Most delicacies, no matter which part of the country they belong to, are incomplete without the tang of onion. But pleasure doesnt come easy. This magical taste mantra gives us our share of tears before agreeing to transform into a delicacy!
What causes the onion to act as a tear-gas bomb? The scientific explanation goes like this
There are juices and chemicals inside onion. When your knife breaks the onions cells a certain compound becomes airborne as a fine mist. This compound is called propanethial-S-oxide, which is a type of sulphoxide. When the misty droplets encounter a wet surface (your eyes or nose membranes) it dissolves into a form of sulphuric acid, which causes irritation.
Some people are hardly affected at all, while others are overly sensitive to these vapours. But to the rest, it is a pain in the, well, eyes! So what can be done to avoid tears while cutting and cooking onion? No sure-shot solution to this has been discovered as yet, but here are some domestic nuske
Use a sharp knife
This is more common sense than a cure. A dull knife will crush the onion cells more than a cleanly slicing sharp blade, and the crushed cells will release more of the deadly spray into the atmosphere. But this method can only reduce the effect. It is no cure because even the sharpest knife slices plenty of cells up and releases the caustic gas.
Hold a wooden matchstick between your teeth -- match head out
Maybe someone thought this up to see how much he could get someone else to act like a clown. The theory is that the match head attracts and absorbs all the bad chemicals.
Hold a piece of bread in your mouth
Some say, chewing bread also helps. But as with the match above, the bread cannot have any significant attractive force on the onion spray. It actually delays the onset of tears so you get time, atleast to chop the onion without weeping. Later you can wash your eyes.
Breathe only through your mouth
It you also feel the irritation in your nose, this could help. But it doesnt help the eyes.
Chew on a raw onion
You must have heard loha lohe ko katte hai. So why not just give it a try!
Dont chop the onion rootor do it last
The reasoning is that the root end of the onion has a higher concentration of these nasty chemicals.
Chop the onion under water, under running water, or pre-soak in water
This under water lore is the most effective amongst all, though trying to hold and contain all the diced onion bits (which float away) under a sink filled with water can be quite a difficult. In theory if the onion was exposed only to water and not air, the sulph-oxide would be washed away and never become airborne. Another way is to have running water nearby the chopping area. One more scheme is to soak the onion peeled (even cut in half or quarters) in water for some length of time to draw out the juices.
Use a fan to blow away or suck up the fumes
If you can get a strong enough fan this method might prove effective. If inside, wherever you blow the fumes (unless its out a window) will be fumigated. With a fan it is best to blow horizontally, away from the face.
Put white vinegar on the chopping block to neutralize chemicals
This is pretty effective. The stinging in the eyes is considerable reduced, but the smell is not very pleasant. But be careful, moist vinegar on the onion interferes with frying, and its flavour may taint some foods.
Burn a candle near the work area
This rarely-known technique is based on the fact that the candle flame pulls air from around it and sends it up the smoke plume. Although surprisingly effective, a single candle usually cannot handle the large amount of aerosol generated by a lot of dicing or fine slicing. This last technique holds the secret to the final solution.
Place the cutting board next to a gas range and turn on a burner or two
The heat and flames draw in the onion mist, burn it, and send it up with the rest of the flame exhaust. In the heat the chemical changes such that it no longer irritates the eyes. One could also use the hood exhaust fan while the burners are on.
This one, if arranged properly, is a sure-shot escape from onion tears I have tried it!