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Ultrasonic Chef's Knife

seattleultrasonics.com

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Re: Ultrasonic Chef's Knife

#661

Post by account42 »

YeGoblynQueenne wrote: post #604
slow_typist wrote: post #540

Earlier quoted context omitted.

How can you know your grandmothers never sharpened it? In my experience grandmothers tend to have a steel lying in a drawer and use it at least before cutting through expensive meat. And they use professional sharpening services once in a year. You wouldn’t actually notice as a child.

Yeah, sorry my comment was a bit misleading. I spent a lot of time around my grans when I was a kid, and later as a young adult and a ... less young adult? We lived in the same houses (two, because my parents were divorced). They didn't sharpen knives. They both took great pride in their cooking, but they would just stare at you if you asked them about things like knife skills or mise en place. They were Greek housew…

Maybe they understood you better if you didn't insist on speaking french? Arranging your ingredients when mixing them comes pretty naturally to most people even if they don't know a fancy phrase for it.

Re: Ultrasonic Chef's Knife

#662

Post by account42 »

whyenot wrote: post #330
tptacek wrote: post #77

Earlier quoted context omitted.

This thing is $399, which is on the expensive side of prestige chef knives, but by no means the extravagant side of it. People who buy knives that cost more than $150 generally buy lots of knives, and this is priced for that market.

It’s $499 with the wireless charger. I see that the charger isn’t required. You can take the battery out of the knife and charge it by USB. I would correct my comment, but it is no longer possible for me to edit it.

That's quite the expensive charger. Makes me wonder what other parts of the knives are overpriced that much.

Re: Ultrasonic Chef's Knife

#663

Post by nerpderp82 »

malfist wrote: post #599
mapt wrote: post #555

Earlier quoted context omitted.

They do not stay sharp. On hard material and when overloaded, they will chip in large, unfixable chunks. On softer material, they continuously sharpen their edges at a microscopic scale, fracturing away tiny chips as they're worn, to new glassy ceramic molecular edges. A well used ceramic blade becomes micro-serrated. This sounds fantastic until you think about what is happening to the shards of hard glassy ceramic w…

If your body didn't have ways to deal with sharp things you eat, we'd never eat fish due to the risk of pin bones. Microscopic shards of ceramic pose very little risk.

Unsubstantiated claim has me convinced!

Re: Ultrasonic Chef's Knife

#664

Post by account42 »

rkomorn wrote: post #480
omega3 wrote: post #477

The tomato test is disingenuous - no one slices a tomato by pressing the knife straight down - you slice it to break the thick skin and follow with a slicing motion. The rest of the graph basically shows no difference between the force used for ultrasonic one and standard knife used inefficiently?

And yet, when people like to show off how sharp their knife is, dropping a tomato on it (blade-up obviously) and watching the tomato split in two is one of the favorite tests. Probably (and precisely) because you can only achieve this with a knife that cuts very well.

That's nice and all but I don't think you want to be the guy that brings an ultrasonic knife to a knife sharpening competition.

Re: Ultrasonic Chef's Knife

#665

Post by mapt »

Zigurd wrote: post #590
mapt wrote: post #555

Earlier quoted context omitted.

They do not stay sharp. On hard material and when overloaded, they will chip in large, unfixable chunks. On softer material, they continuously sharpen their edges at a microscopic scale, fracturing away tiny chips as they're worn, to new glassy ceramic molecular edges. A well used ceramic blade becomes micro-serrated. This sounds fantastic until you think about what is happening to the shards of hard glassy ceramic w…

How much mineral and metal grit does one consume on a regular basis? The ceramic material from a ceramic knife blade is, obviously from just looking at it, very small. I bet the amount of grit I've eaten from having a taste for raw oysters vastly outweighs what I'd get from a lifetime of using ceramic knives.

"grit" is usually spherical or close to it, because it has seen chemical and mechanical weathering. It is often calcium crystals of some type.

This is neither. These are long dagger shapes, significantly larger than a diatom, very hard, sharpened to a fine edge.

Re: Ultrasonic Chef's Knife

#666

Post by literalAardvark »

cactacea wrote: post #651
literalAardvark wrote: post #593

Earlier quoted context omitted.

My thought process was that anyone who is trained or interested would seek to get them sharpened. I've been in this position and my partner at the time decided to use a separate set of knives from me, as my sharp knives made her focus on the danger and pulled her out of her zoned out cooking-with-a-glass-of-wine mood. Fair enough, how she approaches tools isn't my decision.

Respectfully, proper technique is just a matter of searching and reading for 2-3 minutes followed by a bit of practice and repetition to get fast. You can skip the getting fast part if you want. Nobody needs "training" to become proficient with a kitchen knife.

She doesn't care. It's not possible to force someone to be a gear nerd.

She cooks, she enjoys it, she does it with a medium sharp knife that doesn't slip because that's not a real thing, and isn't scaring her because it's just medium sharp.

Easy as

Re: Ultrasonic Chef's Knife

#667

Post by shmeeed »

kristjansson wrote: post #371
sublinear wrote: post #343

Earlier quoted context omitted.

Free idea: put this tech in a mandoline slicer. Even the best tend to struggle with consistency and can only go so thin due to all the friction. An ultrasonic mandoline that can overcome all that would probably fly off the shelves and better match the original industrial intent.

On one hand I would buy that instantly. On the other hand, it’s already missing small pieces thanks to my current mandolin. Not sure I want to make my scariest utensil scarier.

Had to read that twice. I feel you! It's been nearly 20 years and I can still see the scar.

Re: Ultrasonic Chef's Knife

#668

Post by pedro_caetano »

Having worked a fair amount with ultrasound for eye surgery [0] the physics similarities are very striking (the FEA simulation gave me flashbacks) but it's almost funny how the same principles can be translated and applied for an entirely different end purpose (cataract surgery, and slicing tomatoes!)

To use Scott's words it is very cool to see such a tech translation from industry to home use. I would still be cautious about the lifetime of these devices (namely how it will deal with water ingress over time) but the fact that they will come out of a factory is already quite a HW startup feat.

[0] https://en.wikipedia.org/wiki/Phacoemulsification

Re: Ultrasonic Chef's Knife

#669

Post by BrandoElFollito »

I was offered a CHEF'S CHOICE 15XV a few years ago and this is what I use to sharpen the knives at home (very ordinary knives).

I never knew if this was the summum of how sharp my knives could be, or where I bring them on a "sharpness" scale of 1 to 5 for a given knife.

I was also wondering if this depends on the knife - with some knives being better for such electrical sharpener and some worse.

Re: Ultrasonic Chef's Knife

#670

Post by stouset »

wredcoll wrote: post #644
itomato wrote: post #295

Earlier quoted context omitted.

Making the edge is sharpening. Removing the ripples in it is honing.

This is the first time I've heard someone say honing is very important, when I was first learning this, I was told that it was the next thing to pseudoscience!

Absolutely not. A blade can stay sharp for a much longer period of time than it can stay honed. The edge of a piece of paper is extremely sharp, but it only cuts you in specific circumstances due to being difficult to maintain a firm edge.

A knife's edge is closer to that than you'd think. At the scales of sharpness of a good knife, it's impossible to keep the edge straight for very long. A honing rod quickly brings these back in line. I hone knives after maybe a week of use; it only takes a few seconds.

And this is a comically easy property to test. Use a "dull" knife then hone it and try again. It will cut drastically better.

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