How to chop an onion without crying. It’s one of the most famous questions that everyone has a dozen answers to, none of which work; it is a question rivaled perhaps only by how to stop hiccups [1].
But I have the answer.
But first, let’s do a quick review on why onions cause us to cry [2]. Onion cells produce a lot of irritating sulfur compounds that give them a unpleasant flavor. This evolved as a defense mechanism to prevent animals from eating them. When chopping onions, we break through the cell walls and cause all those sulfur compounds to be released into the air as vapors, which then go on to wreak havoc with our eyes. And here is the crucial fact: those sulfur compounds don’t just leech out into the air all at once. A little bit gets out right away, but most of these vapors aren’t released until the newly exposed surfaces react with the air a little and internal fluids start to permeate out. Most of the sulfur compounds won’t be released until a minute or two after chopping.
So much most people already know. So the answer is to work fast, right? No, not quite, we’re still missing something.
I take about a minute to chop half an onion. I can usually get through the first half without any problem at all, but by the time I get to the second half my eyes start to hurt and I’ll have to step away. So it would seem that the second half of the onion had already sat there too long; when I sliced into it, the sulfur compounds were sitting there waiting to leech out and attack my eyes. Right?
Wrong.
The sulfur compounds that attacked my eyes were not coming from the second half of the onion, they were coming from the first half… which is now fully chopped, still sitting on the same cutting board, and right at the point in time where the sulfur compounds really start to come at you. We as humans have a tendency to think that the problem is what we’re focusing on at the moment (in this case, the second half of the onion which I was currently chopping), but oftentimes the problem is really something else (the first half that I’d already finished chopping).
Realizing this was an epiphany. It instantly became obvious how to chop an onion and not tear up:
When you’re done chopping the first half of the onion, move the chopped onions to another part of the kitchen, away from your eyes. Then chop the second half of the onion.
If you follow this advice, and you can chop each half of the onion in about a minute, you should be able to finish both halves without tearing up.
Footnotes
[1] Which is easy, actually: you just will yourself to stop hiccupping. Works 99% of the time.
[2] Actually, onions don’t make me cry at all; they just make my eyes hurt like hell. For whatever reason my body has no lachrymal response to my eyes being chemically burned by sulfur compounds, so I have to either induce tears, throw water in my eyes, or just deal with it. But for the purposes of this blog post, we’ll just call it crying.
