10 Best Tried and True Japanese Knife Sharpeners in 2022 (Kyocera, Nitori, and More)

If you are pretty particular about your knives, you might own a few Japanese knives. Japanese knives offer fantastic sharpness and precision, with some chefs even claiming that food prepared using Japanese knives taste better. However, no matter how sharp your knife may be, all knives eventually become dull and don't cut as neatly as they used to. So to solve this, you need to sharpen them.

Whetstones requires skill and practice, since they grind the entire knife. Using poor technique can actually ruin your precious blades. However, knife sharpeners are best for both beginners as well as for people who simply don't have time to use a whetstone. They require little to no skill to use properly and can make your knives cut as good as new.

Moreover, many Japanese knife sharpeners are designed to be used with Japanese knives, so you might be able to get a knife sharpener from the same brand as your knife, ensuring they'll work harmoniously.

We gathered the 32 best-selling Japanese knife sharpeners on e-commerce sites popular in Japan, such as Amazon, Rakuten, and Yahoo! Shopping, and tested them all.

We tested each product for the following:

1. How well it sharpens our knives
2. How easy is it to use
3. How easy it is to store

※Japanese prices for some products are listed but have been converted into USD for easy viewing.

We tested each product for the following:

1. How well it sharpens our knives
2. How easy is it to use
3. How easy it is to store

First, we tested how sharp each knife sharpener could make our knives.

We purchased santoku knives from Daiso, a popular 100-yen store, and scraped them onto plastic cutting boards exactly 3,000 times. We then followed the manufacturer's instructions to sharpen our knives. After our knives were sharpened, we cut a tomato with our newly sharpened knife to check how much sharpness our knives had regained.

For products that didn't come with instructions, as well as for those that didn't specify how many times we should run our knives through them, we ran our knives through them seven times.

Next, we checked how easy each product was to use. 

We sharpened our knives by checking for the following:

1. How stable and safe the sharpener felt when in use
2. How clear the sharpening method was and how easy it was to sharpen

Finally, we tested to see how compact each product was.

We checked and evaluated each product to see how compact they were and whether or not they had useful features that made them easy to store.

Here are four major points to consider when choosing a Japanese knife sharpener.

There are four main types of sharpeners.

• Rollers
• Cross sharpeners
• Electric sharpeners
  
• Sharpening rods/sharpening steels
  

Let's look at the pros and cons of each type.

Roller sharpeners, or sharpeners with guides, are probably the most commonly sold nowadays. They consist of a V-shaped groove with spinning whetstones and you slide the knife through to sharpen. These sharpeners can sharpen your knives as if you used a whetstone since they sharpen the blade edge vertically in the same way.

Their main drawback is that when viewed under a microscope, the blade edge is very jagged, similar to a saw blade, damaging your knives. While they can make your knives feel sharp for a bit, the sharpness won't last for long. It's best to use these knife sharpeners only once or twice a month.

Cross sharpeners refer to knife sharpeners that feature two whetstones aligned in a V shape. They have an incredibly simple design and are relatively affordable when compared to other types of knife sharpeners.

Their main drawback is that since the cutting stone only hits the very edge of the knife blade, creating a shallow V shape, this can result in a dull blade. Additionally, while regular whetstones sharpen knives in a vertical direction, these whetstones sharpen knives horizontally, which can result in a jagged edge.

Avoid using these knife sharpeners with knives that are already sharp, since they can actually damage your knife. Only use these sharpeners with knives that have an obtuse cutting edge.

Although they're more expensive and louder, electric sharpeners can give you a good edge with little effort. They basically work the same as manual V-shaped types, but the motor means you can sharpen quickly, without having to move the knife so many times. They take up a little more space, and of course, you need to be careful about not getting them wet.

Electric knife sharpeners use a spinning whetstone to sharpen knives. Many electric sharpeners make use of the natural weight of the knife itself, meaning you don't need to control the pressure of your knife. This makes electric knife sharpeners great for those who want to quickly sharpen their knives with as little fuss as possible.

However, electric knife sharpeners can be pretty loud. Additionally, most electric knife sharpeners are designed for right-hand use, so southpaws should check beforehand if they can use a particular product or not.

Sharpening rods are used by grazing the edge of your knife against the rod and can be used to sharpen knives, scissors, peelers, and other blades. They're fairly compact and thin, so they can fit in a drawer. Don't get one that's too short, though, or it will be even more difficult to use.

However, unlike other knife sharpeners, they require you to carefully adjust the pressure and angle at which you sharpen your blades, making them less suited for beginners.

While knife sharpeners are convenient tools, the type of knife you can sharpen with them can vary. It's important to consider the type of knives you have, the materials of your knives, and the blade type of your knives.

Most of these Japanese knife sharpeners are for stainless steel double-beveled knives. If you have a specialty knife, be careful and get a sharpener that's compatible with it.

Traditional Japanese santoku knives often have a single bevel, and these will require a special sharpener. However, many santoku sold recently for home use are double-edged. There are a limited number of sharpeners that can handle single edges, sashimi knives, or serrated edges, as well as ceramic knives, but if the sharpener doesn't specify, don't try it.

If you have a lot of knives, consider a knife sharpener that can handle both single and double-bevel knives.

Whetstones can broadly be divided into three groups, depending on their roughness: rough grind, medium grind, and finishing grind. The roughness is determined by the grit, usually indicated with a # and a number. 

While there's no clear-cut definition, they usually fall under the following.

• Rough grind: #80 to 220 grit
• Medium grind: #400 to 1,500 grit
• Finishing grind: #3,000 grit and above

Depending on the sharpener, it can vary from having a single type of whetstone up to all three types. For daily use, it's best to look for a knife sharpener with both a medium and finishing grind. However, if you plan on sharpening a knife with a chipped edge, it'll be more efficient to use a knife sharpener with a rough grind.

When using a knife sharpener, the last thing we want to do is get hurt. Generally speaking, knife sharpeners that you place down on a flat surface are safer than sharpening rods, since the blade is pointed downward toward the sharpening surface. 

Choosing products that have a rubberized non-slip grip on the bottom or products that have a decent amount of weight to them can prevent them from slipping while you sharpen your knife.

Some sharpeners that you place down on a flat surface might have suction cups that claim to allow you to use them with one hand. However, if the suction cups don't have a lot of grip, they can become undone, meaning it's best to still hold these down with your free hand. When using a sharpening rod, always be sure that nobody is around you before you sharpen your knives.

Using a knife sharpener once or twice a week can help you retain the sharpness of your knives, allowing you to cook with less stress. Moreover, sharper knives are actually safer, since your food won't slip out from under your knife.

However, using knife sharpeners alone can potentially damage your knives, so if possible, it's best to sharpen your knives with a whetstone at least once or twice a month.

If you use a knife sharpener and a whetstone but still can't get your knife sharp enough, it's most likely time to consider a new knife. Check out our articles on knives from the links below.

Lucky for you, our team of editors and experts has tested out a lot of other kitchen tools you can use to slice and dice anything you want.

Writing: Kano Ichiyama/Translation: Susan Lucier-Ogawa, Mitsuki Nagasawa, Izumi Taneda/Photos: Koichi Miura, Yuki Inagaki

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