A Chipped Japanese Kitchen Knife: What Now?

So, you’ve chipped your knife… now what? Keep reading to get the best solution to this unfortunate accident.

Why is a Chipped Knife a Big Deal?

Chipped knives pose several significant concerns. First and foremost, like a dull knife, a chipped blade's reduced cutting efficiency makes it more dangerous. Any compromised edge that might slip or shift unexpectedly near your hands is a safety hazard. Additionally, continued use of an already damaged edge increases the risk of further deterioration. Lastly, repairing a large chip is more expensive than fixing a small one, making prompt attention to the issue crucial.

How do Japanese Knives Get Chipped?

There are three main causes of chipped knives:

1. Cutting items too hard for Japanese steel. While Japanese knives excel at everyday food prep, they struggle with extremely dense, hard items like winter squash, bones, frozen foods, and coconuts. A good rule of thumb is to avoid cutting anything harder than a raw potato. Use a beater knife for tougher tasks—more on that later.
2. Using improper cutting technique. Many people aren't well-versed in proper knife skills, through no fault of their own. Avoid common habits like twisting, wedging, and chopping straight down. These motions stress the steel and are likely to damage the more delicate Japanese blades. Instead, use rhythmic, push-cut motions where the blade edge moves forward and downward simultaneously. At Seisuke, we call this "engaging" the edge—it maximizes your cut while being gentler on the steel. Remember: never force a cut!
3. Using overly hard cutting board materials. Some cutting board materials introduce more shock to the blade edge than others. Bamboo and glass cutting boards, for instance, are notoriously hard and can easily chip a Japanese knife. However, the risk of damage also largely depends on technique. Proper cutting form will preserve your edge much better than improper technique, even on a softer wooden cutting board

Does Steel Type Matter?

Yes—Japanese steels vary in hardness. Broadly speaking, they fall into two categories: stainless and high-carbon.

1. Stainless steels are softer, making them more durable and resistant to chipping. They're more likely to dent or warp rather than chip when stressed. If you're worried about chipping but want the cutting advantage of a Japanese knife, stainless is an excellent choice.
2. High-carbon steels are harder. They hold the sharpest edges and achieve the finest cuts but are more fragile. Lacking considerable flexibility, they'll yield until they can't anymore—and then a large chip may suddenly break off. This can happen quickly, so good technique and an understanding of appropriate cutting tasks are crucial. For those confident in their knife skills and seeking the best cuts, high-carbon steel is extremely rewarding.

For tough cutting tasks, it's best to use a "beater" knife—a rugged, durable blade you might already have at home. This type of knife can handle breaking open tough items, unlike the delicate Japanese knives you'd use for everyday cutting. This allows for equal and efficient distribution of labor between appropriate knives.

How to Fix a Chipped Japanese Knife

If you notice your knife has chipped, stop using it immediately! Further stress can worsen the damage and create a safety hazard. Repair it as soon as possible.

Japanese steels should only be sharpened on whetstones. Start by grinding away the chip on a coarse grit stone (also called a repair stone) to remove material quickly. Once you've reshaped the edge and evened it out, complete the sharpening process with a medium grit stone or fine grit stone, depending on your steel type. Here is our entire library of stones for purchase.

However, using a whetstone requires practice, and you might struggle at first to sharpen adequately. If this is the case, take your knife to a professional sharpener. They can determine the best grit levels for your knife—just ensure they use whetstones rather than belt grinders or other harsh tools unsuitable for Japanese steel.

At Seisuke Knife, we've sharpened everything from dollar-store knives to executive sushi slicers to expensive swords. No chip is too big (we've seen some gruesome cases). We accept both walk-ins and mail-ins—click here for more information on getting your knives sharpened with us.

Conclusion

To avoid chipping your Japanese knife: refrain from cutting extremely tough foods, use proper cutting techniques that don't stress the edge, and incorporate a sturdy beater knife into your food prep to divide the workload. That’s all—stay sharp, everyone!