No one wants to use a blunt knife in the kitchen. It turns cooking from being a pleasure into a chore and is actually a lot more dangerous as the knife can easily slip.
If you’re reading this, you’re probably in a situation where you don’t seem to have any alternative, all your knives have gone dull and you haven’t bought a sharpening stone or sharpening rod yet. I’ve been there too.
So you just carry on using a depressingly blunt knife that struggles to slice through the skin of a tomato.
But do you need to? Or can you solve your problem by ingeniously sharpening your knife with another knife?
Unless you have one knife which is made with extremely hardened steel or ceramic then you technically can’t sharpen a knife with another knife. However; you can use a knife to hone another knife, this helps to realign the blade, making it feel sharper and cut much better.
Can you sharpen a knife with another knife
In the vast majority of home kitchens, it is going to be the case that you can’t technically use one knife to sharpen another.
Sharpening requires microscopic layers of the knife to be stripped away, to reveal a new, sharp edge.
Naturally, to strip away layers of a steel knife, your going to need a significantly harder steel knife to strip it.
To sharpen a knife, you either need an abrasive surface, like a sharpening stone or a very hard surface such as a diamond sharpening rod, where the rod is encrusted with fine diamond particles.
Using a steel knife to sharpen another steel knife is unlikely to work because the steel will be too similar in strength.
However, that’s not always the case.
How to sharpen a knife with another knife
There are some instances when you can a knife to sharpen another knife.
After all, you just need a material significantly harder than the knife you want to sharpen, therefore all you need is a very hard knife.
A western-style chef’s knife will usually measure around 56-58 HRC on the Rockwell Scale, a measure of hardness.
Knives using quality Japanese steel (which tends to be harder) usually measure between 59-62 HRC. So these actually could be sued to sharpen a softer knife, although they wouldn’t be very effectce.
These hard Japanese knives are also pretty expensive, so you would be foolish to use them to sharpen another knife, but if you wanted to you technically could.
A better option, and one I have actually used in times of need, is to use the spine of a ceramic knife to sharpen a steel knife.
Ceramic knives can measure a very hefty 75 HRC on the Rockwell scale, far harder than any steel.
If you use the spine of a ceramic knife to sharpen a steel knife, it will work.
Trust me, I’ve tried it.
Clearly, it’s no ideal, and I only recommend it if both your ceramic and steel knives are pretty cheap items.
But if needs must, you can effectively sharpen a steel knife with a ceramic knife.
You can hone your knife to make it feel sharper
If you don’t have a ceramic knife, the good news is that you can still get the effect of sharpness from using another steel knife.
Honing a knife is essentially the process of realigning the blade, resulting in a straighter cutting edge.
And you only need a material of equal strength to hone a knife, so another steel knife will work.
Imagine a knife’s edge as a miniature version of a saw blade, with thousands of teeth in a row.
With use, these teeth get damaged and fold over, making the knife go out of alignment.
This is an unavoidable process and results in the knife feeling blunt.
Honing a knife will force these teeth back into alignment, as a straight row. It will feel much sharper and will be much better to use.
This will effectively do the same job as a honing steel (often mistakenly called a sharpening steel).
That’s the long steel rod you’ll no doubt have seen in other people’s kitchens. It is much more preferable to have a honing steel than to use your own knives to hone, so next time you get a chance then buy yourself one.
But since you’re reading this article, you probably need help right now, so let’s talk about how to hone your knife with another knife.
How to hone using another knife
Hold a knife in each hand, with the one you specifically want to hone (sharpen) in your dominant hand, right hand for right-handers and left hand for left-handers.
It should go without saying that you need to keep your fingers off the blades. Hold the knives together so that the handle end of each blade is touching the other.
The blades should be at a low angle to each other, around 15 – 20 degrees. This is typically the angle you would hone a knife on an actual honing steel and means that you won’t over-fold those little teeth on the blade and thus make the knife worse!
Gently but firmly brush the knife in your dominant hand along the other blade, pulling away as you go so that by the time you are at the end of the stoke the two tips of the blade should be touching and you will have done a full stroke down each blade.
You need only repeat this a maximum of 6 times per side of the blade. If you find that after that your knife blade is still blunt then it does indeed need to be sharpened and honing isn’t going to help.
The good news though is that knives don’t actually need to be sharpened very often, so honing with another knife will help in most cases.
It is better to use a suitable tool
I would only recommend honing your knife with another knife as a last resort.
It will work, and the results are actually surprisingly good, but there is a real danger of damaging your knives if you aren’t using a proper tool.
Aside from the potential damage, it could cause, you will need an actual knife sharpener anyway if you want to truly sharpen your knife and not just hone it.
If you’re reading this article then you probably need a solution here and now, so honing your knife using another knife will work as a short term solution but in the long term, you should be equipping yourself with the correct tools.
Tools you need to keep your knife sharp
For proper knife maintenance, you should have two tools, a honing steel, and a sharpening rod or whetstone.
Every kitchen should have a honing steel, they’re relatively cheap and they will last you for decades, if not for the rest of your cooking life, so they are a very sensible investment.
They are used to realign the blade and should be used quite frequently.
I recommend honing your knife around every three uses.
Secondly, you want a sharpening rod, these a very often confused with honing steels so make sure you’re getting something which will actually sharpen a knife.
Diamond and ceramic rods are both harder than steel knives so if you get one of those it will do a great job of sharpening.
You’ll only need to sharpen your knife every 6 – 12 months.
So for now, if you have no other option then you can use a knife to hone another knife, but in the long term you should equip yourself with the right tools, it’ll make your knife last a much much longer time.
My honing steel recommendation
Honing and sharpening tools last for decades if they’re looked after properly. That’s why I would always recommend you invest in one of decent quality.
A poor quality honing rod runs the risk of damaging your knife, so if you choose a quality honing rod then there’s a good chance your knives will last longer too.
This 10-inch honing rod from Wüsthof is the only steel you will ever need. Wüsthof are renowned for their high-quality western knives, so this is the perfect kitchen partner.
My ceramic rod recommendation
A ceramic rod would be my go-to choice of sharpener.
They are quick and easy to use and they aren’t too abrasive on the blade steel, so it’s pretty hard to make any mistakes when sharpening with a ceramic rod.
On the downside, ceramic can be very brittle so you just need to make sure you store it carefully, somewhere it won’t get knocked around.
Messermeister make some of the most beautiful chef’s knives you can buy. It’s a brand that oozes with quality and their ceramic sharpening rod is no different, it’s an absolute bargain for the quality you get.