How to maintain a razor-sharp knife
There’s nothing more satisfying than using a freshly sharpened knife, especially if you’ve been putting up with a blunt one for any length of time.
And if you’ve decided to get yourself a really high-quality blade, you’re going to want to maintain that edge. After all, what’s the point of investing in a precision instrument, unless it can perform to its fullest capabilities at all times?
Different types of knives will blunt at different rates, depending on the material they're made from. Japanese-style knives tend to be made of harder steel that retains an edge for longer, whereas Western-style knives instead use softer steel that's easier to sharpen. Eventually though, all knives become blunt, as microscopic parts of the blade get bent over and chipped with use.
In this guide we cover different kinds of sharpening tools, as well as top tips for keeping your knives in great condition for longer - so that your blades can last for life.
The different ways to sharpen a knife
When sharpening your knife blades, always make sure you sharpen the entire length, from heel to tip. Also crucial is to sharpen the knife at the correct angle.
When using a rod or a whetstone, you need to find the right sharpening angle and keep the knife steady. Pull-through knife sharpeners, which can be manual or electric, have the angle ready-made for you - but you need to make sure it matches your blade.
Honing rod or sharpening steel
When you use a rod (otherwise known as a sharpening steel or honing rod), the knife’s edge is dragged along the textured rod, which straightens out tiny parts of the edge which are bent over. This straightening process is known as honing.
The honing steel’s surface is also slightly abrasive; how abrasive will vary between different types of rod. This takes away a very small amount of material, sharpening the blade. When using the rod, always pull the knife along it all the way from tip to heel - otherwise, over time, you could create a dip in the knife as the middle part gets ground down.
It's advised that you hone a blade regularly - around once a week for a blade that gets used often. This will mean you'll have to use more abrasive sharpening techniques, such as a whetstone, less often.
If a knife has become too blunt for a rod to sharpen effectively, or if it has become chipped, whetstones are a more effective way of grinding material off the blade for sharpening. A whetstone, or sharpening stone, is a porous, hard block with an abrasive surface, usually with a coarser grit on one side and a finer grit on the other side.
Whetstones only need to be used for sharpening every few months. They are incredibly versatile and can sharpen all types of knives, as well as other bladed items like garden tools.
Soak your whetstone before use. It’s important to keep it still, so put a cloth or paper towel underneath it. For sharpening, start with the coarser side; to hone your knife, just use the finer side.
First, find the correct angle that the knife should be sharpened at. Manufacturers will usually provide this information, but if you're unsure aim for a 15 to 20 degree angle.
Draw the blade down the stone in a wide, circular manner, holding the blade at a constant angle until the tip of the knife runs off the other edge. Repeat several times on each side of the blade, depending on the dullness of the blade.
Finish on the finer grit to hone. Again, always sharpen all the way from tip to heel.
Pull-through sharpeners can be either manual or electric, and have abrasive wheels that sharpen your knife at a precise angle. Both are a quick and easy way to sharpen a knife. However, you have to be careful about matching the type of blade with the sharpener - not just the angle, but whether your knife is single or double bevelled.
As the name suggests, to use these types of sharpeners you simply need to pull the blade (again, all the way from heel to tip) through the abrasive channels. Usually the sharpener will have two or three channels, labelled from coarse to fine. For manual sharpeners, pull the knife through each channel several times - electric sharpeners should only need one pass.
The stones on pull-through sharpeners will eventually wear out. But for some sharpeners, especially those using a diamond abrasive, this won't happen before many, many years of use - longer than a lifetime. Some sharpeners will allow the stones to be changed out, though these are usually for commercial use.
Can you sharpen serrated knives?
Because the sharp edges of a serrated knife are recessed in each little dip, they don't actually touch the cutting board. This means a quality serrated knife can stay sharp for a very long time - years even. But when the time does come to sharpen it, it's not as simple as sharpening one straight edge.
To sharpen each individual groove in your serrated knife, you will need a thin, abrasive rod. Some sharpening rods will have a tapered end for this. You can alternatively use sandpaper wrapped around a pencil. On the bevelled side of the knife, find the right angle and drag the rod through each serration 4 or 5 times.
Once this has been done for every groove, flip the knife over and give the flat side of the blade a few strokes on a regular sharpening stone, or a piece of fine-grit sandpaper. This will smooth out the burr that you've raised on the edge of the knife.
Some pull-through sharpeners can sharpen serrated knives - check the guidance on the individual product.
How should you clean knives?
To keep your blade in the best possible shape, wash and dry knives by hand straight after use with a non-scratch washing up sponge or a cloth. Never leave them to soak, especially if they have wooden handles. Putting knives in a dishwasher is not advised - dishwashers stress the handles of knives, encourage corrosion and rattle them against other metal utensils, dulling the blades.
How should you store knives?
The ideal method of storing knives is either on a magnetic knife rack or in a knife block - these protect the blades from damage, and display the knives well. It’s not ideal to keep knives rattling around in drawers, as they can become scratched and blunt, but if a drawer is your only option then keep them protected with cloths or in their original boxes. If you’re transporting knives, a knife roll will keep them safe and secure.
Whatever you choose, just make sure the blades aren’t being roughly moved around, and always store your knives dry. Drying your knives straight after washing will prevent tarnishing of any sort, and if you have a wooden knife block, it will stop mould growing on the inside.
Sharpening knives is a fun, empowering and useful skill to learn, and we encourage you to give it a try. However, if you’d rather leave it to the professionals - or perhaps your knife has suffered a particularly nasty chip - you can drop your knife off with a sharpening service. Simply look up local knife sharpening services in your area.
We hope this guide has helped you feel more confident with maintaining a knife. Regardless of whether you’ve got a budget kitchen knife or a high-end blade, a little care will go a long way in keeping it performing at its best and lasting longer.