The Sad Truth About Kitchen Knives
To a chef, there is nothing more important than their knife. It is an extension of their hands and personality – a painter’s brush. Yet, most kitchen knives are designed for the lowest common denominator, with compromises that seriously degrade their performance.
The first compromise lies in the steel. Most mass-produced kitchen knives use a proprietary steel blend, often equivalent to 440a, which prioritizes stain and wear resistance over edge retention. Additionally, the steel is left softer than it could be, theoretically making sharpening easier at home, though in practice it creates a significant gap between theory and reality.
The next compromise is in the factory edge angles. Most kitchen knives come with an edge of at least 25 degrees per side, resulting in a 50-degree included angle. This thick edge is more appropriate for an axe than a fine chef’s knife, sacrificing cutting performance for perceived durability.
Finally, knives often face cruelty and misuse – from the sharpener on an electric can opener to storage in a cluttered drawer. When you add soft steel and thick angles to general abuse, you end up with tools more suited for bludgeoning than delicate food preparation.
Modifying for Performance
The good news is that we can fix these problems. Geometry is far more important than steel when it comes to knife performance. With some basic knowledge and a willingness to invest a little time, you can dramatically increase the cutting ability of your kitchen knives.
First, do no harm. Avoid damaging surfaces like glass, ceramic, or steel cutting boards, and never put your knives in the dishwasher. Store them securely in a block, on a magnetic strip, or with edge guards.
Next, modify for performance. Establishing and maintaining high-performance edges is the focus of this tutorial. It can be as simple as proper steeling technique or as complex as creating specific edge bevel and edge aggression strategies for each knife in your collection.
Finally, modify for comfort. Most knife manufacturers leave the spines squared off, creating an edge that can cut into your fingers. Rounding the spine with a fine grit sandpaper or abrasive cloth can make a world of difference in the comfort and usability of your knives.
Understanding Steel
Steel is a combination of iron and less than 2% carbon. Modern steels also incorporate various alloying elements to impart specific characteristics.
Carbon is the most vital hardening element, with high-carbon steels (over 0.5% carbon) being preferable for kitchen knives. Chromium adds wear and corrosion resistance, while elements like manganese, molybdenum, and vanadium further refine the grain structure and improve hardness, wear resistance, and edge retention.
The great debate between carbon and stainless steel often comes down to corrosion resistance. In the wet, acidic environment of the kitchen, stainless steel knives generally outperform their carbon counterparts, which can degrade rapidly if not properly maintained.
Edge Basics
Most kitchen knives utilize a flat-ground, V-shaped edge. A double-bevel edge adds a secondary, more acute angle behind the primary edge to thin the metal and improve cutting performance, while still maintaining the strength of the thicker primary bevel.
Chisel-ground edges, found on many Japanese knives, are ground on one side only, creating an extremely thin and sharp edge. Convex edges, formed on a belt grinder, have a rounded curve to the edge, resulting in a very sharp profile with more metal behind it.
Regardless of the edge type, sharpening ultimately creates a microscopic serrated pattern, known as “micro-serrations.” The coarseness of the sharpening media determines the prominence of these serrations, which can impact the cutting performance of the knife.
Sharpening Basics
The key to sharpening is creating a consistent burr – a microscopic, rough lip of metal that forms when the two edge bevels meet. Feeling for the burr, rather than relying solely on visual inspection, is crucial for ensuring a complete edge.
Sharpening angles typically range from 10 to 20 degrees per side, with 15/20 degrees being a common and effective compromise for kitchen knives. Harder, high-performance steels can support thinner angles, while softer steels require a more obtuse edge to resist damage.
The abrasives used for sharpening, from waterstones to diamond stones, come in a variety of grits. Coarser grits remove metal quickly but leave a more pronounced micro-serration pattern, while finer grits produce a smoother, more polished edge.
Maintaining a consistent sharpening angle is critical, whether using freehand sharpening, guide systems, or rod-and-clamp setups. Developing this skill takes practice but can be greatly assisted by techniques like the “magic marker” trick.
Sharpening Step-by-Step
To establish a 15/20-degree double-bevel edge on your kitchen knives:
- Start with a coarse stone and grind the edge until you feel a burr form on the opposite side.
- Repeat on the other side until you have a burr along the full length of the edge.
- Optionally, use a fine stone to polish the bevels.
- Adjust to a 20-degree primary edge, creating a narrow primary bevel.
- Raise a burr on this new bevel, then grind it off gently, alternating sides.
- Finish on a fine stone, taking care to remove any remaining burr.
Techniques like the “paper airplane” trick and the “mousepad” method can assist in maintaining consistent angles and creating a convex edge profile, respectively.
Maintenance and Steeling
Edges wear due to a combination of factors, including abrasion, indentation, rolling, chipping, and corrosion. Proper maintenance through regular steeling is crucial to keeping your knives performing at their best.
Steeling realigns the edge, pushing any rolled or damaged portions back into alignment. This should be done before each use, as a newly steeled edge is sharper but less durable than a freshly sharpened one.
Various steel types, from grooved to smooth to ceramic, offer different levels of edge correction and aggression. A light touch and consistent angle are key when steeling, with the goal of maintaining the original 15/20-degree bevel.
Sharpening Systems
From freehand sharpening on bench or waterstones to guided systems and electric sharpeners, there are numerous options for keeping your knives razor-sharp. Each method has its own advantages and learning curve.
Freehand sharpening offers the most control and customization but requires significant practice to master. Guide systems, like the Lansky or EdgePro, provide a more consistent angle but can limit access to the full blade length.
Electric sharpeners, when used properly, can be a convenient option, with the Chef’s Choice 110 being a well-regarded choice. However, poor-quality electric models can be extremely damaging to your knives.
Ultimately, the best sharpening system is the one you’ll use consistently. Developing your skills, whether freehand or with a guided system, will allow you to maintain peak performance on all your kitchen knives.
Conclusion
Knife sharpening is not a mysterious art, but rather a skill that anyone can learn with a little knowledge and practice. By understanding the basics of steel, edge geometry, and sharpening techniques, you can transform your kitchen knives into high-performance tools that make food preparation a delight.
Don’t be intimidated by the initial learning curve – the rewards of maintaining your own razor-sharp blades are well worth the effort. With this Knife Sharpening 101 guide, you’ll be on your way to unlocking the full potential of your knives and elevating your culinary skills to new heights.
