I used to cry every time I cut an onion. Like wrist against the eyes (cause I'm holding the knife), painful crying. Then one day I realised I'd stopped. And I hadn't even noticed it happen.
When Did That Stop?
Back when I was learning to cook, I'd be standing there chopping, and I would get to a point where I felt like I couldn't see, and I would have to stop and hold my eyes shut.
Jump forward a few years, now I have an arsenal of knives. Which is a fairly privileged position to be in, I'm aware.
They're always sharp (a blunt knife is now one of my new pet peeves). I can't not have them sharp.
And it wasn't until the other day I was cutting an onion and I realised I don't cry anymore.
Hadn't noticed it happen. Just stood there mid-onion and thought, oh. When did that stop?
I reckon it's because I have sharp carbon steel knives.
Why Onions Make You Cry
Now I'm not a scientist so don't quote me on this, but I did some digging.
The reason your eyes sting is because you break the onion's cells open. When you break the cells, they create & release gas. A blunt knife crushes its way through and wrecks everything either side of the cut. More broken cells, more of the gas that gets you. A sharp knife still cuts them, but it's far less. Fewer cells broken means less gas. Less gas means less crying.
Which tracks, because you can actually see it happening. Watch a dull knife go through an onion. The whole thing squashes down and resists before it finally gives up. That squash is the damage.
Once you notice it, you start noticing it everywhere. Same way garlic comes out as paste instead of slices. Feels like you're using a spoon to cut things. Tomatoes that squish before they cut, so the first slice is always a write-off.
Nobody Tells You How Slowly It Sets In
A new knife is sharp when you get it. But as it's supposed to be, your knife gets used. I hope daily! But after multiple dinners cooked, the edge will slowly blunt. This happens on all knives. And you won't even realise it.
You adjust. You hold the onion differently. You start dreading the prep more than the actual cooking, which is the wrong way round, because the prep's meant to be the nice part.
That's the bit I'd go back and tell myself when I was starting out. The knife was blunt, that's all it was.
That's Where Carbon Steel Comes In
The really cool thing about ours is that they're carbon steel, so they hold the edge really well. And they're easy to get the edge back on them. Massive benefit to using carbon steel kitchen knives.
They do have a trade off! They require more care. But as long as you don't leave them wet, never put them through the dishwasher and don't throw them at the wall, these blades are going to help you avoid that teary-eyed dinner prep.
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