Knife Sharpening and Maintenance
This entry was posted on December 6, 2010.
MAKING GOOD KNIVES GREAT
It's no secret, any knife you use will eventually get dull. Sharp blades go soft, and those smooth slices you're used to making in your tomatoes and chicken thighs will turn to clunky, jagged scratches. But don't fret! We're here to help keep those blades nice and sharp. Just don't hurt yourself with those fancy new knife edges.
So let's get started. The simplest way to keep a knife sharp is to prevent it from being unnecessarily worn down or damaged. This is very easy, just store them correctly, wash them by hand after every use, and use them only for their intended purpose.
Knives need to be stored in a block set or on a magnetic strip. Storing them in a drawer is a bad idea because the knives will knock against other metal utensils which can cause all kinds of trouble for your knife edge, including chipping, cracking, micro-chipping, and overall unnecessary wear and tear that will dull your blade. If you insist on storing them in a drawer then buy some plastic sleeves for the blades to preserve them.
Washing your knives correctly means washing them by hand, and not letting them sit in a dirty sink for a day before cleaning them. A dishwasher is bad for knives because it knocks them around when they're being washed, which brings up the same problems you get with throwing them into a drawer. And knives, even stainless steel knives, shouldn't be allowed to sit in water. Wash them after you're finished using them. Leaving a knife to sit in water is bad because you can get build up of bacteria inside the micro-abrasions of the blade, and the blade itself can begin to rust. Rust is more likely to happen with an iron blade, but it's still good practice. The other reason you don't want to leave a knife in water is because the liquid can seep into the handle and start causing problems. I once had a knife that would leak dirty black water from the handle because I had let it sit in the sink water for too long. There was no way to clean it, I had to toss it out.
Knives must also be used for their intended purpose. That means not using them to cut off the plastic packaging of your new home appliance, that's what scissors are for. Don't use them as can openers or box cutters or as screwdrivers. Knives are cooking utensils and need to be used properly. This also means being aware of what your cutting surface is. If you're cutting your food on a glass surface it is going to dull your blade. Cutting boards are wooden for a reason- they're easier on your knives. Some people opt for serrated knives when they don't want to spring for a good cutting board. This is because the raised edges in the knife preserve the cutting edge by keeping it from making contact with the plate. But these knives can be difficult to sharpen, so there are different opinions on what's best. The other part of knife maintenance is an obvious and very important one- Sharpening!
In order to sharpen your blades effectively you're going to need an abrasive. There are several different types on the market, and it can be easy to spend several hundred dollars here. But most will agree that the Japanese whetstones are some of the best sharpening utensils around. These stones come in different grits, which refers to the roughness of the stone. A smaller number like 250 will have a very rough surface, one of the roughest available actually. 1000 is a medium-fine grit, and will have a less coarse surface. 6,000 is super fine grit, and will have a surface that will feel almost smooth to the touch. These different grits perform different functions for sharpening your blade, but you'll need all 3 if you really want to have a good, long lasting knife.
Now, this blog would have to be about 50 pages for us to go into every detail about sharpening, and we recommend this website for readers who are interested in becoming masters of their knives. But we're just going to go over the very basics here. First of all you need to know what angle you want to achieve. Different knives have different angles, and the thinner the angle, the sharper your blade. Think back to your geometry- a 90 degree angle is like the corner of a square. 45 degrees is a perfectly diagonal angle. An axe will be about a 50 degree angle. A kitchen cleaver may have a 40 degree angle or so, and a typical kitchen knife will be somewhere between 15 and 35 degrees.
To start sharpening your knife, rub a coarse stone back and forth across the knife edge. This is going to wear away the old, dull metal; and you need a coarse grit for this part because the finer grits are more for shaping and polishing the metal, not so much for wearing it away.
You'll want to use a medium-fine grit when you start to form the angle of the blade and the edge because you're no longer peeling away the metal, but trying to form a shape out of it. So shape the angle of your blade by moving the medium-fine grit back and forth over it until you have your edge. The super fine grit has a very important part in the knife sharpening, and it comes next. Coarse and medium grit abrasives leave micro abrasions in the blade. These abrasions will catch on whatever you're cutting, and will make it more difficult to cut. So you've got to "polish" the blade with a super fine grit to smooth out the abrasions and you will want to finish the edge with a super-fine grit to give your cutting edge an extra sharp, super smooth cut. So you'll be using the super fine grit to almost clean and polish the knife. This will give it a fantastic look and a super accurate cut.
These are just the basic ideas to keep in mind when you're learning how to take care of your knives, but they will help make your knives last longer and act as more effective tools.