A new, well-sharpened knife has a saw-tooth line along its edge and the correct blade geometry, and that is the heart of cutting any ingredient. When you cut something hard, or when the knife bites down into the board, those teeth on the edge are destroyed and the knife goes dull. A knife that has been sharpened incorrectly cannot cut easily, because the ingredient gets caught between the board and the edge: as it comes down it does not meet the edge properly, like teeth that do not meet. The advantage of sharpening on a stone is that the process grinds away the excess steel and brings the blade to a point, so that an edge appears. Preparing the whetstone: 1) soak the stone in water for 5-10 minutes; 2) put a wet cloth underneath it, or better still use a stone holder. Tips for sharpening a double-bevelled knife
1) Sharpen the blade in 3 sections
2) Point the tip up and to the left, at a 45-degree angle
3) Hold the knife at 15-20 degrees to the stone (the spine raised about the thickness of 2-3 stacked coins above the stone)
4) Count the strokes so each section gets the same number (around 30). Uneven counts between sections can leave the edge with a concave curve
5) Use the whole face of the stone, and do not wipe away the slurry that comes off it while sharpening. You can sprinkle more water on the stone when it starts to dry out and drag
6) Sharpen the other side of the blade the same way
7) After both sides are done, draw the edge lightly across the stone a few times to remove the burr. Key points for sharpening a single-bevelled knife: 1) sharpen in 3 sections; 2) point the tip up and to the left at 45 degrees; 3) press so that the bevel face sits flat against the stone; 4) count an equal number of strokes for each section (around 30); 5) use the whole face of the stone; 6) check for the burr, which will appear about 1 mm along the edge; 7) turn the knife over, lay the flat back against the stone and polish 1-3 times to remove the burr (with the flat side on the stone, the middle of the blade should be very slightly hollow)