I never understood this until recently, but it really makes quite a lot of sense. A sharp kitchen knife is expected to cut through food with a fair amount of ease. This means not much pressure is needed for the knife to do its job. The more dull a knife the more pressure is needed and the less likely the knife is to go straight. It might go on the path of the least resistance which does not necessarily mean straight!
Another consideration for why a dull knife is unsafe is that it subconsciously causes us not to properly respect our most important kitchen tool. If we expect the knife to be dull and not cut our skin, chances are we will become very lax in touching and holding our knives.
He could never quite understand how on earth I got my knives to become so dull. He would jokingly actually saw at his hand with the knife (or worse whack at it). I somehow manage to get the knives to still cut in that condition so I really squirm when he does that (It could still cut him!!!)
One day I was at his house when I saw him maintaining one of his own knives, and I saw he was using a slightly different tool to sharpen his knife. It looked simple and compact enough, so I asked my parents to get the same tool for my husband for Christmas so we could sharpen our own knives periodically on our own.
The product is called the Spyderco sharpener.
The product comes with everything pictured above. This tool allows you to basically sharpen anything with a sharp blade. Sharpening knives, scissors, and other tools is all about the angle at which you sharpen it. My dad is much more of an expert at the proper care of each kind of knife so I took the easy way out and showed him each knife and he was able to show me how to sharpen them. There is a booklet and a dvd to show the precise way to sharpen each different tool. Someday, I will look into the other uses for the sharpener!
I also learned a few points of advice over the years to the care of a knife:
- Use olive oil on wooden handled knives once a month or so to keep the wood moisturized. Dry wood can split and crack easier under the pressure of cutting
-Avoid putting knives in the dishwasher because they loose a sharp edge quicker
-Do not cut on glass cutting boards because the glass makes a sharp knife round and dull