Dicing an Onion, the Mathematically Optimal Way

> 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.

This is fun!

I really struggled to effectively cut onions until this: https://www.youtube.com/watch?v=CwRttSfnfcc

Haven't looked back since.

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.

Someone, somewhere, will now spend time growing square onions to fix the problem. Probably someone in Japan.

https://en.wikipedia.org/wiki/Square_watermelon

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.)

Why limit it to just two horizontal cuts?

I’ve always just made equal horizontal and vertical cuts, then slice the onion crosswise.

This results in pretty much no large pieces, and only some smaller pieces (which I prefer over larger ones, anyway).

I don’t care about standard deviation — I only care about minimizing the maximum size (but still without turning them to mush).

(Also, I know this was more of a fun mathematical look at chopping onions vs. practical. But still the “two horizontal cuts” thing seemed to be practical guidance, when it seemed like just equal horizontal and vertical cuts is far superior. But, granted, it’s a little trickier to do.)

EDIT: looking at Youtube, looks like the 2-cut thing is normal. But adding a few more cuts isn’t that much harder, and eliminates the larger pieces from the 2-cut method. I’ll stick to my method, even if it’s a little more work.

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.

Posted less than a day ago (8 points, 2 comments) -

https://news.ycombinator.com/item?id=44894302

I dislike easily 90%+ of the images I recognize as AI-generated, but the ones on this internet web site I think are a good use of the tech.

Enjoyed reading this. I've followed J Kenji Lopez-alt for a while and I've practiced the "aim below" method for a few years now.

I also like that the article ends with the perfect Kenji-ism. "Yes, technically my method is statistically ideal, but like, it's home cooking and it doesn't matter, heterogenity isn't the enemy". Reminds me of Adam Ragusea (https://www.youtube.com/watch?v=5cWRCldqrxM), we're not making fancy french cuisine, we don't need a perfect brunoise!

Once upon a time, my father, who could not cook, harshly criticised my onion chopping technique. This knocked my confidence in the kitchen quite a bit. I refused to learn the fancy techniques of the TV gameshow celebrity chef that my dad was enamoured with.

In my opinion, so long as you are chopping onions, all is well. Sure it could be dangerous, with fingers and egos at stake, but far worse is to not be chopping onions as that means ready meals, take out meals and having a poorer diet.

From their 2-d diagram, I'm having a hard time understanding what they mean by "vertical cuts" and "radial cuts"

Throws it in the food processor.

Too much dork time on their hands. Cooking is fun, not vibe coding.