How to test that a knife is sharp enough?

Question

As per the question - how to I test that a knife is sharp enough?
And/or, how do you know when a knife needs sharpening?

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Edit:

Yesterday I attempted (I feel quite successfully) to hone my knives for the first time ever (requiring me to purchase a honing steel), which immediately made a rather noticable difference (I shall be honing them regularly from now on).

Not sure whether additionally sharpening them as well would be a good idea?

The suggested tomato and paper tests make sense, and I shall try them in the near future and see..

Asked by DMA57361

Answer

I usually notice when cutting onions and tomatoes. With a very sharp knife cutting an onion doesn't cause much tears at all. As it dulls though it does more crushing than slicing which releases more gas into the air, which makes you cry more. Ripe tomatoes help because they are so tender. If it becomes difficult to slice a tomato without crushing it, your knife is too dull.

A well used, properly cared for knife should require sharpening every 6-18 months, depending on usage. Mine get sharpened yearly.

You may find it beneficial to read these related questions, and their answers:

• http://cooking.stackexchange.com/questions/1137/how-can-i-safely-improve-my-cutting-technique
• http://cooking.stackexchange.com/questions/315/how-do-you-care-for-your-knives
• http://cooking.stackexchange.com/questions/1804/why-not-put-knives-in-the-dishwasher

Answered by hobodave

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How can I sharpen my peeler?

Question

Is it possible to sharpen a peeler? And if it is, how should I do it?

Are there any things to look out for? (Such as ending up with concave blades.)

This is the sort of peeler I'm talking about:

Asked by Ladadadada

Answer

Sort of. There's a trick to fix up peeler edges: rub the back side of a paring knife along the blade, at roughly the same angle as the peeler blade's edge. Use the tip of the knife if needed. You may need to do this with both sides of the peeler blade.

I suspect the result is closer to honing the edge, but the trick works well enough that I haven't bought another peeler since my kitchen manager showed it to me.

Answered by BobMcGee

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How to find a competent knife sharpener

Question

I have a santoku that I will be wanting to get professionally sharpened in the next few months. This is the first knife I've owned that was reasonably expensive so I want to make sure I take care of it. Are most professional knife sharpening places familiar with the differences in Japanese knife edges vs a more traditional (for the U.S.) German knife? For example, the angle is different and one side is flat on my santoku compared to, say, a French chef's knife.

Aside from just asking them if they know what they are doing, are there any specifics I should look for or questions to ask in finding someone who can do this properly? Also, is there any kind of reasonable price range I should expect or does that vary too much to say?

Answer

Allow me to help you fast forward through my years of pain trying to get my knives sharpened. I looked all over to find a local sharpening service. I called fancy restaurants, chain restaurants, and restaurant supply stores. I found one who said they performed the service and promptly had three knives really scratched up.

I tried doing the sharpening myself. This isn't a bad idea, but most home sharpening systems won't let you put a true new edge on your knife. The best luck I had was with a Spyderco Sharpmaker. This will do a good job, but I found it to be a pain, and it never really got me the results I was looking for.

Then I discovered sharpening by mail. Its awesome. Ship your knives off, get them back in a state where you should keep bandaids handy. Here is an article from the Wall Street Journal comparing several services -> http://online.wsj.com/article/SB10001424052748703405704575014992111661922.html. I used the Knife Guy and couldn't have been happier. Unfortunately, it looks like he's no longer accepting new customers since the article came out, but the other services they compared seem to have done well.

One other Note. I read in an interview with Alton brown that he only sends his knives off to be professionally sharpened once a year or so. If you use a honing steel properly that's all you should need. I've certainly found that to be the case with me.

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