Modern steel used in knives is very high quality; the spine is the softest, toughest steel possible while the edge is extremely hard. Modern understanding has produced extremely hard edges that if treated right by the user will not dull for months after a sharpening. However, many people nowadays are so careless they will dull the knives in the same week they buy it. Almost all of these people do not have devices or people who can sharpen it for them, so they are stuck with knives that separate food with pressure and not cutting.
Before I begin with the tips, lets see why a sharp knife is better than a dull one. Many of you have knives that are as dull as a butter knife, yet they will still “cut” through vegetables and fruit. These knives separate the pieces you want through pressure, squishing the vegetable to the side at the pressure point. This basically tears up the inside of the fruit or vegetable, which is bad for three reasons. One, it’s kinda ugly. Two, the blade needs lots of vegetable under it to squish the fruit/vegetable down and out of the way, which means that once you get to the skin or peel, which is tough and not squishable, and eventually you have to tear the two pieces apart, which gives the peel a “jagged edge”. Very ugly and unprofessional. Three, a fruit or vegetable is made up of a few cells with juice or water in each one. The crunching sound when you eat an apple is these cells popping. When cutting a fruit or vegetable with a sharp knife, the edge only slices through the cells directly in front of the knife’s path, which means minimal juices wash out onto the surface of the fruit or vegetable. With a dull knife, as I said before the edge squishes through the fruit, tearing up all the cells anywhere near it, which washes tons of juice all over the fruit causing it to go bad much faster. An example of this effect: http://www.youtube.com/watch?v=Dr17wI64BBw . Another reason, of course, is you can get the job done many times faster with a sharp knife rather than a dull one.
Now, how to keep your knives sharp? The most important thing to know that anything harder than the blade will dull the edge IMMEDIATELY. Knifemakers and bladesmiths strive to get the hardest edge possible to keep it from dulling on objects of similar hardness, but there are still many, many things around the house that are harder than an average knife blade. These include
- Counter tops (stone or porcelain, wood should be fine)
Which means a knife edge should NEVER touch glasses, plates, sink edges, measuring glasses or mugs. Remember, a sharp knife is a knife with the thinnest edge possible. Even barely touching this delicate edge against one of the abovementioned will destroy the edge, resulting in a dull knife. This is why you must ALWAYS use a cutting board. Do not cut on plates or hard surfaces like that.
Now all you need to do is take precautions that the knife does not come in contact with these things. This means store it in a place where the knife is not laying on others, keeping it away from porcelain containers, etc.
Now go, and stay sharp.