Picture in your mind’s eye the metallic beat of a lone chef standing over a kitchen’s pass, methodically striking a knife against a honing steel before service. This sometimes twice-daily ritual bears a meditative, pre-show moment of respite for the chef. It’s also a crucial chance for tool maintenance, and is one of the countless moments that come together to ensure a smooth shift.
Ask the chefs, blunt kitchen knives are inferior to sharp ones; they are a dull comparison when it comes to safety, performance, and enjoyment.
What’s happening to a knife’s blade when it goes blunt?
A knife’s sharpness is determined by how well its two flat sides meet at the cutting edge. If you’re wondering why knives get blunt, it all comes down to this delicate point. Imagine the cross section of a sharp blade like an isosceles triangle. When it meets hard materials like glass, crockery, metal or bones, or softer materials over longer periods of time like wood or a sourdough crust, the apex of the triangle distorts. This distortion can occur as micro-splintering, a fragmentation of the blade’s edge, or a burr can form – this is when the apex of the triangle bends over one of the knife’s sides.
As you can imagine, a clean and consistent point running across the entirety of the cutting edge will slice far easier than a fragmented one. Sharpening is essentially a way of shaving off and reforming the inconsistencies on this edge, turning a distorted isosceles triangle into an immaculate one.
Why should blunt knives be avoided?
To be blunt: because blunt knives are dangerous. Which isn’t to say that sharp knives aren’t dangerous too, but they are far more predictable. When chopping through a ripe tomato, for example, a dull blade requires more pressure. This means you have less control when the edge punctures the tomato skin. And it increases the chances of slipping, which subsequently increases the chances of ruining your Caprese salad.
What’s more, sharp knives are more enjoyable to use, whilst producing higher quality results. Whether you’re honing your knife skills, julienning like a professional, or deboning a fish, the precision and control that a razor-sharp blade gives you is unbeatable.
What are the main things we do that damage a knife’s blade, and how can we avoid this to keep knives sharp for longer?
As mentioned, anything that touches a knife’s blade will distort or damage its delicate edge on a microscopic or more significant level. But follow these best practices and you’ll prevent your knife getting dull fast.
Dishwashers: Avoid putting knives in the dishwasher, as dishwashers will blunt your knives. The combination of heat, chemicals, water pressure, and knocking into other objects, make dishwashers perilous for both your knife’s blade and its handle. Instead, clean your knife using a soft dishcloth, warm water, and your normal dish soap.
Glass chopping boards: Solid surfaces such as glass chopping boards blunt knives, by rapidly distorting and damaging the delicate edge. Stick to softer materials for your Chopping Boards, such as wood, which will preserve the sharpness of your blades for longer – it looks better, too.
Improper storage: The best way to store knives is away from other objects, for example by keeping them sheathed in a Scabbard if storing in a drawer, or on a Knife Rack – this may require a stern word with your housemates, partner, or family!
A word from our head sharpener
As Katto's head sharpener Rodrigo Batista always reminds guests at our Sharpening Masterclasses, any knife, no matter how vigilant its owner, will dull over time with use. We stress “with use” as, providing they’re stored properly, knives don't go blunt if they aren't being used. But whilst sharpening is a necessary part of a knife’s lifecycle, it's important to remember that to sharpen a knife is to remove material from it, which should only be done when necessary. To preserve a blade’s longevity, it’s much better to prevent dulling in the first place and only sharpening as a last resort.
When the time does come, we recommend using a Sharpening Stone to sharpen your kitchen knives. We’ve made a video on how to use one here. Alternatively, members of Katto Rewards can get any of their Katto knives sharpened in our workshop for free.