Wednesday, March 17, 2010

Onions: How to avoid the tear gas

Cutting onion can be a pain, literally. The sting is a defensive mechanism utilizing sulfur the onion absorbs from the ground. The onion incorporates sulfur into four different kinds of chemical ammunitions which float in the cell fluid while the enzyme trigger is kept separately in a storage vacuole. When an onion is damaged by chopping or chewing, the enzyme escapes and breaks the ammunition molecules in half to producing the sting. When this sting reaches our eyes, it further breaks down into various sulfur compounds and sulfuric acids which make us cry.

However, these irritating molecules are also responsible for producing the awesome onion flavours we want. These flavours are produced when sulfur reacts with other parts of the onion, and oxygen, so different ways of processing onions will produce different flavours. This is why onions must be rinsed after chopping if it is to be used in salads to remove the pungent flavour.

We were told a lot of different tricks to avoid the sting, but what works for one person doesn't seems to work for another. Here is a list of some methods:
  • Run the knife under hot water before and during cutting
  • Using a very sharp knife
  • Cut onion next to a strong fume or draft
  • Cut onion underwater
  • Cut onion near a steam
  • Wearing contact lenses
  • Chew gums or bread
  • Using Science goggle
  • Talk a lot
  • Breath through your mouth
  • Put vinegar on the chopping board
  • Soak onion in water or salt water
  • Chilling the onion in fridge or under cold water
  • Light a candle near you
  • Look away
We have all experienced some form of relieve using other methods, because they all employ these key points: moisture, temperature, barrier, and aeration. However, when you are cutting several onions finely, extra measure are needed to be taken. I tried all these methods, and none of them stops the sting completely, especially when you are cutting a large quantity. Wetting the onion is a bad idea if the onion is meant for sauté, and vinegar and salt can also alter the flavour profile of your final dish.

The only scientifically proven way is chilling the onion in a cold bath for an hour, but even this is not 100% effective.

Here is what I propose: These methods requires minimum preparation and resources

1. Chill your onion for at least hour either in the fridge, ice bath, or running water (which is cold enough in Vancouver). Make sure to pat them dry before cutting if you are using it for sauté. I store my onion in the fridge at all times.
2. Cut near an open window or fume, making sure the air current is moving away from you.
3. Stand tall, don't slouch.
4. Breath out of your nose and in with your mouth. It is not as effective if you breath out from your mouth.
5. If you are a pro cutter, look away.
6. Get all your other cuttings done first before cutting onions. Use the sharpest knife in the house, cut it quickly (safely). Don't linger too long by the chopping board after it is done.

Feel free to add more methods in addition to these. Dennis finds warm knife trick particularly useful, but make sure to dry the knife before cutting, so you don't end up with excessive water in your final dish.

Onion on Foodista

1 comment:

  1. Recently I cannot cut an onion without crying. It is bad! One trick that I was told in college from one of my guy neighbors is to put a tortilla chip (whole) in your mouth. It works for a little bit.
    Thanks for the info! Welcome to the Foodie Blogroll!