Discuss Cooking - Cooking Forums

Discuss Cooking - Cooking Forums (http://www.discusscooking.com/forums/)
-   Knives (http://www.discusscooking.com/forums/f90/)
-   -   What "sharp" means to me (http://www.discusscooking.com/forums/f90/what-sharp-means-to-me-54390.html)

buzzard767 01-14-2009 04:43 PM

What "sharp" means to me
I see posts all the time on various Internet knife sites where the poster proclaims his knife is as sharp, no, sharper than need be. The usual equipment is a Chef's Choice 120 electric or some sort of Rachael Rayish pull through device or even some semi sophisticated crock stick system. The touters of regular old German sharpening steels afford me the largest grins. I picture them, imitating the slashing motions of some TV chef. Everybody wants to be a Samurai. :lol:

Those knives are not sharp. The next time you watch The Food Network, notice how the chefs will actually saw through a tomato. Their knives aren't even sharp enough to slice the medium with one easy pull or push.

I'm not a pro sharpener or a pro cook. I'm a home cook who happens to be a lover of very nice kitchen knives and one of my hobbies is making them as sharp as possible.

When you buy a big block of knives at the department store you are getting knives sharpened at 22 to 25 degrees per side. I'll be nice and say 22, or a 44 degree "included" angle, bevel A plus bevel B. The boning knife and the vegetable slicing Chef's knives all have the same angle. Hmmmm. It makes sense for the boner to have this angle because it needs to be tough and not break down when hitting bones. Makes sense to me. The slicing knives, however, should be as sharp as possible because it is their job to slice, nothing more. So why do they have the bevel angles of a boning knife? Beats me. I guess it's because the electric sharpeners are set up this way. The steel from which these knives are made is mediocre no matter what the marketers say, but I have no problem getting a 15 to 18 degree edge to hold fairly well on a Wusthof or Forschner. I don't think the 22 degree bevels will go away soon..... :rolleyes:

A sharp knife needs three things, a thin blade, very acute bevels (or bevel), and steel that can handle it. There are two sources of the steel, Japan and Sweden. The Swedish steels made by Uddeholm and Sandvik are so good that several Japanese, as well as some American custom knife makers, are using it. Assuming a blade that will not be used on bone, there is little reason not to make it as sharp as possible consistent with edge retention.

Here is a picture of what I call sharp:


The top knife is an Aritsugu 240mm "A" model Gyuto and the little one is its baby sister 140mm "A" Petty. The shiny stuff you see is the bevel. Big? You bet. It's cut at about 6 degrees. I'm left handed and therefore the bevel on that side. There is no bevel on the right side, merely the gentle angle of the blade itself.

Aritsugu "A"s normally come from the maker unsharpened. You read it right. No bevels whatsoever. Knowing that I would have several hours worth of time cutting the bevel myself with a DMT extra extra coarse diamond stone, I petitioned Aritsugu to cut the bevel for me. It came rougher than crap as expected but at least the hard work had been done with their giant 3-4 foot diameter motorized waterstones. The bevel on the Petty was cut by yours truly but being so short in length it didn't take all day....

Once I flattened Aritsugu's miserable work with a 150 grit Naniwa Omura, I proceeded through my main stones, 1, 2, 4, and 8k Shapton Glass Stones and 10k Naniwa Super Stone. After that I stropped with .5 micron chromium oxide followed by .25 micron diamond spray.

Sharp? Oh yeah. Spooky sharp. Scary sharp. Just as importantly, the edge is holding up extremely well. No chipping whatsoever and I've been beating it up chopping on the cutting board just to see what happens. After two weeks of hard use in the home kitchen I stropped it with chromium oxide and the edge is better than 95% newly sharpened.

Anyway, this is what sharp means to me. You? Oh the included angle - I'm guessing at about 18 degrees. I could cut down the right side a tad and make it sharper yet, but I'm liking the feel of the lefty bias.

jpaulg 01-14-2009 06:39 PM

For me there's several degrees.

Firstly there's sharp enough for a home kitchen or as i prefer to call it not quite blunt, which is where I place the pull throughs and electric sharpeners. You can get a result that most home cooks would be happy with and a disappointing number of professional chefs are prepared to accept.

Then there's sharpish. Which is what you get using ~300 grit whetstones. A lot of chef's accept this because they're not prepared to spend the time getting their knives properly sharp.

Then there is sharp, which is what you get using multiple whetstones, and involves actively re-shaping the bevel to a desired sharpness. The two main tomato tests for this level of sharpness are whether the knife will cut a tomato under its own weight, and whether it will cut a tomato dropped from 6" height in two. My heavy thick Sabatier can keep this level of sharpness. In a professional kitchen to keep this level of sharpness you have to sharpen your knives once a week. I find that repeated light sharpening works far better than intermittent heavy sharpening.

Then you move onto scary sharp which is where Buzzard is at.

On the boning knife issue, I find that I'll quite happily sharpen my boning knife down to a 12 or 15 degree angle for two reasons. Firstly a lot of its use is trimming tendons and filleting not actually boning. Secondly I'm removing flesh from the bone so I use the back of the blade along the bone as a guide whilst keeping the cutting edge angled slightly upwards away from the bone to keep it cutting through flesh.

The thin blade profile preferred by the Japanese does allow for sharper edges and Japanese knives do perform better for precision tasks. The German blades are designed for safety and ergonomics, and are not optimised for cutting. French (Sabatier) blades however are designed to maximise the wedging effect. French blades thicken very noticably front to back and bottom to top, so if you're cutting through hard root vegetables in particular you get the edge cutting the vegetable and the blade acting as a wedge helping to split it apart. As an added bonus it is relatively easy to find Carbon Steel Sabatiers.

Andy M. 01-14-2009 07:09 PM

What sharp means to me:

Sharp enough so I can cut the ingredients that need cutting easily and with minimal effort.

This sharpness lasts for a decent amount of time.

With reasonably priced tools and a reasonable amount of time, I can maintain this level of sharpness.

Katie H 01-14-2009 07:13 PM


Originally Posted by Andy M. (Post 772330)
What sharp means to me:

Sharp enough so I can cut the ingredients that need cutting easily and with minimal effort.

This sharpness lasts for a decent amount of time.

With reasonably priced tools and a reasonable amount of time, I can maintain this level of sharpness.

'Bout the same here, Andy. Our knives are always sharp. Most of the time all I have to do is to gently drop the knife blade on a tomato to make a cut.

Can't say that about my brother's knives or those of my friends. May as well use a butter knife in their homes. Usually bring my knives when I go to visit them and will be cooking/cutting.

One of my brothers used a table knife to slice a baguette during the Christmas holidays. Do I need to tell you how the bread looked?

Andy M. 01-14-2009 07:17 PM


Originally Posted by Katie E (Post 772333)
...Usually bring my knives when I go to visit them and will be cooking/cutting...

I know what you mean. I take two knives and a steel with me to our timeshare in Aruba because of the awful, not as good as Ginsu, crap knives provided.

jpaulg 01-14-2009 07:31 PM

It's like that line from the Meatloaf song Paradise by the Dashboard light:
"Glowing like the metal on the edge of a knife"

Whoever wrote that line was a knife sharpener.

tannerodell 01-14-2009 08:44 PM

My knife of choice is the global chefs. I am in love with it

DrThunder88 01-14-2009 10:50 PM

My goal:

Tilted stone and strop results


Maverick2272 01-15-2009 02:59 AM

This is an area I need some help on. I am constantly sharpening my knives and am mostly happy with the results, they cut veggies and meat real good like the are supposed to without having to doing much if any sawing.
But, I know they could be a lot better, and many are showing tiny nicks all along the edges. I need advice on how to re-do the edges to get rid of the nicks and then re-sharpen good.
I guess I am saying I am OK at keeping an edge, no good at improving or restoring it.
Also, she has garden pruners and tools that need sharpening, and since these are heavy duty and take a beating, I would think I need to give them the same approach as you would maybe a boning knife or heavy duty knife. There I have no clue, but sounds like I want to maintain something around 25 degrees on them?
Right now she takes her axes and maddoxs down to a guy that sharpens them, and they will last most of the summer that way, but she wants to be able to start doing that at home. I maintain the pruners, but find I am sharpening them at least once a week.
To do axes and maddoxs I am thinking I might need a grinder of some sort?

DrThunder88 01-15-2009 05:53 AM

The nicking problem is kind of odd. Unless the knife is being put into a dishwasher or loose in a cabinet, that's usually that's a sign of over-hardening or being ground too thin. The only way to get rid of the nicks is to grind them out. To set the bevel and get rid of the nicks, I recommend a coarse or extra-coarse stone. Diamond stones are especially well suited to this task. A 25-degree angle on each side should be fine for general purpose knives.

I'm not sure about the pruners though.

All times are GMT -5. The time now is 04:11 AM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.