I did a little research to find out about how to prevent crying when cutting onions. My personal experience has shown that it depends on the variety of onion. Some seem stronger than others. That being said, sometimes I don’t get a choice of what onions to use, I have to take what I can get and what I can afford.
Onions are from a family called Alliums. This includes garlic, cloves, leeks and about 400 other plants. To varying degrees, all of them have Amino acid sulfoxides form sulfenic acids. When you cut into an onion, you tend to crush the little cells containing these elements. They produce propanethiol S-oxide. This gas reacts with the water in your tears to form sulfuric acid. The sulfuric acid burns, stimulating your eyes to release more tears to wash the irritant away. Now you know!
The National Onion Association says to reduce the tearing you can try several things:
First, chill the onions for 30 minutes.
Leave the Root Attached
Then, cut off the top and peel the outer layers leaving the root end intact. (The root end has the highest concentration of sulphuric compounds that make your eyes tear.)
Linda’s Note: You must use a very sharp knife. A dull knife tends to crush those little acid cells
Most chefs I’ve seen will cut the onion in half, slicing through the root end like the picture above. I found that slicing this way makes short work of onions.
Peel back the skin, but leave it on the onion at the root base.
When you are prepping onions for dehydrating, don’t bother to dice them. Make the thinnest slices you can. After they are dry, these will crush easily for whatever diced use you may need.
When slicing your onions, be sure not to cut that last little bit holding the root. The less damage to it, the less tearing.
Rack them and dehydrate at 115º. Usually, they are dry overnight.
- Remember, the thicker the slices, the longer it will take for them to dry.
- Onions should be crispy, not leathery.
- Sweet onions like Vidalia will tend to be leathery because of the high sugar contend.