Chop an onion without crying: 13 tips, tricks and strategies

August 13th, 2012

Appliance Talk Ovens & Cooking

It’s a familiar scene – getting the dinner ready, you whip out your trusty blade and prepare to slice and dice some vegetables.

Soon, your eyes begin to sting.  Even if you’re feeling on top of the world, tears begin to well in your eyes, and soon you’re sobbing uncontrollably.

Bloody onions got you again!

Know your enemy

The common onion has been used in cooking for thousands of years, all around the world.  Onions come in many different varieties, from brown and red onions to shallots and spring onions.

Onions have some scientifically notable characteristics.  One is that they have unusually large cells, which according to Dr Karl, are visible even under a cheap microscope (an experiment you can try at home).

These cells are filled with enzymes that when released, react with other materials in the onion to generate an acidic gas.  This gas irritates the eyes and kicks off the waterworks.

Prevention methods

So how can we keep preparing onions from being a crying shame?

There are as many ways of overcoming onion tears as there are cooks, chefs, and old wives to tell tales.

Here is a selection of the many tips, tricks and strategies – some of them should work better than others.  Try them out and see!

1. Keep them cool

The theory goes that refrigerating or freezing onions prevents the acidic gases from escaping during chopping.

This does require a fair bit of forward planning.  Rather than just buying your onions, chopping them up, cooking them and eating them, you need to freeze them before you chop them, then defrost them once they’re chopped, or else you could get some uneven cooking results.

Plus, frozen onions can be a bit more slippery than the regular kind, increasing your risk of accidents.

2. Wear goggles

I knew a guy that used to keep his swimming goggles in the kitchen for just this purpose. Contact lenses are also supposed to work.

While this does keep acidic onion gas out of your eyes, it can still get in through the back door of your eyes via your nose.

Onion goggles make great gifts!

Plus, you may look… kinda dumb.

3. Chop really fast

The faster you chop, the less time there’ll be for the gases to make their way to your orifices, right?

This requires some practice and skill – waving a knife around at lightning speed when you don’t know what you’re doing could be a recipe for disaster.

4. Use a sharp knife

Remember how onions have big cells?  It’s when these cells get ruptured and burst that the enzymes are released to start the acidic chemical reaction.

If you’re cutting onions with a blunt knife, more of these cells are going to get ripped open and more stinging onion gases will be released.

Keep a good edge on your knife to slice between the cells instead of bludeoning them apart, and you’ll release fewer tear-inducing irritants.

5. Crank the rangehood

As the oils and gases are released into the air when you’re chopping, cooking in a well-ventilated area can blow them away before they have a chance to reach your eyes.

A powerful rangehood is one of the mightier fan options, and vented models can release the gases into the atmosphere outside your home.  Keep an eye out for teary birds soaring overhead…

6. Just add water

A gas can’t get into your eyes if it’s trapped underwater, right?  For tear-free chopping, some prople run the tap over their onion, or even chop them when fully immersed in water (the onion, not the cook).

This can make the onion a bit slippery though, increasing the likelihood of chopping-related accidents.  And wet onions can cook at a different consistency and affect how your recipes turn out in the end.

7. Get steamy

Similar to the water theory above, this method relies on steam from a nearby boiling kettle to absorb the acidic onion gases as you chop.

Just watch out for scalds.

8. Sing!

Or talk.  Or mutter.  Or whisper sinisterly under your breath.  Use that mouth of yours!

If you’re concentrating on your cooking and breathing intensely through your nose, you’ll suck those acidic gases straight up through your nose and into the back of your eyeballs.  Breathing through your mouth, drawing the gases over your wet tongue rather than your relatively dry nose, and spending plenty of time exhaling through song can help keep the gases away.

It was a professional chef that first told me about this one, so I’m pretty confident that it should be effective.

9. Chew gum,  suck sugar cubes, or… eat spoons?

Like in the previous example, this strategy tricks you into breathing though your mouth to keep onion gas away from your nose and your tear ducts.

You can chew gum, put a sugar cube between your teeth, or put a spoon on your tongue to serve as an oral fixation and keep the gases out of your nose.

10. Basic chemistry

A few different common household substances can be used to treat your onions, knife and chopping board to neutralise the acids in the onion gas, or even denature the enzymes that produce it in the first place.

These range from salt water, to vinegar (which seems able to do anything), to lemon juice.

The only worry with using these is that they could give your onion a flavour that may not suit your recipe.

11. Light a candle

Better to light a candle than curse the darkness… or sniffle while chopping onions.

The theory goes that the heat from a nearby candle (or lit gas burner) will draw in the onion gases before they can get near your eyes, though it needs to be placed quite close to where you’re chopping.

Just what the kitchen needs – another fire hazard…

12. Leave the root on

While I’m no vegetable expert, I’ve been told that most of the enzymes that create tear-inducing onion gases are contained in the onion’s root – that’s the hairy end.

Leaving the root attached while you chop the rest of the onion serves a practical purpose as well – if you chop an onion in line with its striations (those lines that run out from the root), leaving the root attached will hold the onion together as you chop, so you can neatly and efficiently dice the vegetable into cubes.

13. Use a food processor

Purists might call it cheating, but we’re all about making your cooking simpler and stress-free here at Appliances Online.

A quality food processor will get your onion into tiny pieces in a few seconds, leaving you with more time to get on with your cooking, as well as clear, tear-free vision.

Got an old favourite tip for keeping your eyes free of tears while chopping onions?  Why not share it?