Whether I'm breaking down a chuck roll or chopping fresh mushrooms I've found that a 20 degree edge gives me the perfect balance of sharpness and longevity. There are any number of Japanese-style sharpeners on the market that come with adjustable angles of blade, but for the typical home user the only real reason to go more than 20 is on something like a cleaver while the only reason to go lower is if you're too experienced to be reading this. My personal favorite Japanese sharpener comes with a rotating whetstone with 3 different grit settings: 320 to set the blade, 600 to create the edge, and a ceramic polishing stone to finish. As the name implies, it's important to keep the stones wet. Tap water is fine, start with the lowest grit, once you've run the stone over the blade a half dozen times (or a few dozen times if it's set to a different angle) you'll feel a distinct change as the stone scrapes away enough metal to make a more solid contact. When this happens, simply move on to the next grit, rinse and repeat. After each use be sure to completely rinse any metal residue to keep the grit gritty; it will loose effectiveness if the pores are clogged.
For sharpening a Japanese knife, start with a high-quality whetstone. Soak the stone in water for about 15 minutes. Hold the knife at a consistent 15-degree angle and gently glide it across the stone in a sweeping motion, covering the entire blade. Repeat this process on both sides, using the coarse side of the stone first, then the fine side for a polished edge. Regularly rinse the blade and stone to remove metal filings. Practicing this technique maintains the knife’s sharpness and ensures precise, clean cuts.
As the husband of a former chef, I've taken it upon myself to ensure her knives are always in top condition. Over the years, I've developed a less common but highly effective technique for sharpening her prized Japanese knives, one that combines the precision of a natural water stone with the finishing touch of a newspaper strop. Each time I prepare to sharpen her knives, I start with a natural water stone, specifically an Aotoishi (blue stone). This stone, unlike synthetic ones, has a unique mineral composition that creates a more refined edge. I soak the stone in water for about 15-20 minutes to ensure it’s fully saturated. This step is crucial, as it prevents the stone from drying out and ensures a smooth sharpening process. When the stone is ready, I carefully hold her knife at a consistent angle of about 15 degrees. This angle is perfect for maintaining the delicate balance and sharpness of Japanese blades. Starting with the coarse side of the stone, I use smooth, gentle strokes, pushing the knife away from me as if slicing a thin layer off the stone. I repeat this process for each side of the blade until I feel a burr forming along the edge. This burr indicates that the edge is properly shaped. After reshaping the edge, I switch to the finer side of the stone to hone the blade. This step polishes the edge, making it razor-sharp. Maintaining the same angle, I use the same slicing motion but with less pressure, focusing on smoothing out the edge. This part of the process always requires patience, but it's worth the effort when I see how effortlessly the knife slices through ingredients. The unique touch in my technique comes in the final step: the newspaper strop. I take a sheet of newspaper, fold it several times, and lay it flat on a hard surface. Holding the knife at a slightly higher angle than I used on the stone, I strop the blade, moving it away from me in a sweeping motion. The fine fibers in the newspaper help to polish and refine the edge even further, removing any microscopic burrs left by the stone. This combination of a natural water stone and a newspaper strop not only sharpens her knives to a fine edge but also enhances their durability. Each time she picks up a freshly sharpened knife, I see the joy and satisfaction on her face as she effortlessly prepares meals. Knowing that I've played a part in making her job a little easier and her cooking more enjoyable is incredibly rewarding.