How do you decide that you've reached the ultimate sharpness a particular blade can attain?

Kitchen Knife Forums

Help Support Kitchen Knife Forums:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

tk59

Founding Member
Joined
Feb 28, 2011
Messages
4,279
Reaction score
9
Back in the old Kitchen several month ago, Jon essentially posted a survey of who thought what steels would achieve the sharpest edge. There and elsewhere, I continue to see people post about how certain steels just get way sharper than others and I'd like to ask a couple of follow-up questions:

1. Do you all sharpen different steels differently? ie different stones, different amount of time on each stone, etc.
2. How hard did you try to achieve whatever you consider to be an "ultimate" edge?

The reason I ask is I spend a LOT of time working to achieve "ultimate" edges with all of the knives I ever lay hands on and it's been months since I failed to achieve that sort of edge with any steel regardless of hardness, comp, maker, ht, etc. The big difference I find is pretty much how much time it takes to get there and how long it lasts and that's pretty much it.
 
i've never attained what i think the steel can hypothetically do. a precise and powerful laser and an electron microscope would probably be necessary for that (i have access to the microscope, but not to the laser). i sharpen until the knife will push cut tomatoes and shave arm hair just by touching the edge to the hair. i find that a knife that can do those two things will stay pleasingly sharp through any amount of cutting i'm likely to do at home. i find this level of sharpness to be pretty easy to attain, not taking more than 10 or 15 minutes, starting from a knife that has an adequate bevel angle.

i find going sharper than that level (the sharpness needed for the weight test that Salty showed off your edge with, for instance, which i got with my newest knife that i was re-sharpening from scratch anyway, so figured i might as well, but which i doubt i'll try to achieve with my others that stay at my preferred sharpness level) to take a lot of time and effort with the tools i have at hand (i polish with a kitayama and then strop for a minute or two on .5 CrO and then .25 diamond) and that level of sharpness isn't noticeably different from the normal level i'll accept when actually cutting food. i've become jaded, and i don't think i'll ever obtain that feeling of extreme sharpness that i felt the first time i used a Shun with the OOTB edge, after years of poorly sharpened (by me) German knives. i came to the same conclusion about hops, and i've quit chasing that initial bitterness i experienced upon my first good IPA. first loves are the most intense, in many ways, and can't easily be recaptured, so i've quit chasing them, even thought i know that what i accept as good enough really isn't, in all ways.
 
That's fair. I don't sharpen like that often either but I feel the need to do it once on each blade I get my hands on. I know what you mean by the "feeling" you described trying out your first really sharp edge. It's been a while since I thought about it.
 
How do I decide that I reached the ultimate sharpness a particular blade can attain? When I can convince someone like you or Mario to sharpen my knife.
 
:happy2: I'd sharpen your knives anyday, Rock. I go around asking people for knives to sharpen all the time. I did that to a local sushi chef yesterday and he looked at me like I was ***** crazy. BTW, I know what you mean about Mario. That Heiji Mario sent was hair-whittling sharp and it wasn't even a fresh edge.
 
Yeah, the Shigi he sent me was damned sharp, too. I didn't really need to put my own edge on it, I just like using my own work.
 
I think the first time you use or sharpen a good knife, it seems to be much sharper than any other time, even though it isn't. I think I'm going to spend a lot more time in the mid-range grits of my knives, I spend a lot less time there than I do at the coarser stages, and I want to see if it makes much difference to the edges
 
TK, I feel like we have the exact same outlook and passion for sharpening(although I don't take anything past a 10K SS). After two years and hundreds of knives sharpened, I still get excited to do so each and every time.

I've never agreed with comments like "white gets much sharper than blue", etc. Each knife is different and I think it is hard to talk in general terms like that, as I'm sure my Takeda could make someone re-think that white#2 can get 'the sharpest'. My aogami super, white#2, 19c27, semi-stainless knives all have amazing edges on them, and although different from one another, I consider them to be a similar league as far as performance is concerned.

Not sure if I reached the ultimate edge, but I know that I'm really happy with the edges I produce...they make cutting/cooking so much fun.
 
I'm so very far from that... I only take my edges up to 5K being a novice. Was really stoked when my carbonext came off the 5k with an edge that scared me a little! But after just a week of home use, it seems so dull.

Must have just left a weak wire edge on the side that Dave keeps mentioning. Sigh. Was feeling quite ****** when I realised how crap I was compared to you guys. Back to the stones again this weekend.
 
I have only been sharpening seriously for a couple of years and haven't been passionate about it the majority of that time. When working a lot it was more of a chore than a fun or relaxing exercise. And only recently have I been getting more and more equipment (stones, strops, compounds, etc). So for me, every time I sharpen a knife (that I take my time on, not just a quick touch up before work) it is the best edge I have put on a knife. I am still learning, and get a little better each time, raising the bar, even if only slightly.

Tinh, are you a regular at the sushi bar? Maybe to gain his trust you could bring in one of your knives for him to try so he knows you aren't taking it to a Chef's Choice. Also, are you equally skilled with single bevel sharpening?
 
I'm so very far from that... I only take my edges up to 5K being a novice.
You don't need anything more than a 5k. I used a couple of high grit stones mainly because I had some cool knives for a one shot deal and I wanted to try some different stones that wouldn't grind a lot of Salty's precious metal off. The other reason is high grit stones will remove your burr/wire edge if you are careful.

Must have just left a weak wire edge on the side that Dave keeps mentioning. Sigh. Was feeling quite ****** when I realised how crap I was compared to you guys. Back to the stones again this weekend.
Easiest way to rapidly improve your edge is to finish with a handful of VERY light strokes on both sides of your edge and get a cheap leather strop, load it with chromium oxide or diamond and abrade that wire edge off. Finish with light strokes and listen to the sound. It shouldn't sound like it's slipping across the leather. You should hear a very faint scraping. If you pick up your knife and there's a bunch of leather "dust" on your blade, the scraping isn't faint enough. If you don't want to get a leather strop, almost anything will work but it will take longer. If it still doesn't work, you can raise your angle some to work off the burr. You'll get a microbevel but at least it'll be a stronger edge...
It seems like yesterday that I was in your exact shoes except I learned to sharpen on a crystolon oil stone (yuck) and then went to a 3kSS single water stone solution. That was tough. Lots of gouging for a while.
 
Regardless of steel most of my knives are very close in their level of sharpness due to the angles not the steel itself, the ease of sharpening and the feel of the edge may be different, the only times I may have a knife be sharper than most of the others are the knives I have very large bevels on (i.e. lower angle of sharpening) but at the same time edge retention can come into question depending on steel. I rarely use large bevels and sharpen at super fine angles. I need edge retention in the kitchen and my mind set is more that the edge is coming to a finite point and not just focusing on how low of an angle i am sharpening at.
 
TK, I feel like we have the exact same outlook and passion for sharpening(although I don't take anything past a 10K SS). After two years and hundreds of knives sharpened, I still get excited to do so each and every time.

I've never agreed with comments like "white gets much sharper than blue", etc. Each knife is different and I think it is hard to talk in general terms like that, as I'm sure my Takeda could make someone re-think that white#2 can get 'the sharpest'. My aogami super, white#2, 19c27, semi-stainless knives all have amazing edges on them, and although different from one another, I consider them to be a similar league as far as performance is concerned.

Not sure if I reached the ultimate edge, but I know that I'm really happy with the edges I produce...they make cutting/cooking so much fun.

It's nice to know I'm not alone. I mostly finish on 8k Kit, SS, 12k SS or belgian coticule and then either chromium oxide or diamond loaded strop. The 20k is usually just my shaving stone. I haven't shaved with anything other than a knife in a few months now. I'm looking forward to getting a nice straight razor at some point.
 
...Tinh, are you a regular at the sushi bar? Maybe to gain his trust you could bring in one of your knives for him to try so he knows you aren't taking it to a Chef's Choice. Also, are you equally skilled with single bevel sharpening?
Okay, what actually happened is I showed up and noticed that he had some chipping issues. So I'm staring at this guy's knife trying to figure out what the problem is while he's using it and he's working behind a glass shield so I must have looked a little suspect. I finally decided he was grinding his convex edge too flat with no micro. I basically told him just that and offered to help him with it. That's when he gave me the "are you crazy" look. After some more sharpening talk, I guess he decided it was okay to let me have a go at it. I have to say I wasn't expecting that response and I've never sharpened a large single bevel knife before so I'm a little uptight about it. Luckily, I have some knowledgable back-up.
 
Okay, what actually happened is I showed up and noticed that he had some chipping issues. So I'm staring at this guy's knife trying to figure out what the problem is while he's using it and he's working behind a glass shield so I must have looked a little suspect. I finally decided he was grinding his convex edge too flat with no micro. I basically told him just that and offered to help him with it. That's when he gave me the "are you crazy" look. After some more sharpening talk, I guess he decided it was okay to let me have a go at it. I have to say I wasn't expecting that response and I've never sharpened a large single bevel knife before so I'm a little uptight about it. Luckily, I have some knowledgable back-up.

My story isn't quite related, but yours really reminded me of last weekend, when I was at a Korean/Japanese restaurant (man, can they make food!).
I was watching the chef for a few minutes and finally I asked him about his knife. His response was "not like your knives. This is made in Japan". I tried to explain my situation and the fact that I actually understand knives, shapes, etc. I finally got out of him "Doi", and "95/5". It didn't look like a Doi, and it sure didn't look 95/5 (on a yanagi??), unless it was a kiritsuke, and he added a back bevel. Either way, he wasn't letting me get anywhere near his knife...I was still to far away to tell. Dang!
I find it funny that more chefs don't trust the knowledge of patrons who are asking specifically about their knives. I realize there are those who go and ask because they "ain't never seen a knife like that", but it would have been nice to get a real look at this guy's kit. His skills are likely the best I've seen around here and I would have loved to do a little shop talk.
Oh well.
At least the food was AMAZING!
 
I mostly finish on 8k Kit, SS, 12k SS or belgian coticule and then either chromium oxide or diamond loaded strop.

90% of the time my finishing is just on my 5K SS followed by stropping on felt/diamond and leather/chromium...this is quick and easy, and the 5K finish is really a perfect middle ground for polish and bite.

But I do take my carbon steels up to the 10K once in a while, depending on my mood.

How did the Gesshin compare to the Naniwa SS or other stones you've used?
 
Okay, what actually happened is I showed up and noticed that he had some chipping issues. So I'm staring at this guy's knife trying to figure out what the problem is while he's using it and he's working behind a glass shield so I must have looked a little suspect. I finally decided he was grinding his convex edge too flat with no micro. I basically told him just that and offered to help him with it. That's when he gave me the "are you crazy" look. After some more sharpening talk, I guess he decided it was okay to let me have a go at it. I have to say I wasn't expecting that response and I've never sharpened a large single bevel knife before so I'm a little uptight about it. Luckily, I have some knowledgable back-up.

i lent my Yanagi and Usuba to a sushi chef at a restaurant a friend of mine is a hostess at. both knives were very well received, which made me feel really good. i don't speak Japanese, so i'm just going by what my friend, who does, said, but both knives had been pretty obviously used heavily. i've had knife conversations at several restaurants, both Western and Asian. at New Years Eve, last year, our waiter even went back and brought out one of the knives used in the kitchen, after service was finished. this was at a really good French restaurant. it was a Misono 210 Molybdenum gyuto. i hadn't gone out of my way to get into a knife conversation, he was just very attentive and overheard me wondering aloud at my girlfriend about their cutlery. after he and i started talking about knives, i noticed the we got more service than the tables immediately around us. ;)

anyway, i've been finishing on the Kitayama and then .5 CrO and then .25 diamond (both on balsa) for a few months, now. i had stopped at 6k for a couple years before that, and i had been happy with the 6k finish. it was only when i wondered how much sharper i could get my edges that i bought my first strop, and then bought the Kitayama (and then another strop, and then started making me own strops). i've come to the conclusion that 90% of the keenness of a given edge is determined by how even of a scratch pattern is put down by the medium stones used. you can create a nice sharp knife even when the coarse bevel is sloppy, by fixing it with the medium stones, but it's really hard to fix a knife with finishing stones when the medium stage has been done poorly. i'm planning on getting a Takashima from Jon soon (hopefully next month), but it's more because i want to start trying natural stones than it is because i'm unhappy with the performance i'm getting off the Kitayama.
 
90% of the time my finishing is just on my 5K SS followed by stropping on felt/diamond and leather/chromium...this is quick and easy, and the 5K finish is really a perfect middle ground for polish and bite.

But I do take my carbon steels up to the 10K once in a while, depending on my mood.

How did the Gesshin compare to the Naniwa SS or other stones you've used?

I always keep a couple of 5k edges around in case I want a more aggressive cutter.

As for the stones, I would say the Gesshin 1k is a best in class stone. It's just like a Beston 1.2k but it's spash n go so it dries and I put it away in a few hours rather than days or having to have a permasoak bucket. I need all my storage space for other knife junk and a bucket just doesn't fit nicely into my equation. The finish is similar but probably a bit finer-looking. I think it feels a little harder but again, that's similar and so is the level of feedback. It is also similar in terms of speed. It is my go-to 1k stone.
Gesshin 5k is also splash n go. It is a really nice stone. I like everthing about it except it's a bit slow. If I'm using it to refine a 1k edge, it's great. If I really want to grind out all the 1k scratches, it takes a bit longer so I've started inserting a 3kSS into the progression. The 20k is superfine and damn hard and probably isn't the best stone for kitchen knives, as much as I hate admitting it. There's just very little bite to that edge and since it's so hard, it's a bit difficult to get it to touch every point along the edge unless you purposefully go for a tiny microbevel.
 
i've come to the conclusion that 90% of the keenness of a given edge is determined by how even of a scratch pattern is put down by the medium stones used. you can create a nice sharp knife even when the coarse bevel is sloppy, by fixing it with the medium stones, but it's really hard to fix a knife with finishing stones when the medium stage has been done poorly. i'm planning on getting a Takashima from Jon soon (hopefully next month), but it's more because i want to start trying natural stones than it is because i'm unhappy with the performance i'm getting off the Kitayama.


similarly, I have found over the years that the more time I take getting everything just right at 36grit on the grinder, the easier I can clean it up with 80 grit,
when I'm hand sanding I start at 150grit and work up to 2000, If I take my time at 150 and get everything just right I can get from 150 to 2000 in a matter of 20-30 minutes. If I try and rush the 150 finish it can take significantly longer to get to 2000.
 
I've learned a lot about sharpening by learning to sharpen different things--cheap steel, high end steel, straight razors, scissors, etc.

It is my firm belief that a tool is properly sharp when you never give a second thought to it. When your tool becomes a part of your day, it is not doing it's job. A tool's job is to disappear into your workspace, and let you focus on the task at hand, whether it is cooking dinner, cutting hair, shaving, opening boxes, or skinning a deer.

Sadly, lately, I've had to re-consider my stance on my three knife rule. I no longer think 1 knife is perfect for 90% of tasks. It's more like 45%, because different food items require different kinds of sharp. I found this out when I sharpened a guy's knife to a hair popping edge, and it just fell through carrots---and smashed a tomato. Then I roughed it up on a 1k stone, and it fell through a tomato, but sawed it's way through the carrot. You need polish for fish, teeth for chicken, etc etc.

Surprise, surprise the Japanese had it right about knives again.

*edit* and on medium stone quality, I learned a lot from straight razor guys that sharpen on 2 stones, and 2 stones only, but they don't go from 1k to 6k until the 1k will shave without effort.
 
i find that to be strange, the idea that a knife that will slide through a tomato won't slide through a carrot. the knives i have that will push cut tomatoes don't even know the carrots are there.
 
Maybe the carrot to tomato isn't as good a reference as say, a crispy, charred, grilled tenderloin to a tomato...
 
i cut crispy, charred, grilled tenderloins with no problems using the same knives. i agree that toothy edges can feel different than slick edges, but i don't find either to really cut much different if they are both prepared similarly. i may have a different definition of toothy, though. white steel, for instance, always feels toothy to me, no matter how much time i put in to making the scratch pattern as uniform and polished as possible.
 
Maybe the carrot to tomato isn't as good a reference as say, a crispy, charred, grilled tenderloin to a tomato...

Well, it wasn't a reference. It really happened. Dumbfounded me for sure. Just like the time I had a knife that would shave my armhair, and wouldn't break the peel of a potato.

The thing is, a crispy, grilled tenderloin needs the same toothy edge as a tomato. Unless your tomatoes are bulletproof, straight-outta-the-warehouse, they will benefit from an edge with some bite to it. God knows I cut enough tomatoes at work.

But a carrot needs a polished, push-cutting edge, much like you would want for wood carving.
 
i cut crispy, charred, grilled tenderloins with no problems using the same knives. i agree that toothy edges can feel different than slick edges, but i don't find either to really cut much different if they are both prepared similarly. i may have a different definition of toothy, though. white steel, for instance, always feels toothy to me, no matter how much time i put in to making the scratch pattern as uniform and polished as possible.

What kind of cutlery are you using? Variety is the key here. Comparing a Shigefusa to a Tojiro is really not that great of a leap. Comparing a Takeda to a Chicago Cutlery, however, you will find that different knife designs and steels will require different edges to perform similar tasks.
 
Back
Top