There’s nothing quite like the feel of a new, factory-sharp chef’s knife – or cook's knife as it's also known. It’s easy to fall in love with a knife as you’re slicing up tomatoes and sheets of A4, but even the hardest of carbon steels will eventually lose that razor-sharp edge.
Knife maintenance can be an intimidating rabbit-hole to jump into – as is often the case, there’s a fair bit of conflicting information out there. We’re going to tackle all the basics in this guide – the best ways to keep your knife sharp, how to clean and store it, and good usage habits to get into that will preserve the lifetime of your knife. After all, the best chef's knife is only as good as the care you give it.
Different knife types
How you look after your knife is dependent on what knife you decide to get. Generally knives are split into two camps – Japanese style and western style – that define certain characteristics. Japanese knives are recognisable by their handles (usually wooden with a round or octagonal profile) and they are generally made from carbon steel – a very hard steel that gives a very sharp edge, but is more brittle and takes more maintenance than stainless steel.
Western handles are a more ergonomic shape, usually riveted rather than glued, and most western style blades are made using stainless steel, which is much easier to maintain but doesn’t give you the same razor sharpness. These are generalisations though, as you will find stainless steel Japanese blades made with western handles and vice versa.
Western knives tend to give you a bit more weight and heft, which I find makes them ideal for tougher tasks (chopping through bones and dense root veg, for example). Japanese knives are more suited to delicate slicing and dicing.
You can find more knife buying advice in our best chef’s knife roundup, but my overriding piece of advice is twofold. Understand how you cook and what you need your knife to do, then try as many knives as you can before you commit to something. Alternatively, get something relatively cheap and cheerful and see if you like using it before you invest in something more expensive. It took me many years to realise that I much prefer the weight, shape and size of a santoku knife to a chef’s knife – it suits the sort of food I cook and the work I do in the kitchen. The sooner you get an idea of which knife you instinctively reach for every time you cook, the better.
Then, find a retailer that has lots of stock for you to try. You’ll soon get a feel for what feels nice and balanced in your hand. There’s a misconception that Japanese knives are the best because they’re expensive, pretty and extremely sharp. There’s no question they’re excellent tools, but don’t jump into buying one before you try one because on many levels, they may not be the right fit for you. Many people don’t like the feel of Japanese handles, for example, and if you need a rough and ready knife that you can use for everything then chuck it in the dishwasher, a carbon steel knife won’t be a good choice.
How to clean and store knives
Beyond sharpening, looking after knives is relatively straight-forward. Stainless steel is robust and rugged so it’ll take almost anything you throw at it and keep chugging along. This is why most stainless steel knives are considered dishwasher safe, as they’re pretty resistant to detergent chemicals and heat. The real reason for avoiding the dishwasher is that things can move about in there, and you want to avoid physical damage to the edge of the blade. As always, it’s best to take the care to wash your knives by hand.
With carbon steel knives, you have to be much more careful with cleaning and looking after them. They are much more susceptible to damage from aggressive dishwasher detergent and they will rust if you leave them wet. Always hand wash carbon steel knives and dry them straight away.
When it comes to storage, you just want to avoid any situation where the knives will clatter about. Magnetic knife racks are great for this reason, as they hold your knives firmly in place and stop them bumping together. Knife rolls are good because they keep the knives apart but firmly in place when rolled up. You can also buy sheaths for knife blades in various sizes and materials.
The same rule of thumb can be applied to chopping boards. Wood is always the best choice as it won’t damage the blade when you use it. Plastic is great as well, but glass and other hard surfaces (like cutting on plates, you know who you are) are best avoided.
Finally and perhaps most importantly, never be scared to use your knives! When you invest in a really nice knife, particularly something made of carbon steel, there can be a temptation to baby it and use it sparingly because you’re afraid of damaging it. Knives are tools – they’re made to be used regularly so above all, enjoy using them!
How to keep knives sharp
The killer question we’re all asking is, how do I keep my knife sharp? There are tonnes of different sharpeners out there ranging from very effective to completely useless. For the sake of simplification, we’re going to discuss the options for stainless steel blades here – if you have a carbon steel blade, a whetstone is really your only option. However, whetstones are not nearly as difficult to use as you may think – more on that later.
The vast majority of western knives have a double-bevelled edge of about 20º, which means that the shape of the edge (the bevel) is a triangle shape with an angle of 20º on each side. Knives come with all sorts of different bevels – traditional Japanese slicers often have a single bevel, for example, and you get concave and convex bevels as well as other shapes. The shape of the bevel will determine how you want to sharpen the knife, so it’s worth knowing this ahead of time.
There are two stages to your sharpening process. The first is creating a sharp edge – this is where you grind metal away at the blade to create a cutting edge. As you use the knife that edge degrades – it gets chipped and small burrs form (areas where the metal bends and curls over itself). You can fix these small issues by honing your knives regularly with a honing rod or similar. Honing is a process that re-straightens the edge of your knife, bringing it back to sharpness without removing more metal and creating a brand new edge.
Think of honing as a temporary fix – it’ll sort the edge out for a little while but eventually you’ll need to think about resharpening your knife. For most home cooks, that’s likely to be every 1-3 months, depending how regularly you cook! How can you tell? Just use your knife regularly! You’ll know when it feels blunt, and you’ll know when the honing rod isn’t making a difference anymore.
Stainless steel is softer compared to harder carbon steels and therefore easier to sharpen, giving you more options in terms of what you use. Here’s a rundown of a few different types of sharpener, along with a few thoughts fromJames Ross-Harris – one of the expert knife-makers from Blenheim Forge. James forges Japanese style carbon steel knives at Blenheim Forge in Peckham so he is unashamedly on team whetstone, but he’s nonetheless an expert when it comes to sharpening knives!
Handheld/pull through sharpener
Affordable, convenient and very easy to use, handheld sharpeners are the first port of call for most of us looking to keep knives in tip top condition. I find these do a decent job of keeping a cheap and cheerful stainless steel knife in usable condition, but they’re far from perfect – most of them only sharpen to a specific profile (a 20º double bevel) and for anything other than that, they’re likely to do more harm than good to the edge of your blade. Most have multiple slots for sharpening and honing. On top of that, the cheaper ones (£20 and under) are usually pretty average in my experience – you have to shell out £60 for a good one, at which point there are other options.
James says: ‘I'd recommend avoiding pull through sharpeners and similar contraptions entirely. More often than not they will end up chipping your knife or mangling the edge.’
A honing rod is vital for keeping good care of your knives. Regular honing means sharpening your blade much less often, but it’s also important for the health of the blade and the edge. If you’re honing your knife every time you use it, those small burrs and nicks will rarely become big enough to require sharpening out.
However, honing is not a replacement for sharpening – the two processes are symbiotic and you’ll still need a sharpener of some sort. You can get sharpening rods (also called sharpening steels) that are designed to remove material from the blade and create a new edge. Diamond steels for example are effective but they will remove a lot of material and should be used carefully, as if you don’t use the right angle when sharpening you can easily misalign the blade of your knife. On the flip side, you can change the angle of sharpening which makes rods and steels much more versatile than handheld and electric sharpeners.
James says: ‘Steels and rods do have a time and a place in my opinion. In the right hands, a diamond rod can produce a good working edge, especially when used as a quick fix or when you lack the time or space to set up a sharpening stone. The downside of rods and steels is their tendency to wear away material unevenly, giving your blade a weird shape. Also it takes a fair amount of practice to maintain a consistent angle and pressure.’
Most electric sharpeners work in a similar fashion to pull-through sharpeners, but they use spinning sharpening stones to remove and straighten the edge of the blade. This means they also have the potential to remove a lot of material very quickly, which is a double-edged sword in itself – you can give yourself a very sharp edge in a few minutes, but removing material reduces the life of your blade. The trick is to keep your knife sharp whilst removing as little material from it as possible.
James says: ‘There's no reason in theory why an electric sharpener couldn't produce half decent results, but in practice, anything currently available on the market shouldn't be used to sharpen anything finer than a lawnmower blade.’
For the majority of serious knife users, whetstones are the way to go. Other options may have an advantage in convenience and speed, but they sacrifice in other areas. There’s a learning curve to using a whetstone and it’s a longer process than handheld or electric sharpening, but whetstones give you ultimate versatility as well as the sharpest edge possible.
Whetstones come in a variety of styles and grits (that is, how coarse the stone is). Lower grits (anywhere from 300 to 1000) are coarse, designed to remove material and create a new edge. Whetstones with higher grits, into the 6000-8000 territory, are smoother and will polish a razor sharp finish that you can’t get any other way.
James says: ‘The bottom line is that it's far easier to cause significant damage to your blade with all the alternative sharpeners than it is with a whetstone.’
For all the benefits of a whetstone but without having to learn yourself, find a good professional sharpener in your area! Avoid general sharpening services as they will often use big grindstones that remove a lot of metalin one fell swoop. Ideally you’re looking for a service that specifically handles kitchen knives and offers whetstone sharpening – lots of specialist and independent knife stores do this these days.
James says: ‘Avoid the travelling sharpening vans that will take your knives and return them sharp but missing a significant amount of steel! A good professional sharpener will remove the bare minimum material from your knife on a rotating wheel or belt sander, and always finish the edge by hand on a fine grit stone.’
How to use a whetstone
Youtube is a fantastic resource for anyone looking to learn the basics of sharpening on a whetstone. As with any niche interest, there’s a massive amount of depth to sharpening with whetstones, but at a basic level it’s an easy process. ‘I think using a whetstone passably well is surprisingly easy to learn,’ says James. ‘If you can spread butter on toast it's probably not beyond you.’
James recommends starting with a combination whetstone that has a coarse grit on one side and a finer grit on the other. Go for something that has an 800-1200 grit and a 3000-6000 grit on the other, that allows you to sharpen the edge and then polish it down to razor sharpness.
Start by soaking or wetting the stone (not all stones require soaking, so just follow the accompanying instructions). Try to maintain a consistent angle between the stone and blade – 15-20º as a rule of thumb – then abrade the entire edge evenly with smooth even strokes. Make sure to do the same number of strokes on both sides of the bevel. Over time you’ll find the water creates an abrasive paste with the whetstone and metal – don’t wash it off! This paste will help to grind down the knife blade and create a nice sharp edge. Keep checking the knife blade periodically until you’re happy.
James also recommends using a leather or newspaper strop to further hone and polish knives, if you’re worried about damaging them. ‘Strops are super easy to use and they go a long way to keeping a decent edge on your knife,’ he says. ‘Plus, it’s almost important to cause any significant damage with a strop.’