Ohe San: Japanese Knife Sharpening

For years I sharpened my knives on an oil stone--one side coarse, one side medium--holding the knife at as close to a 22.5 degree angle to the surface of the stone as I could visualize, moving it from heel to tip always in the direction of the blade to avoid feathering the edge, and it worked pretty well. My knives were pretty sharp, and people who saw me using them or joined me to cook in the kitchen generally thought my knives were pretty sharp. But lately, there has been a lot of interest in the culinary world in Japanese knives, and you have to admit that Japanese sushi chefs are masters of fine precise cutting and elegant garnishing, which require very sharp knives. Japanese knives are generally made of harder steel than European knives, so they are more brittle, but they can hold a sharper edge at a finer sharpening angle. They are also usually beveled only on one side, like a chisel.

I've been thinking one day of investing in a few Japanese knives, but first I wanted to work on some Japanese knife sharpening techniques and see if I could make the knives I already have sharper. I visited Manhattan's fantastic Japanese knife shop, Korin, in Tribeca to obtain a two-sided Japanese waterstone, 1000/6000 grit. This is much finer than my old oilstone, but it cuts cleanly and quickly. Japanese knife sharpeners usually work from the tip to the heel, always applying pressure on the forward stroke with the fingers on the section of the knife contacting the stone, building a burr all along the unbeveled edge, and then removing the burr and finishing the backside of the knife. I tried this approach, still always moving the knife in the direction of the blade, which meant switching hands to sharpen both sides of the knife. This is a bit awkward, but I've been getting better results than the way I'd been doing it before. Sometimes I can get a blade razor sharp this way--not just metaphorically, but really sharp enough to shave with--but not consistently. Sometimes razor sharp is too sharp, because the edge can chip when the knife is used for heavier tasks, but it's good to know how to make that kind of edge.

Today I met Mr. Ohe, from the Kikuichi knife company in Sakai, Japan, at a demonstration organized by The Brooklyn Kitchen. Representatives from Kukuichi discussed the history of the company and Japanese knife making, and Mr. Ohe demonstrated knife sharpening and hand engraving. A prizewinning sushi chef was on hand to demonstrate what these knives can do, and knives were available for sale at a discount with free engraving by Mr. Ohe, shown above.

What I found most interesting was that Mr. Ohe did not observe the principle I've always followed of always moving the knife on the stone in the direction of the edge. Here he is, forming the bevel by pushing the knife away from his body on a coarse waterstone, toward the spine of the knife rather than toward the cutting edge--
The best part of a workshop like this is that we could pass around the knife as he was building up the burr on the flat side and feel how pronounced it was--much more so than the burr that I was forming using my technique. The burr is difficult to show in a photograph, but you can feel it with your fingers--carefully to avoid being cut. When the burr formed all along the edge, he removed it and finished the back side of the knife--about one stroke on the flat side (which is actually slightly curved to keep food from sticking to the knife) for every nine strokes on the beveled side of a single beveled Japanese knife. He used a relatively small amount of water when forming the burr on the first side, and then a lot of water when finishing the back side. For Western style double-beveled knives, he recommended an equal number of strokes on each side. He did not switch hands, so on the first side he was pushing the knife away from the sharp edge, and on the second side he was pushing the knife toward the sharp edge, so that any feathering that would result from sharpening the first side would be cleaned up when sharpening the second side. To give the knife a polished edge, he followed this procedure first with a coarse stone if needed, then with a medium stone (1000 grit) and finally with a fine stone (5000 grit)--
Note that he always maintains the same 45-degree angle of the knife to the direction of travel of the stone (not the bevel angle, which should be around 22 degrees for Western knives and around 15-17 degrees for harder Japanese knives). I asked if this was appropriate for a European chef's knife, because the curve changes from the tip to the heel, and he said (through a translator) that he always worked with the blade at this same angle to sharpen the largest possible section of the blade at once.

I went home and soaked my waterstone and tried this technique with two knives that I'm never quite satisfied with--a Wusthof paring knife and a Sabatier boning knife. Maybe it is because they are small and flexible that they aren't as easy to sharpen as a thicker chef's knife, or maybe it's because I use the chef's knives more often, so I'm more practiced at sharpening them. Now those little knives are razor sharp. I think I've got a new sharpening technique.

I'll work with this a bit more, and then I'll sign up for a workshop at Korin, where I bought my waterstone. Then maybe I'll be ready for a Japanese knife.

UPDATE: I've written a follow-up to this post in the next blog entry.

UPDATE: After doing this for some time, I've come to the conclusion that with a European knife that has a bolster, it is necessary to adjust the angle of the blade with respect to the direction of travel, otherwise there will always be a section on one side of the knife that is unsharpened, and looking at other videos of Japanese style sharpening, it does seem that people who know what they are doing don't always maintain the 45-degree angle, particularly if the blade is curved.