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, and are called for in all kinds of recipes.
Unfortunately, they can also be tricky to slice and dice without ending up with your eyes filled with tears, no matter how good a mood you’re in.
Here is a selection of tips, tricks and strategies for avoiding the waterworks when chopping onions – try a few out and see what works best for you!
1. Cool your onions
Onions release a mildly acidic gas when chopped, which irritates the eye and leads to tears. Refrigerating or freezing onions can prevent this gas from escaping during chopping.
However, it does take a degree of forward planning to have some cool onions on hand when you’re preparing a meal, so this may not be as effective when using ingredients picked up at the last minute from the fruit and vegetable shop for an impromptu meal.
2. Cover your eyes
If you seal up your eyes behind swimming goggles or something similar, the irritating gases shouldn’t be able to get into your eyes, right?
Well, it would probably help to be sure, but the gases can still reach the back of your eyeballs via your nose and mouth.
And of course, there’s the problem of looking… well, a bit ridiculous.
3. Chop really fast
If you can get your onions sliced and diced fast enough, you can have them in the pan and cooking away before their gases reach your eyes.
This does require some practice and skill – take care when using your knives!
4. Use a sharp knife
Time for a very short science lesson: Onions have large cells that contain a mixture of enzymes. When these cells are ruptured and burst, the released enzymes start a chemical reaction that creates the acidic gas which irritate the eyes.
Cutting onions with a blunt knife rips open more of these cells and therefore produces more stinging gas.
Using a sharp knife lets you slice between the cells instead of tearing them apart, so fewer tear-inducing irritants will be released.
5. Keep your kitchen well-ventilated
As an onion’s gas is released into the air when you’re chopping, cooking in a well-ventilated area can draw the gas away before it has a chance to reach your eyes.
One option is to chop while running a kitchen rangehood. You can also try opening a few windows or even keeping a desk fan on your benchtop.
6. Just add water
Some prople run the tap over their onion while chopping, or even chop them underwater in the sink, following the logic that an onion’s gas can’t reach the eyes if trapped underwater.
This can make the onion a bit slippery and tricky to chop though, and wet onions can cook at a different consistency, affecting 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 onion’s acidic gas while you chop.
Just watch out for scalds.
Or talk. Or mutter. Whatever. Just use your mouth!
Breathing through your nose sucks acidic onion gas straight 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, can help to keep the gases away.
9. Put something in your mouth
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, suck on a piece of bread or put a spoon on your tongue to keep your mouth busy and 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, 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
The theory goes that the heat from a nearby candle (or lit gas burner) will draw in the onion gas before it can get near your eyes, though it would need to be placed quite close to where you’re chopping.
Always be mindful that the more sources of flame in your kitchen, the more potential fire hazards.
12. Leave the root on
More of the enzymes that create tear-inducing onion gases tend to be found in the onion’s root (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 (the lines that run out from the root), the root 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 anything that can make your cooking simple and stress-free can be very handy.
A quality food processor will reduce 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.