Skip to main content

Why Onions Make You Cry

Here in the Atomic Kitchen, we bring the gamut of emotions. We like to make you laugh.  Today, we might make you cry.  Fair warning: you may need a box of tissues as we explain why cutting onions makes you cry.

Your tears are primarily water.  Saline. Salt water.

Onions can be divided into two categories:  Sweet and Storage.  Sweet onions have a much higher water content, and have a limited shelf life.  They have a milder reaction with your eyeballs and tear ducts because of that high water content.  We're going to address yellow, white and red onions used in cooking – the “storage onions” sometimes referred to as “dry onions,” with a relatively low water content.

You're embarking on a fantastic recipe.  You've got a sharp knife at the ready.  You peel the skin off the onion and place it on the cutting board.  Shortly after making that first slice, your eyes tear uncontrollably.  These do not feel like “Oh, the suffering of humanity!” tears.  They burn.  What is going on?

Lurking within your onion are a mishmash of chemicals separated by cell membranes. In the whole onion state it is stable.  But inside some of those cells are many amino acids, among which are sulfoxides.  When you cut into the onion, you break the cell membranes, releasing a chemical medley through the onion, creating instability in Onion World.  The sulfoxides become sulfenic acids.  These are free to combine with other molecules, and one of the by-products is propanethiol S-oxide, a gas which takes a vapor form.  Propanethiol S-oxide wafts upward, interacting with the moisture in your nose and those saline tears in your lachrymal ducts to create small amounts of sulfuric acid.

Sulfuric acid burns.  Your tear ducts create more tears to wash the irritant away, and before you know it, you look like you just watched “Ol' Yeller.” 

To avoid the waterworks, chill the onion for 30 minutes before cutting it.

Thanks for reading The Atomic Kitchen!  Please share us with your friends. 

Next week:  Acidosis

Last Week:  How to Avoid Curdling

  

Comments

Popular posts from this blog

Going Curdless: Tips to Avoid Curdling

A good rule of thumb for cooking with dairy products, including cream, milk, eggs, butter, cheese and mayonnaise, is:  patience! Sauces made with milk,  cream and cheese may curdle for several reasons: not enough fat content.  Skim milk will curdle more than heavy cream, and low-fat creams and cheeses are more likely to curdle than their whole-fat compadres. too high heat.  Cream sauces must be cooked at low temps. Use a thermometer to ensure temperatures stay lower than 175 degrees F. too much acid.  Cream should be added last (with exceptions like lemon juice). Wine can be very acidic, and should be reduced.  any ingredients should be of medium temperature before cream is introduced, as it will separate at boiling. How curdling occurs: Dairy fats combine to form a rubbery mesh, which squeezes out water. One possibility to prevent curdling is Carrageenan.  There are three kinds, and Lambda Carrageenan is best for sauces because it is water solub...

What Happens In Your Freezer (Pt.1)

The freezer has changed food in America and around the world. I’m fascinated with the story of Clarence Birdseye, who discovered that flash-freezing fish was a practical way to ship seafood to distant inland locations. His name became a brand synonymous with many frozen vegetables and cooking staples. Alas, not everything freezes as well as freshly harvested seafood and vegetables. Here’s a description of foods that freeze badly and what happens. ( Source: National Center for Home Food Preservation ) Cabbage, cucumbers --   These become limp, waterlogged and quickly develop an oxidized color, flavor and aroma. These can be effectively frozen as marinated products. However, “freezer slaw” and “freezer pickles” won’t maintain the same flavor or texture as regular slaw or pickles that were not frozen. Celery, Cress, Lettuce, Parsley, Endive, Radishes – Limp, waterlogged and these also change color, flavor and aroma. Potatoes, baked or boiled – These become soft, crumb...

Avoiding Green Eggs

I do not like green eggs and ham...  well, I'll live with the ham, but there's no need to have green eggs.  If Sam-I-Am knew the secret of cooking perfect eggs, they would not turn green. Even without Seussificaton, egg yolks do turn green.  Here is why: Yolks contain iron.  Egg whites contain hydrogen sulfide, and where the yolks and whites meet, those two chemicals react.  Given sufficient heat, as in overcooking, the yolks will develop a green-colored film.  Even though they are less appetizing, the chemical reaction does not change the flavor of the eggs. There's another way for eggs to turn green.  Cooking or storing eggs in an iron skillet or a metal pan will turn them green as the iron ions from the pan react with the sulfides in the eggs. Kevin Murray, president of Tasteful Events Catering in Rochester, N.Y., offers a few tips to prevent green eggs.  “I am usually cooking in volume, but it definitely depends on t...