against the steel. If you are unsure of what a 20 degree angle is, hold your knife out perpendicular at a 90 degree angle against the steel then cut that in half to 45 degrees then cut in half again to find 22.5 degrees. From there move a smidgen inward to achieve 20 degrees. Some steels have guards on the handle to guide you at a 20 degree angle.
- Keeping your angle in mind, pull the blade toward you and downwards, applying slight pressure. Repeat the stroke on the other side of the blade without changing hands. Repeat 10 more times, alternating sides and loosening pressure gradually. At first it might feel like a bizarre movement but the more you practice the more comfortable it will feel.
Here is a great video from Fine Cooking illustrating everything I’ve covered up to this point.
What is a manual sharpener?
For this post when I refer to manual sharpeners I will be speaking of pull-through sharpeners. These are handheld tools that have a set of abrasive materials that make a small V which you pull your knife through. Some sharpeners may have multiple stages of different abrasives, offering more customization to your knife sharpening needs. Depending on the type of sharpener, some may sharpen scissors, serrated, or santoku knives in addition to straight edge knives. Unfortunately most manual sharpeners only perform on straight edge knives and require additional sharpeners for other knife styles.
- Advantages: quick, easy to use, requires no skill, most have built in angles
- Disadvantages: may not perform well on severely dull blades
How to use a manual sharpener:
Using a manual sharpener is very simple and easy. Since every pull-through manual sharpener is different and has different features, it is best to follow the directions that come with the product.