Ask Kenji Live: What is the Best Way to Cut on Onion?

I was so confused, he looks at least 20 years younger than I remember him from the covid days when I first started following him.. so proud of you Kenji!!

damn. kenji working out and getting fit. looking good!

I remember him talking about the best way to cut onions months / years ago. I’m glad he came back to this with a computer model. How fascinating. Thank you for sharing !

Using math to optimize the chopping of vegetables, I love it

Props for using the term "polar coordinates". I majored in Physics in college and got a PhD in engineering, we covered polar coordinates (spherical AND cylindrical) in math class, and used them a lot in electricity and magnetism. Somehow cutting an onion never came up. That said those classes probably induced about as much crying.

Before this video, I would call my onion cutting "Lazy Radial" and I'm astounded to see that the math supports my half-assed cuts!

Dang! Coming in with the fresh cut in addition to all that hard-earned weight loss?! Dude, you have fully emerged from your chrysalis as an absolute inspiration. Having watched your videos from the old kitchen 4 years ago with the late night vids, to the creative force that you are now is amazing! Keep it up, Kenji!

I clicked on this to check this was actually Kenji - looking great man!

Funny, I think cutting onions was how I first discovered you. The scientific explanations paired with your loose, improvisational approach to cooking is what made me a fan. "But do it however you want" is what makes everyone trust you. Anyway, I've been cutting onions this way ever since. And now you bring the stats to back it up!

I can’t be the only one that gets this warm and fuzzy feeling inside my soul every time Kenji goes nerd?😊

I have ALWAYS wondered why experts did the horizontal cut! Your new way makes sense, thanks. I have a new way of dicing onions!

You are seriously an inspiration! Not only your cooking skills but your physical change from a year ago. My goodness!

Okay that geometry math is pretty dope. I still can't help but to remember a comment Kenji made during one of the COVID cooking videos (I'm paraphrasing): When your wife cuts onions a certain way, that's the right way/leave her alone LOL Unrelated, great to see the progress of him getting back in shape! Keep it up my dude!

Kenji, you are looking phenomenal these days! Would love to see a video about your recent diet strategy.

Here is another approach that should yield similar results but has a few mathematical advantages. Start with a vertical cut in the center. The next cut should end where the outer edge of central ring meets the cutting board. As you make subsequent cuts, each should end at the outer edge of the next ring. With this approach, the correct number of cuts naturally arises from the number of rings in the onion. When considering a quarter of an onion, one must make N cuts including the vertical cut, where N is the number of rings including the central ring. If considering a half of an onion, one must make 2N-1 cuts including the vertical cut. This also means that the radial distance between the starting point of each cut along the outer surface is 90/N. The modeled half onion shown in the diagram starting at ~7:20 has 10 rings, and we would therefore make 19 cuts. Starting from the vertical, each subsequent cut must start at a point 9 degrees along the outer circle from the last cut and end at the boundary between rings as describe above. It should be clear from the diagram that this will give similar results (this method naturally results in 10 cuts for the depicted quarter onion, whereas Kenji's diagram shows 8 cuts). While I believe its relationship to the onion's natural geometry is appealing, I can't say whether the resulting distribution of onion pieces is favorable compared to Kenji's proposed method without a bit of additional work, and my proposed method does require more cuts, so it may be less efficient. However, it removes any confusion about where cuts should be placed, which may be a favorable feature for some.

Something to think about is the inaccuracy of most home chefs' cuts. I would not be surprised if many home cuts end up more like the offcenter Radial cuts when they think that they are really doing perfect radial cuts. It's a natural mistake to make.

Huh, this looks surprisingly close to my usual method of "vertical, but tilt'em just a little bit as you move outward". Happy to see the data!

Thank you so much. I've been searching and searching for this method. I knew there was a way to do it without the horizontal cut.

This may be the most culturally important video you’ve ever made, no hyperbole. This is the kind of information that reserves its own place on the Rosetta Stone. A perfect simulacrum of your style of culinary art: informed, researched, accessible, and drenched in compassion. May we all eat well, and may we thank you for helping us do so ❤️

This is the kind of random crap that most people don't care about, but the fact that you care about it so deeply and evidently is why you are my favorite!