I’ve tried most of them, but to no avail. Will knowing the science behind onion tears help?
The health benefits of onions have been widely documented. They are an excellent source of vitamins; B1, B6, C and K, as well as a very good source of potassium, chromium, biotin, fibre and folic acid. So why do they make us weep?
Table of Contents
The science (seriously simplified)
Cutting an onion releases a sulphur compound in the form of a vaporous gas that is attracted to water and wet places. As your eyes are the closest thing to the cut onion that contains moisture, the vapour rapidly attaches itself to this moisture and forms a mild acid, which irritates the eye and stimulates the tear glands. The chemicals in the onion are both volatile and water soluble.
So what are the methods people have deployed to prevent the tears?
The first ‘tearless onion chopping’ method I tried was to clamp my teeth around the handle of a teaspoon and keep it there for the duration of the process. It is a method that my mother swore worked for her mother, although she admits now that it never worked for her. Well, it doesn’t work for me either. I haven’t tried it since the first time all those years ago, but my memory of it is really quite disgusting.
Apart from getting jaw ache trying to keep the teaspoon in my mouth, I dribbled. I have since read that you should put the spoon bit of the teaspoon in your mouth, presumably to catch your saliva, as there does not seem to be any scientific reason for using a teaspoon at all, except that the vapours would reach the dribble before the eyes.
The results of other methods
- Eating dry bread staved off hunger pangs brought on by cooking smells, but failed to prevent the tears.
- Chewing gum not only failed to stem the flow of tears but also made me hungry because my stomach juices were working overtime with no reward…
- Lighting a candle to burn the vapours, which created a nice romantic glow, but failed to achieve the desired effect – perhaps the candle was just that little bit too far away, or I should have used a scented one?
- Leaving the root intact also failed; even though I have had the efficacy of this mooted by a number of chefs.
- Cutting the onion really quickly with eyes and mouth firmly closed whilst praying I didn’t cut myself. I definitely would not recommend this method, I couldn’t bring myself to shut my eyes completely, so the vapours attacked my eyes and for some reason, probably because my mouth was closed, I didn’t breathe at all during the process and felt lightheaded when I had finished, in tears.
- Using an electric fan to blow the vapours away from my eyes. This just made the whole kitchen a horrible place to be, my eyes continued to sting and water even after the onions were cooked. It was a case of vapour vapour everywhere.
- Soaking onions in water or refrigerating them for half an hour before cutting also did not work. From what I have read, this method changes the chemical structure of the onion and prevents the release of the sulphur compound. I have not found this to be effective.
- Using a food processor worked until I removed the lid to cook the onions and then I was assaulted by the onion fumes, they just seemed more concentrated and vicious. My chef friends weren’t overly impressed with this particular method as they claim it is a form of mutilation. I’m still not sure how to take this as in a lot of food recipes we are instructed to chop, bruise, squash various foods, which all sound like some form of mutilation to me, but I am not a professional chef.
So what does work?
The science behind it would suggest that cutting onions under water, or having wet hands whilst chopping would be the best methods, but I still suffer from the tears, admittedly the effect of the onions on my eyes is less traumatic, but I have not found the method to be foolproof. So, I will have to stick to wearing swimming goggles during the whole cutting, slicing, chopping and cooking process, to prevent the redness and pain that onions, and indeed garlic, can cause.
However, I still have to be careful with this remedy to onion tears and make sure that I have done the onion preparation well in advance of a dinner party, as the red rings around the eye sockets from the pressure of the goggles is not attractive either!
It is gratifying to know that even the revered chef, Delia Smith, failed to find success with trying out countless theories on how not to cry in her first seventeen years of cooking. I am sure that had she found the secret of preventing onion tears she would have shared it with us. So, until we are enlightened, the very best method of chopping onions without the tears is to get someone else to do the chopping for you.
- Murray, Michael N. D The Encyclopedia of Healing Foods New York: Atria Books, 2005
- Delia Smith’s Complete Cookery Course: Book Club Associates, London 1983