A Guide to Knife Sharpening
Brød & Taylor Knife Sharpeners offer a new approach — keeping knives sharp is fast and easy. Sharpening truly dull blades is foolproof. Cooks get to enjoy sharp knives every day. Fine knives are well cared for and last longer. Read on for our full guide to knife sharpening.
A Dull Subject
A sharp knife is a cook’s best friend. It is a joy to use and safer as well. High-quality knives are increasingly popular, but even the best blades will dull with use if not maintained regularly. Lacking a convenient maintenance method, many people tolerate their knives becoming increasingly dull, waiting until they are nearly useless before taking steps to restore their edges. Often they will send them out to be professionally sharpened.The knives are sharpened by grinding away the knife edge with abrasives, which removes metal and shortens the life of the blade. What actually happens to a blade as it becomes dull? A sharp knife is a simple concept. Two planes form a bevel with a microscopically thin edge. Regular use puts enormous pressure on this edge. Although thin, the edge is still very hard and will not simply flatten like a pounded lump of clay. Instead, the edge will bend or roll to the side. When an edge just begins to bend, it is possible to press it back into shape and realign the edge. Traditionally this is done with a hardened steel rod (chef’s steel). Considerable skill is required and improper use can further dull the blade. If left unchecked, the bend will become worse and eventually fold over or flatten, and may even break. Eventually the damage becomes so severe, the only remedy is to remove metal to restore the correct bevel and create a new edge.
Traditional knife sharpening techniques involve grinding with an abrasive: natural or man-made stone, industrial diamonds or even sandpaper. Abrasive sharpening machines can be effective if used properly, but it is easy to over sharpen and even damage knives. These systems don’t have the ability to realign a blade without removing metal. Freehand sharpening is difficult to perform precisely and takes a lot of practice. Coarse abrasives are used to remove metal quickly but leave a rough edge. A succession of finer abrasives or stones are then used to refine the edge, but it is slow work. With an expert hand and the correct materials, sharpening with stones can produce an extremely sharp edge, what insiders call “scary sharp”. This is actually not appropriate for most kitchen knives, unless you happen to be a high-end sushi chef. The best sharpening achieves a balance of sharpness, durability and is fast and easy enough to encourage regular maintenance.
A Quick Look at Knife Characteristics
The composition and characteristics of steel for knife blades is a broad and complex subject, but two of the more basic characteristics are hardness and toughness. Hardness is the resistance of a metal to changing shape or deforming. A hard steel can be sharpened to a very keen edge. Seems like a great choice for a knife blade, but it comes with a price — hard metals tend to be brittle. Toughness is the ability of a metal to absorb a blow without fracturing. Hardness and toughness don’t usually come together, you can have one or the other, but not both. Much of the secret in great knife making is balancing these two characteristics either with exotic specialty metals, or by physically sandwiching different materials together. The most important thing to know is that all metal blades benefit from regular steeling or polishing to keep the hard blade aligned so it doesn’t break. This is especially critical with harder steels (as found in some high-end Japanese knives) as they tend to be more brittle and can break while honing (pushing the edge back into alignment) if allowed to become significantly bent. Knife blade angles are also important. What is the best angle for a specific blade and task? Opinions vary, but the range can be from 12 degrees for the sharpest filleting knives, to 20 degrees for a blade that will hold up better to rough chopping. Clearly, the larger the blade angle, the more durable the blade will be, although perhaps not quite as sharp. A good knife sharpening system needs to accommodate a variety of blade angles for both sharpening and honing.
A New Approach to Knife Sharpening
Brød & Taylor sharpeners use a completely different sharpening technique, borrowed from the high-technology metal machining industry. Two extremely hard man-made tungsten carbide sharpeners are ground to a precision, specialized shape. Mounted on a spring-action bars, the patented system functions as three distinctly different sharpeners, with the function determined by the angle of the knife as it is pulled through. They are unique in their ability to perform three knife sharpening functions:
- Coarse Sharpening – quickly restore the correct bevel shape to very dull or damaged knives.
- Honing/Steeling – realign a bent edge without removing metal. Great for daily maintenance.
- Polishing – create a super-smooth and sharp edge.
Precision-ground, ultra-hard tungsten carbide sharpening surface
The figure to the right shows a cross-section of the tungsten carbide sharpener in the Brød & Taylor Professional and Classic sharpeners. The “leading edge” of the sharper is ground to a sharp corner. This actually sharpens by cutting a correct bevel on a metal blade with a few quick strokes. This coarse sharpening is done only rarely, when the edge is to too dull to restore by honing alone. The “trailing edge” is ground with a small, smooth bevel. The beveled corner pushes, re-aligns and smooths the edge into shape. It only takes seconds to realign a blade and maintain a sharp knife. No special skills are required. The honing process (drawing the knife through the sharpener with the tip up) works just like a well-controlled chef’s steel. Proper angle and pressure are maintained by the spring-action bars. Finally, the flat surface of the carbide is finished to a mirror surface, allowing very fine edges of knives to be polished to ultimate sharpness. Holding the sharpeners bars spread wide, the sharp blade is guided back and forth across the flat surfaces of the sharpeners without pressure. The metal at the extreme edge of the blade is polished – or burnished – and becomes extremely sharp. Regular honing and polishing will greatly extend the life of the blade, keeping it sharp while removing virtually no metal. See our How It Works page for descriptions and videos of each technique.
The upper left corner cuts a new bevel, the beveled surface at the upper right hones the edge to a perfect V shape, and the top flat surface polishes.
What’s the Best Angle?
The Brød & Taylor sharpener also allows control of the bevel angle. With light pressure the sharpener will cut a more delicate but sharp 12 degree angle bevel. Fully compressing the springs will cut at a sturdy 20 degrees. Note: always hone the knife with at least as much pressure as was used to cut the bevel. If in doubt, use a bit less pressure when sharpening a bevel, and a little more when honing. More pressure when honing will never damage the blade, but if too little pressure is used the honing may not reach the very tip of the edge. In all cases, polishing with the sharpener bars spread wide will burnish the very edge.
How to Sharpen a Knife
Begin by restoring the bevel with Coarse Sharpening. Pull the knife through with the tip down (usually just 3-4 pulls). Use only moderate pressure and let the sharpener do the work. A very light touch will create a finer and sharper edge, while heavier pressure will create a sturdier chopping edge. Next, hone the edge by pulling through with the tip up until the knife pulls through smoothly. The number of pulls may vary, normally 6-12. It is not possible to over-hone a blade. If desired, finish with polishing for an even sharper edge.
Regular Knife Maintenance
Hone knives each time you use them with 6-8 pulls through the sharpener (tip up). It only takes a few seconds. If you need that extra degree of sharpness, polish the edge with a few strokes back and forth. Let the sharp edge glide across the smooth flat surfaces of the sharpener with no more downward pressure than the weight of the knife. Wipe the blade clean with a damp cloth and you are ready to enjoy using a truly sharp knife. After use, wash promptly, wipe clean and store carefully. If storing knives in a drawer, cover with a blade protector.
Sharpening Serrated Knives
Serrated knives present a real challenge to nearly every sharpening technique. It’s the reason that your serrated knife is probably not nearly as sharp as it used to be. Traditional techniques require the use of cone shaped hand sharpeners. Motorized sharpeners only touch the tips of the serrations and worse, may damage the blade by sharpening both sides of the blades with a fixed angle. Look carefully at your serrated knife and you will see that one side is flat. The scalloped bevels are formed into one side only, usually the right-hand side. The Brød & Taylor sharpener is able to hone the entire knife edge, because the spring-loaded sharpening surface hugs the surface of each serration, both curve and tip. See How It Works for a quick video demonstration, or Compare Models for the full line of sharpeners that work on both serrated and smooth edges.
It is convenient for a knife to resist discoloring or rusting in normal use. But it was not that many years ago that chefs had to make a difficult choice. Choose a great sharpening performance with a knife that corrodes and discolors easily (high carbon steel) or a stainless steel knife that is easy to care for but would never be as sharp or hold a keen edge. Things have changed dramatically with the development of high carbon stainless steels. For a price, you can purchase knives that possess both corrosion resistance and good sharpening performance. Just like the name, these materials stain “less”. It is always good practice to hand wash knives carefully and wipe them dry to avoid spots.
Keeping knives sharp does not have to be complicated or time-consuming. Use the Brød & Taylor sharpener to hone before each use. Polish when you need that extra degree of sharpness. Always hand wash and wipe dry. Don’t put good knives in a dishwasher where corrosive detergents can eat away at the thin metal edge, and don’t pile them in a sink or drawer where delicate edges can be damaged. After a week with a wonderfully sharp knife, you will never believe you survived all those dull years.