Caring for your steel knives
No knife will stay sharp forever, but with proper care you can keep it sharp for quite a long time (several months). Keeping a knife sharp is much easier than sharpening it. Once a blade loses its edge, it can take a lot of work to get it back (depending on the type of steel and its hardness).
To keep them sharp, it’s best to never put a knife into a dishwasher. Dishwasher detergents have abrasive silicates in them so this is like putting your knife into a sand-blaster. Also, the edge of your knife is likely to bang into something else while the dishwasher is running and that could chip the edge and cause significant damage.
Wash your knives immediately after cutting anything acidic (tomatoes, citrus, etc.), and try to never let them sit overnight without washing them.
Dry your knives immediately after washing them.
It’s best to only use plastic or wooden cutting boards. Glass, ceramic, tile or steel cutting surfaces will dull and damage a blade.
Store your knives in a wooden block, on a magnetic strip, or something similar, rather than loose in a drawer.
Hone the edge once every week or two by stroking each side 3 to 5 times on a ceramic surface. This can be done on the rim of a ceramic coffee cup, or you can invest in a ceramic rod sharpening system or a very smooth stone (1000-grit or higher) to use for this purpose.
Draw the knife across the ceramic surface at a low angle (close to flat) with only slightly more than the weight of the knife. The exact angle of theblade is not critical this process, but it must be less than the angle of the edge. An angle of 10 to 15 degrees from the surface is usually sufficient for honing the blade.
Honing a knife
(NOT for serrated knives. See the next tip.)
After drawing the knife across the ceramic surface in one direction, flip it over and do the same in the opposite direction. Do each side of the edge an equal number of times.
Honing is not sharpening, but it helps keep the blade sharp. Draw the knife across the ceramic surface at a low angle (close to flat) with only slightly more than the weight of the knife. The exact angle of the blade is not all that important for this process, but it must be less than the angle of the edge. An angle of 10 to 15 degrees from the surface is usually sufficient for honing the blade.
Serrated knives
Once it is sharp, a serrated blade should stay sharp for years, and there's not much you need to do to keep it that way. Here are some tips to get the maximum life out of your serrated knife (in addition to the care tips above):
Only use it to slice baked goods (bread, cake, muffins, etc.) or the occasional sandwich or tomato.
You really shouldn't need to do this, but if you feel like it isn't cutting like it should, you can stroke the back of the blade (the flat side) a few times on a very smooth rod or stone (1000-grit or smoother). Keep the blade absolutely flat against the surface - do not angle it at all.
Never put the serrated side of the blade onto a stone.
Serrated blades should really be professionally sharpened when they finally get dull. Each individual serration must be separately sharpened. The only kind of sharpener that should be used for this purpose is a ceramic rod system like the one I recommend from Idahone.
Testing an edge
You need to be able to know if your knife still "has an edge" or if it needs to be sharpened. There are a couple of easy ways to test an edge. Even if the knife has lost its edge, it may still feel pretty sharp on your thumb or finger.
Slice a tomato. This is really the only way to test a serrated blade, but you can use it for regular blades as well. If you can draw the knife across a tomato with slightly more than the weight of the blade, and it cuts the tomato cleanly, then it is still sharp. There should be no need to "saw" the tomato or nick the skin with the point of the knife, or anything like that. Just place the blade on the tomato and draw the knife towards you and see if it cuts.
Use a Bic "Stic" pen. Although there are devices made specially for testing an edge (you can get one from Razor Edge Systems), I've found that a simple Bic Stic pen works almost as well. Just hold the pen at about a 45 degree angle, hold the knife so it is straight up and down, and drop the edge of the knife straight onto the pen (like I'm doing in the photo below). Don't push on it - just let the weight of the blade settle onto the plastic pen. If it is sharp, the blade will "stick" and it won't slide down the plastic barrel of the pen. If it has lost its edge, it will just slide off. This is easy to do with a large, heavy knife, but it's a bit challenging with a smaller, lighter knife. With a lighter knife, you have to push down a bit. Over time, the pen will get all nicked up, but you can restore it by scrubbing it with some medium grit sandpaper until it is smooth again.
I'm using a Razor Edge Systems tester, but you can also just use a Bic Stic pen.
