I made my own version of this a while back, and it lets you create your own cutting methods, plot the statistical distribution, and share your ideas via permalink. It also lets you tweak onion parameters, such as number of layers and the layer thickness distribution curve).
Along the way I discovered two things:
1. I came up with my own method ("Josh’s method" in the app above) where the neither the longitudinal cuts nor the planar cuts are full depth, so the number of cuts at the narrower core is less than at the wider perimeter.
2. After all this hyper-optimization about size, it turns out what really matters when cooking is the THICKNESS, since ultimately determines the cooking rate. The only way to avoid thin outliers that burn long before the rest are cooked is to discard more of the tip of the onion, where the layers are the thinnest.
The 3D version of the simulator is still in progress--turns out 3D geometry is a lot harder than 2D. :)
Hopefully you're not bothering to core the top and the bottom of the onion; fussy, a waste of time, and works against his later goal of keeping the root intact while dicing.
I do it more or less this way - except I keep the root intact until the end. It keeps the onion structurally intact until I'm done with the dicing. At which point, the root takes a single chop to lop off, and then the whole thing scatters into tiny, mostly uniform dices. It's quite satisfying.
Chef Jean Pierre is the best, he explains so good that I really need to listen once to remember forever. Before discovering him, I wasn't interested in cooking at all and I listened to all the other chefs like Ramsay and Oliver but they don't tell you the complete story.
This is silly. I’ve seen Indian street vendors do it the most efficient way. You tilt the knife with the front part down and the back maybe a quarter inch above the surface. That way as you slice the onion the little quarter inch holds it together as you turn it 90 degrees and make the perpendicular set of cuts.
> It turns out that making horizontal cuts almost never helps with consistency.
They made the horizontal cuts evenly spaced between the cutting surface and the top of the onion, which is nonsensical to me. I believe that a single horizontal cut at around 15-20% height would be better for uniformity than a horizontal cut at 50% height.
Which is exactly how I was taught to do it while working in kitchens 25 years ago.
The other thing is that this seems to ignore that the onion is round in the other direction too. As far as I can see, it only covers the first dice cut.
Yeah, that's the way that I cut onions: you make vertical cuts followed by one single horizontal cut slightly above the cutting board.
This way of calculating doesn't take into account the creative ways you can make cuts. You could also do mostly vertical slices, and then slightly angle inwards when you do the final few cuts. That would get you a more optimal distribution as well.
A lot of people insist that this is the way. However, at some point, I figured out that making the horizontal cut (or cuts) before you make vertical cuts is a lot easier. You can do it by simply putting the onion with the root on the board and cutting down at an angle of about 5-10 degrees. When the tip of the knife hits the board, simply don't press down all the way to keep the root intact. Then put it down normally and make the vertical cuts. You can easily manage 3 or 4 horizontal cuts this way. And there's no awkward cutting towards yourself with a sharp knife. All this business of first making lots of vertical cuts and then attempting a horizontal cut is a lot more fiddly. The vertical cuts affect the structural integrity of the onion. This makes the horizontal cuts harder. And it also makes the process of dicing harder.
Of course, as the article points out, the horizontal cuts don't really do much that a chef should care about. You can dice an onion super fine with just vertical cuts very close together. And it's a lot faster and easier. You might angle some of the cuts towards the edges. But honestly, even that is unnecessary and a bit overkill. With a good knife, you can put the vertical cuts really close together. So close that any kind of angle would mean the cuts cross each other. Once you are that close, a horizontal cut really does not matter. And if you do a rough cut, the size matters even less.
If you are interested in this topic, there's a French chef on Youtube called Jean Pierre who is full of practical wisdom and techniques. You can learn a lot from him. And he's highly entertaining to watch too. He's very opinionated on onions. Or Onyo as he pronounces it. You won't see him making horizontal cuts, ever.
Yes! They had all those visualisations and you could see the problem areas from vertical slicing were at the bottom of the onion, a couple of horizontal slices down there would have given the best solution.
Evenly spaced horizontal cuts might make sense from a modeling standpoint, but not from a practical one. In real-life onion dicing, no one's slicing horizontally all the way up like that, it’s usually one or two low cuts to help break up the base
A single low horizontal cut (15-20% from bottom) specifically targets the elongated base pieces - this would likely outperform the evenly-spaced horizontal cuts they tested while remaining practical for home cooks.
This ignores the obvious solution of not cutting all the way through. If every other radial cut is only through half the layers, you avoid making the inner pieces too small. It's funny how common it is for people to claim some sort of optimality with lots of math and analysis while completely failing to consider a better possibility. Never take seriously claims that someone found a "mathematically optimal" way of doing something. They didn't.
If you want diced onions, the cook generally wants onion chunks below a certain cubic mass, so they cook and dissolve easily and uniformly. It does not matter if some pieces are 50% of that size, some are 20% and some are 80%.
With that, 1-2 horizontal slices and a bunch of straight downward slices are the safest and easiest way to achieve that.
That technique also expands to onion rings, sauteed onions and such.
Just the opposite! When sautéing, too-small pieces have burned by the time the larger ones have cooked, giving the dish a bitter burnt flavor and ugly black flecks.
Burnt bits add unpleasant acridness to the finished dish. And pieces that are 20% of the general size are very like to be overcooked when the rest are properly cooked, so limiting those is important.
When cutting potatoes into chunks, for something like a stew, I often find myself thinking about this problem, and how I would write a program for a robot to do it.
They are fairly well approximated as ellipsoids of different sizes. Typically, I want pieces around half the volume of the smallest potatoes, but with the range of sizes, this means cutting the larger ones into at least 5 pieces.
While it would be simple to make parallel slices giving equal volume, these would have very different shape to the halved smalls. Some can be quartered to give nice chunks, others into thirds with 2 perpendicular cuts...
I used to work in fast food and this bad boy has a rate of 0.5 onions/sec and all of the resulting pieces are perfectly uniform squares. If you've ever wondered where the perfectly diced onions garnishing your burger came from, this is it.
It was a pain to clean though, as the blades were exceedingly sharp. Someone would cut their fingers about once a week on those things.
> It was a pain to clean though, as the blades were exceedingly sharp. Someone would cut their fingers about once a week on those things.
Much better than the various food cutting tools available to consumers which (apart from knives) are always exceedingly dull IME to the point of being useless. An the weird shapes make them impossible to sharpen yourself.
These commercial tools are often odd-shaped (this one is a foot and a half tall) and not dishwasher friendly. Even if you found a way to somehow fit it into the dishwasher, the jets may not reach the blades.
To translate the final answer from math to human (as I’m going to be explaining this to my mother when I chat with her next!):
Imagine the half onion is a half rainbow. You know there’s another half rainbow lurking below the surface, the onion’s ghost of the sphere it once was. Place your knife as usual for each of your ten dice cuts, but instead of cutting straight down towards the cutting board, angle it slightly inward towards the end of the onion’s ghostly half-rainbow sphere below the board. Check your fingers for safety and then make your cut. Assuming your knife isn’t a plasma cutter, you’ll be stopped at the cutting board without ever reaching the onion at the end of the rainbow, and that’s cool. Set your knife at the next dice point and try again :)
(This still improves on the other dicing cases and only costs 1% uniformity by using 100% radius as the target.)
> Place your knife as usual for each of your ten dice cuts,
what does this mean, exactly? I don't cut onions. Also I assume there is some pre-step where you cut the onion in half on some axis, but I don't know which.
If you inspect the onion diagrams in the article carefully, they show various ways to cut an onion, as if origami diagrams but with knives. Still, I think you’ll want to learn the traditional methods of dicing an onion independently first, and then with that knowledge revisit this article and my description; this is last-10% optimization work that hinges on knowing that first-90% of how to dice an onion at all.
Standard deviation is a poor measure because you care more about avoiding big pieces than small ones. Penalizing for having a few tiny pieces doesn’t make sense.
You probably don’t even care about the “standard” deviation at all. You care about the deviation from some desired size. Probably the more accurate problem is “what is the fewest number of straight cuts I can make such that all pieces are below some target size”.
Thank you, this exactly! Seems like you want to reduce the standard deviation only considering pieces that are larger than the mean, but still relative to the mean. Would be very curious to see the results redone using that approach.
Readit News
I made my own version of this a while back, and it lets you create your own cutting methods, plot the statistical distribution, and share your ideas via permalink. It also lets you tweak onion parameters, such as number of layers and the layer thickness distribution curve).
Along the way I discovered two things:
1. I came up with my own method ("Josh’s method" in the app above) where the neither the longitudinal cuts nor the planar cuts are full depth, so the number of cuts at the narrower core is less than at the wider perimeter.
2. After all this hyper-optimization about size, it turns out what really matters when cooking is the THICKNESS, since ultimately determines the cooking rate. The only way to avoid thin outliers that burn long before the rest are cooked is to discard more of the tip of the onion, where the layers are the thinnest.
The 3D version of the simulator is still in progress--turns out 3D geometry is a lot harder than 2D. :)
Pull requests are welcome! https://github.com/joshwand/onion-simulator
I really struggled to effectively cut onions until this: https://www.youtube.com/watch?v=CwRttSfnfcc
Haven't looked back since.
https://old.reddit.com/r/FastWorkers/comments/1dl1xpz/fast_o...
Thanks much!
They made the horizontal cuts evenly spaced between the cutting surface and the top of the onion, which is nonsensical to me. I believe that a single horizontal cut at around 15-20% height would be better for uniformity than a horizontal cut at 50% height.
The other thing is that this seems to ignore that the onion is round in the other direction too. As far as I can see, it only covers the first dice cut.
This way of calculating doesn't take into account the creative ways you can make cuts. You could also do mostly vertical slices, and then slightly angle inwards when you do the final few cuts. That would get you a more optimal distribution as well.
Of course, as the article points out, the horizontal cuts don't really do much that a chef should care about. You can dice an onion super fine with just vertical cuts very close together. And it's a lot faster and easier. You might angle some of the cuts towards the edges. But honestly, even that is unnecessary and a bit overkill. With a good knife, you can put the vertical cuts really close together. So close that any kind of angle would mean the cuts cross each other. Once you are that close, a horizontal cut really does not matter. And if you do a rough cut, the size matters even less.
If you are interested in this topic, there's a French chef on Youtube called Jean Pierre who is full of practical wisdom and techniques. You can learn a lot from him. And he's highly entertaining to watch too. He's very opinionated on onions. Or Onyo as he pronounces it. You won't see him making horizontal cuts, ever.
Deleted Comment
If you want diced onions, the cook generally wants onion chunks below a certain cubic mass, so they cook and dissolve easily and uniformly. It does not matter if some pieces are 50% of that size, some are 20% and some are 80%.
With that, 1-2 horizontal slices and a bunch of straight downward slices are the safest and easiest way to achieve that.
That technique also expands to onion rings, sauteed onions and such.
If some pieces are twice the size of your average size, these pieces will be raw, when the others are done.
And if you have some pieces that are half the size of the average they will burn by the time the rest are done.
Deleted Comment
They are fairly well approximated as ellipsoids of different sizes. Typically, I want pieces around half the volume of the smallest potatoes, but with the range of sizes, this means cutting the larger ones into at least 5 pieces. While it would be simple to make parallel slices giving equal volume, these would have very different shape to the halved smalls. Some can be quartered to give nice chunks, others into thirds with 2 perpendicular cuts...
I used to work in fast food and this bad boy has a rate of 0.5 onions/sec and all of the resulting pieces are perfectly uniform squares. If you've ever wondered where the perfectly diced onions garnishing your burger came from, this is it.
It was a pain to clean though, as the blades were exceedingly sharp. Someone would cut their fingers about once a week on those things.
Much better than the various food cutting tools available to consumers which (apart from knives) are always exceedingly dull IME to the point of being useless. An the weird shapes make them impossible to sharpen yourself.
Veggies aren't meat.
This is the same for my frying pans. Just rinse them. When was the last time you saw someone use soap to clean a bbq?
Imagine the half onion is a half rainbow. You know there’s another half rainbow lurking below the surface, the onion’s ghost of the sphere it once was. Place your knife as usual for each of your ten dice cuts, but instead of cutting straight down towards the cutting board, angle it slightly inward towards the end of the onion’s ghostly half-rainbow sphere below the board. Check your fingers for safety and then make your cut. Assuming your knife isn’t a plasma cutter, you’ll be stopped at the cutting board without ever reaching the onion at the end of the rainbow, and that’s cool. Set your knife at the next dice point and try again :)
(This still improves on the other dicing cases and only costs 1% uniformity by using 100% radius as the target.)
what does this mean, exactly? I don't cut onions. Also I assume there is some pre-step where you cut the onion in half on some axis, but I don't know which.