Don’t Cry Over Cut Onions

Don't cry over cut onions @ Common Sense Homesteading

Don’t cry over cut onions!  My brother told me about this simple trick you can use to process large batches of eye-burning onions without shedding a tear.  In case you don’t have the “trick” item on hand, I’ve got other options that work pretty well, too.

Why do onions make you cry?

Short answer:  Onions make you cry because they release a sulfenic acid in gaseous form.  Yup – acidic gas.  Tears are our bodies natural protection.

Science Focus give more details:

Onions take up sulphur from the soil while growing. This is combined with amino acids within the onionโ€™s cells to form amino acid sulfoxides. In 2002, Japanese researchers identified an enzyme, also present in onions that unlocks the sulfoxides when the onion is cut. The resulting reaction produces sulfenic acid that rapidly reforms into a gas called syn-Propanethial-S-oxide. When this stuff hits the sensitive surface of our eyes, it causes the stinging that leads to tears.

BytesizeScience has a pretty cool video on all the gory details.  :-)

What are the Health Benefits of Onions?

The World’s Healthiest Foods details the health benefits of onions, including protecting the heart, supporting bone and connective tissue, acting as an anti-inflammatory and protecting from cancer.  You get the most benefits when the onions are raw, but gentle cooking preserves some of them, too.  Just don’t turn your onions into charcoal.  (See, it’s worth the pain of cutting them up, not just for the taste!)

Don’t Cry Over Cut Onions – My Favorite Tips to Avoid Onion Tears

My all time favorite technique (which was suggested by my brother) that I now use regularly for processing large batches of onions (for instance, when I’m canning salsa), is to put a small fan on the counter next to where I’m chopping.  Use the fan to blow away the sulfenic acid gas and keep it out of your eyes – no tears.

Don't Cry over Cut Onions - Use a Fan @ Common Sense Homesteading

I’ve got a little Massey personal fan that we received as a hand me down from my in-laws.  A larger fan would work, too – the small ones are just more convenient (and pretty inexpensive).

Now, if you don’t have a fan handy, there are some other options you can use to reduce eye irritation while chopping onions:

Chill your onions in the fridge or freezer or by running them under cold water – Chilling reduces the oxidation rate, meaning they produce less of those irritating compounds.  Also, hot air and hot gas (including sulfenic acid laden gas) rises faster than cold gas, and cold tends to be less irritating than hot.  The water will dilute the juices so less of them get airborne.

Wear goggles – This will keep fumes out of your eyes, but unless you’ve got sealed goggles, you’re still still going to get it.  Plain safety glasses won’t cut it.  I don’t like the really flimsy ones, either.  A couple extra bucks will get you ones that are fog and impact resistant for other tasks.

Chew gum – If for some reason you are really desperate, don’t have a fan, or refrigeration, or water or goggles, yes, chewing gum does help – a little.  It works because you tend to breathe through your mouth more, so you suck less gas into your nose/sinuses.  Feeble relief at best, but it might distract you enough to make you less miserable.

If you’ve enjoyed this post, Like it, Pin it, Stumble it, Share it.  Help end needless onion pain.  ๐Ÿ˜‰

You may also enjoy:

How to Harvest, Cure and Store Onions โ€“ Root Cellaring, Braiding, Dehydrating and Freezing

Featured on Simple Lives Thursday #114.

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  1. says

    Thanks for the link to the goggles. I purchased a pair of ‘onion goggles’ on Amazon last year and absolutely LOVE them (they are the ONLY thing that has worked for me, and I’ve tried them all). Thankfully, the ones you posted are half the price and now I can get another pair for my daughter.

  2. Sherry M says

    a few years ago I got a SUPER good chef’s knife. (Shun) It greatly reduced the amount of tears when I chop onions because it’s so sharp it doesn’t break as many of the cells. Not to mention how much less effort it takes to cut stuff up!

  3. Kevin says

    During my attendance at Culinary School many years ago, the simple trick taught to prevent the onion cry, is to use a very sharp knife. I can chop dozens of room temp or chilled onions in my tiny apartment kitchen and not shed a tear, if I use a sharp chef’s or paring knife… no fan, no gum, no goggles…

  4. Carol says

    I’m surprised that Maureen finds the goggles work well. I was told by someone many years ago that it’s not the fumes going into your eyes, it’s when you breathe them in. I tested their theory and found that if I take a big breath (from a different direction to the onions) and hold it in while I cut, and then slowly exhaling, it helps. I then take another big breath (away from the onions) and keep going.I don’t need to cover my eyes at all. This worked, but isn’t beneficial if you’re cutting many onions at once. (Light-headed after a little while.) I think this is also why the fan works so well. It’s because it’s blowing the fumes away from your nose and you’re not breathing them in.

  5. Nan says

    Here’s another trick: Hold several wooden matches in your mouth as you
    cut onions. (No, don’t light the matches. That definitely would distract you from the onion tears, but might lead to other complications.) Maybe the
    match heads absorb some of the gas?

  6. Heather says

    You could use swim goggles, those would be sealed off. That would be so funny to walk into the kitchen and see that! When I used to cut tons of onions for the dairy bar chili just turning on the cold water would do the trick. Or I would get all the onions in a huge stock pot and dump a bunch of ice on them. I would only pull one from the ice as I cut them.

  7. says

    I also found I am less likely to shed tears if I leave the root end attached until the last chop. (Half the onion, lay the flat side down, then cut out in rays like a sun or make slices.) I think the gasses must be more highly concentrated in the root.

  8. says

    I agree with the others above that having a super sharp knife greatly reduces the tear-factor. I read the science about it somewhere, and it was as Sherry said – a blunt knife squashes more cells as it cuts, releasing more gas. A sharp knife slices cleanly through, minimising the number of cells releasing gas.

    Journey11’s tip helps, too – because they leave the base on until the end, there’s less cut surface area exposed to the air and so less gas given off. Also, when they cut through the middle and lay it flat, they’re stopping that surface from releasing gas too.

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