# What sharpness is worth it?



## abepaniagua (Jul 19, 2018)

As a home cook, I am trying to keep my knives sharp enough for daily use. I have a santoku, pairing knife and a gyuto. The first 2 are Tojiros DP (VG-10) and the last is a #2. I've been able to keep all three sharp but not as sharp as they can be or as I would like.

My desire would be to cut onions easier. For some reason, the knives are sharp but i can't cut onions like this guys does (here, starting at 2:23). I have a munetoshi gyuto, and I sharpened it a bit on a Shapton Pro 1k, then used the Arashiyama 6k to sharpen and light edge-trailing strokes with it. Do I need to spend more time? Or is that kind of sharpness unsustainable for a home cook who cooks on a daily basis?


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## Pensacola Tiger (Jul 19, 2018)

Sharpness is only one aspect of what makes a great cutter, and it's for from the most important. The grind, especially whether the knife is "thin behind the edge" is much more important. If is too thick in that area, you experience difficulty in cutting anything that is over about a quarter-inch thick. I suspect that your knives could benefit from some judicious thinning.

Tojiro DP's are good knives, but they aren't known for great grinds. You don't say what the third knife is, but I suspect that all three of your knives could benefit from some judicious thinning, especially of the tip area.


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## abepaniagua (Jul 19, 2018)

Pensacola Tiger said:


> Sharpness is only one aspect of what makes a great cutter, and it's for from the most important. The grind, especially whether the knife is "thin behind the edge" is much more important. If is too thick in that area, you experience difficulty in cutting anything that is over about a quarter-inch thick. I suspect that your knives could benefit from some judicious thinning.
> 
> Tojiro DP's are good knives, but they aren't known for great grinds. You don't say what the third knife is, but I suspect that all three of your knives could benefit from some judicious thinning, especially of the tip area.



Sorry, forgot to add it. It is a Munetoshi Gyuto 210mm


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## andur (Jul 19, 2018)

VG-10 is notorious for not getting up to a very high sharpness (not saying its impossible but compared to high carbon steels the difference is Huge). Now White steel will get screaming sharp. I've gone full circle in the last 10 years from a pure high carbon steel to VG-10 and now back to pure steels. I just enjoy the sharpening ease. Spend a minute or two on a 2 stone progression is all I do for a good edge to my taste. When sharpening my VG10 knives I need to spend 5 times as long for an OK edge. 

The 1k and 6k progression seems very good! I might try leading edge strokes (to get rid of the burr) for alloyed steel. 

The edge in the video looks nice, I'm fairly confident I can get an edge like this every time but it won't stay That sharp for a whole chopping session or a large meal. In other words I sharpen every other day to keep an edge like this. I think if I'm not misaken it's a tradition to sharpen knives every day in a Japanese kitchen?


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## andur (Jul 19, 2018)

Pensacola Tiger said:


> Tojiro DP's are good knives, but they aren't known for great grinds


Yep! I've taken all my Tojiros to the grinder. Thin the DP VG-10 down and it's an excellent knife!


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## Pensacola Tiger (Jul 19, 2018)

I've not a lot of experience with Munetoshi gyutos, just his boning knife, so I'm just going on what you are reporting, but the tip area is probably not as the as it could be for best performance. 

How do your knives cut things like bell peppers?


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## abepaniagua (Jul 19, 2018)

Pensacola Tiger said:


> I've not a lot of experience with Munetoshi gyutos, just his boning knife, so I'm just going on what you are reporting, but the tip area is probably not as the as it could be for best performance.
> 
> How do your knives cut things like bell peppers?



It does well. I'm actually going to prepare some today and let you know.


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## Pensacola Tiger (Jul 19, 2018)

abepaniagua said:


> It does well. I'm actually going to prepare some today and let you know.



If it cuts thin things like peppers, but doesn't do well on thicker things like onions, carrots, or sweet potatoes, it is very likely that the grind, not the edge, is to blame.

Here's a link to Jon Broida's video on thinning a knife: 

I'd suggest that the Munetoshi will be the easiest knife to thin, as the stainless cladding on the Tojiro DP's is very "gummy" on the stones. The Munetoshi is iron clad and will be much easier to work with.


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## nutmeg (Jul 19, 2018)

I think 6k may be too high. Something in the 3k, evtl 4k range would be my maximum.


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## Benuser (Jul 20, 2018)

In addition only: VG-10 is a bit a special case. Gets screaming sharp, but loses that very quickly to stay at a very acceptable level almost forever.
I need a full progression for deburring alone. The burr has to got abraded, it doesn't fall off after weakening as with simple carbons. If it were it would leave a terribly damaged edge behind. 
The burr abrasion can be performed by longitudinal strokes, after stropping as usual. Only when the burr doesn't become smaller and just flips sides, it's time to go to the next stone, for light stropping and deburring again. 
It's the only steel I use up to five stones with.


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## aaamax (Jul 21, 2018)

andur said:


> I think if I'm not misaken it's a tradition to sharpen knives every day in a Japanese kitchen?



Interesting. I never have thought about that and wonder what takes place there. I'm guessing that a daily touch up as in any hardworking kitchen is needed. Or do they go full out?

I will say though that the board being used makes a night and day difference as to how long any given edge lasts. When stuck with what ever the house provides, read: hard-ass plastic derivatives, my edge goes to crap very quickly and I have an extremely light touch. When I bring my own board which is just a simple pine baking peel, my edge can last for days.


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## andur (Jul 21, 2018)

Having gone full circle from blue to white to VG10 to blue to white in 10 years I'm now in the phase of seeing benefits of easy sharpening. I'll gladly sharpen a white steel knife for about a minute and on two stones. Way better than taking 10 minutes and 5 stones on a VG10 and still struggling to get the burr off ! But then the VG10 will stay sharp for a week and that's also nice...
I guess that is why we have to have so many knives!


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## Paraffin (Jul 21, 2018)

aaamax said:


> Interesting. I never have thought about that and wonder what takes place there. I'm guessing that a daily touch up as in any hardworking kitchen is needed. Or do they go full out?



Somewhere there is a YouTube clip from a cooking show, where one of the famous sushi chefs shows off his knives. And they're seriously ground down; both narrowed and shortened in length. He shows a newer knife of the same kind for comparison. Maybe someone else here remembers that clip and can link to it. So in that case, I'm guessing it's all-out sharpening every day and not a touch-up.

Regarding VG-10, yeah it's a pain to sharpen, but then lasts a long time after the initial board contact dulls it down just slightly. My wife's main knife is a Shun Premier santoku in VG-Max, which is some small variation on VG-10. Not fun to sharpen, but then I can ignore it for another couple of months.


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## Benuser (Jul 22, 2018)

The remaining sharpness after the first dulling is indeed very acceptable, and stays so for a lot of time.


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## Nemo (Jul 22, 2018)

Benuser said:


> The remaining sharpness after the first dulling is indeed very acceptable, and stays so for a lot of time.


A similar thing is often said of PM steels like R2/SG2 and SRS15.

Is anyone able to compare the dulling curves of PM steels and VG10?


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## Marek07 (Jul 22, 2018)

Nemo said:


> A similar thing is often said of PM steels like R2/SG2 and SRS15.
> 
> Is anyone able to compare the dulling curves of PM steels and VG10?


I'd be very interested in answers to Nemo's query too. Only have a couple of VG10 knives to compare so my opinion is not informed enough. However, _my impression_ is that R2/SG2 knives definitely stay keener for longer. Please post your thoughts.
Caveat: my R2/SG2 knives are of considerably higher cost & quality than the VG10s I have.


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## Benuser (Jul 22, 2018)

Nemo said:


> A similar thing is often said of PM steels like R2/SG2 and SRS15.
> 
> Is anyone able to compare the dulling curves of PM steels and VG10?


That first dulling with VG-10 occurs almost instantly. Not so with R2. And with R2 I found it very easy to restore.


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## Nemo (Jul 22, 2018)

Benuser said:


> That first dulling with VG-10 occurs almost instantly. Not so with R2. And with R2 I found it very easy to restore.


So with VG10, is it almost as though the steel can't manitain the polish that you need to use to abrade the burr properly?


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## Benuser (Jul 22, 2018)

Nemo said:


> So with VG10, is it almost as though the steel can't manitain the polish that you need to use to abrade the burr properly?


Not sure I understand completely. I use fine stones with VG-10 for deburring, not to polish the edge. Perhaps I should give it a full sharpening through the entire progression, but never tried so far.


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## Nemo (Jul 22, 2018)

Benuser said:


> Not sure I understand completely. I use fine stones with VG-10 for deburring, not to polish the edge. Perhaps I should give it a full sharpening through the entire progression, but never tried so far.


Ah... that makes sense- I see the distinction. Thanks.


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## Marek07 (Jul 22, 2018)

Benuser said:


> That first dulling with VG-10 occurs almost instantly. Not so with R2. And with R2 I found it very easy to restore.


*+1*
R2 holds a good edge for a long time and it's a delight to sharpen. Responds to fine stones very well.


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## andur (Jul 22, 2018)

You make me want to go try an R2 knife now!


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## Nemo (Jul 22, 2018)

andur said:


> You make me want to go try an R2 knife now!


That's a good thing.

Still can't decide whether I need to try a VG10 knife.


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## abepaniagua (Jul 23, 2018)

I would confirm and agree that although my VG-10 Tojiro holds an edge for a very long time. It doesn't get as sharp as the munetoshi (w#2) but keeps it longer.


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## panda (Jul 23, 2018)

You could just get a Marko 52100, stays sharp and is easy as hell to sharpen.


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## Chef Doom (Jul 28, 2018)

abepaniagua said:


> As a home cook, I am trying to keep my knives sharp enough for daily use. I have a santoku, pairing knife and a gyuto. The first 2 are Tojiros DP (VG-10) and the last is a #2. I've been able to keep all three sharp but not as sharp as they can be or as I would like.
> 
> My desire would be to cut onions easier. For some reason, the knives are sharp but i can't cut onions like this guys does (here, starting at 2:23). I have a munetoshi gyuto, and I sharpened it a bit on a Shapton Pro 1k, then used the Arashiyama 6k to sharpen and light edge-trailing strokes with it. Do I need to spend more time? Or is that kind of sharpness unsustainable for a home cook who cooks on a daily basis?


 You have a knife quality problem.


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## rick alen (Jul 28, 2018)

R2 takes a slightly keener edge than SRS-15, but the latter holds its sharp much longer. You can't compare either of these steels to VG-10. SRS-15 will certainly have it beat in all areas. Never used R2 on the board, but with a proper microbevel I tend to believe it would hold a serviceable edge longer than VG-10. With these PM steels you have lots of very fine and hard carbides in a good solid matrix. And both are very easy to restore.

Given the above I use R2 strictly for cutting in-hand and slicing, SRS-15 for chopping it up on the board.


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## stringer (Aug 5, 2018)

Paraffin said:
"Somewhere there is a YouTube clip from a cooking show, where one of the famous sushi chefs shows off his knives. And they're seriously ground down; both narrowed and shortened in length. He shows a newer knife of the same kind for comparison. Maybe someone else here remembers that clip and can link to it. So in that case, I'm guessing it's all-out sharpening every day and not a touch-up."



I don't know about a YouTube clip, but this reminded me of an Iron Chef Morimoto tweet:
https://twitter.com/chef_morimoto/status/448914879370379264?s=19


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## stringer (Aug 5, 2018)

He also sands the handles every day so they stay balanced as the blade is ground down. He grinds away the whole knife in a year or two.


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## rick alen (Aug 5, 2018)

I can't seem to find it now but Ming Tsai did a show with Morimoto where Morimoto shows how his yani's wear down over 3 years. He says the wear on the handles (pretty extreme also) is from scrubbing them clean, not sanding. Commentors remarked that Morimoto was unusually hard on his knives when it came to sharpening, and cleaning likely for that matter.

His quick-smoke technique was interesting. He took various spice nuts/barks/pods and torched them, put a large wine glass over to collect some smoke, then placed glass over some sliced raw fish for 3 minutes.


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## rick alen (Aug 6, 2018)

Oh ya, and drank saki out of the "smoked" glass afterward. Worth a try sometime.


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## HRC_64 (Aug 6, 2018)

...his scrubbie is probably maroon scotchbrite


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## rick alen (Aug 6, 2018)

Found the episode


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## Ilia (Sep 8, 2018)

abepaniagua said:


> As a home cook, I am trying to keep my knives sharp enough for daily use. I have a santoku, pairing knife and a gyuto. The first 2 are Tojiros DP (VG-10) and the last is a #2. I've been able to keep all three sharp but not as sharp as they can be or as I would like.
> 
> My desire would be to cut onions easier. For some reason, the knives are sharp but i can't cut onions like this guys does (here, starting at 2:23). I have a munetoshi gyuto, and I sharpened it a bit on a Shapton Pro 1k, then used the Arashiyama 6k to sharpen and light edge-trailing strokes with it. Do I need to spend more time? Or is that kind of sharpness unsustainable for a home cook who cooks on a daily basis?


Between 1000 and 6000 would be good to insert 3000 and the penetration of the knife into the product not only depends on the sharpening but from the geometry...


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