Tools and Techniques: Taking Care of Your Knife

Grinding, honing, stropping, lapping:

Isn't it all the same thing?!

That's cute, Timmy... now let me hit you with some knowledge.

Let's start with this: The thinner the edge, the sharper the blade will be. Straight razors are able to shave hair because the have a very thin, delicate edge.

So why don't chefs chop onions with straight razors? 


Well, the key word here is DELICATE. Think about the last nail you tried to hammer into the wall; no matter how softly you tap it with that hammer it starts to bend, right? Now imagine tapping on a nail as thin as a human hair. Doesn't work, right?

When attempting to put a proper edge on a knife, a little knowledge about the materials that you are working with can go a long way.

Example:

Harder metals can hold an edge for longer, but are more difficult to sharpen and less resistant to chipping.

Softer metals are easier to shape into a sharp cutting edge, but they will dull quickly and require more frequent maintenance.

Most quality knives on the market today are produced with a combination of these two attributes in mind. Some cooks desire a very hard edge that requires little effort to maintain once it's been shaped; others want a softer, more flexible blade that can easily take a razor edge with a few swipes of a honing steel.

Tools and Terms:

Grinding: Grinding is the process of removing metal from the surface of the edge in order to achieve the desired shape. The tools used for this step are called "grinding stones" and they come in progressively finer grits, just like sand paper; the finer the grit, the less metal is removed when you pass it across the stone.


Honing: Honing is used to maintain an edge that you already have on a blade. A "honing steel" (that rod thingy  that your dad pretends to know how to use when he carves the thanksgiving turkey) is made from very hard metal which is designed to realign the fine, delicate edge that you just ruined by slamming it repeatedly into a cutting board. We'll talk about how to use it properly later on.

Stropping: We've all seen "ye olde" barber doing his thing with the razor and the leather strop, but what the hell is it for? Well, human hair is surprisingly strong and to cut it the edge needs to be thin enough actually slip between the individual cells that the hair is built from. The blade is so thin that taking any metal away from it would remove the edge entirely, so instead the metal is drawn out and refined using the strop.

Lapping: Lapping is the final step in polishing a knife: Every time you scrape a piece of metal against a rough surface, tiny scratches are left. Lapping utilizes a surface which is fine enough to leave only infinitesimal scratches that result in the smoothest, mirrored surface possible. The smoother the surface, the higher the polish, the lower the friction created when drawing a knife through whatever it is you are cutting. 


Okay, Timmy, that's enough knowledge for today. Write it out fifty times in Greek and tomorrow I'll start telling you how to put it all together.


Peace.


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