[condiment]

A talented chef might cut vegetables at 25hz, while the blade is moving at 44khz. So whatever cutting improvement is conferred by the ultrasonic tech will certainly be applied towards fast cutting. It seems that the main benefit for fast cutting would be that food doesn't stick to the blade.

I'll cut bread with my chef's knife (amazon shun knockoff) when I want to make less of a mess. One interesting thing I noticed is that when Scott was cutting bread in the video he was cutting a croissant and no crumbs fell.

It will be interesting to see the knife in the hands of real chefs. Two things I'm curious about are whether the ergonomics of the button are good, and whether the ultrasonic action atomizes foods as they're being cut, changing the experience of cooking in some way.

[niccl]

I'd really like to see a citation for 25 Hz. It feels to me like a decimal point might be missing. And how does the knife moving at twice the frequency of the vegetables being cut work? do they do two complete cycles of the knife for every cut of the veges? that's not what I've seen watching cooking shows (which might not be the best thing to watch for this to be seen, of course)

[tempestn]

Hz vs kHz. Your parent's point is that the knife is vibrating far faster than even the fastest chefs would be slicing.

[oofbey]

25 chops per second would be EXTRAORDINARY. Possible? Probably but only with super elite training. Most competent home chefs can probably do 5 Hz and probably struggle to get to 10 Hz.

[mminer237]

The fastest button mashing record appears to be 16 Hz, so I definitely do not believe it is possible to chop with a knife in the double digits.

[0xbadcafebee]

Can somebody count Jacques' garlic chopping speed then? Perhaps someone younger than 80 could do it faster? https://www.youtube.com/watch?v=H3ENOZgEqXg#t=1m20s

[lkbm]

Looks like around 12Hz, counting the forward rock and back rock as distinct chops. I'm not sure a rocking motion is what people mean here, though. This only works for mincing something you've already cut up, not slicing an onion.

[0xbadcafebee]

Maybe the solution is an ultrasonic slap chop? (https://www.amazon.com/Slap-Chop-Stainless-Vegetable-Accesso...) Many slices at once, preserve whatever the ingredient is without crushing it, doesn't stick to the blade. It may sound ridiculous, but if it makes kitchen prep easier and faster, I might cook more.

[scythe]

The sixteenth notes in "Crazy Train"[1] are nominally 552 per minute, or 9.2 Hz. Moving a knife at 10 Hz is probably very difficult. I would expect 2-3 Hz is a normal pace for a skilled knife user and 4-5 Hz is showing off.

1: https://youtube.com/watch?v=tMDFv5m18Pw#t=0m32s

[superkuh]

Cerebellar oscillation (in the inferior olive) gate motor control interrupt speed and are generally limited to ~10 Hz in humans.

[john_minsk]

That escalated quickly. Thank you!

[pixelfarmer]

Which is why humans use tech and tricks to get things done. Gravity Blast is one example: https://www.youtube.com/watch?v=ir_KZNsTNiQ

[mattmaroon]

Damn, I was set to completely dismiss this as entirely useless overcomplication but making stuff not stick to the knife would be nice.

[mckn1ght]

That’s where a lot of mess comes from, so I’m very interested in this tech. The worst are cucumbers, they stick to the blade and new slices pop them up and they roll everywhere. I get some better results by slightly angling the blade but it’s not perfect.

The blade quality doesn’t look great but I think any decent cook that knows how to hone will do just fine with it.

I’m not sure I’d spend the money and replace my expensive knives for a relatively rare edge case but it’s a neat innovation that might catch on elsewhere, or maybe they’ll make premium lines.

[bsder]

> The worst are cucumbers, they stick to the blade

Is this issue possibly that amateur knives are too "polished"?

This doesn't seem to be a "professional chef" problem yet seems to be a significant "amateur chef" problem.

Is this simply the case that a knife with professional use takes enough dings and scratches that foods won't vacuum seal to the face of the knife?

[inimino]

Technique. Pros use a slicing motion that moves the knife through the food before it detaches, home cooks use 5% of the blade and all the cucumber rounds are stuck to same place on the side of the middle of the knife.

[temp0826]

Maybe instead of building it into the knife, it needs to be something you could attach to any knife

[john_minsk]

Interesting idea, but I would say that it is orders of magnitude harder compared to having an integrated system. Vibration in such a compact space with a very sharp blade... I want this system be stable around me.

I would say, if this idea becomes popular, knife producers can create their own versions in the new models, or retrofit old knives at the shop.

[blincoln]

Yeah, I'm already somewhat skeptical of the whole concept, having DIY'd a vibroblade out of an X-acto knife and a SonicCare toothbrush and finding it to be completely ineffective.[1]

I think trying to make an ultrasonic vibration add-on for regular knives would be even harder to make into a useful product than an integrated knife/transducer.

If the handle is rigidly fixed to the blade, there would be very little vibration. So it seems like the only way to make an add-on would be as a sleeve over the regular handle. That would make for a bulky handle, and it seems like it would need a counterbalancing weight at the back. So the result would be very unwieldy, like one of those electric turkey-carving knives that are basically kitchen hedge-trimmers.

I'm waiting to see what skilled chefs think of this knife. The idea of an ultrasonic vibroblade has always seemed like a neat one to me, and I'd be happy to hear that someone managed to make one that was genuinely useful.

[1] https://www.beneaththewaves.net/Projects/SonicCarereg_Lock_P...

[thfuran]

https://www.sciencedirect.com/topics/engineering/ultrasonic-...

The premise is obviously sound, though it's possible this particular product doesn't work very well.

[popoflojo]

Ultrasonic cutting board. "Are you tired of spending $1800 on a whole set of ultrasonic knives only to have them break every time your Brother in law throws them in a bowl of soapy water after a dinner party? Well know you don't have to. Image buying 6 cheap knives at a garage sale and turning them into chefs quality knives instantly, without even touching a sharpener!"

[fooker]

That's a pretty good idea.

If this was a small 40$ attachment you could put on the dull edge of any knife, this would be great.

[Voultapher]

The thing you are looking for is convex edge geometry https://youtu.be/cZ2Y7lyzq24?t=885. Done right it can massively help with food release.

[dsr_]

Cucumbers: put your cutting board in a sheet pan. Now they roll away but stop at the rim.

Also works for helping with fluid containment.

[masfuerte]

I had a similar problem with spring onions. So I give them a lengthways slice first. The half moons don't roll.

[tptacek]

I mean, for both potatoes and cucumbers, I just use a v-slicer. $40.

The other weird thing about this is that neither a potato nor a cucumber demands an ultra-sharp knife.

[andbberger]

if you have a nice knife and cut by dragging the knife towards you with tip in contact with the board instead of cutting directly down, food will not stick

[SilverElfin]

The video comparison of this knife cutting through potato compared to a regular one is very enticing. My own experience is that there is more sticking even on my knives that have those scooped out edges that are supposed to prevent sticking.

[mattmaroon]

Yeah, those do reduce sticking, but they certainly don’t prevent it entirely.

[tptacek]

I'm not saying it can't work, just that they didn't show it, and after the required thin-tomato-slice that's the thing I'd most want to see the knife doing.

[knifemaster]

For reference it would be also nice to see your (and your Slack friends) knife handling skills.

[tptacek]

Wh...why? I'm not selling anything. I'm just saying dicing an onion is a better test of a chef's knife than taking a single thin slice of a tomato. Seems like that's an argument you can just take on directly.

I don't think there's anything interesting about my onion dice. You'd be seeing a video of a banged up MAC, scraped up from all the times I've casually sharpened it in a hurry, doing the standard one-cross-cut Jacques Pepin onion dice. You know, an onion dice.

(The "Slack friend" thing was just that I felt bad about sharing a link I'd gotten just a few minutes while pretending as if I'd known about it myself. I have no idea their level of expertise! Probably better than mine though.)

[knifemaster]

I was getting the impression that you are "selling" the fact that the performance of this knife is based on false advertising, and using personal anecodes and some anonymous people as a supporting argument. That's basically the only issue.

Aside from that, in my opinion dicing an onion is a much more simple task for a knife than taking a very thin slice of a tomato. And in both cases it is likely more about the technique/handling and the sharpening than the actual knife material or technology. But the average person does not care about those things, so this knife could at least in principle be something useful for them. Not for someone who is willing to invest some time in the aforementioned things though, like you (and me too, for that matter).

[tptacek]

No I genuinely don't know if this is a useful product or not. I think it would be a more interesting world if it was, so I guess I'm rooting for it. But I've got those two indications that I should be wary: nobody really used the knife in the video, and he did that weird knife ranking that happens (in a weird way) to probably favor his new electronic knife.

[jorvi]

Well, I can't speak to "false advertising", but the thin slice he did with the tomato and the grape you can just achieve with a well-sharpened knife. Both sides of a whetstone and then a strop will get you there.

As for the sticking, this is solved by vertical fluting already.

Ultrasonic vibration is a complicated solution for a problem that has already been solved by the simple solution of just sharpening your knives. And you don't need to get expensive either. A Sharpal diamond stone, leather strop and a good workhorse knife like a Victorinox Santoku will get you there :)

[tptacek]

He acknowledges you can do that with a well-sharpened knife. Of course you can do it with a well-sharpened knife. It's exactly the demo every single sharp knife does! His claim is that the ultrasonic knife will always do that cut, whether or not you assiduously keep it sharp, which is what I have to do with my MAC and Yuki to make it cut tomatoes like that.

But most chef-knife cutting isn't thin tomato slices, and you can always do that cut with a good thin serrated bread knife, too. I want to see it dice an onion. Seems like a small ask.

[sethammons]

> As for the sticking, this is solved by vertical fluting already.

This is absolutely NOT "solved." I have such knifes and potatoes stick nearly as bad. To the point I have wondered if they make it worse.

[eightysixfour]

> It will be interesting to see the knife in the hands of real chefs.

Not really? I feel like this is for the other people, the folks who don't have the training to use a chefs knife super well. I'd rather see a decent home cook compare it to their knife in general prep.